Principles of surgery

PART II
Specific Considerations

CHAPTER 37
Inguinal Hernia

BASIC SCIENCE QUESTIONS

1. Poupart’s ligament is composed of fibers from which muscle aponeurosis?

A. Rectus abdominis

B. Transversalis

C. Internal oblique

D. External oblique

Answer: D

The inguinal ligament is also known as Poupart’s ligament and is comprised of the inferior fibers of the external oblique aponeurosis. The ligament stretches from the anterior superior iliac spine to the pubic tubercle. The ligament serves an important purpose as a readily identifiable boundary of the inguinal canal, as well as a sturdy structure used in various hernia repairs. (See Schwartz 9th ed., p 1308, and Fig. 37-1.)

Image

FIG. 37-1. Ligaments that contribute to the inguinal canal include the inguinal ligament, which spans the anterior superior iliac spine to the pubic bone. Cooper’s ligament is seen as the lateral extension of the lacunar ligament, which is the fanning out of the inguinal ligament as it joins the pubic tubercle. The iliopubic tract originates and inserts in a similar fashion to the inguinal ligament, yet it is deep to it. m. = muscle.

2. The iliopubic tract

A. Makes up the anterior border of the femoral canal

B. Makes up the posterior border of the femoral canal

C. Makes up the lateral border of the external inguinal ring

D. Makes up the medial border of the external inguinal ring

Answer: A

The iliopubic tract is an aponeurotic band that begins at the anterior superior iliac spine and inserts into Cooper’s ligament from above. It often is confused with the inguinal ligament secondary to common origin and insertion points. However, the iliopubic tract forms on the deep side of the inferior margin of the transverses abdominus and transversalis fascia. The inguinal ligament is on the superficial side of the musculoaponeurotic layer of these structures. The shelving edge of the inguinal ligament is a structure that more or less connects the iliopubic tract to the inguinal ligament. The iliopubic tract helps form the inferior margin of the internal inguinal ring as it courses medially, where it continues as the anterior and medial border of the femoral canal. (See Schwartz 9th ed., p 1308.)

3. Which nerve travels with the spermatic cord, entering the inguinal canal at the internal ring, and exiting at the external ring?

A. Iliohypogastric nerve

B. Ilioinguinal nerve

C. Genitofemoral nerve

D. Lateral femoral cutaneous nerve

Answer: B

The ilioinguinal nerve emerges from the lateral border of the psoas major and passes obliquely across the quadratus lumborum. At a point just medial to the anterior superior iliac spine, it crosses the internal oblique muscle to enter the inguinal canal between the internal and external oblique muscles and exits through the superficial inguinal ring. The nerve supplies the skin of the upper and medial thigh. In males, it also supplies the penis and upper scrotum, while supplying the mons pubis and labium majus in females.

The iliohypogastric nerve arises from T12–L1 and follows the ilioinguinal nerve. After the iliohypogastric nerve pierces the deep abdominal wall in its downward course, it courses between the internal oblique and transversus abdominis, supplying both. It then branches into a lateral cutaneous branch and an anterior cutaneous branch, which pierces the internal oblique and then external oblique aponeurosis above the superficial inguinal ring. A common variant is for the iliohypogastric and ilioinguinal nerves to exit around the superficial inguinal ring as a single entity.

The genitofemoral nerve arises from L1–L2, courses along the retroperitoneum, and emerges on the anterior aspect of the psoas. It then divides into the genital and femoral branches. The genital branch remains ventral to the iliac vessels and iliopubic tract as it enters the inguinal canal just lateral to the inferior epigastric vessels. In males, it travels through the superficial inguinal ring and supplies the scrotum and cremaster muscle. In females, it supplies the mons pubis and labia majora. The femoral branch courses along the femoral sheath, supplying the skin anterior to the upper part of the femoral triangle.

The lateral femoral cutaneous nerve arises from L2–L3, but emerges from the lateral border of the psoas muscle at the level of L4. It crosses the iliacus muscle obliquely toward the anterior superior iliac spine. It then passes inferior to the inguinal ligament where it divides to supply the lateral aspect of the thigh. (See Schwartz 9th ed., p 1310, and Fig. 37-2.)

Image

FIG. 37-2. Anterior view of the five major nerves of the inguinal region.

4. Which of the following is one of the three borders of Hesselbach’s triangle?

A. Superior epigastric artery

B. Edge of the transversalis muscle

C. Inguinal ligament

D. Internal inguinal ring

Answer: C

Direct hernias, on the contrary, are protrusions medial to the inferior epigastric vessels, in Hesselbach’s triangle. The borders of the triangle are as such: the inguinal ligament forms the inferior margin, the edge of rectus abdominis is the medial border, and the inferior epigastric vessels are the superior or lateral border. (See Schwartz 9th ed., p 1312.)

5. Which of the following makes up one of the borders of the femoral ring?

A. Medial edge of the rectus muscle

B. Femoral artery

C. Iliopubic tract

D. Septum femorale

Answer: C

The femoral ring is bordered by sturdy structures that lend to its inflexibility. The posterior boundary consists of the iliacus fascia and Cooper’s ligament, and the anterior boundary is the iliopubic tract and inguinal ligament, internally and externally, respectively. Medially, the border is made up of the aponeurosis of transverses abdominis and the transversalis fascia and laterally, the canal is bordered by the femoral vein and its connective tissue. Normal contents of the femoral canal include areolar preperitoneal tissue and fat and lymph nodes, most notably the node of Cloquet at its upper end. The distal end of the canal is closed by fatty tissue called the septum femorale. Once the integrity of this septum is lost, femoral herniation occurs. (See Schwartz 9th ed., p 1312.)

6. In performing a laparoscopic hernia repair, which of the following potential spaces is entered?

A. Prussak’s space

B. Bogros’s space

C. Space of Disse

D. Space of Traube

Answer: B

Two potential spaces exist deep to the peritoneum, and these are encountered once the peritoneal flap is created. Between the peritoneum and the posterior lamina of the transversalis fascia is Bogros’s space. This area contains preperitoneal fat and areolar tissue. A less prominent space exists between the posterior and anterior laminae of the transversalis fascia termed the vascular space, as this is the location of the inferior epigastric vessels. The space of Disse is in the liver, Prussak’s space is in the middle ear, and Traube’s space is in the left upper abdomen. (See Schwartz 9th ed., p 1313.)

CLINICAL QUESTIONS

1. What percentage of adult patients with a unilateral inguinal hernia will have an unrecognized contralateral hernia?

A. 7%

B. 14%

C. 22%

D. 39%

Answer: C

In a study examining only patients with primary unilateral inguinal hernias, 22% were found to have an occult contralateral hernia during laparoscopic inguinal hernia repair. Although asymptomatic at time of diagnosis, these hernias have the potential to become clinically significant as the patient ages. (See Schwartz 9th ed., p 1306.)

2. Which of the following disorders is associated with an increased incidence of groin hernias?

A. Down syndrome

B. Osteogenesis imperfecta

C. VACTERL association

D. Biliary atresia

Answer: B

Osteogenesis imperfecta is a connective tissue disorder and is associated with an increased risk for groin hernias. Collagen disorders such as Ehlers-Danlos syndrome also are associated with an increased incidence of hernia formation (Table 37-1). Tissue analysis has revealed that there is a relationship between the aneurysmal component and hernias, owing to a pathologic extra-cellular matrix metabolism. (See Schwartz 9th ed., p 1308.)

TABLE 37-1 Connective tissue disorders associated with groin herniation

Osteogenesis imperfecta

Cutis laxa (congenital elastolysis)

Ehlers-Danlos syndrome

Hurler-Hunter syndrome

Marfan syndrome

Congenital hip dislocation in children

Polycystic kidney disease

Alpha1-antitrypsin deficiency

Williams syndrome

Androgen insensitivity syndrome

Robinow’s syndrome

Serpentine fibula syndrome

Alport’s syndrome

Tel Hashomer camptodactyly syndrome

Leriche’s syndrome

Testicular feminization syndrome

Rokitansky-Mayer-Küster syndrome

Goldenhar’s syndrome

Morris syndrome

Gerhardt’s syndrome

Menkes’ syndrome

Kawasaki disease

Pfannenstiel syndrome

Beckwith-Wiedemann syndrome

Rubinstein-Taybi syndrome

Alopecia-photophobia syndrome

3. In the setting of an equivocal examination, which of the following has the greatest sensitivity in diagnosing an inguinal hernia?

A. Repeat examination by a second surgeon

B. Ultrasound

C. CT scan

D. MRI

Answer: D

Although CT scan is useful in ambiguous clinical presentations, little data exist to support its routine use in diagnosis. The use of MRI in assessing groin hernias was examined in a group of 41 patients scheduled to undergo laparoscopic inguinal hernia repair. Preoperatively, all patients underwent US and MRI. Laparoscopic confirmation of the presence of inguinal hernia was deemed the gold standard. Physical examination was found to be the least sensitive, whereas MRI was found to be the most sensitive. False positives were low on physical examination and MRI (one finding), but higher with US (four findings). With further refinement of technology, radiologic techniques will continue to improve the sensitivity and specificity rates of diagnosis, thereby serving a supplementary role in cases of uncertain diagnosis. (See Schwartz 9th ed., p 1318.)

4. A four-layer, suture repair of an inguinal hernia is a

A. Pott’s repair

B. Shouldice repair

C. McVay repair

D. Lichtenstein repair

Answer: B

Shouldice repair: With the posterior inguinal floor exposed, an incision in the transversalis fascia is performed between the pubic tubercle and internal ring. Care is taken to avoid injury to any preperitoneal structures, and these are bluntly dissected to mobilize the upper and lower fascial flaps. The first layer of repair begins at the pubic tubercle where the iliopubic tract is sutured to the lateral edge of the rectus sheath, then progressing laterally. The inferior flap of the transversalis fascia, which includes the iliopubic tract, is sutured continuously to the posterior aspect of the superior flap of the transversalis fascia until the internal ring is encountered. At this point, the internal ring has been reconstituted. The suture is not tied here, but rather is continued back upon itself in the medial direction. At the internal ring, the second layer is the reapproximation of the superior edge of the transversalis fascia to the inferior fascial margin and the shelving edge of the inguinal ligament. The suture is then tied to the tail of the original stitch. A third suture is started at the tightened inguinal ring, joining the internal oblique and transversus abdominis aponeuroses to external oblique aponeurotic fibers just superficial to the inguinal ligament. This layer is continued to the pubic tubercle where it reverses upon itself to create a fourth suture line, which is similar and superficial to the third layer.

Pott’s repair: high ligation of the sac only, with no repair of the inguinal canal—used for indirect hernias only.

McVay repair: Once the cord has been isolated, a transverse incision is performed through the transversalis fascia, thereby entering the preperitoneal space. A small amount of dissection of the posterior aspect of the fascia is performed to allow mobilization of the upper margin of the transversalis fascia. The floor of the inguinal canal is then reconstructed to restore its strength. Cooper’s ligament is identified medially, and it is bluntly dissected to expose its surface. The upper margin of the transversalis fascia is then sutured to Cooper’s ligament. The repair is continued laterally along Cooper’s ligament, occluding the femoral canal.

Lichtenstein repair: Initial exposure and mobilization of cord structures is identical to other open approaches. Particular attention must be paid to blunt dissection of the inguinal canal to expose the shelving edge of the inguinal ligament and pubic tubercle, as well as provide a large area for mesh placement. Unlike the tissue-based repairs, the Lichtenstein repair does not include routine division of the transversalis fascia, thereby preventing the identification of a latent femoral hernia…. Instead, the floor and internal ring are reinforced through the application of the mesh. (See Schwartz 9th ed., p 1321, and Fig. 37-3.)

Image

FIG. 37-3. The Shouldice repair. A. The iliopubic tract is sutured to the medial flap, which is made up of the transversalis fascia and the internal oblique and transverse abdominis muscles. B. This is the second of the four suture lines. After the stump of the cremaster muscle is picked up, the suture is reversed back toward the pubic tubercle approximating the internal oblique and transversus muscles to the inguinal ligament. Two more suture lines will eventually be created suturing the internal oblique and transversus muscles medially to an artificially created “pseudo” inguinal ligament developed from superficial fibers of the inferior flap of the external oblique aponeurosis parallel to the true ligament.

5. Contraindications for a transperitoneal laparoscopic inguinal hernia repair include

A. Inability to tolerate general anesthesia

B. Previous gastric surgery

C. Morbid obesity

D. Diabetes

Answer: A

There are several contraindications to the transperitoneal laparoscopic technique that must be taken into consideration. Because laparoscopy must be performed using general anesthesia, the patient must be able to hemodynamically tolerate both general anesthesia and the effects of pneumoperitoneum. As well, previous lower abdominal surgery, such as prostatectomy, or lower midline incisions for other abdominal procedures, are a relative contraindication to a laparoscopic approach secondary to the presence of scarred tissue in the preperitoneal space. (See Schwartz 9th ed., p 1332.)

6. Which of the following has the lowest recurrence rate after open inguinal hernia repair?

A. Basini repair

B. Shouldice repair

C. McVay repair

D. Marcy repair

Answer: B

Recurrence rates of tissue-based repairs vary according to procedure; however, large-scale analyses continue to confirm the Shouldice repair as the most superior. Surgeons who perform a large volume of the Shouldice repair are able to demonstrate recurrence rates around 1%. In less experienced hands, such low recurrence rates are not demonstrated, yet overall, recurrence rates for the Shouldice repair are consistently lower than those of the Bassini or McVay repair. The Marcy repair is a Bassini with narrowing of a widened internal ring. (See Schwartz 9th ed., p 1334.)

7. Ischemic orchitis is best treated with

A. Re-exploration to relax tension at the internal ring

B. Re-exploration for orchiectomy

C. Nonsteroidal anti-inflammatory agents

D. Nothing (no treatment is necessary)

Answer: C

Ischemic orchitis usually presents within the first week following inguinal hernia repair. The patient may present with a low-grade fever, but more commonly with an enlarged, indurated, and painful testicle. This complication occurs in 1% of all herniorrhaphies, but increases in the reoperations for recurrent inguinal hernias. Ischemic orchitis is likely caused by injury to the pampiniform plexus, not the testicular artery. Densely adherent or large hernia sacs that require extensive dissection may lead to injury of the pampiniform plexus. Reassurance, NSAIDs, and comfort measures are enacted to allow self-limited resolution of this complication. Long-term effects of ischemic orchitis are rare. (See Schwartz 9th ed., p 1337.)

8. A “sports hernia” is best described as

A. A direct inguinal hernia in an athlete

B. A stress-related groin hernia in an athlete

C. A small tear or weakness in the posterior inguinal canal

D. Pubis osteitis

Answer: C

Despite a classical presentation, the absence of clinical findings makes the diagnosis of a hernia more dubious. Occult hernias such as these may, in fact, be a sports hernia, otherwise known as asportsman’s hernia or athletic pubalgia. They are commonly seen in athletes that perform repetitive kicking, twisting, or turning, as in hockey, soccer, and football, which results in a weakness or tearing of the posterior inguinal wall. A similar abrupt motion in a nonathlete also may lead to this condition. The hernia often is not identified until the time of surgical exploration, where a number of different anomalies may be visualized. These include tearing of the transversalis fascia or conjoined tendon, tearing of the internal oblique or avulsion of the internal oblique at the pubic tubercle, or tear of the external oblique aponeurosis or widened external ring. The lack of standardization in the literature makes analysis difficult because oftentimes groin pain of other origins is included in the discussion of sports hernias. (See Schwartz 9th ed., p 1340.)