Figure 72-42. Spigelian hernia. A: Usual site of occurrence. B: Transverse section of abdominal wall showing site of defect.

UNUSUAL HERNIAS

Spigelian Hernia

A Flemish anatomist, Adriaan van der Spieghel, first described the semilunar line, which is the lower

limit of the posterior rectus sheath. Also called the spontaneous lateral ventral hernia, a Spigelian hernia

protrudes through an area of weakness just lateral to the rectus sheath and just below this line (Fig. 72-

42). The hernia is usually interparietal, rarely penetrating the external oblique fascia, and therefore can

be difficult to appreciate. Most of the time, this hernia appears below the arcuate line. This is an

unusual hernia; only 744 cases have been described in the literature. The usual presentation is lower

abdominal swelling just lateral to the border of the rectus muscle. Spigelian hernias often occur in

elderly female patients. They are usually small, about 1 to 2 cm in diameter, although large hernias up

to 14 cm in diameter have been described. Omentum and small or large bowel may enter the sac.

Incarceration and strangulation are common complications of this hernia. Because the hernia is deep to

the external oblique fascia, the clinical presentation may not be obvious. Pain and tenderness may be

the only signs. Plain roentgenograms may show a bowel shadow in this area, and CT can demonstrate

the defect well. Treatment is operative repair. A transverse incision is centered over the mass. The

external oblique aponeurosis is split to reveal the protrusion. If a large sac is present, it is divided and

sutured. The aponeurotic defect is triangular, with its base at or near the lateral border of the rectus

muscle. The defect is closed by joining the separated transversus and internal oblique layers. Another

option is a laparoscopic repair, done using an intra-abdominal or preperitoneal approach. Recurrence is

uncommon.

Table 72-15 Types of Lumbar Hernia

Lumbar Hernia

The lumbar region is the area bounded inferiorly by the iliac crest and superiorly by the 12th rib,

posteriorly by the erector spinae group of muscles, and anteriorly by the edge of the external oblique

muscle as it extends from the 12th rib to the iliac crest. The three varieties of lumbar hernia are

described in Table 72-15. These hernias require repair if they are large, and because of the size of the

defect, synthetic mesh is used. For the inferior lumbar hernia, a rotation flap of fascia lata can be used

(Fig. 72-43).

Obturator Hernia

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This hernia is the result of abdominal contents protruding through the obturator canal in the pelvis. This

canal is the opening in the superior part of the obturator membrane covering the foramen formed by

the union of the pubic bone and ischium, through which the obturator nerve, artery, and vein pass from

the pelvic cavity into the thigh. A recent history of profound asthenia and weight loss is not unusual,

which is most likely due to the loss of the protective fat in the obturator canal.160 This may account for

the fact that women, more often than men, are afflicted with this hernia because their broader pelvis

results in a larger obturator canal. The diagnosis of an obturator hernia is difficult because it is rare and

physical examination is rarely helpful because the associated mass is concealed beneath the adductor

muscles of the thigh. The main symptom is intermittent pain. During repair, the defect is approached

transperitoneally; the hernia is reduced and mesh placed over the defect. Depending on the expertise of

the responsible surgeon, either a conventional open or laparoscopic operation is reasonable.

Figure 72-43. Technique of repair of inferior lumbar hernia.

Sciatic Hernia

A sciatic hernia is a protrusion of a peritoneal sac through the major or minor sciatic foramen (Fig. 72-

44). These very rare hernias present with a swelling on the buttock. The sciatic nerve may be involved.

A ureter can become obstructed if it is included with the herniated tissues. The treatment of these

hernias is surgical. Both transperitoneal and transgluteal approaches have been described. A

combination of the two is sometimes used. The defect usually requires a prosthetic mesh repair.

Supravesical Hernia

This hernia is anterior to the urinary bladder and forms when the integrity of the transversus abdominis

muscle and the transversalis fascia fail, both of which insert into the Cooper ligament. The preperitoneal

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space is continuous with the retropubic space of Retzius, and the hernial sac protrudes into this area.

The sac of the hernia is directed laterally, emerges at the lateral border of the rectus muscle, and

presents in the inguinal, femoral, or obturator region. It can also be associated with an inguinal,

femoral, or obturator hernia. Treatment of this hernia depends on recognizing it at the time of groin

exploration and reinforcing the defect.

A second variety of these hernias is known as an internal supravesical hernia. They are classified

according to whether they cross in front of, beside, or behind the bladder (Fig. 72-45). Bowel symptoms

predominate in patients with these hernias, and urinary tract symptoms develop in up to 30%. The

treatment is surgical, and a transperitoneal approach is used through a low midline incision. The hernias

can usually be reduced without difficulty. The neck of the sac should be divided and closed.

Interparietal Hernia

This hernia is one in which the hernial sac lies between the layers of the abdominal wall. It may be

either preperitoneal (between the peritoneum and the transversalis fascia) or interstitial (between the

muscle layers of the abdominal wall). The majority are inguinal, in which case they are designated

inguinal interstitial hernias. An inguinal crural hernia occurs when the sac passes behind the inguinal

ligament in the region of the femoral ring.

Figure 72-44. Sciatic hernia. 1: Suprapiriform. 2: Infrapiriform. 3: Subspinous.

The cause of these hernias appears to be related to congenital abnormalities; they have been

associated with failure of the testis to descend, congenital pouches, and other abnormalities, such as

absence of the cremaster and absence of the external abdominal ring.

The diagnosis of these hernias is difficult because no swelling of the abdominal wall is obvious unless

the hernia is large. Pain is commonly the only symptom, and it is not unusual for patients to present

with intestinal obstruction secondary to incarceration. CT, ultrasonography, and laparoscopy can be

helpful in making the diagnosis. Not infrequently, the correct diagnosis is made only at operation. The

defect is repaired according to the principles described for inguinal and incisional hernias.

Flank Hernia

Relaxation of lateral abdominal wall is an underrecognized consequence of the lateral flank incision

which leads to a lateral bulge, mostly without an associated fascial defect, usually in patients who have

undergone urologic, vascular, or neurosurgical procedures which result in transection of the intercostal

nerves and resulting atrophy. In majority of these cases, patients mainly complain of asymmetric

appearance, but sometimes they can have discomfort associated with organs getting trapped in the

bulge and both these problems can hugely impact patients’ quality of life.

Littre Hernia

Littre hernia is a groin hernia containing a Meckel diverticulum. These hernias sometimes also contain

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the appendix. If the diverticulum is symptomatic or strangulated, then it is mandatory to resect it at the

time of the hernia repair.

Figure 72-45. Internal supravesical hernias.

Perineal Hernia

These hernias are more common in older female patients and are related to a lax pelvic floor. They are

termed anterior or posterior according to their relationship to the transverse perineal muscle. The

anterior hernias usually present as a swelling in the labium or lateral vaginal wall. The posterior hernias

present between the rectum and the ischial tuberosity. Surgical repair requires a transperitoneal

approach, and, if the opening is large, a prosthetic mesh repair is required.

Perivascular Hernia

These hernias present through defects between the inguinal ligament and the iliopubic bone. They are

known by various eponyms according to their position. The hernia protruding through a defect in the

lacunar ligament is Laugier hernia. The hernia protruding through the pectineal fascia is Cloquet hernia.

The hernia extending anterior to the femoral vessels but behind the inguinal ligament is Velpeau hernia.

The hernia behind the vessels is Serafini hernia. Lateral to the femoral artery are two hernias, the

anterior one being Hesselbach hernia and the more posterior one Partridge hernia (Fig. 72-46).

Complications of Ventral Hernia Repair

The complications of abdominal wall hernia repair are not infrequent, and their incidence depends on

the size and type of hernia defect, the type of prostheses used, and the repair technique employed. The

complications of hernia repair can be categorized according to whether they are related to the patient,

or the operative technique and are listed in Table 72-16. Except for the complications unique to

laparoscopy, complications occur at similar rates in both laparoscopic and conventional procedures.

Figure 72-46. Perivascular hernias and their eponyms.

Complications Related to Patients

Ileus. Ileus can be seen with either the conventional or the laparoscopic procedure but is more common

with the latter. Treatment is symptomatic, and spontaneous resolution is the rule. Nasogastric

decompression is occasionally needed.

10 Recurrence. Several factors contribute to the poor results obtained in repairing incisional hernias.

These include pre-existing comorbid conditions, including debilitation from cancer, morbid obesity, the

use of steroids, and chemotherapy. Lateral detachment of the mesh and inadequate mesh fixation caused

by mesh distraction is another important cause of recurrence and is more commonly seen in the inlay

techniques.91,115 Historical recurrence rates of 30% to 40% following ventral hernia repair have been

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