Cerebral revascularisation in stroke prophylaxis.

Over 700 cerebral vascular operations have been undertaken on the Surgical Unit of St Bartholomew's Hospital, London, for stroke prophylaxis, the majority being carotid endarterectomies. One of the unique features of the latter procedure is the marked instability of postoperative blood pressure. The relation of this change to interference with carotid baroreceptor function was studied by per-operative carotid sinus nerve recording. It was possible to relate nerve activity to the postend-arterectomy changes in the mechanical properties of the vessel wall in the region of the carotid sinus. Postoperative hypotensive episodes could be reversed by the injection of local anaesthetic alongside the carotid sinus nerve through a cannula left in situ at operation.The complications of 425 carotid endarterectomies were analysed by computer and specific risk factors were found to be hypertension, the presence of contralateral internal carotid artery disease, and the presence of lower limb vascular disease. The carotid angiograms of 200 patients were studied with respect to the extent of the disease at the origin of the internal carotid arteries. The operative complication rate was found to be closely related to the severity of this disease, all severe complications occurring in patients with severe bilateral internal carotid artery stenosis or occlusion. This finding has led to the introduction of the term the ;reperfusion syndrome', and the mechanism of the complication is still under study.Seventy-nine extraintracranial revascularising procedures have been undertaken and this operation has been shown to carry a very low morbidity. The postoperative incidence of recurrent transitory ischaemic attacks (TIAs) and strokes is low, but the longest follow-up period is still only 4 years. The value of the procedure for TIAs and strokes is under study, as is its place in the treatment of patients with dementia.