Persistent Sciatic Artery as a Rare Cause of Sciatic Neuropathy: A Case Report

BACKGROUND: Persistent Sciatic Artery (PSA) is a rare congenital vascular anomaly, affecting 0.05% of the population. It arises from the failure of regression of the embryonic sciatic artery, which normally recedes as the superficial femoral artery (SFA) becomes dominant in lower limb perfusion. In cases of persistence, the sciatic artery remains as a continuation of the internal iliac artery. PSA is classified based on its persistence and anatomical relationship with the SFA and is associated with complications such as limb ischemia, aneurysmal degeneration, and thromboembolism, which may clinically manifest as gluteal pain, claudication, or acute ischemia. RESULTS: We describe the case of a 50-year-old woman with a longstanding history of left-sided sciatica and paresthesia, refractory to medical therapy. Neurological examination revealed a positive Tinel's sign along the course of the sciatic nerve, and imaging studies confirmed a Pillet-Gauffre type 1 PSA, in close anatomical contiguity with the nerve. Angio-CT excluded associated aneurysmal changes. In the absence of motor involvement, a conservative management strategy was adopted, with referral for vascular surgical evaluation. INTERPRETATION: Sciatic nerve compression secondary to PSA is exceedingly rare, with most documented cases attributed to aneurysmal dilation exerting mass effect. Electrophysiological features of PSA-related sciatic neuropathy are unreported. This case emphasizes the possibility of including PSA within the differential diagnosis of sciatic pain, particularly when conventional aetiologies have been excluded. Recognition of this vascular anomaly is essential for accurate diagnosis and appropriate management, as surgical intervention does not uniformly result in symptoms resolution.