HERNIA REPAIR
Inguinal Hernia Repair Incisional Hernia
ANATOMY
The inguinal canal is an oblique space measuring 4 cm in length that lies above the medial half of the inguinal ligament. At its medial end there is a triangular opening, called the external inguinal ring, that lies above and lateral to the pubic crest. The internal inguinal ring is located at the lateral end and represents an opening within the transversalis fascia. The boundaries of the internal inguinal ring are superiorly the transverus abdominis arch, inferiorly the iliopubic tract, and medially the inferior epigastric vessels. The thickened fascia overlying the epigastric vessels is called Hesselbach’s ligament. The internal inguinal ring is located 1 cm above the femoral artery pulse or midway between the anterior superior iliac spine and pubic tubercle.
The relationships of the inguinal canal are as follows:
The contents of the inguinal canal include the following:
Male: the spermatic cord travels through the inguinal canal and consists of three nerves, three arteries, and three other structures. The nerves are the ilioinguinal nerve, the genital branch of the genitofemoral nerve, and the sympathetic nerves. The three arteries are the spermatic artery from the aorta, the artery to the vas deferens from the superior vesicle, and the cremasteric artery from the deep epigastric artery. The remaining other three structures include the vas deferens, the pampiniform venous plexus, and the lymphatic channels. The cord has three coverings—the outer external spermatic fascia, the middle cremasteric muscle layer, and the inner internal spermatic fascia—which are derived from the external oblique fascia, internal oblique muscle, and transversus fascia, respectively.
Female: the round ligament of the uterus, ilioinguinal nerve, and genital branch of the genitofemoral nerve.
Several named condensations of fascia or ligaments in relation to the inguinal canal are used during various repairs of inguinal hernias:
PREOPERATIVE WORK-UP
Exacerbating factors contributing to the development of hernia must be identified. These include chronic constipation, chronic cough, prostatic hypertrophy, and any other condition that would chronically elevate intra-abdominal pressure. Appropriate measures must be taken to correct or at least improve these exacerbating conditions preoperatively. This is particularly important in order to achieve lower hernia recurrence rates. A very large inguinoscrotal hernia that contains a large proportion of the intra-abdominal contents is known as loss of domain. Acutely reducing these contents within the abdomen during the process of hernia repair may cause diaphragmatic compromise, leading to postoperative respiratory failure. To prevent this complication, repeated abdominal pneumoperitoneum needs to be undertaken to increase the capacity of the intra-abdominal cavity. In patients with uncontrolled ascites secondary to cirrhosis, elective repair of the hernia may be hazardous because it can lead to hepatic decompensation and death. Before repair of a symptomatic hernia in these patients, placement of a temporary peritoneovenous shunt (LaVeen or Denver shunt) or transjugular intrahepatic portosystemic shunt should be considered.
Patients presenting acutely with a strangulated hernia require emergent operative intervention and therefore are rapidly assessed and resuscitated. Symptomatic incarcerated hernias must be repaired urgently.
In the presence of a large inguinal or inguinoscrotal hernia, it is wise to place a Foley catheter, because the bladder can often become part of the wall of the sliding hernia. Prophylactic antibiotics are administered.
Operative Procedure
POSITION
The patient is placed in the supine position.
ANESTHESIA
For a routine uncomplicated hernia repair, local anesthesia with sedation is generally adequate. In the presence of strangulation or incarceration, general anesthesia is preferred. Alternatively, spinal anesthesia can be used, particularly in elderly patients with comorbid conditions.
INCISION
An incision is usually made parallel to and approximately 2 cm above the inguinal ligament. For adequate exposure the incision should extend from the level of the pubic tubercle to the internal ring at the level of the femoral pulse. Some surgeons prefer a skin-crease incision, which tends to be placed farther away from the pubic tubercle medially and has the disadvantage of causing difficult access to the external ring.
EXPOSURE AND OPERATIVE TECHNIQUE
Numerous methods of hernia repair have been described in the literature: Bassini, McVay, Shouldice, and the tension-free Lichtenstein, to name a few. Interested readers can obtain details in well-known textbooks dealing with the subject. The initial dissection is identical for all procedures, but procedures differ in how the floor of the hernia is repaired.
Before the hernia repair is begun, local anesthesia is administered. Either 1% lidocaine or a mixture containing 1% lidocaine, 0.25% Marcaine, and bicarbonate solution can be used. First the ilioinguinal nerve is infiltrated. This is located approximately 1 cm medial and inferior to the anterior superior iliac spine. Intradermal and the subcutaneous tissues are infiltrated at the site of the proposed incision. The skin and the subcutaneous tissue are incised with a no. 10 scalpel. Two branches of the superficial epigastric veins are invariably encountered; they are clamped, divided, and ligated with 3-0 silk sutures. A self-retaining Weitlaner retractor is placed. At the lateral end of the incision the subcutaneous tissue is further incised until the external oblique fascia is identified. At this point further local anesthesia is infiltrated beneath the external oblique fascia. The rest of the subcutaneous tissue is now incised down to the level of the external oblique fascia. The self-retaining retractor is repositioned.
At this point the external ring is identified on the medial aspect. With a no. 15 scalpel an incision is made into the external oblique fascia along its fibers. The edges of this incision are grasped with Kelly clamps, and the external oblique fascia is carefully dissected free from the underlying areolar tissue and both the ilioinguinal and genitofemoral nerves. While these two nerves are protected, the inguinal canal is opened by extending the incision toward the external ring. The two nerves are then carefully freed, preserved, and retracted out of the way. If needed, these nerves can be directly infiltrated to provide local anesthesia.
The entire cord needs to be carefully freed from the floor of the inguinal canal. This is best started at the level of the pubic tubercle. The operator grasps the cord structures with the left hand, and using the right index finger palpates the pubic tubercle and gently elevates the cord using a combination of blunt and sharp dissection. A quarter-inch Penrose drain is placed around the cord to facilitate retraction. The cremasteric muscles are divided, and the cremasteric artery is ligated to carefully delineate the internal ring. Particular care is taken to avoid injuring the inferior epigastric vessels that are present on the medial border of the internal ring.
To identify the indirect sac, dissection is commenced on the anterolateral aspect of the cord. First, the spermatic coverings arising from the internal oblique and the transversus muscle are divided. A shiny white sac is identified, grasped with hemostats, and dissected free from the cord structures. If the distal end of the sac is visualized, this is also grasped so that the entire sac can be resected. The sac is dissected proximally toward the internal ring. The sac needs to be opened to inspect its contents and to exclude the presence of a sliding hernia. If the distal end of the sac is not visualized, it can be transected at any convenient location along the spermatic cord. The distal end is left open to allow drainage. If the sac is devoid of any abdominal contents, it is twisted and suture ligated at the level of the internal ring with 2-0 absorbable sutures. If, on the other hand, a sliding hernia is present, the sac is trimmed to the level of the sliding structure and closed with continuous 2-0 absorbable sutures.
Fig: The hernia sac is dissected free from the cord and then opened to reduce its contents. A Penrose drain placed around the cord provides traction that facilitates dissection.
After the indirect sac has been resected, the internal ring is evaluated. If it is widened due to the presence of the hernia sac and its contents, it can be reconstructed with continuous or interrupted 3-0 polypropylene sutures. Once the internal ring is refashioned, it should barely admit the tip of the surgeon’s index finger. The internal ring repair should not be made too tight because this can compromise testicular blood supply.
Attention is now directed toward repairing the floor of the inguinal canal. Several methods are described in the literature, as indicated earlier. Some of these repairs are described here.
Bassini Repair
The conjoined tendon is retracted upward, and the aponeurosis of the transversus abdominis muscle is approximated to the iliopubic tract that lies adjacent to the inguinal ligament with several interrupted 3-0 silk sutures.
The second layer of the repair involves suturing the conjoined tendon to the inguinal ligament with interrupted 2-0 silk sutures. This suture line extends from the pubic tubercle to the medial border of the internal ring.
If during this layer of repair a great deal of tension is noted, several small relaxing incisions can be made in the anterior rectus sheath.
Several sutures can be used to approximate the conjoined tendon to the inguinal ligament proximal to the cord. However, care must be taken to not constrict the cord.
McVay Repair
This is the technique used commonly when there is a large direct inguinal hernia. The attenuated posterior inguinal wall that consists only of thin transversalis fascia is excised, revealing the underlying preperitoneal connective tissue. The segment of posterior wall that is attached to Cooper’s ligament should also be excised even though it may appear to be strong. The defect after excision of all the attenuated layers should reveal the preperitoneal connective tissue, Cooper’s ligament, pectineus muscle fascia, external iliac and inferior epigastric vessels, and femoral sheath. To allow for tension-free reconstruction of the posterior inguinal wall, a 6- to 7-cm relaxing incision is made in the anterior rectus sheath. There are numerous eponyms associated with this relaxing incision, which brings the transversalis fascia down to Cooper’s ligament for suturing and reconstructing the inguinal canal.
Starting at the pubic tubercle, the strong edge of the transverse abdominis aponeurosis is sutured to Cooper’s ligament with interrupted 3-0 polypropylene sutures until the femoral vein is reached. The next suture placed is referred to as the transition suture because the transversus abdominis aponeurosis is now sutured to the anterior femoral sheath rather than to Cooper’s ligament. From this transition suture the transversalis fascia is approximated to the anterior femoral sheath to the level of the internal ring. The rectus abdominis prevents development of a hernia at the defect in the anterior rectus sheath created by the relaxing incision. The cord is replaced within the inguinal canal.
Shouldice Repair
With a no. 15 scalpel an incision is made in the transversalis fascia until the preperitoneal fat can be seen. This incision is extended from the internal ring to the pubic tubercle. The resulting upper transversalis fascia flap is bluntly separated from the underlying pre-peritoneal fat until the thickened edge of the rectus sheath on the deep aspect is visualized and grasped with several Allis clamps. The repair involves placing four lines of sutures.
The first suture line is started at the pubic tubercle using 3-0 continuous polypropylene, and the white line is approximated to the free edge of the inferior transversalis fascial flap.
At the internal ring the suture is tied and then continued medially by approximating the free edge of the superior flap to the shelving edge of the inguinal ligament. When the pubic tubercle is reached, the suture is tied and divided.
The third suture line is started at the level of the internal ring where the conjoined tendon is approximated to the inguinal ligament and tied when the pubic tubercle is reached.
Using the same suture, the fourth suture line attaches these same structures to one another and is tied at the level of the internal ring. The cord is replaced within the inguinal canal, and the external inguinal aponeurosis is reapproximated with continuous 2-0 absorbable sutures. The subcutaneous tissue is closed with interrupted 3-0 absorbable sutures. The skin is approximated with subcuticular 4-0 absorbable sutures.
Lichtenstein Tension-Free Mesh Repair
If there are any discrete defects within the transversalis fascia, the herniating sac is inverted and the edges of the defect are approximated with interrupted 3-0 polypropylene sutures. For a tension-free mesh repair, the length and width of the floor of the inguinal canal are measured. The polypropylene (Marlex) mesh is fashioned to the shape of the floor of the inguinal canal. An opening is fashioned on the lateral aspect of the polypropylene mesh to allow it to pass around the cord structure at the level of the internal ring. The polypropylene mesh is secured to the floor with continuous 3-0 polypropylene monofilament sutures starting at the pubic tubercle. The retracted ilioinguinal nerves are placed over the mesh. The wound is irrigated and hemostasis achieved, particularly of the cord structure. At this point the patient, if awake, can be asked to cough to test the integrity of the repair.
CLOSURE
The external oblique fascia is reapproximated starting at the external ring using 2-0 absorbable sutures. The subcutaneous tissue is irrigated, and any debris is removed. The skin is approximated with subcuticular 4-0 absorbable sutures, and the testis is gently drawn into the scrotum to avoid iatrogenic undescended testis.