This plate shows the key anatomic features of importance that the skilled surgeon must know thoroughly during any type of laparoscopic operation for inguinal and femoral hernia repair.
The first concept is to recognize that the parietal peritoneum covers certain structures forming five ligaments that are useful landmarks in identifying the hernia spaces when approaching the groin from the intraperitoneal route as in the TAPP repair. These ligaments include the median umbilical ligament (1) running from the bladder to the umbilicus, the medial umbilical ligaments (3), which are the remnants of the obliterated umbilical arteries, and the lateral umbilical ligaments (4) formed by the peritoneum covering the inferior epigastric vessels (13). The spatial relationships of these ligaments allow recognition of the various types of hernias. A direct inguinal hernia (19) occurs in the medial space bounded by the inferior epigastric vessels or lateral umbilical ligament, the iliopubic tract (21), the pubic tubercle (23) (the medial end of the muscular conjoined tendon [internal oblique muscle]). An indirect inguinal hernia presents through the internal ring (18) above the iliopubic tract and is lateral to the lateral umbilical ligament containing the epigastric vessels (13) on the posterior surface of the rectus muscle (2). A view of the femoral hernia space (20) can be seen below the iliopubic tract (21) and medial to the femoral vessels exiting through the femoral canal. During the laparoscopic repair, the direct, indirect, and femoral spaces should all be covered with mesh.
The second important concept concerns the spaces that occur beneath the peritoneal covering (17). The preperitoneal space is the space bounded by the peritoneum posteriorly and the transversalis fascia anteriorly. The space of Retzius is that space between the pubis and the bladder. The lateral extent of this space is named Bogro's space. The transversalis fascia forms the floor of the inguinal canal and the iliopectineal arch, iliopubic tract, and crura of the deep inguinal ring. The iliopectineal arch divides the vascular compartment (iliac vessels) from the neuromuscular compartment (iliopsoas muscle, femoral nerve, and the lateral femoral cutaneous nerve). The iliopubic tract is an aponeurotic band that begins near the anterior superior iliac spine and inserts on the pubic tubercle (23) medially. In its medial extent, it contributes to the formation of Cooper's ligament (22). It forms the inferior margin of the deep musculoaponeurotic layer made up of the transversus abdominis muscle and aponeurosis and the transversalis fascia. Laterally, it extends to the iliacus and psoas fascia. It forms with fibers of the transversalis fascia, the anterior margin of the femoral sheath and the medial border of the femoral ring and canal. Its lower margin is attached to the inguinal ligament. The iliopubic tract is an important landmark. Dissection or tacking of preperitoneal mesh should not take place inferior to the iliopubic tract except in the limited region of Cooper's ligament. Dissection or tack placement centrally beneath the iliopubic tract will injure the femoral vein, artery, and nerve, whereas placement laterally may damage the lumbar nerve branches. The superior and inferior crura of the deep inguinal ring are formed by the transversalis fascia. Cooper's ligament is formed by the periosteum of the superior pubic ramus and the iliopubic tract.
The inferior epigastric vessels give off two branches: the external spermatic vessel that travels in the spermatic cord and the iliopubic branch. The latter may form a corona mortis. This vascular anomaly presents as a branch of either the inferior epigastric or the external iliac that passes over the pubic tubercle en route to the obturator system. Either the arterial or the venous system may be involved in this “crown of death,” which may cause significant hemorrhage during dissection and exposure of Cooper's ligament or mesh fixation with penetrating tacks.
Finally, there are two zones that must be avoided during preperitoneal dissection and fixation of mesh. The first is the lateral zone that is bounded on the medial side by the spermatic cord, superiorly by the iliopubic tract and by the iliac crest laterally. This is known as the “triangle of pain.” (Plate 220, Figure 2.) This area contains the femoral (10), lateral femoral cutaneous (8), anterior femoral cutaneous, and the femoral branch of the genitofemoral nerves. Injury to these nerves may cause chronic neuralgia. The second is the inferior zone bounded by the vas deferens (24) medially, the gonadal vessels (15) laterally, and posteriorly by the peritoneal edge. This zone is known as the “triangle of doom,” as it contains the external iliac vein (12), the deep circumflex iliac vein, and the femoral artery (11). (Plate 220, Figure 2.)