Temporary Clipping in Intracranial Aneurysm Surgery

Abstract

The intra-operative rupture of intracranial aneurysms (IA) occurs in 5–30% of cases as reported in the literature. This event is frequently associated with an increase in mortality and morbidity. The aim of this study was to evaluate the prognostic importance of temporary clipping in intracranial aneurysm surgery. A series of 304 cases of IA treated surgically were selected by excluding giant or Hunt-Hess grade >3 aneurysms. Two groups of patients were compared: one of 157 cases that had temporary clipping (TC) during surgery and the other of 147 patients who did not have TC.

The neuroprotective measures used were the infusion of Thiopental and maintenance of adequate blood pressure by use of Bitartrate Metaraminol and Ephedrine. The surgical complications, chiefly intra-operative rupture of the sac and consequences of malpositioning the clip with associated clinical complications, were considered. The two groups were compared using χ² that showed a statistically significant reduction of the surgical complications in those patients who had TC. The associated poor clinical outcome was reduced from 7.5% to 2.5%. The main prognostic factor in determining the ischemic damage was the occlusion time of the local arterial circulation. The mean occlusion time in these patients was limited to four minutes and in only 12 cases reached 15–16 minutes without ischemic complications. Temporary clipping reduces the risk of intra-operative rupture of aneurysm and permits a better dissection of the sac with an adequate positioning of the definitive clip. In cases of small aneurysm with an easily accessible neck (that predict a temporary occlusion of the local arterial circulation) we consider the maintenance of optimal blood pressure very important. However we do not consider it essential to use electrophysiologic monitoring or other particular techniques of neuroprotection (which are vital in the surgery of giant or complex aneurysms).