Temporary Clipping and Induced Hypotension in Cerebral Aneurysm Surgery

In order to find out the effect of induced hypotension and temporary clipping during aneurysmal surgery on postoperative patients, we analysed 143 cases who had received surgery from September, 1982 to April, 1988. We divided these surgical cases into two groups, those without temporary clipping and those with temporary clipping during surgery, excluding cases of definite surgical complications. Of the patients in the non-temporary clipping group, we evaluated the relationship between the degree of the mean blood pressure(MBP) during surgery with the postoperative conduction of the patients according to the preoperative clinical grade. Of those in the temporary clipping group, we also evaluated the relationship between the degree of the MBP, site and duration of the temporary clipping during surgery with the postoperative condition of the patients according to preoperaitve clinical grades. The rate of temporary deterioration, delayed sequela and death, possibly from induced hypotension or the temporary clipping procedure, was higher in those whom the MBP was lowered to 60 mmHg during surgery than in those whom the MBP was maintained at 80 mmHg and 70 mmHg(temporary deterioration : 27.3% vs. 23.1% vs. 13.3%, delayed sequela : 4.5% vs. 0.0% vs. 0.0%, and death : 9.1% vs. 0.0% vs. 3.3%, respectively in non-temporary clipping group and temporary deterioration : 33.3% vs. 22.2% vs. 21.1%, and death : 22.2% vs. 0.0% vs. 10.5%, respectively in temporary clipping group). In the non-temporary clipping group, preoperative clinical grades 1,2 and 3 patients did not deteriorate until after 20 minutes of hypotension(MBP : < or = 60 mmHg). However, patients of preoperative clinical grade 4 and 5 showed temporary deterioration after 10 minutes of hypotension(MBP : < or = 60 mmHg). There was no deterioration in patients whom the duration of the temporary clipping was within 15 minutes at an intracranial internal carotid artery and a middle cerebral artery at various MBP's, but, in the cases who had a temporary clipping at the anterior cerebral artery, the safety duration of the temporary clipping was 15 minutes at 80 mmHg, 7 minutes at 70 mmHg and 3 minutes at 60 mmHg of the MBP. Induced hypotension during aneurysmal surgery had some risk and it increased in hypertensive, poor clinical grade patients, and when the MBP was lowered to 60 mmHg. The safety duration of a temporary clipping might be increased with the raising of the MBP or administration of a brain protective agent at the time of the temporary clipping during surgery.

Subtemporal Approach for Basilar Bifurcation and Basilar-Superior Cerebellar Artery Aneurysms

The pterional(Transsylvian) and subtemporal approaches are main surgical route for direct clipping of basilar bifurcation and basilar-superior cerebellar artery aneurysms. In general , the pterional approach has the advantage for high placed aneurysm and the subtemporal approach has the advantage for low placed and posterior directed aneurysm of basilar bifurcation. The authors has been performed surgery for 5 cases of basilar bifurcation and basilar-superior cerebellar artery aneurysms through subtemporal route during 1.5 years with good results in 3 cases, fair result in 1 case, and death in 1 case. We described about this 5 cases detaily and discussed the subtemporal approach for these lesions.