Robert J. Fitzgibbons, Jr., MD, FACS
Harry E. Stuckenhoff Professor, Department of Surgery
Creighton University School of Medicine
Alan T. Richards, MD, FACS
Associate Professor, Staff Surgeon
Creighton University School of Medicine
University of Nebraska Medical Center
Thomas H. Quinn, PH.D.
Professor, Department of Biomedical Sciences
Creighton University School of Medicine
Abdominal wall hernias are so common that their management constitutes the largest part of the average general surgeon’s practice. In the past, personal recollections and single-center series written by experts with a vested interest in publishing good results were the principal data sources that surgeons relied on in choosing the optimum treatment strategy for a patient. In recent years, fortunately, population-based studies have provided much better data on the true failure rates associated with the various herniorrhaphies. In addition, trials designed to examine the natural history of hernias have shed some light on nonoperative treatment options.
In this chapter, we describe many different operations for abdominal wall hernias. A well-known surgical dictum states that when numerous different operations exist to treat the same disease, the perfect procedure does not exist. This dictum does not hold true for abdominal wall herniorrhaphy, however. Because the disease is so heterogeneous, many different procedures are needed to address individual patients’ needs; thus, it can be said that multiple perfect procedures exist.
In the United States, approximately 1,000,000 abdominal wall herniorrhaphies are performed each year, of which 750,000 are for inguinal hernias, 166,000 for umbilical hernias, 97,000 for incisional hernias, 25,000 for femoral hernias, and 76,000 for miscellaneous hernias.1 About 75% of all abdominal wall hernias occur in the groin. Worldwide, some 20 million groin hernias are repaired each year.2 Inguinal hernias are more common on the right side than on the left. They occur seven times more frequently in males than in females; only 8% of groin hernia repairs are performed in women. Femoral hernias account for fewer than 10% of all groin hernias; however, 40% present as emergencies (i.e., with incarceration or strangulation), and mortality is higher for emergency repair than for elective repair. In male patients, indirect inguinal hernias are the most common type, occurring approximately twice as frequently as direct inguinal hernias; femoral hernias account for a much smaller percentage. In female patients, indirect inguinal hernias are also the most common type, but femoral hernias are seen more frequently than direct hernias, which are rare in this population. Emergency operations are more frequently required for female patients. In a study from the Swedish Hernia Registry that analyzed 90,648 inguinal hernia operations (88,753 in men, 6,895 in women) between 1992 and 2003, emergency operations were more frequently needed in women (16.9%) than in men (5.0%), leading to bowel resection in 16.6% and 5.6% of cases, respectively.3 Femoral recurrences were particularly common in women whose diagnosis at the time of the primary repair was direct or indirect hernia (41.6%, compared with 4.6% for men), a finding strongly suggesting that a hernia was missed at the original procedure. Femoral hernias are also more common in older patients and in those who have previously undergone inguinal hernia repair.
The prevalence of abdominal wall hernias is difficult to determine, as the wide range of published figures in the literature illustrates. The major reasons for this difficulty are (1) the lack of standardization in how inguinal and ventral hernias are defined, (2) the inconsistency of the data sources used (which include self-reporting by patients, audits of routine physical examinations, and insurance company databases, among others), and (3) the subjectivity of physical examination, even when performed by trained surgeons. Most authorities, however, subscribe to the two-peak theory for inguinal hernias, which states that that a new diagnosis of an inguinal hernia is most likely in patients younger than 1 year and in patients older than 55 years. Clearly, though, hernias can be diagnosed across any given age group.4 A 1996 analysis of a geographically defined population in the United Kingdom estimated that the lifetime risk of having to undergo an inguinal hernia repair was 27% for men and 3% for women.5
The incidence of the most common type of ventral hernia, incisional hernia, depends on how the condition is defined. The best definition of incisional hernia is any abdominal wall gap, with or without a bulge, that is perceptible on clinical examination or diagnostic imaging within 1 year after the index operation. A definition that requires the presence of a visible bulge will lead to underestimation of the true incidence of the condition. The reported incidence of incisional hernia after a midline laparotomy ranges from 3% and 20%, and it doubles if the index operation was associated with infection. Incisional hernias are most common after midline and transverse incisions, but they are also well documented after paramedian, subcostal, McBurney (gridiron), and Pfannenstiel incisions.6 An analysis of 11 publications dealing with ventral hernia incidence after various types of incisions concluded that the risk was 10.5% for midline incisions, 7.5% for transverse incisions, and 2.5% for paramedian incisions.7 Upper midline incisions are associated with the highest incidence of ventral hernia formation, transverse or oblique incisions with the lowest. Muscle-splitting incisions probably have a lower incidence of incisional hernias, but such incisions restrict access to the abdominal cavity. Most incisional hernias are detected within 1 year of surgery; the most common cause is believed to be separation of aponeurotic edges in the early postoperative period. The male-to-female incidence ratio is 1:1, even though early evisceration is more common in males.
At present, little information is available on the risk of major complications arising from untreated abdominal wall hernias. The main reason for this scarcity of data is that surgeons are taught, first, that all hernias, even asymptomatic ones, should be repaired at diagnosis to prevent potential strangulation or bowel obstruction, and second, that herniorrhaphy becomes more difficult the longer repair is delayed. As a result, it is difficult to find a whole population in which at least some of the members do not routinely have their hernias repaired regardless of symptoms. In these circumstances, accurate estimates of the natural history of the disease are impossible.
The natural history of an untreated, minimally symptomatic inguinal hernia was addressed in a randomized, controlled trial from 2006, in which 364 men were assigned to ‘watchful waiting’ (WW), and 356 men underwent routine operation.8 Only two patients in the WW group required emergency operations for strangulation over the follow-up period of 2 to 4.5 years. This result translated into a rate of 1.8 per 1,000 patient-years (0.18%), or about one fifth of 1% for each year that the hernia remains unrepaired. The two patients who required emergency operations recovered uneventfully. The question that remained to be answered was, which group fared better overall, the WW group or the group whose hernias were repaired immediately in accordance with conventional teaching? The answer to this question was at variance with conventional assumptions. At the conclusion of the study, functional status, as measured by quality-of-life instruments and pain scales, was identical in the two groups. About one third of the patients in the WW group crossed over to undergo operative treatment, principally because of symptom progression. However, there appeared to be no penalty for delaying surgery. Before this study, most surgeons assumed that a hernia would become harder to repair the longer it remained (because of enlargement and buildup of scar tissue) and that patients whose operations were delayed would experience more complications. The investigators found, however, that postoperative complication rates were the same in patients who underwent immediate surgery as in those who were assigned to watchful waiting but had to cross over to surgical treatment.
Classification of Inguinal and Ventral Hernias
Numerous classification schemes for groin hernias have been devised, usually bearing the name of the responsible investigator or investigators (e.g., Casten, Lichtenstein, Gilbert, Robbins and Rutkow, Bendavid, Nyhus, Schumpelick, and Zollinger). The variety of classifications in current use indicates that the perfect system has yet to be developed.9 The main problem in developing a single classification scheme suitable for wide application is that it is impossible to eliminate subjective measurements so as to ensure consistency from observer to observer. The advent of laparoscopic herniorrhaphy has further complicated the issue in that some of the measurements needed cannot be obtained via a laparoscopic approach. At present, the Nyhus system enjoys the greatest degree of acceptance [see Table 1].
A classification system for abdominal wall hernias outside the groin has been proposed by Zollinger [see Table 2].10 Ventral incisional hernias are common enough to warrant their own discrete classification system. The scheme most often used for categorizing incisional hernias [see Table 3] was the result of a 1998 consensus conference held in conjunction with the European Hernia Society’s annual congress.11 This system is important in that it affords investigators a reliable means of comparing results between one procedure and another or between one center and another.
Abdominal Wall Anatomy
The skin of the lower anterior abdominal wall is innervated by anterior and lateral cutaneous branches of the ventral rami of the seventh through 12th intercostal nerves and by the ventral rami of the first and second lumbar nerves. These nerves course between the lateral flat muscles of the abdominal wall and enter the skin through the subcutaneous tissue.
The first layers encountered beneath the skin are Camper’s and Scarpa’s fasciae in the subcutaneous tissue. The only significance of these layers is that when sufficiently developed, they can be reapproximated to provide another layer between a repaired abdominal wall and the outside. The major blood vessels of this superficial fatty layer are the superficial inferior and superior epigastric vessels, the intercostal vessels, and the superficial circumflex iliac vessels (which are branches of the femoral vessels).
The external oblique muscle is the most superficial of the great flat muscles of the abdominal wall [see Figure 1]. This muscle arises from the posterior aspects of the lower eight ribs and interdigitates with both the serratus anterior and the latissimus dorsi at its origin. The posterior portion of the external oblique muscle is oriented vertically and inserts on the crest of the ilium. The anterior portion of the muscle courses inferiorly and obliquely toward the midline and the pubis. The muscle fibers give way to form its aponeurosis, which occurs well above the inguinal region. The obliquely arranged anterior inferior fibers of the aponeurosis of the external oblique muscle fold back upon themselves to form the inguinal ligament, which attaches laterally to the anterior superior iliac spine. In most persons, the medial insertion of the inguinal ligament is dual: one portion of the ligament inserts on the pubic tubercle and the pubic bone, whereas the other portion is fan-shaped and spans the distance between the inguinal ligament proper and the pectineal line of the pubis. This fan-shaped portion of the inguinal ligament is called the lacunar ligament. It blends laterally with Cooper’s ligament (or, to be anatomically correct, the pectineal ligament). The more medial fibers of the aponeurosis of the external oblique muscle divide into a medial crus and a lateral crus to form the external or superficial inguinal ring, through which the spermatic cord (in females, the round ligament) and branches of the ilioinguinal and genitofemoral nerves pass. The rest of the medial fibers insert into the linea alba after contributing to the anterior portion of the rectus sheath.
Beneath the external oblique muscle is the internal oblique muscle. The fibers of the internal oblique muscle fan out following the shape of the iliac crest, so that the superior fibers course obliquely upward toward the distal ends of the lower three or four ribs while the lower fibers orient themselves inferomedially toward the pubis to run parallel to the external oblique aponeurotic fibers. These fibers arch over the round ligament or the spermatic cord, forming the superficial part of the internal (deep) inguinal ring.
Beneath the internal oblique muscle is the transversus abdominis. This muscle arises from the inguinal ligament, the inner side of the iliac crest, the endoabdominal fascia, and the lower six costal cartilages and ribs, where it interdigitates with the lateral diaphragmatic fibers. The medial aponeurotic fibers of the transversus abdominis contribute to the rectus sheath and insert on the pecten ossis pubis and the crest of the pubis, forming the falx inguinalis. Infrequently, these fibers are joined by a portion of the internal oblique aponeurosis; only when this occurs is a true conjoined tendon formed.12
Aponeurotic fibers of the transversus abdominis also form the structure known as the aponeurotic arch. It is theorized that contraction of the transversus abdominis causes the arch to move downward toward the inguinal ligament, thereby constituting a form of shutter mechanism that reinforces the weakest area of the groin when intra-abdominal pressure is raised. The area beneath the arch varies. Many authorities believe that a high arch, resulting in a larger area from which the transversus abdominis is by definition absent, is a predisposing factor for a direct inguinal hernia. The transverse aponeurotic arch is also important because the term is used by many authors to describe the medial structure that is sewn to the inguinal ligament in many of the older inguinal hernia repairs.
The rectus abdominis forms the central anchoring muscle mass of the anterior abdomen. It arises from the fifth through seventh costal cartilages and inserts on the pubic symphysis and the pubic crest. It is innervated by the seventh through 12th intercostal nerves, which laterally pierce the aponeurotic sheath of the muscle. The semilunar line is the slight depression in the aponeurotic fibers coursing towards the muscle. In a minority of persons, the small pyramidalis muscle accompanies the rectus abdominis at its insertion. This muscle arises from the pubic symphysis. It lies within the rectus sheath and tapers to attach to the linea alba, which represents the conjunction of the two rectus sheaths and is the major site of insertion for three aponeuroses from all three lateral muscle layers. The line of Douglas (i.e., the arcuate line of the rectus sheath) is formed at a variable distance between the umbilicus and the inguinal space because the fasciae of the large flat muscles of the abdominal wall contribute their aponeuroses to the anterior surface of the muscle, leaving only transversalis fascia to cover the posterior surface of the rectus abdominis.
The innervation of the anterior wall muscles is multifaceted. The seventh through 12th intercostal nerves and the first and second lumbar nerves provide most of the innervation of the lateral muscles, as well as of the rectus abdominis and the overlying skin. The nerves pass anteriorly in a plane between the internal oblique muscle and the transversus abdominis, eventually piercing the lateral aspect of the rectus sheath to innervate the muscle therein. The external oblique muscle receives branches of the intercostal nerves, which penetrate the internal oblique muscle to reach it. The anterior ends of the nerves form part of the cutaneous innervation of the abdominal wall. The first lumbar nerve divides into the ilioinguinal nerve and the iliohypogastric nerve [see Figure 2]. These important nerves lie in the space between the internal oblique muscle and the external oblique aponeurosis. They may divide within the psoas major or between the internal oblique muscle and the transversus abdominis. The ilioinguinal nerve may communicate with the iliohypogastric nerve before innervating the internal oblique muscle. The ilioinguinal nerve then passes through the external inguinal ring to run parallel to the spermatic cord, while the iliohypogastric nerve pierces the external oblique muscle to innervate the skin above the pubis. The cremaster muscle fibers, which are derived from the internal oblique muscle, are innervated by the genitofemoral nerve. There can be considerable variability and overlap.
The blood supply of the lateral muscles of the anterior wall comes primarily from the lower three or four intercostal arteries, the deep circumflex iliac artery, and the lumbar arteries. The rectus abdominis has a complicated blood supply that derives from the superior epigastric artery (a terminal branch of the internal thoracic [internal mammary] artery), the inferior epigastric artery (a branch of the external iliac artery), and the lower intercostal arteries. The lower intercostal arteries enter the sides of the muscle after traveling between the oblique muscles; the superior and the inferior epigastric arteries enter the rectus sheath and anastomose near the umbilicus.
The endoabdominal fascia is the deep fascia covering the internal surface of the transversus abdominis, the iliacus, the psoas major and minor, the obturator internus, and portions of the periosteum. It is a continuous sheet that extends throughout the extraperitoneal space and is sometimes referred to as the wallpaper of the abdominal cavity. Commonly, the endoabdominal fascia is subclassified according to the muscle being covered (e.g., iliac fascia or obturator fascia).
The transversalis fascia is particularly important for inguinal hernia repair because it forms anatomic landmarks known as analogues or derivatives. The most significant of these analogues for groin hernia surgeons are the iliopectineal arch, the iliopubic tract, the crura of the deep inguinal ring, and Cooper’s ligament (i.e., the pectineal ligament). The superior and inferior crura form a ‘monk’s hood’-shaped sling around the deep inguinal ring. This sling has functional significance, in that as the crura of the ring are pulled upward and laterally by the contraction of the transversus abdominis, a valvular action is generated that helps preclude indirect hernia formation. The iliopubic tract is the thickened band of the transversalis fascia that courses parallel to the more superficially located inguinal ligament. It is attached to the iliac crest laterally and inserts on the pubic tubercle medially. The insertion curves inferolaterally for 1 to 2 cm along the pectineal line of the pubis to blend with Cooper’s ligament, ending at about the midportion of the superior pubic ramus. Cooper’s ligament is actually a condensation of the periosteum and is not a true analogue of the transversalis fascia.
Hesselbach’s inguinal triangle is the site of direct inguinal hernias. As viewed from the anterior aspect, the inguinal ligament forms the base of the triangle, the edge of the rectus abdominis forms the medial border, and the inferior epigastric vessels form the superolateral border. (It should be noted, however, that Hesselbach actually described Cooper’s ligament as the base.)
Below the iliopubic tract are the critical anatomic elements from which a femoral hernia may develop. The iliopectineal arch separates the vascular compartment that contains the femoral vessels from the neuromuscular compartment that contains the iliopsoas muscle, the femoral nerve, and the lateral femoral cutaneous nerve. The vascular compartment is invested by the femoral sheath, which has three subcompartments: (1) the lateral, containing the femoral artery and the femoral branch of the genitofemoral nerve; (2) the middle, containing the femoral vein; and (3) the medial, which is the cone-shaped cul-de-sac known as the femoral canal. The femoral canal is normally a 1 to 2 cm blind pouch that begins at the femoral ring and extends to the level of the fossa ovalis. The femoral ring is bordered by the superior pubic ramus inferiorly, the femoral vein laterally, and the iliopubic tract (with its curved insertion onto the pubic ramus) anteriorly and medially. The femoral canal normally contains preperitoneal fat, connective tissue, and lymph nodes (including Cloquet’s node at the femoral ring), which collectively make up the femoral pad. This pad acts as a cushion for the femoral vein, allowing expansion such as might occur during a Valsalva maneuver, and serves as a plug to prevent abdominal contents from entering the thigh. A femoral hernia exists when the blind end of the femoral canal becomes an opening (the femoral orifice) through which a peritoneal sac can protrude.
Between the transversalis fascia and the peritoneum is the preperitoneal space. In the midline behind the pubis, this space is known as the space of Retzius; laterally, it is referred to as the space of Bogros. The preperitoneal space is of particular importance for surgeons because many of the inguinal hernia repairs (see below) are performed in this area. The inferior epigastric vessels, the deep inferior epigastric vein, the iliopubic vein, the rectusial vein, the retropubic vein, the communicating rectusioepigastric vein, the internal spermatic vessels, and the vas deferens are all encountered in this space.13
Choice of Prosthetic Material
For most abdominal wall hernias, the procedure of choice includes the use of a prosthesis. A detailed discussion comparing and contrasting various prosthetic materials is beyond the scope of this chapter; however, some general statements may be made. As a rule, North American surgeons tend to consider polypropylene mesh the favored prosthetic material, whereas European surgeons are more likely to employ polyester mesh. Of course, the use of mesh presupposes a situation in which the prosthesis can be isolated from contact with intra-abdominal viscera by one or more layers of human tissue (e.g., peritoneum). In situations where contact with intra-abdominal viscera cannot be avoided, a standard mesh prosthesis should not be used. Either the prosthesis should be composed of a nonmesh material, such as expanded polytetrafluoroethylene (ePTFE), or a dual-layer prosthesis should be used, with a standard plastic mesh on the side facing the abdominal wall (to encourage an intense fibroplastic response) and an adhesion barrier of some type coating the peritoneal side. Numerous dual-sided prosthetics, incorporating a variety of adhesion barriers, are now available [see Table 4]. It has consistently been shown that when these materials are used, adhesions are not only less common but also less tenacious than when mesh alone is used. Often, bowel adhesions can be literally wiped from the peritoneal surface of a dual-layer prosthesis with gentle blunt traction, in sharp contrast to the typically tedious and sometimes impossible dissection of bowel loops from a mesh prosthesis. Although all of the dual-layer prostheses currently on the market are approved for decreasing adhesions to the adhesion barrier side, no manufacturer has sought approval for complete prevention of adhesions. Consequently, the long-term effects of these less severe (but still present) adhesions are unknown; further study is required to address this issue.
A number of so-called biologic prostheses have been developed that are designed to promote vessel ingrowth and eventual remodeling of tissue to resemble the native type [see Table 5]. Although biologic prostheses are much more expensive than synthetic prostheses, they may be the better choice when the operative field is contaminated or when an abdominal wall defect is so large that the prosthesis cannot be covered by skin. Clearly, more study is required before their exact place in the armamentarium of the abdominal wall hernia surgeon can be determined.
At present, there is some controversy regarding the weight of the polypropylene mesh used in abdominal wall hernia repairs. (The controversy almost certainly applies to the other types of mesh prosthesis as well.) Data from randomized studies indicate that use of a lightweight mesh results in less long-term pain than use of a normal mesh, without having any negative effect on the recurrence rate.14,15 Lighter-weight mesh also addresses the theoretical concern about the possible carcinogenic effects of polypropylene, as has been suggested by experimental studies in rats, though it should be kept in mind that there has never been a documented case of a sarcoma developing in a human being as a result of an inguinal hernia prosthesis.16 To illustrate the difference between a lightweight mesh and a normal one, a 7.5 × 15 cm piece of polypropylene mesh (Prolene; Ethicon, Inc., Somerville, New Jersey) weighs about 80 g/m2, whereas a similarly sized piece of a polypropylene-poliglecaprone 25 (Monocryl; Ethicon, Inc., Somerville, New Jersey) lightweight mesh (UltraPro; Ethicon, Inc., Somerville, New Jersey) weighs less than 30 g/m2 after absorption of the poliglecaprone 25 component. North American surgeons have been slow to accept the use of lightweight mesh for inguinal hernia repair, fearing a higher recurrence rate (as was suggested by one of the earlier randomized trials).17 Many also have some concerns about possible bias in the data, noting that the research supporting the use of lightweight mesh has been almost exclusively funded by industry. Nevertheless, the randomized trials mentioned earlier cannot be entirely discounted.
Inguinal Hernia Repair: Choice of Procedure
Practical considerations do not allow a description of every single named inguinal hernia repair in the literature. The nonprosthetic named repairs alone number more than 70.18 For the purposes of this chapter, inguinal hernia repairs may be grouped according to (1) whether the operation makes use of the anterior space, the posterior space, or both and (2) whether a prosthesis is included or omitted [see Table 6]. In reality, most of the numerous eponyms used to name inguinal herniorrhaphies refer not to fundamentally distinct operations but, rather, to relatively minor modifications of standard hernia procedures [see Table 6]. Accordingly, rather than address every known variant, we describe only the major repairs on which these variants are based.
The most important consideration in choosing an inguinal hernia procedure is the experience of the surgeon. Knowing the ideal operation for a given clinical scenario is of no significance if the surgeon is not skilled in performing it. On the assumption that the surgeon’s expertise is equal to the task, the next consideration should be to tailor the operation to the patient’s particular hernia. For example, a simple Marcy repair would be completely adequate for a pediatric patient with a Nyhus type 1 hernia [see Table 1] but not for an elderly patient who has an indirect hernia in conjunction with extensive destruction of the inguinal floor. The conventional anterior prosthetic repairs are particularly useful in high-risk patients because they can easily be performed with local anesthesia.19 On the other hand, giant prosthetic reinforcement of the visceral sac (GPRVS), especially when bilateral, necessitates general or regional anesthesia and thus is best for patients with bilateral direct or recurrent hernias or, perhaps, for patients with connective tissue disorders that appear to be associated with their hernia. If surgery has previously been done in either the anterior or the preperitoneal space, the surgeon should choose a procedure that uses the undissected space. If local or systemic infection is present, a nonprosthetic repair is usually considered preferable, though the newer biologic prostheses now being evaluated may eventually change this view. Uncorrected coagulopathy is a contraindication to elective repair.
Inguinal Hernia Repair: Operative Technique
Steps Common to Prosthetic and Nonprosthetic Repairs
The various anterior herniorrhaphies have a number of initial technical steps in common; they differ primarily with respect to the specific details of floor reconstruction.
Step 1: choice of anesthetic Local anesthesia is entirely adequate, especially when combined with intravenous sedation. In specialty hernia clinics, it is the approach most commonly employed. In general practice, however, general anesthesia is the rule. This approach is reasonable in fit patients but is associated with a higher incidence of postoperative urinary retention.20 If general anesthesia is used, a local anesthetic should be given at the end of the procedure as an adjuvant to reduce immediate postoperative pain. Regional (spinal or epidural) anesthesia can also be used, but it is less popular, having the highest incidence of systemic side effects (primarily cardiovascular).19
We prefer local anesthesia combined with I.V. infusion of a rapid-acting, short-lasting, amnesic, and anxiolytic agent (e.g., propofol). This technique affords the patient all the benefits of general anesthesia in terms of comfort, without the higher incidence of urinary retention seen with regional or general endotracheal anesthesia. An added benefit is that the patient can be aroused from sedation periodically to perform Valsalva maneuvers to test the repair.
The techniques and drug dosages employed by different experts vary considerably. Compounding factors include the age of the patient and the amount of I.V. sedation used. Our preference is to use a solution containing 50 ml of 0.5% lidocaine with epinephrine and 50 ml of 0.25% bupivacaine with epinephrine. The epinephrine is optional and may be omitted if the patient has a history of coronary artery disease or if there is concern about delayed bleeding. In an adult of normal size, 70 ml of this solution is injected before preparation and draping: 10 ml is placed 1 cm medial and 1 cm inferior to the anterior superior iliac spine in an attempt to block the major nerves innervating the groin area [see Abdominal Wall Anatomy, above], and the other 60 ml is used as a field block along the orientation of the eventual incision in the subcutaneous and deeper tissues. Care is taken to ensure that some of the material is injected into the areas of the pubic tubercle and Cooper’s ligament, which are easily identified by tactile sensation (except in very obese patients). The remaining 30 ml of the solution is reserved for discretionary use during the procedure.
Step 2: initial incision Traditionally, the skin is opened by making an oblique incision between the anterior superior iliac spine and the pubic tubercle. For cosmetic reasons, however, many surgeons now prefer a more horizontal skin incision placed in the natural skin lines. In either case, the incision is deepened through Scarpa’s fasciae and the subcutaneous tissue to expose the external oblique aponeurosis. The external oblique aponeurosis is then opened through the external inguinal ring. If a prosthesis is to be used, a large space is created beneath the external oblique aponeurosis from the anterior rectus sheath medially to the anterior superior iliac spine laterally to prepare for the eventual placement.
Step 3: care of the sensory nerves The iliohypogastric nerve is identified; it can be either left in situ or freed from the surrounding tissue and isolated from the operative field by passing a hemostat under the nerve and grasping the upper flap of the external oblique aponeurosis. Routine division of the iliohypogastric nerve along with the ilioinguinal nerve is practiced by some but is not advised by most, though there does not seem to be any consistent correlation with postoperative groin pain either way. The ilioinguinal and genitofemoral nerves are usually left with the cord structures. The genitofemoral nerve cannot always be identified with certainty. It will be sacrificed in those procedures that include division of the cremaster muscle (e.g., Shouldice repair).
Step 4: mobilization of cord structures The cord structures are bluntly dissected away from the inferior flap of the external oblique aponeurosis to expose the inguinal ligament (shelving edge) and the iliopubic tract. This dissection is continued over the pubic tubercle and onto the anterior rectus sheath for at least 2 cm, defining the point where the most medial edge of a prosthesis will eventually be sutured if a Lichtenstein prosthetic repair is being performed. This measure facilitates en masse lifting of the cord structures with the fingers of one hand at the pubic tubercle so that the index finger can be passed underneath to meet the ipsilateral thumb or the fingers of the other hand. Mobilization of the cord structures is completed by means of blunt dissection, and a Penrose drain is placed around them so that they can be retracted during the procedure.
Step 5: division of cremaster muscle For decades, complete division of the cremaster muscle with concomitant sacrifice of the genitofemoral nerve was common practice, especially with indirect hernias. The purpose of this step was to facilitate identification of the sac and to lengthen the cord for better visualization of the inguinal floor. It is clear, however, that adequate exposure can almost always be obtained by opening the muscle longitudinally, which reduces the chances of damage to the cord and prevents testicular descent. Accordingly, the latter approach should be considered best practice unless circumstances argue for division of the muscle.
Step 6: management of hernial sac The term high ligation of the sac is used frequently in discussing inguinal hernia repair; its historical significance has ingrained it in the descriptions of most of the older operations. For our purposes in this chapter, high ligation of the sac should be considered equivalent to reduction of the sac into the preperitoneal space without excision. The two methods work equally well and are highly effective. Proponents of sac inversion believe that this measure results in less pain (because the richly innervated peritoneum is not incised) and may be less likely to cause adhesive complications. To date, however, no randomized trials have been done to determine whether this is so.21Sac eversion in lieu of excision does protect intra-abdominal viscera in cases of unrecognized incarcerated sac contents or sliding hernia.
Many surgeons (especially urologists) believe that complete excision of all indirect inguinal hernial sacs, even when inguinal-scrotal, is important for preventing excessive postoperative hydrocele formation. The downside of this practice is that the incidence of ischemic orchitis from excessive trauma to the cord rises substantially. The logical sequela of ischemic orchitis is testicular atrophy, though this presumed relationship has not been conclusively proved. In our view, it is better to divide an indirect inguinal hernial sac in the midportion of the inguinal canal once it is clear that the hernia is not sliding and no abdominal contents are present. The distal sac is not removed, but its anterior wall is opened as far distally as is convenient. We have not observed an increased incidence of hydroceles with this approach.
Direct hernial sacs are separated from the cord and other surrounding structures and reduced into the preperitoneal space. Dividing the superficial layers of the neck of the sac circumferentially—thereby, in effect, opening the inguinal floor—usually facilitates reduction and helps to maintain it while the prosthesis is being placed. The opening in the inguinal floor also allows the surgeon to palpate for a femoral hernia. Sutures can be used to maintain reduction of the sac, but they have no real strength in this setting; their main purpose is to allow the repair to proceed without being hindered by continual extrusion of the sac into the field, especially when the patient strains.
Step 7: repair of inguinal floor Methods of repairing the inguinal floor differ significantly among the various anterior herniorrhaphies and thus are described separately under the relevant headings [see Nonprosthetic Repairs and Prosthetic Repairs, below].
Step 8: relaxing incision A relaxing incision is employed only if a nonprosthetic repair is being performed. The incision is made through the anterior rectus sheath and down to the rectus abdominis, extending superiorly from the pubic tubercle for a variable distance, as determined by the degree of tension present. A so-called hockey-stick incision oriented laterally at the superior end is a common choice. The posterior rectus sheath is strong enough to prevent future incisional herniation. The relaxing incision works because as the anterior rectus sheath separates, the various components of the abdominal wall are displaced laterally and inferiorly.
Step 9: closure Closure of the external oblique fascia serves to reconstruct the superficial (external) ring. The external ring must be loose enough to prevent strangulation of the cord structures yet tight enough to ensure that an inexperienced examiner will not confuse a dilated ring with a recurrence. A dilated external ring is sometimes referred to as an industrial hernia, because over the years it has occasionally been a problem during preemployment physical examinations. Scarpa’s fascia and the skin are closed to complete the operation.
The Marcy repair is the simplest nonprosthetic repair performed today. Its main indication is for treatment of Nyhus type 1 hernias (i.e., indirect inguinal hernias in which the internal ring is normal). It is appropriate for children and young adults in whom there is concern about the long-term effects of prosthetic material. The essential features of the Marcy repair are high ligation of the sac and narrowing of the internal ring. Displacing the cord structures laterally allows the placement of sutures through the muscular and fascial layers [see Figure 3].
Bassini repairEdoardo Bassini (1844–1924) is considered the father of modern inguinal hernia surgery. It was during the 19th century that many of the great anatomists—Scarpa, Cooper, Hesselbach, Bogros, Retzius, Cloquet, Gay, and others—made their discoveries. By combining high ligation of the hernial sac with reconstruction of the inguinal floor (based on the principles formulated by the 19th-century anatomists), as well as taking advantage of the developing disciplines of antisepsis and anesthesia, Bassini was able to reduce recurrence and morbidity substantially. Before Bassini’s achievements, elective herniorrhaphy was almost never recommended, because the results were so bad. Bassini’s operation, known as the radical cure, became the gold standard for inguinal hernia repair for most of the 20th century.
The initial steps in the procedure are as previously described [see Steps Common to Prosthetic and Nonprosthetic Repairs, above]. Bassini felt that the incision in the external oblique aponeurosis should be as superior as possible while still allowing the superficial external ring to be opened, so that the reapproximation suture line created later in the operation would not be directly over the suture line of the inguinal floor reconstruction.22 Whether this technical point is significant is debatable. Bassini also felt that lengthwise division of the cremaster muscle followed by resection was important for ensuring that an indirect hernial sac could not be missed and for achieving adequate exposure of the inguinal floor.
After performing the initial dissection and the reduction or ligation of the sac, Bassini began the reconstruction of the inguinal floor by opening the transversalis fascia from the internal inguinal ring to the pubic tubercle, thereby exposing the preperitoneal fat, which he then bluntly dissected away from the undersurface of the superior flap of the transversalis fascia [see Figure 4a]. This step allowed him to properly prepare the deepest structure in his famous ‘triple layer’ (comprising the transversalis fascia, the transversus abdominis, and the internal oblique muscle).
The first stitch in Bassini’s repair includes the triple layer superiorly and the periosteum of the medial side of the pubic tubercle, along with the rectus sheath. In current practice, however, most surgeons try to avoid the periosteum of the pubic tubercle so as to decrease the incidence of osteitis pubis. The repair is then continued laterally, and the triple layer is secured to the reflected inguinal ligament (Poupart’s ligament) with nonabsorbable sutures. The sutures are continued until the internal ring is closed on its medial side [see Figure 4b]. A relaxing incision was not part of Bassini’s original description but now is commonly added.
Concerns about injuries to neurovascular structures in the preperitoneal space and to the bladder led many surgeons, especially in North America, to abandon the opening of the transversalis fascia. The unfortunate consequence of this decision is that the proper development of the triple layer is severely compromised. In lieu of opening the floor, a forceps (e.g., an Allis clamp) is used to grasp tissue blindly in the hope of including the transversalis fascia and the transversus abdominis. The layer is then sutured, along with the internal oblique muscle, to the reflected inguinal ligament as in the classic Bassini repair. The structure grasped in this modified procedure is sometimes referred to as the conjoined tendon, but this term is not accurate, because of the variability in what is actually grasped in the clamp. This imprecise ‘good stuff to good stuff’ approach almost certainly accounts for the inferior results achieved with the Bassini procedure in the United States.
The Maloney darn derives its name from the way in which a long nylon suture is repeatedly passed between the tissues to create a weave that one might consider similar to a mesh. After initial preparation of the groin (see above), a continuous nylon suture is used to oppose the transversus abdominis, the rectus abdominis, the internal oblique muscle, and the transversalis fascia medially to Poupart’s ligament laterally. The suture is continued into the muscle around the cord and is woven in and out to form a reinforcement around the cord [see Figure 5]. On the lateral side of the cord, it is sutured to the inguinal ligament and tied. The darn is a second layer. The sutures are placed either parallel or in a criss-cross fashion and are plicated well into the inguinal ligament below. The darn must be carried well over the medial edge of the inguinal canal. Once the darn is complete, the external oblique fascia is closed over the cord structures. The Maloney darn can be considered a forerunner of the mesh repairs, in that the purpose of the darn is to provide a scaffold for tissue ingrowth.23
Shouldice repair Steps 1 through 6 of this repair are performed essentially as previously described [see Steps Common to Prosthetic and Nonprosthetic Repairs, above]. Particular importance is placed on freeing of the cord from its surrounding adhesions, resection of the cremaster muscle, high dissection of the hernial sac, and division of the transversalis fascia during the initial steps of the procedure.24A continuous nonabsorbable suture (typically of monofilament steel wire) is used to repair the floor. The Shouldice surgeons believe that a continuous suture distributes tension evenly and prevents potential defects between interrupted sutures that could lead to recurrence.
A second wire suture is started near the internal ring, approximating the internal oblique muscle and the transversus abdominis to a band of external oblique aponeurosis superficial and parallel to Poupart’s ligament—in effect, creating a second, artificial Poupart’s ligament. This third suture line ends at the pubic crest. The suture is then reversed, and a fourth suture line is constructed in a similar manner, superficial to the third line. At the Shouldice clinic, the cribriform fascia is always incised in the thigh, parallel to the inguinal ligament, to make the inner side of the lower flap of the external oblique aponeurosis available for these multiple layers. In general practice, however, this step is commonly omitted.
The results at the Shouldice clinic have been truly outstanding and continue to be so today. For a time, the Shouldice repair was the gold standard against which all newer procedures were compared. The major criticism of this operation is that it is difficult to teach because surgeons have problems understanding what is really being sewn to what. Unless one is specifically trained at the Shouldice clinic and has the opportunity to work with the surgeons there, one may find it hard to identify the various layers in the medial flap reliably and reproducibly—a step that is crucial for developing the multiple suture lines. To compound the difficulty, modifications developed outside the Shouldice clinic have given rise to different versions of the procedure. For example, some surgeons use three continuous layers instead of four for reconstruction of the inguinal floor.
McVay Cooper’s ligament repair This operation is similar to the Bassini repair, except that it uses Cooper’s ligament instead of the inguinal ligament for the medial portion of the repair. Interrupted sutures are placed from the pubic tubercle laterally along Cooper’s ligament, progressively narrowing the femoral ring; this constitutes the most common application of the repair—namely, treatment of a femoral hernia [see Figure 7]. The last stitch in Cooper’s ligament is known as a transition stitch and includes the inguinal ligament. This stitch has two purposes: (1) to complete the narrowing of the femoral ring by approximating the inguinal ligament to Cooper’s ligament, as well as to the medial tissue, and (2) to provide a smooth transition to the inguinal ligament over the femoral vessel so that the repair can be continued laterally (as in a Bassini repair). Given the considerable tension required to bridge such a large distance, a relaxing incision should always be used. In the view of many authorities, this tension results in more pain than is noted with other herniorrhaphies and predisposes to recurrence. For this reason, the McVay repair is rarely chosen today, the main exception being for treatment of a patient with a femoral hernia or a patient with specific contraindications to mesh repair.
Lichtenstein repair This operation is now considered the gold standard for inguinal herniorrhaphy. The initial preparation of the inguinal floor does not differ substantially from that carried out in a nonprosthetic repair. The transversalis fascia is not opened—a practice that has occasionally been criticized on the grounds that it might cause an occult femoral hernia to be missed. To date, however, an excessive incidence of missed femoral hernias has not been reported in men. The situation may be different in women: evidence from the large population-based Swedish study cited earlier suggests that femoral recurrence is much more common than one might assume when the entire myopectineal orifice is not addressed (as is the case with a McVay procedure or any of the preperitoneal operations).3
The key to the operation is the placement of a large prosthesis (at least 15 × 10 cm for an adult) extending from a point 2 cm medial to the pubic tubercle (to prevent the pubic tubercle recurrences all too commonly seen with other operations) to the anterior superior iliac spine laterally. The medial end is rounded to correspond to the patient’s particular anatomy, and a continuous suture of either nonabsorbable or long-lasting absorbable material is begun between the prosthesis and the anterior rectus sheath 2 cm medial to the pubic tubercle [see Figure 8]. The suture is continued laterally in a locking fashion, securing the prosthesis to either side of the pubic tubercle (not into it) and then to the shelving edge of the inguinal ligament. The suture is tied at the internal ring.
A slit is made on the lateral side of the prosthesis to create two tails, a wider one (approximately two thirds of the total height) above and a narrower one below. The tails are positioned around the cord structures and placed beneath the external oblique aponeurosis laterally to about the anterior superior iliac spine, with the upper tail placed on top of the lower. A single interrupted suture is placed to secure the lower edge of the superior tail to the lower edge of the inferior tail and the inguinal ligament—thereby, in effect, creating a shutter valve. This step is considered crucial for preventing the indirect recurrences occasionally seen when the tails are simply reapproximated. The maneuver provides a cradling effect as well, preventing direct contact between the cut edges of the prosthesis and the cord structures, which could result in damage when linear approximation is used. The suture also incorporates the shelving edge of the inguinal ligament so as to create a domelike buckling effect over the direct space, thereby ensuring that there is no tension, especially when the patient assumes an upright position. The Lichtenstein group has developed a customized prosthesis with a built-in domelike configuration, which, in their view, makes suturing the approximated tails to the inguinal ligament unnecessary.
A few interrupted sutures are placed to attach the superior and medial aspects of the prostheses to the underlying internal oblique muscle and rectus fascia. Care is taken to tie these loosely (with an ‘air knot’) and to avoid placing them laterally so as to minimize the risk of damaging the intramuscular and therefore invisible portions of the important nerves. On occasion, the iliohypogastric nerve, which courses on top of the internal oblique muscle, penetrates the medial flap of the external oblique aponeurosis. In this situation, the prosthesis should be slit to accommodate the nerve. The prosthesis can be trimmed in situ, but enough laxity must be maintained to allow for the difference between the supine and upright positions, as well as for possible shrinkage of the mesh.
If a femoral hernia is recognized, the transversalis fascia is opened and the hernia reduced to expose Cooper’s ligament. The Lichtenstein group’s approach is still to suture the inferior edge of the prosthesis to the inguinal ligament. The femoral space is then addressed by suturing the posterior surface of the prosthesis to Cooper’s ligament, thereby covering the entire myopectineal orifice, and finally by completing the superior and lateral sutures. We prefer to forgo the approximation of the inferior edge of the prosthesis to the inguinal ligament in favor of using interrupted sutures between that edge and Cooper’s ligament, much as in a McVay repair (the ‘Fitztenstein’ technique). A transition stitch is required between the inferior edge of the prosthesis, Cooper’s ligament, and the inguinal ligament on the medial side of the femoral vein. This stitch closes the femoral canal and sets the stage for the lateral side of the prosthesis to be sutured to the inguinal ligament. The rest of the operation then proceeds in the same manner as a classic Lichtenstein repair.
The mesh plug technique was first developed by Gilbert and subsequently modified by Rutkow and Robbins, Millikan, and others [see Figure 9].25–27The groin is entered via a standard anterior approach. The hernial sac is dissected away from surrounding structures and reduced into the preperitoneal space. A flat sheet of polypropylene mesh is rolled up like a cigarette, tied, inserted in the defect, and secured with interrupted sutures to either the internal ring (for an indirect hernia) or the neck of the defect (for a direct hernia).
A prefabricated prosthesis that has the configuration of a flower is commercially available and is recommended by Rutkow and Robbins. This prosthesis is tailored to each patient’s particular anatomy by removing some of the ‘petals’ to avoid unnecessary bulk. Many surgeons consider this step important for preventing erosion into surrounding structures (e.g., the bladder); indeed, such complications have been reported, albeit rarely.
Millikan further modified the procedure by recommending that the inside petals be sewn to the ring of the defect. For an indirect hernia, the inside pedals are sewn to the internal oblique portion of the internal ring; this forces the outside of the prosthesis underneath the inner side of the defect and makes it act like a preperitoneal underlay. For direct hernias, the inside petals are sewn to Cooper’s ligament and the shelving edge of the inguinal ligament, as well as to the conjoined tendon; this, again, forces the outside of the prosthesis to act as an underlay.
The patch portion of the procedure is optional and involves placing a flat piece of polypropylene in the conventional inguinal space so that it widely overlaps the plug, much as in a Lichtenstein repair. The difference with a plug-and-patch repair is that only one or two sutures—or, sometimes, no sutures—are used to secure the flat prosthesis to the underlying inguinal floor. Some surgeons, however, place so many sutures that they have in effect performed a Lichtenstein operation on top of the plug (sometimes referred to as a ‘plugstenstein’ repair).
To the credit of its proponents, the plug-and-patch repair, in all of its varieties, has been skillfully presented and has rapidly taken a significant share of the overall inguinal hernia market. It is not only fast but also extremely easy to teach, which has made it popular in both private and academic centers. A randomized, controlled trial has shown it to be equivalent to the Lichtenstein repair in terms of recurrence and morbidity.28 However, numerous case reports in the literature have described removal of plugs for pain, migration, or erosion, and as a result, the plug-and-patch repair has been the focus of considerable medicolegal scrutiny.
Posterior (Preperitoneal) Herniorrhaphy
A key technical issue in a preperitoneal hernia repair is how the surgeon chooses to enter the preperitoneal space. In fact, within this general class of repair, it is the method of entry into this space that constitutes the major difference between the various procedures.
Many approaches to the preperitoneal space have been described. For example, the space can be entered either anteriorly or posteriorly. If an anterior technique is to be used, the initial steps of the operation are similar to those of a conventional anterior herniorrhaphy. If a posterior technique is to be used, any of several incisions (lower midline, paramedian, or Pfannenstiel) will allow an extraperitoneal dissection. The preperitoneal space can also be entered transabdominally. This approach is useful when the patient is undergoing a laparotomy for some other condition and the hernia is to be repaired incidentally. Of course, the transabdominal preperitoneal laparoscopic repair described elsewhere [see 5:28 Laparoscopic Hernia Repair], by definition, enters the preperitoneal space from the abdomen.
Reed credits Annandale as being the first surgeon to describe the anterior method of gaining access to the preperitoneal space.29 Bassini’s operation, as classically performed, is technically an anterior preperitoneal operation, but it is never discussed in this group, because in the American variant of the procedure, the preperitoneal space is not entered. Cheatle suggested the posterior approach to the preperitoneal space for repair of an inguinal hernia but used a laparotomy to do it.30 Cheatle and Henry subsequently modified the operation so as to render it entirely extraperitoneal (the Cheatle-Henry approach), which made the procedure more acceptable to surgeons.31
The preperitoneal nonprosthetic method remained popular into the second half of the 20th century, championed by proponents such as Nyhus and Condon, who emphasized the importance of the iliopubic tract as the inferior border in primary closure of direct or indirect hernia defects.32 Today, however, these operations are of little more than historical significance, because it is now universally agreed that better results are obtained in this space when a prosthesis is used. Indeed, after 1975, Nyhus and Condon began routinely placing a 6 × 14 cm piece of polypropylene mesh to buttress the primary repair for all recurrent hernias.33 When contraindications to a prosthesis are present [see Table 7], most surgeons would opt for a conventional anterior herniorrhaphy (e.g., a Bassini or Shouldice repair) rather than a preperitoneal nonprosthetic herniorrhaphy.
The most important step in any preperitoneal prosthetic repair is the placement of a large prothesis in the preperitoneal space on the abdominal side of the defect. The theoretical advantage of this measure is that whereas in a conventional repair, abdominal pressure might contribute to recurrence, in a preperitoneal repair, the abdominal pressure would actually help fix the mesh material against the abdominal wall, thereby adding strength to the repair. The hernia defect itself may or may not be closed, depending on the preference of the surgeon. The strength of the repair depends on the prosthesis rather than on closure of the defect; however, such closure may decrease the seroma formation that inevitably occurs at the site of the undisturbed residual sac. Although these seromas almost always are self-limiting and disappear with time, they can be confused with recurrences by both patients and referring physicians. Accordingly, some surgeons prefer to take every step possible to prevent them.
Read-Rives repair The posterior space is accessed directly through the groin, and thus, the initial part of a Read-Rives repair, including the opening of the inguinal floor, is much like that of a classic Bassini repair. The inferior epigastric vessels are identified and the preperitoneal space completely dissected. The spermatic cord is parietalized by separating the ductus deferens from the spermatic vessels. A 12 × 16 cm piece of mesh is positioned in the preperitoneal space deep to the inferior epigastric vessels and secured with three sutures placed in the pubic tubercle, in Cooper’s ligament, and in the psoas muscle laterally. The transversalis fascia is closed over the prosthesis and the cord structures replaced. The rest of the closure is accomplished much as in a conventional anterior prosthetic repair.
Stoppa-Rignault-Wantz repair (GPRVS)
GPRVS has its roots in the important contribution that Henri Fruchaud made to herniology. In describing the myopectineal orifice that bears his name [see Figure 10], Fruchaud, who was Stoppa’s mentor, popularized a different viewpoint on the etiology of inguinal hernias.34Instead of subdividing hernias into direct, indirect, and femoral and then examining their specific causes, he emphasized that the common cause of all inguinal hernias was the failure of the transversalis fascia to retain the peritoneum. This concept led Stoppa to develop GPRVS, which reestablishes the integrity of the peritoneal sac by inserting a large permanent prosthesis that entirely replaces the transversalis fascia over the myopectineal orifice of Fruchaud with wide overlapping of surrounding tissue. With GPRVS, the exact type of hernia present (direct, indirect, or femoral) is unimportant, because the abdominal wall defect is not addressed.
Step 1: skin incision. A lower midline, inguinal, or Pfannenstiel incision may be used, depending on the surgeon’s preference. The inguinal incision is placed 2 to 3 cm below the level of the anterior superior iliac spine but above the internal ring; it is begun at the midline and extended laterally for 8 to 9 cm.35
Step 2: preperitoneal dissection. The fascia overlying the space of Retzius is opened without violation of the peritoneum. A combination of blunt and sharp dissection is continued laterally posterior to the rectus abdominis and the inferior epigastric vessels. The preperitoneal space is completely dissected to a point lateral to the anterior superior iliac spine [see Figure 11]. The symphysis pubis, Cooper’s ligament, and the iliopubic tract are identified. Inferiorly, the peritoneum is generously dissected away from the vas deferens and the internal spermatic vessels to create a large pocket, which will eventually accommodate a prosthesis without the possibility of rollup. In the inguinal approach, the anterior rectus sheath and the oblique muscles are incised for the length of the skin incision. The lower flaps of these structures are retracted inferiorly toward the pubis. The transversalis fascia is incised along the lateral edge of the rectus abdominis, and the preperitoneal space is entered; dissection then proceeds as previously indicated.
Step 3: management of hernial sac. Direct hernial sacs are reduced during the course of the preperitoneal dissection. Care must be taken to stay in the plane between the peritoneum and the transversalis fascia, allowing the latter structure to retract into the hernia defect toward the skin. The transversalis fascia can be thin, and if it is inadvertently opened and incorporated with the peritoneal sac during reduction, a needless and bloody dissection of the abdominal wall is the result.
Indirect sacs are more difficult to deal with than direct sacs are, in that they often adhere to the cord structures. Trauma to the cord must be minimized to prevent damage to the vas deferens or the testicular blood supply. Small sacs should be mobilized from the cord structures and reduced back into the peritoneal cavity. Large sacs may be difficult to mobilize from the cord without undue trauma if an attempt is made to remove the sac in its entirety. Accordingly, large sacs should be divided, with the distal portion left in situ and the proximal portion dissected away from the cord structures. Division of the sac is most easily accomplished by opening the sac on the side opposite the cord structures. A finger is placed in the sac to facilitate its separation from the cord. Downward traction is then placed on the cord structures to reduce any excessive fatty tissue (so-called lipoma of the cord) back into the preperitoneal space. This step prevents the ‘pseudorecurrences’ that may occur if the abnormality palpated during the preoperative physical examination was not a hernia but a lipoma of the cord.
Step 4: management of abdominal wall defect. It is this step that varies most from one author to another. In Nyhus’s approach, the defect is formally repaired, and only then is a tailored mesh prosthesis sutured to Cooper’s ligament and the transversalis fascia for reinforcement [see Figure 12]. Rignault prefers to close the defect loosely to prevent an unsightly early postoperative bulge.36 In Stoppa’s and Wantz’s technique, the defect is usually left alone, but the transversalis fascia in the defect is occasionally plicated by suturing it to Cooper’s ligament to prevent the bulge caused by a seroma in the undisturbed sac.
Step 5: parietalization of spermatic cord. The term parietalization of the spermatic cord, [see Video 1] popularized by Stoppa, refers to a thorough dissection of the cord aimed at providing sufficient length to permit lateral movement of the structure [see Figure 13]. In Stoppa’s view, this step is essential, in that it allows a prosthesis to be placed without having to be split laterally to accommodate the cord structures; the keyhole defect created when the prosthesis is split has been linked with recurrences. In Rignault’s opinion, creation of a keyhole defect in the mesh to encircle the spermatic cord is preferable, the rationale being that this gives the prosthesis enough security to allow the surgeon to dispense with fixation sutures or tacks. Minimizing fixation in this area is important because of the numerous anatomic elements in the preperitoneal space that can be inadvertently damaged during suture placement.
Step 6: placement of prosthesis. Dacron mesh, being more pliable than polypropylene, conforms well to the preperitoneal space and is therefore considered particularly suitable for GPRVS. Stoppa’s technique is most often associated with a single large prosthesis for bilateral hernias. The prosthesis is cut in the shape of a chevron [see Figure 14a], and eight clamps are positioned strategically around the prosthesis to facilitate placement into the preperitoneal space [see Figure 14b].
Unilateral repairs require a prosthesis that is approximately 15 × 12 cm but is cut so that the bottom edge is wider than the top edge and the lateral side is longer than the medial side. In Wantz’s technique, three absorbable sutures are used to attach the superior border of the prosthesis to the anterior abdominal wall well above the defect [see Figure 15]. The sutures are placed from medial to lateral near the linea alba, the semilunar line, and the anterior superior iliac spine. A Reverdin suture needle facilitates this task. Three long clamps are then placed on each corner and the middle of the prosthesis of the inferior flap. The medial clamp is placed into the space of Retzius and held by an assistant. The middle clamp is positioned so that the mesh covers the pubic ramus, the obturator fossa, and the iliac vessels and is also held by the assistant. The lateral clamp is placed into the iliac fossa to cover the parietalized cord structures and the iliopsoas muscle. Care must be taken to prevent the prosthesis from rolling up as the clamps are removed.
Step 7: closure of wound. The surgical wound is closed in accordance with anatomic guidelines once the surgeon is assured that there has been no displacement or rollup of the prosthesis.
Kugel-Ugahary repair The Kugel and Ugahary repairs were developed to compete with laparoscopic repairs. They require only a small (2 to 3 cm) skin incision placed 2 to 3 cm above the internal ring.37,38In Kugel’s operation, the incision is oriented obliquely, with one third of the incision lateral to a point halfway between the anterior superior iliac spine and the pubic tubercle and the remaining two thirds medial to this point. The incision is deepened through the external oblique fascia, and the internal oblique muscle is bluntly spread apart. The transversalis fascia is opened vertically for a distance of about 3 cm, but the internal ring is not violated. The preperitoneal space is entered and a blunt dissection performed. The inferior epigastric vessels are identified to confirm that the dissection is being done in the correct plane. These vessels should be left adherent to the overlying transversalis fascia and retracted medially and anteriorly. The iliac vessels, Cooper’s ligament, the pubic bone, and the hernia defect are identified by palpation. Most hernial sacs are simply reduced; the exceptions are large indirect sacs, which must sometimes be divided, with the distal sac left in situ and the proximal sac closed. To prevent recurrences, the cord structures are thoroughly parietalized to allow adequate posterior dissection.
The key to Kugel’s procedure is a specially designed 8 × 12 cm prosthesis made of two pieces of polypropylene with a single extruded monofilament fiber located near its edge. The construction of the prosthesis allows it to be deformed so that it can fit through the small incision; once inserted, it springs open to regain its normal shape, providing a wide overlap of the myopectineal orifice. The prosthesis also has a slit on its anterior surface, through which the surgeon places a finger to facilitate positioning.
Ugahary’s operation is similar to Kugel’s, but it does not require a special prosthesis. In what is known as the gridiron technique, the preperitoneal space is prepared through a 3 cm incision, much as in a Kugel repair. The space is held open with a narrow Langenbeck retractor and two ribbon retractors. A 10 × 15 cm piece of polypropylene mesh is rolled onto a long forceps after the edges have been rounded and sutures placed to correspond to various anatomic landmarks. The forceps with the rolled-up mesh on it is introduced into the preperitoneal space, and the mesh is unrolled with the help of clamps and specific movements of the ribbon retractors.
Both operations have been very successful in some hands and have important proponents. However, because they are essentially blind repairs, considerable experience with them is required before the surgeon can be confident in his or her ability to place the patch properly.
Combined Anterior and Posterior (Preperitoneal) Herniorrhaphy
Bilayer prosthetic repairThe bilayer prosthetic repair involves the use of a dumbbell-shaped prosthesis consisting of two flat pieces of polypropylene mesh connected by a cylinder of the same material. The purpose of this design is to allow the surgeon to take advantage of the presumed benefits of both anterior and posterior approaches by placing prosthetic material in both the preperitoneal space and the extraperitoneal space.
The initial steps are identical to those of a Lichtenstein repair. Once the conventional anterior space has been prepared, the preperitoneal space is entered through the hernia defect. Indirect hernias are reduced, and a gauze sponge is used to develop the preperitoneal space through the internal ring. For direct hernias, the transversalis fascia is opened, and the space between this structure and the peritoneum is developed with a gauze sponge. The deep layer of the prosthesis is deployed in the preperitoneal space, overlapping the direct and indirect spaces and Cooper’s ligament. The superficial layer of the device occupies the conventional anterior space, much as in a Lichtenstein repair. It is slit laterally or centrally to accommodate the cord structures and then affixed to the area of the pubic tubercle, the middle of the inguinal ligament, and the internal oblique muscle with three or four interrupted sutures.
Inguinal Hernia Repair: Complications
An analysis of nearly 18,000 herniorrhaphies in Sweden determined that 15% of these operations were performed to treat recurrent hernias.39 This figure is remarkably consistent with the data from most other large series. A population-based study conducted by the Rand Corporation documented recurrence rates ranging from 10% to 30%, depending on the characteristics of the hernia (e.g., a lower rate after repair of simple small hernias and a higher rate after repair of recurrent hernias).40
Because routine use of prosthetic material in herniorrhaphy is a comparatively recent phenomenon, most of these historical data have to do with sutured repairs. Many surgeons now believe that sutured repairs inevitably result in distortion of the anatomy and in tissue approximation under tension, leading to high recurrence rates. If this belief is correct, then it may be assumed that the overall hernia recurrence rate should decrease dramatically over the next several decades as the percentage of prosthetic herniorrhaphies being performed increases. Two well-controlled, highly funded, randomized trials that examined various aspects of inguinal hernia management have now lent some support to this assumption.8,41 Both trials included the Lichtenstein tension-free repair as the control operation; the recurrence rates at 2 years were 4% and 1% for that operation.
It is generally recognized that inguinal herniorrhaphy results in greater morbidity than was previously appreciated. Now that modern hernioplasty techniques have reduced recurrence rates to a minimum, chronic postoperative groin pain syndromes have emerged as the major complication facing inguinal hernia surgeons. In a critical review of inguinal herniorrhaphy studies between 1987 and 2000, the incidence of some degree of long-term groin pain after surgery was as high as 53% at 1 year (range, 0% to 53%).42 This complication is more likely to be observed in younger patients and in patients who report preoperative pain attributable to their hernia. Other risk factors have also been identified [see Table 8]. Chronic postoperative groin pain occurs without regard to the type of repair performed (tissue repair versus tension free; open versus laparoscopic) and does not depend on the method by which the nerves are treated intraoperatively (division versus preservation).43
Treatment is difficult and often fails entirely. The difficulty is compounded when workman’s compensation issues cloud the picture. The first possibility that must be ruled out is a recurrent hernia. As a rule, all three types of pain (somatic, neuropathic, and visceral) are best treated initially with reassurance and conservative treatment (e.g., anti-inflammatory medications and local nerve blocks); frequently, the complaint resolves spontaneously. The only exception to this rule might be the patient who complains of severe pain immediately (i.e., in the recovery room), who might be best treated with immediate reexploration before scar tissue develops. Otherwise, reexploration is scrupulously avoided in the first year after the procedure to allow for the possibility of spontaneous resolution. When groin exploration is required, neurectomy and neuroma excision, adhesiolysis, muscle or tendon repair, and foreign body removal are all possibilities. The results are often less than satisfying.
Ischemic Orchitis and Testicular Atrophy
Orchitis or atrophy may result if the testicular blood supply is compromised during herniorrhaphy. Orchitis is defined as postoperative inflammation of the testicle occurring within the first 2 postoperative days. Patients experience painful enlargement and hardening of the testicle, usually associated with a low-grade fever; the pain is severe and may last several weeks. Ischemic orchitis is most likely attributable to thrombosis of the veins draining the testicle caused by dissection of the spermatic cord. It may progress over a period of months and eventually result in testicular atrophy. This latter development is not inevitable, however. In fact, the occurrence of testicular atrophy is quite unpredictable, in that most patients with this condition have no history of testicular problems associated with the index herniorrhaphy. The vast majority of patients who experience testicular complications go on to recover without atrophy. Bendavid, in a study of the incidence of testicular atrophy at the Shouldice Hospital, found that this complication occurred in only 19 (0.036%) of 52,583 primary inguinal hernia repairs and in only 33 (0.46%) of 7,169 recurrent inguinal hernia repairs.44
Postherniorrhaphy bleeding—usually the result of delayed bleeding from the cremasteric artery, the internal spermatic artery, or branches of the inferior epigastric vessels—can produce a wound or scrotal hematoma. Injuries to the deep circumflex artery, the corona mortis, or the external iliac vessels may result in a large retroperitoneal hematoma.
Osteitis pubis has diminished in frequency since surgeons began to realize the importance of not placing sutures through the periosteum. In laparoscopic repairs, staples are used to attach the mesh to Cooper’s ligament, which may cause osteitis in some cases.
The increasingly liberal use of prosthetic material in conventional herniorrhaphy and the routine use of such material in laparoscopic herniorrhaphy make the discussion of complications related directly to foreign material a timely one. Tissue response, which is variable from person to person, can be so intense that the prosthetic material is deformed by contraction. Erosion can result in intestinal obstruction or fistulization, especially if there is physical contact between intestine and prosthesis.45,46 Erosion into the cord structures has also been reported.47
The other controversial issue is the possibility of damage to the spermatic cord caused by the normal fibroplastic response to polypropylene mesh. Such damage may lead to infertility through obstruction of the vas deferens. This was the conclusion in a 2005 paper describing 14 patients attending several specialty infertility clinics.48 Nine of the patients had undergone bilateral tension-free inguinal herniorrhaphies with mesh; the remaining five had undergone unilateral repairs but also had pathologic conditions (e.g., testicular atrophy or torsion) on the opposite side. All patients underwent surgical exploration with intraoperative vasography. The vasogram identified the site of the obstruction in the inguinal region, and the surgical exploration determined that the mesh was the cause of the obstruction. These distressing findings certainly call for continued vigilance. It has been suggested, however, that there may be another explanation for infertility after mesh herniorrhaphy: this complication might be the consequence of a more traditional injury mechanism at the time of surgery, such as ligation, division, or cauterization, followed by scarring to a moist, conveniently adjacent structure (which in this case would be the mesh).49
Prostheses used for inguinal herniorrhaphies, unlike those used for ventral herniorrhaphies, rarely become infected. The reason why the groin is apparently a protected area is unclear. If a prosthesis composed of a mesh material (e.g., polypropylene) becomes infected, it can usually be salvaged with drainage alone. This should be the initial treatment for all infected mesh prostheses, with removal being reserved for refractory cases. If, however, a prosthesis composed of a nonmesh material (e.g., ePTFE) becomes infected, it can never be sterilized and virtually always must be removed. Rejection of the prosthesis because of an allergic response is possible but extremely rare. What patients call rejection in their histories is usually the result of infection.
Incisional Hernia Repair
Incisional hernias occur as a complication of previous surgery. As noted, their incidence depends on how they are defined [see Epidemiology, above]. In the literature, the incidence of incisional hernia ranges from 3% to 12% of all laparotomy incisions,6,50 and it is twice as high if the operation was associated with infection.
The root cause of incisional hernia is undoubtedly multifactorial. In the past, incisional hernias were believed to be mostly iatrogenic, related to surgical technical factors at the index operation (e.g., slippage of knots, breakage of sutures, tearing of fascia by sutures, rough handling of tissues, closure of the abdomen under tension, and poor choice of suture material).51 Today, however, it is clear that noniatrogenic factors [see Table 9] play a much larger role than was previously recognized. Nevertheless, the importance of careful attention to technical detail in the closure of any abdominal incision should not be minimized.
Surgeons’ practices in closing laparotomies tend to be far more dependent on tradition than on high-quality level I scientific evidence.52 There are, however, some general recommendations that can be made on the basis of current data and experience. Most authorities believe that the best way of preventing incisional hernias is to close the incision with a continuous monofilament nonabsorbable suture, with the stitches placed 1 cm from the skin edge and 1 cm apart. To prevent excessive tension, the length of the suture should be four times the length of the wound.52 Monofilament sutures perform better than braided sutures because bacteria tend to form colonies among the braids of multifilament sutures.54–57 Nonabsorbable suture material has the advantage of greater longevity than absorbable suture material, but it is more likely to result in sinus formation and chronic wound pain.7,52 The incidence of wound dehiscence or wound infection is not affected by the suture material or the closure method. Studies of various suture materials have determined that incisional hernia rates are essentially the same with polydioxanone as with polypropylene but may be higher with polyglactin.52
Various patient-related risk factors for incisional hernia have been identified [see Table 10].58,59 Although some controversy remains, the current consensus is that there appears to be an association between these comorbid conditions and the incidence of incisional hernia. The type of wound incurred also plays a role. Incisional herniation is most common after midline laparotomies, especially upper midline incisions, and less common after transverse or oblique incisions.6 An analysis of 11 publications addressing ventral hernia incidence after various types of incisions found the risk to be 10.5% for midline incisions, 7.5% for transverse incisions, and 2.5% for paramedian incisions.7 Over longer periods, the incidence increases, with the majority of incisional hernias developing in the first 4 years after the operation.60 It is anticipated that as the use of minimally invasive surgical techniques increases, the incidence of incisional hernia will drop. Hernias developing within 10 mm and 12 mm port sites are well documented; hernias in 5 mm port incisions are rare. At present, long-term data on the incidence and natural history of port-site hernias are lacking.61
Genetic factors are important as well: familial predisposition to incisional hernia has long been recognized by surgeons caring for patients with this condition. An increased incidence of incisional herniation in patients with certain connective tissue diseases (e.g., osteogenesis imperfecta, Marfan syndrome, and Ehlers-Danlos syndrome) has been documented. Finally, the molecular details of incisional hernia causation are now beginning to be appreciated. Type 1-type 3 collagen imbalance, abnormal matrix metalloproteinase (MMP) expression, and growth factor relations are among the molecular-level processes that are currently under intense scrutiny by the scientific community with regard to the etiology of incisional hernia.
Not every patient who presents to a surgeon with an incisional hernia is necessarily a candidate for surgical repair. There are three indications for operation: (1) a hernia that is symptomatic, causing pain, discomfort, or changes in bowel habits; (2) a hernia resulting in an unsightly bulge that affects the patient’s quality of life; (3) a hernia that poses a significant risk of bowel obstruction (e.g., a large hernia with a narrow neck).
Primary suture repair Historically, primary suture repair was the procedure of choice for most incisional hernias; prosthetic material was reserved for particularly difficult cases. In the latter part of the 20th century, large population-based studies changed this way of thinking, revealing that primary suture repair was associated with a much higher recurrence rate then most surgeons would have assumed (25% to 55%).11 Studies comparing primary suture with prosthetic repair showed that the recurrence rate was dramatically lower with the latter.62 In a randomized, controlled study from the Netherlands, even small incisional hernias (< 10 cm2) had a recurrence rate of 67% when primary suture repair was employed.63 Nevertheless, for patients who have no significant comorbid conditions [see Table 10] and who have a solitary defect less than 3 cm in diameter, primary closure with nonabsorbable suture material may be considered. Some surgeons perform a simple edge approximation after flaps have been developed on either side of the defect. Others use a Mayo ‘vest over pants’ repair.
Component separation repair This operation was initially described by Ramirez in 1990 and has become increasingly popular since then.64 Although first envisioned for treatment of hernias no larger than 10 cm, it is now being used to repair more substantial defects. Perhaps its most common application is in contaminated wounds, where a conventional prosthetic repair would be contraindicated.65–67
A long midline incision is made through the scar to expose the hernia. The hernial sac is dissected up to its neck, deep to the fascial edge. The skin and the subcutaneous fat are dissected away from the anterior sheath of the rectus abdominis and the aponeurosis of the external oblique muscle. The aponeurosis of the external oblique muscle is transected longitudinally just lateral to the lateral side of the rectus sheath [see Figure 16]. It is important to extend the incision onto the chest wall at least 5 to 7 cm cranial to the costal margin. The external oblique muscle is separated from the internal oblique muscle as far laterally as possible. This step is safe because the neurovascular bundle (comprising the intercostal nerves and vessels) lies deep to the internal oblique muscle. The result is that the internal oblique muscle and the rectus abdominis slide medially, so that the edges of the hernial defect can be brought together without tension and sutured primarily.68 If primary closure still is not possible without undue tension, 2 to 4 cm of additional length can be gained by separating the posterior rectus sheath from the rectus abdominis. Care must be taken not to damage the neurovascular bundle that runs between the internal oblique muscle and the transversus abdominis to enter the rectus sheath posterolaterally.
The use of prosthetic material to reduce tension has unquestionably reduced the recurrence rate after incisional hernia repair, especially in single-center series.69 For example, in a Finnish study of 84 consecutive patients treated with a retromuscular polypropylene mesh repair and followed for 3 years, the recurrence rate was 5%. In a separate U.S. study, no recurrences were reported in 102 patients after 28 months of follow-up.70
Prosthetic material may be positioned in three different ways for an incisional herniorrhaphy—namely, as an overlay (onlay), an inlay, or an underlay (sublay) [see Figure 17]. A mesh overlay may be placed on top of any of a variety of simple repairs. Although some series have reported that this approach yields acceptable results in selected patients, most surgeons feel that it offers little advantage over the simple repair that the prosthesis overlies and that it typically is associated with a similarly disappointing recurrence rate.11
Prosthetic inlay (bridging) repair became popular in the 1990s, in keeping with the tension-free ideal for inguinal herniorrhaphy. The principle underlying this technique is that for a prosthetic repair to be truly tension free, the defect should be bridged. Although this repair is theoretically attractive, it has not been nearly as successful for incisional hernias as for inguinal hernias. The recurrence rate is especially high in obese patients. Recurrences invariably develop at the mesh-native tissue interface. In the previously cited study from the Netherlands,63 the recurrence rate even with mesh repairs (mostly onlay and inlay) was 32% for large defects and 17% for small (< 10 cm2) defects.
When a hernia defect is bridged with a mesh prosthesis, every attempt should be made to isolate the material from the intra-abdominal viscera so as to prevent erosion and subsequent fistula formation or adhesive bowel obstruction. Such isolation may be accomplished with a peritoneal flap constructed from the peritoneal sac or with omentum. When contact with intra-abdominal organs cannot be avoided, ePTFE should be strongly considered for the prosthesis. Alternatively, one of the dual-layer prostheses that have mesh on one side and some type of adhesion barrier to protect the viscera on the other may be considered [see Table 4]. As yet, however, none of the dual-layer prostheses have a long enough track record to ensure that they will be safer than polypropylene alone would be.
The issue of contact between the intra-abdominal viscera and the prosthesis has been further addressed by techniques that combine some features of component separation repair with the tension-free concept. An example is the so-called keel operation of Maingot, which was popular in the middle of the 20th century. The anterior rectus sheath is incised longitudinally, and the medial edge is allowed to rotate behind the rectus abdominis. This, in effect, lengthens the posterior rectus sheath, allowing it to be closed primarily, which isolates the intra-abdominal viscera. If possible, the lateral edges of the incised rectus sheath on each side are approximated to each other. Otherwise, an inlay prosthesis may be used in the hope that the closure of the posterior sheath will render failure less likely than it would be with a simple bridging onlay repair [see Figure 18].
Sublay prosthetic repair
Sometimes referred to as the retromuscular approach, a sublay prosthetic repair is characterized by the placement of a large prosthesis in the space between the abdominal muscles and the posterior fascia—or the transversalis fascia or the peritoneum, [see Video 2] depending on what part of the abdomen is being repaired (there is no posterior fascia inferior to the arcuate line).27 In this chapter, we illustrate the version of the operation described by Flament [see Figure 19], but very similar operations have been attributed to Velamenta, Stoppa, and Wantz.71–73The operation was originally envisioned for treatment of large and multiply recurrent hernias in cases where most of the abdominal wall had to be reconstructed. Because it has proved so successful, it is now being increasingly used to repair ever smaller defects. Sublay prosthetic repair is currently considered the most effective conventional incisional hernia repair and is therefore the one against which all other procedures must be measured.
Extensive flaps are created by dissecting the skin and subcutaneous tissue off the external fascia well lateral to the hernia defect on either side. This step often allows the musculoaponeurotic components of the abdominal wall to be advanced to the point where the posterior and anterior fascial layers can be closed primarily. Once the flaps have been created, the fascia is opened at the edges of the defect, thereby affording entry into the plane between the posterior surface of the deepest muscle and the underlying peritoneum and posterior fascia. A combination of blunt and electrocautery dissection works best for creating this large space, which will eventually accommodate a sizable prosthesis (at least 5 cm long and wide).74 The posterior rectus sheaths are approximated to each other primarily if possible. If the posterior sheath cannot be approximated because of tension, then the use of ePTFE or a dual-layer prosthesis should be considered instead of the standard mesh. The prosthesis is then placed in the space beneath the muscle and secured in this position with sutures that are placed with a suture passer through small stab incisions at the periphery of the retromuscular pocket. The sutures pull the prosthesis well lateral and firmly affix it to the abdominal wall; they are then tied in the subcutaneous tissue above the fascia. To prevent excessive skin flap dissection, it is usually best to bring the two tails through the full thickness of the abdominal wall, including the skin. The tails must exit through two separate fascia sites but through the same small skin incision, so that when the knot is tied, it resides in the subcutaneous tissue. Some surgeons prefer to avoid using full-thickness sutures because of concern over the possibility of wound pain resulting from neuromuscular entrapment. The prosthesis is therefore either sutured or stapled to the posterior fascia as far laterally as possible. An increasingly popular choice for the most complicated hernias is to incorporate component separation into the procedure.
A 2006 study from Sweden confirmed the superiority of this operation, reporting a 7.3% recurrence rate for sublay prosthetic repair, compared with 19.3% for onlay mesh repair and 29.1% for suture repair.75 Sublay prosthetic repair has been successfully employed to treat massive hernias with substantial loss of domain.76 Laparoscopic incisional hernia repair was designed with the principles of this operation in mind. Indeed, current experience with laparoscopic methods has encouraged surgeons to place prosthetic material intraperitoneally even when performing conventional open ventral herniorrhaphies, so as to minimize the need for extensive abdominal wall dissection.77,78
There is overwhelming proof that tension-free prosthetic repairs yield lower recurrence rates than direct suture repairs do. In a Medline search for complications of incisional hernia repair, recurrence rates ranged from 31% to 63% for direct suture repairs and from 0% to 32% (mostly less than 10%) for prosthetic repairs.63,79 Although the primary adverse outcome of hernia repair is recurrence, the short-term morbidity of open hernia repair must also be assessed. In one meta-analysis, the overall complication rate after open repair was 27%.80 Ileus, postoperative pain, sepsis, fistulization, and necrotizing fasciitis have all been documented. A 3.5% rate of enterocutaneous fistula formation within a 3-year follow-up period has also been reported.81 Prothesis-related infection, though rare with inguinal hernia repairs, remains a major problem with incisional hernia repairs. It occurs in as many as 25% of repairs in some series, delays healing for prolonged periods, and is one of the most important risk factors for re-recurrence. Higher rates of prosthesis infection are associated with preexisting infection, ulceration of the skin overlying the hernia, obesity, incarcerated or obstructed bowel within the hernia, and perforation of the bowel during hernia repair. Seromas are common, especially when a large prosthesis is required or there has been extensive flap dissection of the subcutaneous layer from the fascia. Untreated seromas commonly become infected secondarily. Suction drains can be useful but are likely to result in prosthesis infection if left in place too long. Strategies for preventing and managing seromas are largely based on empiricism and personal opinion; objective data are virtually nonexistent. It is not always necessary to remove the mesh if infection develops. A trial of local wound care after opening the incision and debriding the infected area is warranted. Some authorities believe that ePTFE prostheses are less prone to infection; however, once infection is established, ePTFE prostheses, unlike mesh prostheses, are almost never salvageable.
A dilemma arises when a patient has a large incisional hernia and the wound is contaminated either by skin infection or by injury to the bowel during the repair at the time of adhesiolysis. In this situation, a nonabsorbable mesh would have a significant chance of becoming infected, and an enterocutaneous fistula could complicate matters further. In the past, the use of absorbable mesh made of polyglycolic acid was recommended to prevent evisceration. Granulation tissue forms over the mesh, making skin grafting possible. The mesh itself is absorbed in about 3 weeks, leaving no permanent foreign body to serve as a persistent focus of infection. Unfortunately, however, recurrence of the incisional hernia is inevitable. Currently, many surgeons prefer to use one of the newer biologic prostheses in this setting. This has now become the best indication for these very expensive materials. Long-term data are not yet available.
Periumbilical Hernia Repair
This life-threatening condition is seen in the newborn. It may also be found in the fetus during ultrasound examination of a pregnant patient. There is an all-layer deficiency of the abdominal wall, to the right of a normal umbilicus, through which the bowels protrude. There is no hernial sac. Gastroschisis is discussed in more detail elsewhere [see 9:2 The Pediatric Surgical Patient].
Like gastroschisis, this condition is seen in the fetus in utero and in the newborn. It is a hernia into the umbilical cord; the hernial contents are therefore covered by Wharton’s jelly and amnion. Omphalocele is also discussed in more detail elsewhere [see 9:2 The Pediatric Surgical Patient].
Umbilical and Paraumbilical Hernia
Unlike an omphalocele, an umbilical hernia is covered by skin. If the defect is located to one side of the umbilicus, it is called a paraumbilical hernia (this variant is more common in adults). Umbilical hernias developing during childhood are congenital, whereas those developing during adult life are acquired. Accordingly, in adult patients, it is important to look for an underlying cause of increased intra-abdominal pressure (e.g., ascites or an intra-abdominal tumor). The differential diagnosis of an umbilical hernia includes a caput medusae of varices at the umbilicus from portal hypertension, a metastatic tumor deposit (so-called Sister Mary Joseph node), a granuloma, an omphalomesenteric duct cyst, and a urachal cyst.
Management of umbilical hernia is determined by the age of the patient. The majority of hernias occurring in children younger than 2 years will heal spontaneously; therefore, watchful waiting is the rule, and only symptomatic hernias are operated on. In children older than 2 years and in adults, surgical correction is required, with the type of repair employed depending on the size of the hernia. If the defect is small (< 3 cm), a direct suture repair may be performed. Alternatively, the Mayo repair may be used. A subumbilical semilunar incision is made, the hernial sac is opened, the contents of the sac are reduced into the abdomen, and the sac is excised. An overlapping or waistcoating technique is employed, in which the upper edge of the linea alba is placed so as to overlap the lower and then is fixed in this position with nonabsorbable mattress sutures. Because the Mayo repair results in increased tension, there has been controversy about its efficacy in adults. In various series, recurrence rates ranging from 1% to 40% have been reported in adult patients.82
For larger umbilical and paraumbilical hernias, particularly those in adults, a mesh repair is preferred. The sac is dissected away from the undersurface of the rectus and the linea alba circumferentially, then reduced into the abdomen. If the peritoneum remains intact, a mesh prosthesis may be placed in a subfascial position and secured with sutures. Alternatively, a mesh plug may be inserted and secured to the edges of the defect with a series of sutures.83 If the abdomen is entered, a dual-layer prosthesis with an adhesion barrier on the visceral side is recommended. In a series of 100 adult patients with a median follow-up period of 4.5 years, the recurrence rate was 11.5% for suture repairs and 0% for mesh repairs.84
Miscellaneous Ventral Abdominal Wall Hernia Repairs
Epigastric hernias occur through a single defect or multiple defects in the linea alba. In most patients with these hernias, only a single decussation of the fibers of the linea alba is present, as opposed to the triple decussation seen in most persons.85 The reported incidence of epigastric hernia ranges from less than 1% to as high as 5%. They are two to three times more common in men than in women, and 20% are multiple. Most defects are smaller than 1 cm and contain only incarcerated preperitoneal fat, with no peritoneal sac. For this reason, they generally cannot be visualized laparoscopically.
The usual complaint is a painful nodule in the upper midline. As a rule, reduction of the preperitoneal fat followed by simple closure of the defect resolves the complaint. Given the relatively high recurrence rate (up to 10%), some surgeons prefer to place a postage stamp-sized piece of prosthetic material in the preperitoneal space to reinforce the repair. Others bridge the defect by suturing the prosthesis circumferentially. Some authorities recommend exposure of the entire linea alba because of the incidence of multicentricity. We believe that this practice leads to unnecessary morbidity. Instead, we make a small incision with the patient under local anesthesia and explain to him or her that additional repairs may be required later.
Left untreated, an epigastric hernia can become large enough to develop a peritoneal sac into which intra-abdominal contents can protrude. Usually, however, the sac is wide, and serious complications are infrequent.
In diastasis recti, the two rectus abdominis muscles are separated quite widely, and the linea alba is stretched and protrudes like a fin. Although the protrusion is easily reducible and almost never produces complications, many patients find it unsightly and request treatment. The usual therapy involves removing a strip of the weakened linea alba and reapproximating it; however, this could result in tension, which in turn might lead to recurrence. The alternative would be a mesh repair.
Parastomal hernia is one of the most common complications of stoma formation. Its incidence is much higher than is generally appreciated. There is good evidence to suggest that more than 50% of patients will eventually be found to have a paracolostomy hernia if followed for longer than 5 years.86 The rate of herniation with small bowel stomas is also discouraging, though less so than that with colostomies. The results of parastomal hernia repair are particularly dismal, with recurrence being the rule rather than the exception.
Some parastomal hernias can be accounted for by poor site selection or technical errors (e.g., making the fascial opening too large or placing a stoma in an incision), but the overall incidence is too high to be explained by these causes alone. Placement of the stoma lateral to the rectus sheath is widely touted as a cause of parastomal hernia, but high-quality scientific evidence to support this claim is not available. Obesity, malnutrition, advanced age, collagen abnormalities, postoperative sepsis, abdominal distention, constipation, obstructive uropathy, steroid use, and chronic lung disease are also contributing factors.87,88
Newer techniques for stomal construction, such as extraperitoneal tunneling, have had little impact on the incidence of parastomal hernia. Fortunately, patients tolerate these hernias well, and life-threatening complications, such as bowel obstruction and strangulation, are rare. Most are asymptomatic. Routine repair, therefore, is not recommended; repair is appropriate only when there is an absolute or relative indication [see Table 11]. If repair is considered, patients must be informed that there is a significant chance that the hernia will recur.
Three general types of parastomal hernia repairs are currently performed: (1) fascial repair, (2) stomal relocation, and (3) prosthetic repair. Fascial repair involves local exploration around the stoma site, with primary closure of the defect. This approach should be considered of historical interest only because the results are so poor. Stomal relocation yields much better results and is considered the procedure of choice by many surgeons. This approach is especially appropriate for patients who have other stomal problems, such as skin excoriation or suboptimal stomal construction. The use of a prosthesis with a stomal relocation is not generally recommended, because of the inherent danger of contamination. In the past few years, the popularity of stomal relocation has waned because of the realization that patients who undergo this procedure are subjected to a triple threat of hernia recurrence: (1) at the old stoma site, (2) at the new stomal site, (3) in the laparotomy incision used to move the stoma.
Prosthetic repair appears to be the most promising approach, but it is necessary to accept the complications inherent in the placement of a foreign body. The stomal exit site must be isolated from the surgical field to lower the risk of prosthesis infection. The prosthesis can be placed extraperitoneally by making a hockey-stick incision around the stoma, with care taken to ensure that the incision is outside the periphery of the stomal appliance. Once the subcutaneous tissue is divided, dissection proceeds along the fascia until the sac is identified and removed. The defect is then closed with an overlying prosthesis buttress sutured in place. Alternatively, the fascial defect is bridged with the prosthesis for a tension-free repair.
The extraperitoneal approach seems logical but can be technically demanding, in that it is sometimes difficult to define the entire extent of the hernia defect. Moreover, the considerable undermining involved can lead to seroma formation and eventual infection. As an alternative, an intra-abdominal prosthetic approach has been described that is theoretically attractive because it avoids the local complications of the extraperitoneal operation and incorporates the mechanical advantage gained by placing the prosthesis on the peritoneal side of the abdominal wall.89,90 Intra-abdominal pressure then serves to fuse the prosthetic material to the abdominal wall rather than being a factor in recurrence. Either ePTFE or polypropylene mesh with an adhesion barrier can be used for the prosthesis. One technique is to slit the prosthesis and create a keyhole in its center, then suture this directly around the peritoneal side of the stoma so that it widely overlaps the hernia defect. Sugarbaker’s practice is to mobilize the bowel thoroughly, then lateralize it with the prosthesis—in effect, creating a long tunnel in addition to covering the hernia defect.90 The detractors of the intra-abdominal approach argue that the risk of complications (e.g., adhesive bowel obstruction and fistula formation) outweighs the advantages. The intra-abdominal approach is particularly well suited for adaptation to laparoscopic methods.91–93
A spigelian hernia, first described 400 years ago by the Flemish anatomist Adriaan van den Spiegel,94 is a hernia through a defect in the spigelian fascia. The spigelian fascia is the area between the semilunar line and the lateral border of the rectus abdominis. The majority of spigelian hernias occur just below the arcuate line, where the posterior rectus sheath becomes deficient. This region, known as the spigelian belt, is a band between the iliac crest and a line drawn 6 cm above [see Figure 20].95 These rare hernias are being reported with increasing frequency: there are more than 100 cases in the surgical literature.
A spigelian hernia may present as a bulge lateral to the rectus. However, because many of these hernias are interparietal, they may not be clinically apparent; often, they are picked up incidentally during laparoscopy. A significant percentage of patients present with an incarcerated or even strangulated hernia. If such a hernia is interparietal, the diagnosis frequently is not made until a laparotomy is done for treatment of the acute process.
The standard treatment is operative repair.96 A transverse incision is made over the bulge. The anterior rectus sheath is incised transversely, and the sac is dissected as far as its neck and either excised or inverted. The defect is then repaired with a continuous suture of nonabsorbable material. Alternatively, a mesh plug may be placed in the defect and sutured to the edges of the defect. Laparoscopic methods are increasingly being employed to repair spigelian hernias.97
In a Richter’s hernia, part of the bowel wall herniates through the defect. The herniated bowel wall may become ischemic and gangrenous, but intestinal obstruction does not occur. The overlying skin may be discolored. The herniated bowel wall is exposed by opening the sac, and the neck of the sac is enlarged to allow delivery of the bowel into the wound. The gangrenous patch is excised and the bowel wall reconstituted. The hernia is then repaired.
Supravesical hernias develop anterior to the urinary bladder as a consequence of failure of the integrity of the transversus abdominis and the transversalis fascia, both of which insert into Cooper’s ligament. The preperitoneal space is continuous with the retropubic space of Retzius, and the hernial sac protrudes into this area. The sac is directed laterally and emerges at the lateral border of the rectus abdominis in the inguinal region, the femoral region, or the obturator region. It may therefore mimic a hernia from any of these areas, and it sometimes is associated with a hernia from one of these regions. It is important to recognize this hernia during groin exploration for a suspected groin hernia and then to repair the defect appropriately.
A variant of this hernia, known as an internal supravesical hernia, may also arise. These hernias are classified according to whether they cross in front of, extend beside, or pass behind the bladder. Bowel symptoms predominate in patients with these defects, and urinary tract symptoms may develop in as many as 30%. Treatment is surgical and is accomplished transperitoneally via a low midline incision. The sac can usually be reduced without difficulty, and the neck of the sac should be divided and closed.
The lumbar region is the area bounded inferiorly by the iliac crest, superiorly by the 12th rib, posteriorly by the erector spinae group of muscles, and anteriorly by the posterior border of the external oblique muscle as it extends from the 12th rib to the iliac crest. There are three varieties of lumbar hernia.
- The superior lumbar hernia of Grynfelt. In this variety, the defect is in a space between the latissimus dorsi, the serratus posterior inferior, and the posterior border of the internal oblique muscle.
- The inferior lumbar hernia of Petit. Here the defect is in the space bounded by the latissimus dorsi posteriorly, the iliac crest inferiorly, and the posterior border of the external oblique muscle anteriorly.
- Secondary lumbar hernia that develops as a result of trauma—mostly surgical (e.g. renal surgery)—or infection.98 In the past, it was encountered relatively frequently as a consequence of spinal tuberculosis with paraspinal abscesses, but it is less common today. Surgical repair is discouraged because the natural history is more consistent with that of diastasis recti than that of a true hernia. Denervation appears to play a significant role in the pathogenesis. In other words, this ‘hernia’ really reflects a weakness in the abdominal wall more than it does a dangerous hernia defect. Therefore, appropriate repair is commonly followed by gradual eventration, which is perceived by the patient as a recurrence.
Lumbar hernias should be repaired if they are large or symptomatic. A prosthesis or a tissue flap of some kind is usually required for a successful repair. A rotation flap of fascia lata can be used for inferior lumbar hernias. Laparoscopic repair of lumbar hernias is now being performed with increasing frequency and is proving successful.99