Arteriovenous Malformations of the Body and Extremities: Analysis of Therapeutic Outcomes and Approaches According to a Modified Angiographic Classification

Abstract

To propose a modified angiographic classification for peripheral arteriovenous malformations (AVMs) and to determine its value for assessing therapeutic outcomes and approaches to ethanol embolization of AVMs in the body and extremities. AVMs of the trunk and extremities were categorized according to the angiographic morphology of the nidus: type I (arteriovenous fistulae), type II (arteriolovenous fistulae), type IIIa (arteriolovenulous fistulae with non-dilated fistula), and type IIIb (arteriolovenulous fistulae with dilated fistula). Sixty-six patients (41 women; mean age 28.3 years, range 5-53) with inoperable AVMs in the body and extremities who underwent staged ethanol embolizations were retrospectively analyzed. Therapeutic outcomes and approaches were evaluated according the above classification system. The 66 AVMs were composed of 30 (45%) type IIIb, 13 (20%) type II, 12 (18%) mixed types IIIa and IIIb, 9 (14%) mixed types II and IIIb, and 2 (3%) type IIIa. Ethanol embolization was most effective for type II (100%), and more effective for type IIIb (83%) than for type IIIa or mixed types (< or = 50%). Despite the use of the transarterial approach, direct puncture and transvenous approaches were more relevant for treating type II AVMs. Only the transarterial approach was used for treating type IIIa; both direct puncture and transarterial approaches were used for treating the other types. The described angiographic classification provides considerable information concerning the characteristics of AVMs in the body and extremities, the optimal therapeutic approach, and the likely therapeutic outcome.