Retreatment of persistent pulmonary arteriovenous malformations: factors associated with technical success and durable occlusion.

AIM: To evaluate factors that contribute to successful retreatment of persistent Pulmonary Arteriovenous Malformations (PAVMs) after initial embolization, focusing on long-term occlusion outcomes. MATERIALS AND METHODS: This study reviewed consecutive treatments for persistent PAVMs re-treated at a single institution. The success of repeat treatment was assessed on follow-up imaging. RESULTS: Twenty-four retreatment procedures in 19 patients were included (median age 59, range 9-71). Most PAVMs were simple (71%) rather than complex (29%), and saccular (71%) rather than non-saccular (29%). PAVMs were primarily treated with coils (88%) rather than plug or coil and plug (12%). The nidus was primarily treated in only 4/24 (17%). Primary treatment persistent flow or recanalization through the existing embolization material was seen in 15/24 (63%), reperfusion via recruitment of additional feeding arteries in 7/24 (29%), and both in 2/24 (8%). Retreatment technical success was 88%. Re-embolization into the nidus either through the existing embolic material or via a recruited vessel was performed in 11/24 (46%), and all remained occluded throughout follow-up. Overall durable long-term occlusion was seen in 71% with cumulative median follow-up of 31 months. Durable PAVM occlusion was associated with re-treatment of the nidus (p = 0.005), but not simple (p = 0.68) or saccular PAVM (p = 0.68), retreatment with non-fibered coils (p = 0.26), fibered coils (p = 0.36) or plug (p = 0.54), prior recanalization/persistence (p = 0.68), or prior reperfusion (p = 0.54). No major procedural complications occurred. CONCLUSION: Retreatment of persistent PAVMs led to high immediate technical success (88%) and durable occlusion (71%) on mid-term follow-up. Nidus-directed retreatment was associated with 100% durable occlusion.