Unplanned Shunting Is Associated with Higher Stroke Risk after Eversion Carotid Endarterectomy

Abstract

Shunting during eversion carotid endarterectomy (eCEA) may be technically challenging. Whether shunting practice patterns modify perioperative stroke risk after eCEA is unclear. We aimed to compare eCEA outcomes based on shunting practice. The Vascular Quality Initiative (2011-2019) was queried for eCEAs performed for symptomatic and asymptomatic carotid stenosis. Univariable and multivariable analyses compared outcomes based on whether shunting was routine practice, preoperatively-indicated, intraoperatively-indicated, or not performed. There were 13,207 eCEAs identified. Average age was 71.4years and 59.4% of patients were male sex. Ipsilateral carotid stenosis was >80% in 45.6% and there was severe contralateral carotid stenosis in 8.6%. Early ipsilateral symptoms within 14days of eCEA were transient ischemic attack in 5.6% and stroke in 7%. The majority of cases were performed under general anesthesia (82.7%). Electroencephalogram monitoring and stump pressures were utilized in 30.9% and 14.7%, respectively. Shunting was routine (25.4%), preoperatively-indicated (1.9%), intraoperatively-indicated (4.7%), or not implemented (68%). Preoperatively-indicated shunting was more often performed in patients with early symptomatic carotid stenosis or severe contralateral carotid stenosis. After routine shunting, preoperatively-indicated shunting, intraoperatively-indicated shunting, and no shunting, median operative duration was 110, 101, 112, and 97min, respectively (P<0.001), and ipsilateral perioperative stroke prevalence was 0.6%, 1.2%, 1.9%, and 0.7%, respectively (P=0.004). On multivariable analysis, longer operative time was associated with routine shunting (MR 1.17, 95% CI 1.15-1.19, P<0.001), preoperatively-indicated shunting (MR 1.09, 95% CI 1.04-1.15, P<0.001), and intraoperatively-indicated shunting (MR 1.12, 95% CI 1.09-1.16, P<0.001) compared with no shunting. Compared with no shunting, routine shunting (OR 0.91, 95% CI 0.54-1.54, P=0.74) and preoperatively-indicated shunting (OR 1.53, 95% CI 0.47-4.99, P=0.48) were not associated with stroke; however, intraoperatively-indicated shunting was associated with increased stroke (OR 2.74, 95% CI 1.41-5.3, P=0.003). Shunting type was not associated with perioperative mortality. Intraoperatively-indicated shunting during eCEA was associated with longest operative duration and increased perioperative stroke risk. Surgeon familiarity with shunting and planning to shunt in advance may permit more expeditious shunting and prevent stroke.