Hypothermic circulatory arrest in neurovascular surgery: evolving indications and predictors of patient outcome

One of the largest contemporary neurosurgical experiences with hypothermic circulatory arrest was analyzed for trends in patient selection and clinical variables affecting outcome.

During a 12-year period, 60 patients underwent 62 circulatory arrest procedures: 54 had posterior circulation aneurysms, 4 had anterior circulation aneurysms, and 2 had other lesions (hemangioblastoma and vertebral artery atherosclerosis).

The surgical morbidity and mortality rates associated with hypothermic circulatory arrest were 13.3 and 8.3%, respectively. At late follow-up, 76% of the patients had good outcomes (Glasgow Outcome Scale scores of 1 and 2), 5% had poor outcomes (Glasgow Outcome Scale scores of 3 and 4), and 18% had died. After 1992, circulatory arrest was limited to posterior circulation aneurysms and included increasing numbers of basilar trunk aneurysms. Patient outcome correlated with preoperative neurological condition (admission Glasgow Coma Scale score, P < 0.001; Hunt and Hess grade, P = 0.037; and age, P = 0.007). Preservation of perforating arteries was paramount to achieving a good outcome (P = 0.005); duration of circulatory arrest was not.

Current indications for hypothermic circulatory arrest include only giant and complex posterior circulation aneurysms that cannot be treated using conventional techniques or that recur after endovascular coiling. Surgical morbidity and mortality rates reflect the increasing complexity of the aneurysms treated but are still more favorable than the natural history of these lesions. This experience demonstrates that management in specialized neurovascular centers can minimize the morbidity associated with circulatory arrest so that it remains a viable treatment option for complex posterior circulation aneurysms.