Pipeline Embolization for Salvage Treatment of Previously Stented Residual and Recurrent Cerebral Aneurysms

Introduction: This study assessed the safety and effectiveness of the Pipeline embolization device (PED) for persistent and recurrent aneurysms previously treated with either a vascular reconstruction device (VRD) or a flow diverter (FD). Methods: A prospective, IRB-approved database was analyzed for patients treated with PED for aneurysms previously treated with a stent. Results: Twenty procedures were performed on 18 patients, 11 with prior FD, 7 with VRD, and 2 previously treated with both. Overall, 15 aneurysms were saccular (75%), and size was 13.5 ± 7.6 mm. Location was internal carotid artery (ICA) in 14 cases (70%) and posterior circulation in 6 cases (30%). Average prior treatments were 1.7. Previously FD cases were re-treated at an average of 18.1 months from most recent treatment. Each case used 1 device, 82% with distal coverage and 82% with proximal coverage of prior stent. Balloon remodeling was performed in 3 cases (27%) and no in-stent thrombosis was observed. Previously VRD stent-coiled cases were re-treated at an average of 87.5 months. These cases used on average 1.9 devices, 89% with distal and 100% proximal coverage. Adjunctive coiling was performed in 1 case (11%), balloon remodeling in 5 cases (56%), and 2 cases (28%) developed thrombosis that resolved with abciximab. Re-VRD cases were longer (59.1 vs. 33.7 min, p = 0.02) than re-FD. Angiographic follow-up was available for 16 cases (80%). In re-FD, occlusion was complete in 56% and partial progressive in 33% at 17.1 months digital subtraction angiography. In re-VRD, occlusion was complete in 57% and partial progressive in 27% at 8.1 months. Two complications occurred (10%), including one asymptomatic cervical ICA occlusion and one stent occlusion with associated mortality (5%). Clinical follow-up was 17.8 months on average (range 0.5-51.9). Conclusions: Salvage flow diversion for previously stented aneurysms is technically challenging but offers good prospects of aneurysm obliteration with acceptable complication rates.