CAROTID ENDARTERECTOMY AFTER NASCET AND ACAS - A STATEWIDE STUDY

Purpose: Since the North American Symptomatic Carotid Endarterectomy T rial (NASCET) and the Asymptomatic Carotid Artery Stenosis Study (ACAS ) established the efficacy of carotid endarterectomy at large academic centers, there have been two community-based studies of outcomes afte r this operation. The purpose of this study was to perform a statewide survey to evaluate postoperative morbidity and mortality after caroti d endarterectomy among patients throughout Maine. Methods: A statewide registry was established to collect prospective data on carotid opera tions from January I to December 31, 1995. All surgeons and hospitals in the state were solicited to participate. All carotid endarterectomi es were intended to be included; the only exclusion criterion was out- of-state residence. Comorbidities, preoperative studies, surgical indi cations, operative technique, and postoperative outcomes were analyzed . State administrative data were used to assess registry coverage. Res ults: Ten of 17 hospitals participated, and 58% of all carotid endarte rectomies performed in the state were included. Three hundred sixty-fo ur operations were entered into the registry, forty-four percent of th e operations were performed for transient ischemic attack, 37% for asy mptomatic stenosis, and 19% for stroke. The postoperative stroke rate was 2.5% with a total neurologic complication rate of 4.7% (transient ischemic attack and stroke). There was one postoperative death (mortal ity rate 0.3%). Patients with symptoms had a higher incidence of posto perative stroke (4.0% vs 0% asymptomatic; p < 0.05) and transient isch emic attacks (3.8% vs 0.8% asymptomatic). Hospital stroke rates varied from 0% to 7%. Stroke rate did not differ significantly between low-v olume hospitals (2 to 28 patients/year, 3.3%) and high-volume hospital s (29 to 101 patients/year, 2.3%) or between low-volume surgeons (fewe r than 11 operations/year, 1.7%) and high-volume surgeons (more than 1 2 operations/year, 2.4%). Among 26 reporting surgeons, stroke rate var ied from 0% to 10%; the absolute number of strokes per surgeon varied between zero and two. Conclusion: The statewide registry showed a post operative stroke plus death rate of 2.8%, comparable with the NASCET a nd ACAS findings. Although this study had inherent limitations, the re sults from one state, including a variety of community practices, achi eved results comparable with those of landmark trials.