An abdominal wall hernia consists of a protrusion of intra-abdominal tissue through a fascial defect in the abdominal wall. Inguinal hernias are very common (approximately 75% of abdominal wall hernias) with other types of hernias occurring at weak areas of abdominal wall fascia. Typically a hernia consists of visceral contents, a peritoneal sac, and overlying tissue (e.g., skin, subcutaneous tissue). Hernias may be reducible where the protruding contents can be replaced into the abdominal cavity either spontaneously or with manual pressure. Hernias may also be irreducible where the protruding contents are unable to be reduced. There are two classifications of irreducible hernias, incarcerated and strangulated. An incarcerated hernia is irreducible protruding content that is usually due to a small hernia neck. The tissue or contents protruding remain viable and are not causing an obstruction or inflammation. A strangulated hernia is irreducible protruding material in which blood supply has been compromised. Ischemia, often progressing to necrosis of the protruding tissue or contents, is considered a surgical emergency.
Inguinal anatomy is essential knowledge for the general surgeon. The canal exists between two openings within the abdominal wall known as the internal (deep) inguinal ring and the external (superficial) inguinal ring. The internal inguinal ring is a lateral hiatus within the transversalis fascia, where the external inguinal ring is a medial hiatus within the external oblique fascia. The canal can range from 4 cm to 6 cm in length and is typically cone shaped. The inguinal canal is bordered anteriorly by the external oblique aponeurosis, posteriorly by the transversus abdominis and transversalis fascia, laterally by the internal oblique, and inferiorly by the inguinal ligament. The spermatic cord passes through the internal ring and out the external ring before descending into the scrotum. The spermatic cord consists of the vas deferens, three arteries/veins, and the pampiniform plexus.
Several additional structures are important to identify during open inguinal hernia repair. The iliopubic tract is an aponeurotic band that begins at the anterior superior iliac spine and courses medially before inserting on the superior aspect of the Cooper's ligament. The shelving edge of the inguinal ligament is the superior attachment of the inguinal ligament to the iliopubic tract. The iliopubic tract forms the inferior border of the internal inguinal ring as it courses medially before becoming part of the femoral canal. Additionally, the lacunar ligament in the medial aspect of the inguinal ligament as it fans out and inserts on the pubic tubercle. Lastly, the conjoined tendon inserts on the pubic tubercle as the culmination of the internal oblique and transversus abdominis fibers.
Two types of inguinal hernias may occur. These are classified as a direct and indirect hernia. An indirect hernia passes through the deep (internal) inguinal ring and is located lateral to the inferior epigastric vessels. A direct hernia passes through a weakened area of transversalis fascia in Hesselbach’s triangle (lateral edge of rectus abdominis, inferior edge of the inguinal ligament, and medial to inferior epigastric vessels). A Pantaloon hernia is a combination of a direct and indirect hernia.
History and clinical examination determine diagnosis, and no supplemental imaging is needed unless there are extenuating circumstances. CT imaging or ultrasound may be useful in the face of possible bowel obstruction; however, they are not required for surgical intervention.
Inguinal hernias typically are asymptomatic until a bump or swelling of the groin is noted. Some patients may report pain when straining or during heavy lifting. Pain and discomfort are mostly associated with larger hernias usually requiring manual compression for reduction or lying supine with manual compression. Bilateral examination of the groin may reveal a mass that is either reducible or irreducible. An exam should be done supine, as well as, standing, with coughing and straining to identify small reducible hernias. The practitioner palpitates the external ring by invaginating the scrotum with an index finger to a point lateral and superior to the pubic tubercle. Coughing or straining during this examination is critical to the palpation of protruding tissue to diagnose a hernia.
There are no absolute contraindications to open inguinal hernia repair. As in all elective surgery, the patient must be optimized medically before surgery.
Some relative contraindications would be:
A standard open surgical tray should be adequate for the procedure. This procedure has many variations which may require special equipment; however, some of the essential equipment has been listed below.
A single operating surgeon may perform this procedure; although, usually there is an assistant. A surgical tech or circulating nurse are required. An anesthesiologist will need to be present as well.
The patient should be preoperatively medically optimized.
Laterality should be noted, consented for, and marked in the preoperative area.
The patient is positioned supine on the operating table. The correct surgical site is clipped free of hair and prepped in the standard sterile fashion.
The operating surgeon should stand on the side of an inguinal hernia with the assistant standing on the opposing side.
There are two options for repair, open and laparoscopic. An open repair will be discussed here. Please see laparoscopic inguinal hernia repair chapter for further information.
After appropriately selected anesthesia is delivered, the surgeon makes a 5 cm to 6 cm linear incision parallel to the inguinal ligament overlying the proposed region of the external ring. The surgeon dissects until the fibers of the external oblique are identified. The external oblique fascia is opened parallel to the fibers and carried through the external ring revealing the spermatic cord and possible site of a hernia (usually located in an anteromedial position). The ilioinguinal nerve may be found at this juncture. There is great debate on the preservation vs sacrifice of this nerve, and the surgeon preference or experience dictates the choice. The surgeon then mobilizes the spermatic cord from the pubic tubercle and identifies the hernia sac as indirect or direct. Primary repair of hernias is very rarely performed and may be indicated in cases of gross contamination from a strangulated inguinal hernia or in the presence of a femoral hernia. The Lichtenstein tension-free hernioplasty is the preferred method of repair. Many meshes exist, and each mesh procedure varies based on the product. The basic concept is that the mesh will cover the fascial defect and recreate and strengthen the inguinal floor to prevent from further hernias following repair. The external oblique fascia may be reapproximated, as per surgeon preference, as well as the re-creation of the external ring.
Recurrence of hernias is the biggest concern with this surgical technique. Most commonly, the hernia will recur at the pubic tubercle, and without proper technique, this recurrence is more likely. Patient compliance with avoidance of heavy lifting or strenuous activity is also vital to reduce the rate of recurrence. Chronic pain has been described by many patients and is the main driving point of the great debate between preservation and sacrifice of nerves during dissection.
Surgical repair is recommended electively to avoid incarceration or strangulation. However, reducible inguinal hernias can be safely observed in the elderly population with a sedentary lifestyle or high morbidity for surgery. Open inguinal hernia repair can be performed under general anesthesia, sedation, regional, or local anesthetic.
Postoperatively, the patient is instructed to avoid lifting objects heavier than ten pounds and avoiding strenuous activity for a minimum of four to six weeks. There is much variation in the procedural technique of open inguinal hernia repair. However, the overall goal is accomplished with the basic methods described above.