Grading and Timing of Operation of Cerebral Aneurysms

Abstract

The progress in microsurgery, neuroanaesthesia, pre- and postoperative intensive care has resulted in a considerable improvement of the mortality and morbidity of cerebral aneurysms. The operation itself, therefore, became devoid of risks. This situation is reflected in the negligible mortality and morbidity in patients operated in grade I and II and with only 5% in patients in grade III. The importance of primary and/or secondary impairment of cerebral function following rupture of the aneurysm for the prognosis is particularly evident when considering the high mortality and morbidity of patients who are in grade IV and particularly in grade V (Table 1) (PIA et al., 1979 (2)). It remains unclear which prognostic effect, negative or positive, is brought about by the operation itself and what effect does the operation have upon the already existing cerebral lesions. Favourable therapeutic development led to the discussion about the timing of operation. In contrast to grading which generally reflects the degree of impairment of cerebral function, the two most important sequelae of aneurysm rupture, namely vasospam and secondary bleeding, cannot be measured and estimated exactly. Vasospasm and particularly rebleeding can be prevented through correctly timed, i.e. early operation. The serious consequences of vascular spasm and recurrent bleeding as well as the very limited help offered by conservative therapy are so well-known, that statistical evaluation does not seem necessary here.