Endoluminal cryotherapy to prevent recanalization after endovascular occlusion with platinum coils

PURPOSE: Endovascular embolization with platinum coils is sometimes followed by recanalization. The present study was undertaken to assess whether cryoablation of the endothelial lining could prevent recanalization after coil occlusion. MATERIALS AND METHODS: Recanalization rates of canine maxillary and vertebral arteries (n = 20) occluded with platinum coils with or without previous cryoablation (with temperatures of -40 degrees C to -45 degrees C for 90 seconds) were analyzed by angiography immediately and at 1 and 3 months in five animals. Pathologic recanalization and fibrosis was assessed at 3 months with use of a qualitative scoring system. Findings were compared with Mann-Whitney tests. RESULTS: Recartalization after coil occlusion occurred in 50% and 60% of cases with cryoablation at 1 and 3 months, respectively, compared with 100% without ablation (P = .012 and P = .029). There was no significant difference in pathologic scores (P = .348). The brachial plexus in the vicinity of vertebral arteries was injured by cryotherapy in three animals in which an ipsilateral neurologic deficit developed. CONCLUSIONS: Cryotherapy was moderately effective in the prevention of recanalization after coil occlusion. Deep nerve injury was excessive with the protocol used in the present study.