Microsurgical treatment of recurrent and residual previously clipped/or coiled intracranial aneurysms: a single center series of 22 patients

Objective: Recurrent and residual intracranial aneurysms (RA) are encountered with both clipping and endovascular treatment, and microsurgical treatment may be the only option at times. We present a series of 22 patients with RA that underwent microsurgical treatment, emphasizing on treatment strategies, occlusion rate, durability, and outcome. Methods: This was a retrospective analysis of 22 patients with 23 RA treated with microsurgery. There was a total of 11 previously coiled and 12 previously clipped aneurysms. Data on demography, previous treatments, aneurysm characteristics, surgical indications, microsurgical treatment strategy, post-surgical occlusion rate, durability of treatment, complications, and functional outcome were collected. Results: Clipping was performed on 21 (91.3 %) aneurysms, clipping and bypass on 1 aneurysm, and trapping and bypass on 1 aneurysm. Complete occlusion was achieved with 22 (95.7 %) aneurysms. Previous coils were removed in one case and previous clips were removed in 4 cases. One patient that had previous coiling and 2 patients that had previous clipping suffered complications. Good functional outcome was achieved for all retreated cases except one. Median follow-up was 5 years and no recurrence has been detected so far. Conclusion: Outcome for microsurgical retreatment of RA is good provided proper selection of cases and treatment strategy is adhered to. The best clinical judgement is needed to prevent unnecessary morbidity from retreatment or a catastrophic rupture from a delay in retreatment. Ideally, the most efficient strategy to deal with RA is to prevent their occurrence altogether during the primary treatment as RA are definitely harder to treat compared to virgin aneurysms.