DOES A ROUTINE OPERATION FOR INTRACRANIAL ANEURYSM INCUR BRAIN-DAMAGE

A biochemical marker of brain cell damage, the BB-isozyme of the intra cellular enzyme Creatine Kinase (CK), was used to evaluate any possibl e injury to the brain, caused by an operation for a ruptured intracran ial aneurysm (SAH). CSF-CK BB was assessed before and at intervals aft er operation in a series of 60 patients, aged 29-71 (mean 51 years) op erated on for intracranial aneurysms, all but one after SAH. The m/f r atio was 18/42. 35 of the 60 patients were operated on acutely, i.e. w ithin 72 hours after the SAH. CK BB was determined as CKB-activity aft er immunological inactivation of CKM. Normally there should be almost no detectable enzyme activity in the CSF. The pre-operative CK BB-acti vity was 0.01 + - 0.01 mikrokatal in the patients in Hunt and Hess gra de I who were operated on > 7 days after their SAH, and 0.05 + - 0.04 in those operated on acutely, probably still reflecting the effects of the SAH on the brain. The mean per-operative CK BB increase was 0.11 + - 0.17 for patients who had an uneventful postoperative course, comp ared to 0.39 + - 0.49 for those showing some degree of immediate post operative deterioration. This difference is significant at the 1% leve l. 52 of the 60 patients showed a rise of CK BB after operation. The m ean increase for those patients operated upon in a good state and with out any complication or postoperative deterioration was 0.02 + - 0.03 mikrokatal, which could therefore be considered as a ''normal'' or acc eptable elevation. The per-operative increase for the whole group was 0.14 + - 0.19 and 0.28 + - 0.38 after late and early operation respect ively. A temporary arterial clip was applied for 1 to 27 (totally) min utes in 18 patients. The mean increase for that group did not differ s ignificantly from the rest. The study shows that an operation for intr acranial aneurysm causes at least some brain cell damage even in the a bsence of any clinical signs of deterioration, and more so with early than with late operation. The use of a temporary clip, at least for le ss than 7 minutes, does not per se cause any further brain cell damage , as mirrored by the CK BB.