The groin is the lowest part of the abdominal wall. The area spans from the top of the iliac crest (hip bone) across the abdomen and extends down to the pubic bone and the junction of the thigh and lower abdomen
Most inguinal hernias occur in men and a small percentage of women develop inguinal hernias. The reason for the much higher prevalence in men relates to major anatomical and embryologic differences.
In the male fetus, the testicle develops in the abdominal cavity and descends over time to it’s final location within the scrotum. The layers of the abdominal wall descend along with the testicle and become other structures surrounding testicle. The inner most lining is in communication with the abdominal cavity. Normally, this inner lining disappears and the connection between the abdominal cavity and scrotum is obliterated. In 5% of men this communication persists and intra-abdominal contents can slide into the inguinal canal and scrotum. This is referred to as an indirect inguinal hernia and is considered congenital. In other words, it’s a groin hernia that a person is born with.
When women develop inguinal hernias it is almost always of the indirect variety. The mechanism of formation is different but the end result is the same lining sliding alongside a uterine ligament that traverses the inguinal canal and anchors into the pubic bone.
Another factor that contributes to a higher prevalence in males is due to major differences in boney pelvis anatomy between sexes. The inguinal floor in males is generally broader and subjected to internal forces at higher pressures. This promotes gradual weakening of the floor and eventual eventration or bowing outward of the muscular floor. This type of hernia has been referred to as a direct inguinal hernia. This type of inguinal hernia is thought to develop as the result of “wear and tear”.
How are hernias repaired?
Inguinal hernias can be repaired in an open or laparoscopic fashion both with and without mesh. Mesh free repairs are referred to as primary repairs and several techniques have been described over the last century. In the past 30 years the use of mesh has become increasingly used. At this time most surgeons will use mesh as it has been demonstrated to reduce the incidence of hernia recurrence. In the last 20 years there has been increasing use of laparoscopic techniques to repair groin hernias. Laparoscopic techniques almost always require mesh for satisfactory repair.
What is the difference between open and laparoscopic techniques?
The open repair requires a 4-6 inch oblique incision in the groin. The hernia(s) are identified and reduced (pushed back into place). Mesh is typically placed on top of the inguinal floor increasing its strength and durability and covering the potential openings through which tissue can slide. This is referred to as an “onlay” technique.
The laparoscopic techniques allow complete visualization of the inguinal region including the femoral space. Once the anatomy is delineated and the hernia(s) are reduced, mesh is placed under the abdominal wall defects. This is referred to as an “underlay”.
What are the advantages of the laparoscopic techniques?
Laparoscopic inguinal hernia repair allows repair of both sides simultaneously through three small incisions. Laparoscopic repair has also been demonstrated to be beneficial in those patients who are undergoing surgery for recurrent inguinal hernias. The recovery is generally quicker and with less pain and swelling. Patients are generally able to return to work sooner and most patients can return to full activity within 3 to 4 weeks.
Recovery from open surgical repair is highly variable but most patients will experience significant groin discomfort and swelling for days to weeks. Return to full activity generally occurs 6 weeks after surgery.
What is the recurrence rate for repaired inguinal hernias?
When performed by highly trained and experienced surgeons that recurrence rate is identical between open and laparoscopic hernias and is 1-2%.