Chronic traumatic popliteal arteriovenous fistula presenting twenty years after shotgun injury: a case report and critical literature review

Abstract

Traumatic arteriovenous fistulas (AVFs) account for only 2.5–4% of penetrating vascular injuries, yet their natural history is insidious: most remain hemodynamically compensated for years before clinical decompensation. Delayed popliteal AVF poses unique diagnostic and therapeutic challenges because of the anatomically confined surgical field, proximity of neurovascular structures, and historical amputation rates of 10–20%. This report is prepared in accordance with the CARE criteria for case reports. A 64-year-old male smoker presented with a 10-day history of progressive left popliteal pain and a pulsatile mass, precisely 20 years after conservative management of a shotgun injury to the same limb. Physical examination revealed a continuous machinery-type bruit and thrill. CT angiography confirmed a direct popliteal arteriovenous communication, a 25 mm secondary venous aneurysm, proximal arterial dilation to 16 mm, and—critically—incidental cardiomegaly with ascending aortic dilation (44 mm), may reflect chronic systemic high-output circulatory adaptation secondary to AV shunting. Open surgical repair with fistula ligation and aneurysmorrhaphy was performed. This case exemplifies the full natural history of a chronic traumatic AVF: prolonged asymptomatic compensation, progressive vascular remodeling, venous aneurysm formation, and systemic cardiac adaptation. We present an analysis of pathophysiology, diagnostic modalities, and evidence-based treatment selection alongside a proposed five-step management algorithm. Traumatic popliteal AVF can remain silent for decades. The coexistence of venous aneurysm, chronic cardiac remodeling, and 20-year-old scar tissue argues for individualized management guided by echocardiographic hemodynamics and anatomic complexity.