are gradually reabsorbed by the body in a predictable fashion. Preclinical in vivo and in vitro studies

have shown favorable results with these materials, and further clinical evaluation with these materials is

currently underway.48 Fast absorbable prostheses such as polyglactin are not durable and almost never

result in long-term correction of an abdominal wall defect but are sometimes useful as a temporary

substitute when a nonabsorbable prosthesis is contraindicated (i.e., a grossly infected wound).

GROIN HERNIAS

Groin hernias are described as inguinal and femoral, the inguinal hernias being further subdivided into

direct and indirect hernias (some authorities refer to these as medial and lateral hernias, respectively).

Groin hernias may be primary or recurrent. An indirect hernia occurs as a protrusion of abdominal

contents through the internal ring, lateral to the inferior epigastric vessels, into the inguinal canal.

Indirect inguinal hernias (lateral hernias) are situated within the spermatic cord and therefore may

extend into the scrotum. In female patients, the hernia follows the round ligament and may present as a

swelling in the labium. A direct hernia (medial hernia) is a protrusion through the triangle of

Hesselbach medial to the inferior epigastric vessels. These hernias develop through an area where the

endoabdominal fascia is not protected by overlying muscle. Direct hernias do not usually involve the

cord, as they tend to protrude forward. However, they occasionally track alongside the cord down the

entire length of the inguinal canal and even enter the scrotum. For this reason, the only absolute

distinction between a direct and an indirect hernia is the relationship to the inferior epigastric vessels.

Inguinal hernias are more common in men (with a 15% lifetime risk among men aged >25 years) with

a male to female age-adjusted ratio of 7.5:1.49 A femoral hernia protrudes through the femoral canal,

which is bordered by the inguinal ligament superiorly, the pubic ramus medially and inferiorly, and the

femoral vein laterally. This hernia presents below the inguinal ligament (Fig. 72-21). In a sliding hernia,

part of the sac is formed by the viscera, on the left side the sigmoid colon or bladder, and on the right

side the cecum or bladder (Fig. 72-22).

Figure 72-21. A: Inguinal hernia. This presents above the inguinal ligament and extends below it. B: Femoral hernia. This presents

below the inguinal ligament.

Epidemiology

3 1. Inguinal hernias occur in persons of all ages, from the neonate to the elderly. Inguinal hernias

constitute approximately 75% of abdominal wall hernias, with femoral hernia accounting for 5%.

Femoral hernias are more common in women, but a woman with a groin hernia is still five times

more likely to have an inguinal hernia (usually indirect) than a femoral. Incisional, umbilical, and

epigastric hernias account for 15% and miscellaneous hernias make up the other 5%. The lifetime

risk of developing a groin hernia is approximately 25% in males and 5% in females. Inguinal

hernias are more common on the right than the left and are 10 times more likely in males than in

females.50 Indirect inguinal hernias are twice as common as direct hernias. The reported

prevalence of inguinal hernia in the general population varies widely in the literature primarily

due to a lack of a consistent reporting mechanism; for example, questionnaire versus actual

physical examination. The most reliable data use hernia repair as a surrogate for the prevalence.51

For example, in a study using the Danish Hospital registry, the country’s population of 5,639,885

people was studied. There were 46,717 groin hernia repairs reported between 2005 and 2010

making it possible to estimate prevalence for various age groups as shown in (Fig. 72-23).

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Figure 72-22. Sliding hernia (right indirect inguinal).

4 2. The figure confirms a bimodal incidence pattern peaking at the extremes of life with an initial peak

at 0 to 5 years followed by a second peak at 70 to 80 years.51 Right-sided inguinal hernias are

more common than left. In men, indirect inguinal hernias outnumber direct by about 2:1, with

femoral hernias making up a much smaller proportion. The literature dealing with groin hernia in

women is insufficient making management decisions difficult. For females, indirect inguinal

hernias are the most common which are five times more common than femoral hernias, with

direct hernias occurring rarely. Overall, femoral hernias account for fewer than 10% of all groin

hernias and the prevalence is higher in females than in males. Femoral hernias are especially

dangerous as 40% of all femoral hernias present as emergencies, with incarceration or

strangulation and need emergency repair which is associated with high mortality. A study from

the Swedish Hernia Registry analyzing 90,648 inguinal hernia operations (83,753 males, 6,895

females) between 1992 and 2003 revealed a higher percentage of emergency operations in women

(16.9%) than in men (5%).52 Femoral recurrences are particularly common in women in whom the

diagnosis at the time of the primary repair was a direct inguinal hernia, strongly suggesting a

missed femoral hernia at the original procedure since direct hernias are very rare in women.

Femoral hernias are also more common in older patients and in those who have previously

undergone inguinal hernia repair. Risk factors for the development of an inguinal hernia are listed

in Table 72-3.

Classification

The primary purpose of a classification system for any disease is to stratify for severity so that

reasonable comparisons can be made between various treatment strategies.53 However, with the

multiplicity of operative techniques and approaches for repair of groin hernias, no one classification

system has been accepted by all practitioners. The reason why it is so difficult to develop a classification

system that all surgeons can agree on is that in the final analysis, the physical examination represents an

important component and no one has been able to eliminate its subjectivity. The European Hernia

Society, Nyhus, Gilbert, Schumpelick, Harkins, Casten, Halverson and McVay, Lichtenstein, Bendavid,

Stoppa, Alexandre, and Zollinger have developed groin hernia classification systems. The European

Hernia Society classification is a simple system using three variables, location (M = medial, L =

lateral, and F = femoral) and size of the defect (1 [≤1 finger], 2 [1 to 2 fingers], and 3 [≥3 fingers])

and status (P = primary, R = recurrent, and X = unknown) (Table 72-4).54 This system and the Nyhus

system, which is detailed in Table 72-5, are widely used by hernia surgeons.

Table 72-3 Risk Factors for the Development of an Inguinal Hernia

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Figure 72-23. Prevalence of combined inguinal and femoral hernia repair (i.e., all groin hernias), stratified by age and gender. The

results indicate the percentage of persons at a given age in the population who were operated for a groin hernia during the study

period. Example: 4.19% CI 4.04% to 4.34% of all males aged 75 to 80 years in Denmark were operated for a groin hernia at least

once during the study period. From Burcharth J, Pedersen M, Bisgaard T, et al. Nationwide prevalence of groin hernia repair. PLoS

One 2013;8(1):e54367, with permission.

Clinical Diagnosis

Groin hernias present with a swelling that has a cough impulse. With indirect hernias, the swelling may

extend down into the scrotum. The swelling reduces when the patient lies down. Sometimes, the hernia

does not reduce easily and the patient has to reduce it manually. Applying pressure over the

midinguinal point (midway between the anterior superior iliac spine and the pubic tubercle and just

above the inguinal ligament) with the fingertip will control an indirect hernia and prevent it from

protruding when the patient strains. A direct hernia will not be controlled with this maneuver.

Similarly, if the scrotum is invaginated with the index finger and the tip of the finger is placed through

the external inguinal ring into the canal, and the patient is then asked to strain, an indirect hernia will

push against the fingertip, whereas a direct hernia will push against the pulp of the finger. It should be

noted that the accuracy of this clinical assessment is questioned by many authorities. A femoral hernia

presents as a swelling below the inguinal ligament and just lateral to the pubic tubercle (Fig. 72-21).

Table 72-4 EHS Classification of Groin Hernias

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CLASSIFICATION

Table 72-5 Nyhus Classification of Groin Hernias

DIAGNOSIS

Table 72-6 Differential Diagnosis of a Groin Hernia

Differential Diagnosis

The clinical presentation of a groin hernia, especially when large, is frequently obvious to the examiner.

Smaller hernias and recurrent hernias can be confused with a number of different conditions that can be

mistaken for a hernia (Table 72-6).

A hydrocele extending into the scrotum or an encysted hydrocele of the cord can involve the groin

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area. The distinguishing features are that the examining hand can get above a hydrocele but not above a

hernia and that a hydrocele transilluminates very clearly. A varicocele does not transilluminate, has the

characteristic feel of a “bag of worms,” and is more tube-like in conformation. Lesions of the testicle

may sometimes mimic a hernia, particularly in inflammatory conditions, such as epididymo-orchitis. The

distinguishing features are intense pain extending down into the scrotum. The testicle itself is enlarged

and tender, as is the epididymis. On rectal examination, the seminal vesicles are tender. This condition

may be bilateral. Torsion of the testicle is distinguished by the fact that the testicle is absent from the

scrotum and the swelling in the groin feels firm. A sonogram reveals a solid mass in the testicle, which

has been pulled up because of the torsion. Testicular tumors, if large enough, may extend up to the

groin area, but they have a solid feel and sonography can distinguish them.

Pseudohernia is a condition that occurs in patients with denervation of the abdominal wall

musculature (e.g., after polio). The abdominal wall muscles bulge forward on straining and have the

appearance of a hernia. An aneurysm of the femoral artery may present as a groin swelling but with an

expansile impulse and sometimes a bruit. If thrombosis develops in the aneurysm, pulsation may be lost.

In this instance, the aneurysm becomes tender. Femoral aneurysms move from side to side but not up

and down. A saphena varix usually presents below the inguinal ligament and represents a varicosity of

one of the branches of the long saphenous vein as it emerges from the hiatus. It is particularly common

in pregnancy. Like a hernia, the varix has a cough impulse and becomes more prominent when the

patient is standing. Compression over the femoral hiatus obliterates this lesion. The varix is sometimes

associated with varicose veins farther down the lower limb. The overlying skin has an associated bluish

discoloration. A lipoma within the spermatic cord is a very common condition and, from anatomic

studies and surgical dissection, is now regarded as a hernia of the extraperitoneal fat.55 If found at

surgery, the lipoma is removed to avoid a persistent bulge in the inguinal region despite a successful

hernia repair.

Enlargement of inguinal lymph nodes may also be mistaken for herniation. Inflammatory nodes are

usually tender; metastatic lymphadenopathy is usually not tender. If inguinal lymph nodes are replaced

by metastasis, a primary lesion should be looked for in the skin in any part of the lower limb. The

perineum and anal canal should also be examined. Lymphadenopathy can also be caused by lymphoma,

and groin nodes may be the only site. Lymphadenopathy characteristically appears as a wellcircumscribed mass below the inguinal ligament that one can get above with the examining hand.

Lymph nodes are solid on ultrasonography, and for this reason, it may be difficult to differentiate nodes

from a femoral hernia containing omentum.

Surgical Indications

5 Historically, surgeons have recommended repair of inguinal hernias at diagnosis unless specific

contraindications are present. This recommendation is based on the presumption that the morbidity and

mortality associated with a bowel obstruction and/or strangulation is greater than the risks of

operation. This concept was challenged for asymptomatic or minimally symptomatic patients based on

two randomized controlled trials comparing a strategy of watchful waiting to routine repair for male

inguinal hernia patients with minimal symptoms. In 2006, Fitzgibbons and colleagues randomized 724

patients to watchful waiting versus tension-free hernia repair from five North American Centers and

found no difference in quality of life at 2 years and an acceptably low rate of hernia accidents (1.8 per

1,000 patient-years) in the watchful waiting group.56 Similar results were determined in the other trial

conducted in the United Kingdom.57 It should be noted that long-term follow-up from these randomized

controlled trials have demonstrated a crossover rate of up to 70% by 10 years for patients in the

watchful waiting group, with crossover being much higher for patients older than 65 years of age.58 The

most common reason for crossover was increasing pain. Despite the high crossover rate, only 2.5% of

the patients in the watchful waiting group developed incarceration for which they underwent surgery

with no mortality. In summary, watchful waiting is a safe strategy for asymptomatic or minimally

symptomatic hernias. However, patients who opt for this strategy should be informed that it is safe to

delay surgery for several years, but increasing symptoms will more than likely make them choose to

have their hernia repaired over the next 10 years.

An alternative to surgical repair is a mechanical device known as a truss which consists of a belt with

a pad that is applied to the groin after spontaneous or manual reduction of a hernia and has been used

for centuries. It serves to maintain reduction and possibly prevents enlargement of the hernia. There are

insufficient studies to determine how effective trusses actually are and whether they are as good as

surgery for the control of symptoms. Most patients find them cumbersome to use and difficult to keep

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