Spigelian hernia

Last reviewed 01/2018

A Spigelian hernia is an acquired ventral hernia through the linea semilunaris, the line where the sheaths of the lateral abdominal muscles fuse to form the lateral rectus sheath. Spigelian hernias are nearly always found above the level of the inferior epigastric vessels, and most often occur where the semicircular line - fold of Douglas - cross the linea semilunaris. Commonly, the patient is over the age of 50 years. Men and women are equally affected.

The patient presents with pain that is localised to the hernial site and is aggravated by any movement that raises intra-abdominal pressure. Later, the pain becomes more dull, constant, and diffuse.

A soft, reducible mass may be present in the lower abdominal area which disappears on pressure. When the mass is reduced, the hernial orifice can usually be palpated. Diagnosis is more difficult when the hernia dissects within the layers of the abdominal wall - internal and external obliques - or may be located at a distance from the linea semilunaris. Ultrasound and CT scan may help to confirm the diagnosis.

Spigelian hernias have a high incidence of incarceration and should be repaired. Treatment is by primary aponeurotic closure.