VALIDITY OF TEST OCCLUSION STUDIES PRIOR TO INTERNAL CAROTID-ARTERY SACRIFICE

Twenty-nine patients with lesions of the neck, skull base, and caverno us sinus had test balloon occlusions of the internal carotid artery (I CA) to determine the feasibility of sacrifice of the artery. Only one patient (3.4%) showed evidence of cerebrovascular compromise. Sixteen patients who tolerated test occlusions went on to ICA sacrifice. Ten p atients had permanent balloon occlusion (PBO) of the ICA for cavernous aneurysms or to ''trap'' carotid-cavernous fistulae (CCF). Complicati ons occurred in three patients (30%) with permanent morbidity in one p atient (10%). One patient with CCF had PBO of the proximal ICA only, r esulting in an unstable neurologic state and ultimately in death. Two patients had resection of skull base tumors 2 and 6 days after PBO of the ICA. Both suffered strokes and one died. Three patients had surgic al sacrifice of the ICA without PBO. Two of these patients suffered ce rebral ischemia without permanent sequelae. We conclude that test occl usion of the ICA with clinical monitoring will miss a significant numb er of patients with inadequate cerebrovascular reserve. Sensitivity is improved by controlled reduction of systemic blood pressure during th e test occlusion. Resection of a skull base tumor soon after PBO of th e ICA should be done in a delayed fashion or preceded by extracranial- intracranial arterial bypass. Patients who have had the artery sacrifi ced should be monitored in an intensive care setting for 48 hours to a void hypotension, which could cause cerebrovascular ischemia. (C) 1994 John Wiley & Sons, Inc.