Carotid Endarterectomy With Shunt for Preoperative or Intraoperative Indication Is Associated With Increased Rate of Stroke

Abstract

Carotid endarterectomy (CEA) is performed frequently both with and without the use of shunting, and previous studies have shown similar 1% to 2% rates of stroke with both techniques in asymptomatic patients. The rate of stroke when shunting is performed for a preoperative or intraoperative indication remains understudied. We aimed to evaluate the rate of stroke by shunt indication and to compare this cohort with routine shunt and no shunt cohorts in a large national registry. The Vascular Quality Initiative CEA registry was used to identify patients undergoing CEA for asymptomatic carotid stenosis from 2013 to 2019. Exclusion criteria included symptomatic patients (defined as ipsilateral transient ischemic attack or stroke within 6 months of operation), concomitant coronary intervention, proximal or distal endovascular intervention, and urgent or emergent procedures. Categorical variables were analyzed using χ2 test, and continuous variables were analyzed using analysis of variance. Multivariable logistic regression was used to evaluate demographic and perioperative predictors of stroke. There were 69,903 CEAs identified, which consisted of 33,459 without shunt, 31,711 routine shunts, 1369 shunts for preoperative indication, and 3364 shunts for intraoperative indication patients. The cohort with shunt for preoperative indication was more likely to be male, to be transferred from an outside hospital, and to have contralateral internal carotid artery (ICA) occlusion. In addition, the cohorts with shunt for indication had slightly increased procedure length, rates of re-exploration at time of initial operation, and protamine use (Table I). The rate of stroke was increased in shunt for preoperative and intraoperative indication cohorts (no shunt, 0.8%; routine shunt, 0.9%; preoperative indication, 1.8%; intraoperative indication, 1.3%; P < .01). On multivariable analysis, both shunt for preoperative indication and shunt for intraoperative indication are associated with stroke. Other perioperative and demographic variables associated with stroke include hypertension, any prior neurologic event, contralateral ICA occlusion, completion angiography, postoperative hemodynamic instability requiring intravenous medications, and re-exploration at the time of initial operation (Table II). The proportion of shunt for preoperative indication varies by region (East, 1.4%; North, 2.2%; South, 1.5%; West, 4.3%; P < .01). Regional variation is present in preoperative indication for shunt as the proportion of patients with contralateral ICA occlusion or >60% contralateral ICA stenosis varied widely (East, 55.3%; North, 62.9%; South, 52.2%; West, 47.6%; P < .01). CEA with shunt for preoperative or intraoperative indication is associated with increased rates of stroke, even in asymptomatic patients, suggesting a high-risk cohort that is poorly defined by registry data. Identifying this cohort may alter the risk-benefit ratio of the operation and inform clinical decision-making.Table IDemographic characteristics, preoperative workup, and intraoperative variablesDemographic characteristicsNo shunt (n = 33459)Routine shunt (n = 31711)Shunt: Preop indication (n = 1369)Shunt: Intraop indication (n = 3364)PAge, years (SD)70.7 (8.7)71.0 (8.8)70.4 (9.1)71.1 (8.9)<.01Sex (male)20263 (60.6)18715 (59.0)876 (64.0)1918 (57.0)<.01Comorbidities HTN29950 (89.5)28615 (90.2)1236 (90.3)3079 (91.5)<.01 CAD9092 (27.2)9061 (28.6)404 (29.5)926 (27.6)<.01 CHF3659 (10.9)3637 (11.5)157 (11.5)391 (11.6).15 Diabetes11988 (35.8)11881 (37.5)508 (37.1)1280 (38.0)<.01 Current Smoker7976 (23.8)8043 (25.4)330 (24.1)885 (26.3)<.01 ESRD352 (1.1)366 (1.2)16 (1.2)49 (1.5).16 ASA Class ≥45539 (16.6)6026 (19.0)274 (20.0)605 (18.0)<.01 Lived at Home33178 (99.2)31343 (99.1)1346 (98.4)3313 (98.5)<.01 Transfer OSH383 (1.1)341 (1.1)35 (2.6)46 (1.4)<.01Neurologic History Ipsi Neuro Event >6 months1891 (5.7)1803 (5.7)147 (10.8)214 (6.4)<.01 Ipsi Stroke >6 months1110 (3.3)1075 (3.4)103 (7.5)138 (4.1)<.01 Contra CEA5213 (15.6)5169 (16.3)156 (11.4)528 (15.7)<.01 Contra ICA Occlusion937 (2.8)1620 (5.2)370 (27.4)336 (10.3)<.01 Ipsi Stenosis ≥70%30362 (92.1)28306 (91.3)1232 (91.4)2932 (90.2)<.01 Contra Stenosis ≥70%6116 (18.6)5888 (19.0)314 (23.3)624 (19.2)<.01 Anatomic High Risk1433 (4.3)1232 (3.9)53 (3.9)147 (4.4).06Operative Factors Procedure Length (SD)114 (44)112 (42)122 (44)121 (43)<.01 Protamine23494 (70.2)21643 (68.3)985 (72.0)2581 (76.8)<.01 Patch27831 (83.3)30607 (96.5)1289 (94.2)3165 (94.1)<.01 Re-explore at Initial Operation459 (1.4)390 (1.2)19 (1.4)72 (2.1)<.01ASA, American Society of Anesthesiologists; CAD, coronary artery disease; CHF, congestive heart failure; Contra, contralateral; ESRD, end stage renal disease requiring dialysis; HTN, hypertension; ICA, internal carotid artery; Ipsi, ipsilateral; Neuro, neurologic event >6 months from procedure; OSH, outside hospital; SD, standard deviation. Open table in a new tab Table IIMultivariable logistic regression: strokeStrokeOdds ratio (OR)95% Confidence intervalPP2Y12 Inhibitor0.640.53-0.77<.01Male Gender0.810.69-0.96.02Shunt for Intraop Indication1.431.02-2.01.04Shunt for Preop Indication1.611.05-2.53.03Completion Angiogram1.691.22-2.35<.01Hypertension1.701.20-2.40<.01Contralateral ICA Occlusion1.781.34-2.38<.01Any Prior Neurologic Event1.931.63-2.29<.01Postop IV Medication for Hemodynamic Instability3.432.91-4.05<.01Re-explore at Initial Operation9.5411.31-17.08<.01 Open table in a new tab