The accuracy of carotid back pressure as an index for shunt requirements. A reappraisal.

Publisher Website
Google Scholar
Abstract
The accuracy of a carotid back pressure obtained to determine the need for an internal shunt was questioned. Not all patients undergoing carotid endarterectomy require a carotid shunt while clinically significant cerebral ischemia can be prevented by selective use of a carotid shunt. Carotid endarterectomies (139) were performed under general anesthesia at normal carbia and blood pressure. Indications for these procedures included stroke with maximum recovery (60); transient ischemic attacks (49); asymptomatic lesions (25); and non-lateralizing symptoms (5). Indications for use of a shunt consisted of previous ipsilateral stroke or an internal carotid artery back pressure of < 25 mm Hg. All operations were performed under general anesthesia, and before carotid clamping 10,000 U of heparin were administered i.v. Operations (70) were done with a shunt in place, 60 (86%) of which required shunting because of prior cerebral infarction and 10 (14%) for back pressure of < 25 mm Hg. In 60 other operations, no shunts were used because back pressure was > 25 mm Hg; in 34 (49%) unshunted patients, back pressure ranged from 25-50 mm Hg. Two serious complications occurred: 1 death among 122 patients (0.8%) and 1 stroke among 139 operations (0.7%). The death was due to a cholesterol embolus in the middle cerebral artery in the shunted group and the stroke occurred in the unshunted group. These data support selective shunting. Patients without prior cerebral vascular accidents whose back pressure is > 25 mm Hg have a similar operation by avoiding the inconvenience and inherent risk of an internal shunt.