Vascular malformations, rare causes of sciatic neuropathy: a case series.

BACKGROUND Sciatica is typically a clear-cut symptom complex commonly related to an impingement at the spinal nerve level. Etiologies of sciatic neuropathy outside the neural foramina are uncommon. OBJECTIVE To describe 4 patients presenting with radiating leg pain due to sciatic nerve involvement, all with a vascular etiology. METHODS Four patients presenting with neuropathic pain were retrospectively reviewed. Preoperative 3 Tesla magnetic resonance imaging was used to identify these lesions, which most commonly showed diffuse T2 changes with nerve enhancement upon administration of contrast. RESULTS Exploration revealed vascular lesions. All patients went on to external and limited internal neurolysis of the involved sciatic nerve segment. Intraoperative histological study confirmed the presence of a venous angioma, an arteriovenous malformation, a venous malformation associated with Klippel-Trenaunay syndrome, and a capillary hemangioma. Follow-up demonstrated stable neurological examinations with reduction in pain at 1 year or greater. CONCLUSION In patients with sciatic distribution symptoms and signs, after initial negative spine imaging, high-resolution imaging of the sciatic nerve itself should be undertaken to address rarer causes such as vascular abnormalities. In these cases, exploration and fascicular biopsy provided a diagnosis; external and limited internal neurolysis improved pain.