Drainage of pelvic abscesses through the greater sciatic foramen.

A computed tomographic (CT) guided transgluteal approach through the greater sciatic foramen was used to drain pelvic abscesses and fluid collections in 21 patients. Ideal catheter placement should traverse the lower portion of the greater sciatic foramen at the level of the sacrospinous ligament. This avoids the vascular and neural elements that are located slightly cephalad at the level of the piriformis muscle. Percutaneous drainage through this approach was successful in avoiding surgery in 17 patients (81%). Pain was the most common complication and was generally associated with a more cephalad approach, transgressing the piriformis and the sacral plexus. CT-guided percutaneous drainage of pelvic abscesses through the greater sciatic foramen should be used when the more standard transperitoneal approach is not possible.