Treatment of recurrent intracranial aneurysms after neck clipping: Novel classification scheme and management strategies

BACKGROUND: Recurrent aneurysms after initial clipping have been discussed as an important issue in the surgical management of aneurysm. OBJECTIVE: To report our experience with recurrent cerebral aneurysms after neck clipping and to discuss classification and recommended management. METHODS: Aneurysm treatments from a single institution over a 20-year period were retrospectively reviewed. Twenty-three recurrent aneurysms in 23 patients weremanaged during the study period. Recurrent aneurysmswere classified using the concepts of closure line and closure plane, as follows. Type 1: neck situated in an almost different site from the previous clip. Type 2: existing closure plane and reconstructive closure plane are almost the same. Type 3: existing closure plane and reconstructive closure plane cross (type 3a); in rare cases, the existing closure line is sufficiently distant fromthe neck (type 3b). Type 4: no reconstructive closure line is identifiable. RESULTS: Nine patients presented with subarachnoid hemorrhage at recurrence. The mean interval to recurrence was 15.0 years.Management comprised clipping with elective subsequent old-clip removal (n = 7), clipping with preceding old-clip removal (n = 2), bypass occlusion (n = 1), coating (n = 1), combined surgery (n = 1), endovascular surgery (n = 4), and observation (n = 3). Therapeutic intervention was not indicated in 4 patients. Types 3a and 4 requiredmore complex surgical procedures or coil embolization. Procedural complications were observed in 2 patients. CONCLUSION:Asmall but definite propensity toward recurrence after neck clipping exists, and most recurrent aneurysms require some form of retreatment. The novel classification scheme may provide conceptual clarity and therapeutic guidance for decision making.