Obturator Hernia

Excerpt

The obturator hernia was first described by Arnaud de Ronsil in 1724. More than 100 years later, Henry Obre performed the first successful obturator hernia repair in 1851. Migration of intra-abdominal contents through the obturator foramen constitutes an obturator hernia (see Image. Obturator Hernia). The hernia sac most often contains small bowel, though other intra-abdominal structures may also be involved, including preperitoneal fat, omentum, and large bowel. (Source: Conti et al, 2022) Obturator hernias are rare, accounting for approximately 0.05 to 1.5% of all hernias.

The obturator foramen is a large pelvic aperture bounded by the ischium and pubic bone (see Image. Obturator Foramen). In adults, this opening may measure 2 to 3 cm in length and 0.5 to 1 cm in width. A thin, fibrous membrane spans the bony margins of the foramen. The internal and external surfaces of this orifice serve as attachment sites for the obturator internus and externus muscles, respectively.

The internal iliac artery gives rise to the obturator artery, which divides into medial and lateral branches that encircle the foramen. The obturator nerve, artery, and vein pass from the pelvis into the thigh through the obturator canal, located at the superior aspect of the foramen. The obturator nerve lies most cranially within this neurovascular bundle and divides into anterior and posterior branches upon exiting the canal. Unlike the rest of the obturator foramen, the obturator canal is not covered by a fibrous membrane.

Female individuals have larger, more triangular obturator foramina than male individuals. Herniation of structures through the obturator foramen occurs more frequently in women, particularly those of advanced age and low body mass, due to anatomic predisposition. The sigmoid colon generally overlies the left obturator foramen. Thus, obturator hernias are more common on the right in both sexes.

Diagnosis is often challenging, as presenting signs and symptoms are frequently nonspecific. Clinicians should maintain a high index of suspicion, especially in older patients with low body mass, and promptly obtain computed tomography (CT) of the abdomen and pelvis. Treatment is surgical, employing open or minimally invasive techniques. Morbidity and mortality rates depend on the presence of complications and the timeliness of surgical intervention.