Improved neurologic function after cerebrovascular accident with extracranial-intracranial arterial bypass.

This study, by use of direct measurement, sought to investigate the role of diminished cerebral blood flow on neurologic function after cerebrovascular accident (CVA). Twenty-seven patients had mean middle cerebral artery pressure (MCAP) measured intraoperatively prior to a superficial temporal artery to middle cerebral artery bypass. The ratio of MCAP to mean systemic blood pressure (BP) was less than 0.500 in 11 patients. Six of these 11 had preoperative neurologic deficit and four of these six had improved neurologic function after revascularization. In 16 patients the MCAP/BP was greater than 0.500, and none of the seven patients with neurologic deficit improved postoperatively. In general, the MCAP/BP correlated well with the angiographic severity of cerebrovascular disease. In 16 patients, unsuitable for conventional bypass, autogenous saphenous vein was used as a bypass from the subclavian or other extracranial artery to a cortical branch of the middle cerebral artery. One cerebral death and one CVA occurred postoperatively early in the series, but there have been no untoward events since deep barbituate anesthesia has been used. Diminished cerebral blood flow after CVA may leave a pool of viable but nonfunctional neurons. Extracranial-intracranial bypass may improve neurologic function in such patients.