Microsurgical Clipping for Recurrent Aneurysms After Initial Endovascular Coil Embolization

Objective Surgical treatment for recurrent lesions of embolized aneurysms is difficult and challenging for many neurosurgeons because intra-aneurysmal coil masses are sometimes scarred to the wall of the aneurysm or adherent to adjacent vital structures. To assess the efficacy and safety of surgical treatment without coil removal for recurrent aneurysms after previous coil embolization, we retrospectively studied clinical results, angiographic results, and complications in patients treated with additional microsurgical clipping. Methods From April 2003 to April 2013, 7 patients with recurrent previous embolized aneurysms underwent microsurgical treatment. Results This series included 1 man and 6 women receiving endovascular coiling as the first-line treatment. One patient's aneurysm was unruptured, whereas the other 6 were ruptured. The aneurysm locations were posterior communicating ( n = 3), anterior communicating ( n = 2), ophthalmic ( n = 1), and posterior inferior cerebellar ( n = 1). The initial sizes ranged from 3–11.5 mm in diameter (mean, 6.6 mm), and the aspect ratios were 1.2 to 3.4 (mean, 1.9). In these aneurysms, the initial coiling result was complete occlusion in 5 patients, and neck remnants in 2 patients. The mechanism underlying aneurysm recurrence was coil compaction in 3 aneurysms, aneurysm regrowth in 3 aneurysms, and fundal migration in 1 aneurysm. The median recurrence latency was 28.8 months (range, 0.7–115 months). Microsurgical clippings without coil removal were used in 6 patients; a parent artery occlusion under bypass protection was done in 1 case with a posterior inferior cerebellar aneurysm. Fenestrated clips in combination with another type of clip were successfully used for 4 of 6 patients who were treated with direct neck clipping. No postoperative morbidity was observed, and postoperative imaging studies revealed complete occlusion of the aneurysms in all cases. There were no recurrences of aneurysms during the follow-up period (mean, 44.7 months; range, 0.5–118 months). Conclusions The microsurgical clipping without coil removal for recurrent lesions of embolized aneurysms is effective and safe when it is technically feasible. The tandem clipping in combination with a fenestrated clip is a crucial method for direct neck clipping without coil removal for previously coiled recurrent aneurysms. For unclippable lesions, a parent artery occlusion under bypass protection should be taken into consideration.