Transvenous Embolization of a Dominant Outflow Vein Arteriovenous Malformation Following Failed Arterial Intervention

Purpose: The heterogeneity of peripheral arteriovenous malformations (AVMs) necessitates an individualized approach to treatment. Classification systems continue to evolve, and newer systems provide treatment algorithms based on angiographic findings. In particular, AVMs with a dominant outflow vein (DOV) can be effectively treated and even cured by retrograde transvenous embolization. Despite these recent findings, transarterial approaches continue to be used. We present a case of a left thigh AVM with a DOV that failed two previous transarterial interventions but achieved angiographic success by a transvenous approach.

Materials and Methods: We present a 52-year-old man found to have a left thigh AVM after developing deep venous thrombosis (DVT, 2015) presenting with recurrent pain and swelling of the left leg. He was status post left superficial femoral artery stenting (2017) and stent extension 3 months before presentation (2019). Completion angiograms revealed failure to achieve complete angiographic resolution after either procedure. Symptomatic recurrence was thought to be secondary to incomplete treatment because of multiple small arteries supplying the AVM (Cho type II), as suggested by postprocedural computed tomography and magnetic resonance imaging. He was referred to interventional radiology for transvenous treatment.

Results: The AVM with a DOV was confirmed, and the patient underwent successful retrograde transvenous coil embolization without the use of a liquid embolic agent. Contrary to the two previous procedures, there was complete angiographic resolution with absent early venous filling characteristic of AVMs. At the 4-week follow-up, he reported resolution of the recurrent pain, but the swelling persisted because of the chronic nature of the DVT.

Conclusions: Proper preprocedural image evaluation and AVM classification are critical for procedural planning. AVMs with a DOV are rare and may fail transarterial therapy when multiple feeding vessels are present. They can be successfully treated with retrograde transvenous embolization, even after failed arterial therapy. Classification systems and treatment modalities for AVMs continue to evolve and require pathophysiologic knowledge and proficiency in image interpretation to implement.