What is a femoral hernia?
A femoral hernia is a protrusion of the abdominal contents through the femoral canal forming a hernial sac that appears as a swelling or bulge in the upper thigh. Due to the close proximity, a femoral hernia is often mistaken for an inguinal hernia especially since the latter is more common.
How does a femoral hernia develop?
The femoral canal is present within the femoral sheath, which is a fascia that extends from abdominal wall and surrounds the femoral blood vessels for about one inch below the inguinal ligament. The femoral sheath has 3 compartments; the outermost is occupied by the femoral artery, followed by the femoral vein in the middle and the innermost (medial) compartment forms the femoral canal which contains the lymphatics.
The upper opening of femoral canal is referred to as the femoral ring and the opening of the femoral ring is plugged by the femoral septum. The femoral septum is pushed down as the hernial sac passes down the femoral canal. The hernial sac expands after passing through the lower end of the femoral canal to form a swelling in the upper part of the thigh. Occasionally a large expanding femoral hernia may turn upward to pass over the inguinal ligament.
Femoral Hernia Risks and Complications
A femoral hernia is more common in women and relatively rare in men. There is a possibility of developing an inguinal hernia after a femoral hernia – about 10% of women and 50% of men with femoral hernias will develop an inguinal hernia. Femoral hernias are common on the right side. The narrow neck of the femoral hernia sac lies at the femoral ring which is below and in the outer (lateral) side of pubic tubercle and this is used to differentiate femoral from inguinal hernia.
Complications of a femoral hernia (like incarceration and strangulation) are more common because of the narrow unstretchable neck. This makes a femoral hernia a more dangerous type of hernia that requires surgical intervention. Femoral hernias have the highest rate (about 20%) of strangulation.
Femoral Hernia Surgery
As mentioned above, the femoral hernia is at high risk for incarceration and strangulation and surgery is therefore recommended upon diagnosis. The repair involves dissecting out of the hernial sac, reduction of the hernial sac and elimination of the defects in the femoral canal. The femoral canal defect can be obliterated with or without a mesh. Strangulated hernia repair is done without the mesh and after checking the viability of the hernial sac contents. If non-viable, appropriate measures are taken to resect the affected part and then continue with repair.
Femoral Hernia vs Inguinal Hernia
An inguinal hernia can be confused with femoral hernia due to the close proximity of the site. A finger invagination test also can be used to confirm inguinal hernia.
- A hernial sac that originates above and medial to the pubic tubercle is an inguinal hernia.
- A hernia which originates below and on the outer side of the pubic tubercle is a femoral hernia.
- A hernial bulge below the inguinal ligament is femoral hernia.
- Large hernias descending to the scrotum is usually inguinal hernia.