Any method that decreases the risk of intraoperative rupture should improve outcome if complications associated with its use do not negate positive effect. If application time is limited and a form of cerebral protection and appropriate monitoring of cerebral function are used, temporary clip application may meet these requirements. The efficacy of temporary occlusion as an adjunct to aneurysm clipping may be limited by technical considerations with respect to regional anatomy, aneurysm size, and aneurysm consistency. In areas of limited access, positioning proximal clips may not be feasible. The use of endovascular techniques of balloon occlusion may provide proximal control in these situations (9, 106). The decision to use total circulatory arrest and profound hypothermia, as opposed to temporary clip application, remains largely a matter of the surgeon's judgment. The role of proximal parent vessel ligation must also be considered in the decision-making process regarding the treatment of giant or technically difficult aneurysms (114). Further refinements in cerebral monitoring that can accurately reflect intracellular processes in all territories affected by the application of temporary clips or balloon occlusion and development of more effective forms of cerebral protection may permit safer use of this technique. An adequately controlled clinical trial of temporary occlusion with or without putative "cerebral protection" is needed to confirm the efficacy of this technique.

THE possible implications of total-body cooling have long interested investigators, clinicians and science-fiction writers. In the confusion of today's literature, it is sometimes difficult to classify authors correctly. Herein, perhaps, lies the excuse for this report, since there are already excellent monographs and reviews,^{1234567891011121314151617} on many separate phases of the subject. Two progress reports have already appeared in the Journal.^18,19 It is our intention to assess the many forms of therapeutic hypothermia now in vogue and to direct readers to reliable sources. Also, since new concepts are continually developing, it is hoped this review, like a daily newspaper, will . . .