Patterns of aneurysm recurrence after microsurgical clip obliteration.

Background: Microsurgical clip obliteration remains a time-honored and viable option for the treatment of select aneurysms with very low rates of recurrence.

Objective: We studied previously clipped aneurysms that were found to have recurrences to better understand the patterns and configurations of these rare entities.

Methods: A retrospective review was performed of 2 prospectively maintained databases of aneurysm treatments from 2 institutions spanning 14 years to identify patients with recurrence of previously clipped intracranial aneurysms.

Results: Twenty-six aneurysm recurrences were identified. Three types of recurrence were identified: type I, proximal to the clip tines; type II, distal; and type III, lateral. The most common type of recurrence was that arising distal to the clip tines (46.1%), and the least frequently encountered recurrence was that arising proximal to the tines (19.2%). Laterally located recurrences were found in 34.6% of cases.

Conclusion: We describe 3 different patterns of aneurysm recurrence with respect to clip application: those occurring proximal, distal, or lateral to the clip tines.