Obturator hernia
Updates to Article Attributes
Obturator hernias are characterised by bowel herniating between the obturator and the pectineus muscles. They are a rare type of abdominal hernia and can be very difficult to diagnose clinically.
Epidemiology
Typically obturator hernias occur in older women 2,3 or patients with chronically raised intra-abdominal pressure (e.g. ascites, COPD, chronic cough) 3. It has been suggested that the female predominance of these hernias is the result of pregnancy, which leads to relaxation of the pelvic peritoneum and a wider and more horizontal obturator canal 3.
Clinical presentation
In general, obturator, hernias are asymptomatic unless they 1:
-
theycompress the obturator nerve: Howship-Romberg sign (only present in approximately half of cases) 3 - contain bowel which incarcerates/obstructs/strangulates
Pathology
The obturator foramen is occluded by the obturator membrane, which is pierced anterosuperiorly by the obturator artery, vein and nerve. This neurovascular bundle then travels along a 2-3 cm oblique tunnel, the obturator canal. It is through this deficiency that an obturator hernia occurs. Presumably, due to the sigmoid colon on the left, these hernias are more common on the right 3.
The layers that the hernial neck passes through include:
- obturator internus muscle fibres
- obturator membrane
- obturator externus muscle fibres
The hernia will then lie superficial to obturator externus and deep and inferior to pectineus muscle.
The hernia may contain any of the following:
- no more than peritoneum filled with fluid, as seen in patients with ascites
- small bowel (most common)
- colon 3
- appendix
- omentum
- Meckel diverticulum
- ovary/fallopian tube
- and even uterus 3
Radiographic features
The diagnosis is readily made on CT/MRI with either fluid or bowel able to be traced along the aforementioned course to lie in the medial upper thigh.
Signs of complication, including:
- bowel obstruction
- strangulation resulting in perforation
Treatment and prognosis
Treatment involves surgery and repair of the hernial orifice.
History and etymology
Howship-Romberg sign is named for the German neurologist, Moritz Heinrich Romberg (1795-1873) 5, and British surgeon John Howship (1781-1841) 4.
Differential diagnosis
If a hernia contains bowel or can be clearly traced through the obturator foramen, then there are very few alternative diagnoses.
If seen with ultrasound, it may be mistaken for a bursa or acetabular labral cyst.
-<p><strong>Obturator hernias</strong> are characterised by bowel herniating between the obturator and the <a href="/articles/pectineus-muscle">pectineus muscles</a>. They are a rare type of <a href="/articles/abdominal-hernia">abdominal hernia</a> and can be very difficult to diagnose clinically.</p><h4>Epidemiology</h4><p>Typically obturator hernias occur in older women <sup>2,3</sup> or patients with chronically raised intra-abdominal pressure (e.g. <a href="/articles/ascites">ascites</a>, <a href="/articles/chronic-obstructive-pulmonary-disease-1">COPD</a>, chronic cough) <sup>3</sup>. It has been suggested that the female predominance of these hernias is the result of pregnancy, which leads to relaxation of the pelvic peritoneum and a wider and more horizontal obturator canal <sup>3</sup>.</p><h4>Clinical presentation</h4><p>In general obturator, hernias are asymptomatic unless <sup>1</sup>:</p><ul>-<li>they compress the <a href="/articles/obturator-nerve-1">obturator nerve</a>: <a href="/articles/howship-romberg-sign">Howship-Romberg sign</a> (only present in approximately half of cases) <sup>3</sup>- +<p><strong>Obturator hernias</strong> are characterised by bowel herniating between the obturator and the <a href="/articles/pectineus-muscle">pectineus muscles</a>. They are a rare type of <a href="/articles/abdominal-hernia">abdominal hernia</a> and can be very difficult to diagnose clinically.</p><h4>Epidemiology</h4><p>Typically obturator hernias occur in older women <sup>2,3</sup> or patients with chronically raised intra-abdominal pressure (e.g. <a href="/articles/ascites">ascites</a>, <a href="/articles/chronic-obstructive-pulmonary-disease-1">COPD</a>, chronic cough) <sup>3</sup>. It has been suggested that the female predominance of these hernias is the result of pregnancy, which leads to relaxation of the pelvic peritoneum and a wider and more horizontal obturator canal <sup>3</sup>.</p><h4>Clinical presentation</h4><p>In general, obturator hernias are asymptomatic unless they <sup>1</sup>:</p><ul>
- +<li>compress the <a href="/articles/obturator-nerve-1">obturator nerve</a>: <a href="/articles/howship-romberg-sign">Howship-Romberg sign</a> (only present in approximately half of cases) <sup>3</sup>