A Regional Experience with Carotid Endarterectomy in Patients with a History of Neck Radiation

Background: Historically, a history of neck radiation has been considered as an anatomic risk factor for poor outcomes after carotid endarterectomy (CEA). However, this is based on small and primarily single institution reports with few comparative series. This study uses a regional quality database to compare perioperative outcomes of CEA in patients with and without a history of neck radiation (RAD and NORAD, respectively). Methods: The Vascular Study Group of New England database was queried for all CEA from 2003 to 2017. The RAD group included a history of neck radiation. Primary end points included perioperative stroke (30-day), myocardial infarction (MI) (in-hospital), death (30-day), a composite end point including major adverse events (MAEs: stroke, MI, and death), and long-term survival. Results: Overall, 18,832 patients underwent CEA (18,551 NORAD, 281 RAD). Baseline demographics differed in the following: the RAD group more frequently had a history of contralateral carotid artery stenting (1.4% vs. 0.3%, P = 0.009), anatomic high risk features (12.8% vs. 1.3%, P < 0.001), and contralateral carotid occlusion (5.3% vs. 2.4%, P = 0.005). The NORAD cohort comprised mostly women (38.9% vs. 29.5%, P < 0.001), had American Society of Anesthesiologists class 4 or 5 (8.0% vs. 4.6%, P = 0.035), had higher body mass index (28.3 +/- 5.6 vs. 27.1 +/- 5.4, P < 0.001), on a beta blocker preoperatively (68.0% vs. 62.3%, P = 0.042), and had major cardiovascular comorbidities including coronary artery disease (29.6% vs. 22.1%, P = 0.006). There were no differences in the percent stenosis, proportion symptomatic (37.4% vs. 34.2%, P = 0.259), use of preoperative antiplatelet agents or statins. Electroencephalography monitoring was more frequently used in RAD (54.5% vs. 46.0%, P = 0.005). There was no difference in perioperative complications, including stroke (RAD 0.4% vs. NORAD 0.7%, P > 0.999), MI (0.4% vs. 0.9%, P = 0.736), death (0.7% vs. 0.6%, P = 0.683), MAE (2.1% vs. 2.2%, P > 0.999), or long-term survival (79.9% vs. 85.0%, P = 0.357). When only symptomatic or asymptomatic stenosis was considered, there remained no difference in primary end points. However, perioperative neurologic events (transient ischemic attack or stroke) was higher in symptomatic RAD versus symptomatic NORAD (6.7% vs. 2.6%, P = 0.020). Conclusions: This regional experience with CEA in RAD patients shows similar perioperative morbidity, mortality, and long-term survival when compared with CEA for standard surgical patients (ORAD). Symptomatic presentation was associated with higher perioperative neurologic events, but this was not reflected in stroke rates. RAD is not always a contraindication to CEA and select patients can expect outcomes comparable to standard surgical patients.