Australia & New Zealand Society of Vascular Surgeons

Stump pressure measurements have been used to select patients for bypass shunting during carotid endarterectomy. Based on the assumption that low ICA back flow reflects inadequate cerebral perfusion, ‘acceptable’ stump pressures are empiric and have not been validated against clinically assessed neurological function. The performance of carotid surgery under local anaesthetic provides an opportunity to relate stump pressure to cognitive function. The practice of carotid endarterectomy in Victoria’s largest rural centre, over a four year period, was assessed retrospectively. Most cases were performed by one of two vascular surgeons. Local anaesthetic was the preferred approach of one operator whose shunt rate was compared to that of the second surgeon who had a policy of selective shunting based on stump pressures. 317 carotid endarterectomies performed between March 1999 and March 2003 were available for the purpose of comparison. 206 were conducted under local anaesthetic with a shunt rate of 7.8%. Among 111 cases where selective shunting was applied under general anaesthetic the rate was 54%. Patient demographics of the two groups were comparable and there was no appreciable difference in patch rate, operation time or postoperative length of stay. Stroke and death rates for the two groups were within an acceptable range. The large disparity between shunt rates of the two groups placed the level at which ICA back pressure is deemed ‘acceptable’ in question. It has prompted the conduct of a prospective study of stump pressure measures and cognitive function with carotid cross-clamping under local anaesthetic.