Low carotid stump pressure as a predictor for ischemic symptoms and as a marker for compromised cerebral reserve in octogenarians undergoing carotid endarterectomy

Abstract

BackgroundCarotid artery occlusive disease can cause stroke by embolization, thrombosis, and hypoperfusion. The majority of strokes secondary to cervical carotid atherosclerosis are believed to be of embolic etiology. However, cerebral hypoperfusion could be an important factor in perioperative stroke. We retrospectively reviewed the stump pressure (SP) of carotid endarterectomy (CEA) of patients at Pennsylvania Hospital to identify whether physiologic perfusion differences account for differences in perioperative stroke rates, particularly in octogenarians. MethodsWe conducted a retrospective review of our prospectively maintained database for CEA performed between 1992 and 2015. SP was measured and recorded for 1190 patients. A low SP was defined as systolic pressure <50 mm Hg. Shunts were used only for patients under general anesthesia with SP <50 mm Hg, for awake patients with neurologic changes with carotid clamping, and in some patients with recent stroke. ResultsSymptomatic patients were more likely to have SP <50 mm Hg compared with asymptomatic patients (35.6% vs 26.2%; P = .0015). Patients having SP <50 mm Hg had a higher postoperative stroke rate compared with patients with SP >50 mm Hg (2.9% vs 0.9%; P = .0174). Octogenarians were more likely to have a lower SP compared with patients younger than 80 years (35.7% vs 27.7%; P = .0328). Symptomatic patients with low SP were at highest risk for perioperative stroke (6.4% vs 1.2%; P = .001) compared with patients without these factors. ConclusionsSP is a marker for decreased cerebrovascular reserve and along with symptomatic status identifies those at highest risk for periprocedural stroke with CEA. Whereas patients older than 80 years may benefit from carotid intervention, they are likely to be at somewhat elevated stroke risk because of higher prevalence of low SP, and shunting does not eliminate this risk.