DOES A ROUTINE OPERATION FOR INTRACRANIAL ANEURYSM INCUR BRAIN-DAMAGE

A biochemical marker of brain cell damage, the BB-isozyme of the intracellular enzyme Creatine Kinase (CK), was used to evaluate any possible injury to the brain, caused by an operation for a ruptured intracranial aneurysm (SAH). CSF-CK BB was assessed before and at intervals after operation in a series of 60 patients, aged 29-71 (mean 51 years) operated on for intracranial aneurysms, all but one after SAH. The m/f ratio was 18/42. 35 of the 60 patients were operated on acutely, i.e. within 72 hours after the SAH. CK BB was determined as CKB-activity after immunological inactivation of CKM. Normally there should be almost no detectable enzyme activity in the CSF. The pre-operative CK BB-activity was 0.01 + - 0.01 mikrokatal in the patients in Hunt and Hess grade 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, compared to 0.39 + - 0.49 for those showing some degree of immediate post operative deterioration. This difference is significant at the 1% level. 52 of the 60 patients showed a rise of CK BB after operation. The mean increase for those patients operated upon in a good state and without any complication or postoperative deterioration was 0.02 + - 0.03 mikrokatal, which could therefore be considered as a ''normal'' or acceptable elevation. The per-operative increase for the whole group was 0.14 + - 0.19 and 0.28 + - 0.38 after late and early operation respectively. A temporary arterial clip was applied for 1 to 27 (totally) minutes in 18 patients. The mean increase for that group did not differ significantly from the rest. The study shows that an operation for intracranial aneurysm causes at least some brain cell damage even in the absence of any clinical signs of deterioration, and more so with early than with late operation. The use of a temporary clip, at least for less than 7 minutes, does not per se cause any further brain cell damage, as mirrored by the CK BB.