OBJECTIVE Carotid artery stenosis (CAS) is associated with an annual stroke risk of 2%-5%, and revascularization with carotid endarterectomy (CEA) can reduce this risk. While studies have demonstrated that hospital CEA volume is associated with mortality and myocardial infarction, CEA volume cutoffs in studies are relatively arbitrary, and no specific analyses on broad complications and discharge disposition have been performed. In this study, the authors systematically set out to identify a cutoff at which CEA procedural volume was significantly associated with major complications and nonroutine discharge. METHODS Asymptomatic and symptomatic CAS patients undergoing CEA were retrospectively identified in the Nationwide Readmissions Database (2010-2018). The association of CEA volume with outcomes was explored as a continuous variable using locally estimated scatterplot smoothing. The identified volume cutoff was used to generate dichotomous volume cohorts, and multivariate analyses of patient and hospital characteristics were conducted to evaluate the association of CEA volume with major complications and discharge disposition. RESULTS Between 2010 and 2018, 308,933 asymptomatic and 32,877 symptomatic patients underwent CEA. Analysis of CEA volume with outcomes as a continuous variable demonstrated that an increase in volume was associated with a lower risk until a volume of approximately 7 cases per year (20th percentile). A total of 6702 (2.2%) asymptomatic and 1040 (3.2%) symptomatic patients were treated at the bottom 20% of hospital procedure volume. Increased rates of complications were seen at low-volume centers among asymptomatic (3.66% vs 2.77%) and symptomatic (7.4% vs 6.87%) patients. Asymptomatic patients treated at low-volume centers had an increased likelihood of major complications (OR 1.26, 95% CI 1.07-1.49; p = 0.007) and nonroutine discharge (OR 1.36, 95% CI 1.24-1.50; p < 0.0001). Symptomatic patients treated at low-volume centers were also more likely to experience major complications (OR 1.47, 95% CI 1.07-2.02; p = 0.02) and nonroutine discharge (OR 1.26, 95% CI 1.07-1.47; p = 0.005). Mortality rates were similar between low- and high-volume hospitals among asymptomatic (0.36% and 0.32%, respectively) and symptomatic (1.06% and 1.49%, respectively) patients, while volume was not significantly associated with mortality among asymptomatic (OR 1.06, 95% CI 0.67-1.65; p = 0.81) and symptomatic (OR 0.81, 95% CI 0.43-1.54; p = 0.52) patients in multivariate analysis. CONCLUSIONS CEA patients, asymptomatic or symptomatic, are at a higher risk of major complications and nonroutine discharge at low-volume centers. Analysis of CEA as a continuous variable demonstrated a cutoff at 7 cases per year, and further study may identify factors associated with improved outcome at the lowest-volume centers.

中文翻译：

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低容量中心的颈动脉内膜切除术与主要并发症和非常规出院的可能性较高有关。

目的 颈动脉狭窄 (CAS) 与每年 2%-5% 的卒中风险相关，颈动脉内膜切除术 (CEA) 进行血运重建可以降低这一风险。虽然研究表明医院 CEA 量与死亡率和心肌梗死相关，但研究中 CEA 量的截止值相对随意，并且尚未对广泛的并发症和出院处置进行具体分析。在这项研究中，作者系统地着手确定 CEA 手术量与主要并发症和非常规出院显着相关的临界值。方法 在全国再入院数据库（2010-2018 年）中回顾性识别接受 CEA 的无症状和有症状 CAS 患者。使用局部估计的散点图平滑将 CEA 体积与结果的关联作为连续变量进行探索。确定的容量截止值用于生成二分容量队列，并对患者和医院特征进行多变量分析，以评估 CEA 容量与主要并发症和出院处置的关联。结果 2010 年至 2018 年间，308,933 名无症状患者和 32,877 名有症状患者接受了 CEA。对 CEA 数量（以结果作为连续变量）的分析表明，数量的增加与较低的风险相关，直到数量达到每年约 7 例（第 20 个百分位）。共有 6702 名（2.2%）无症状患者和 1040 名（3.2%）有症状患者接受了医院手术量最低 20% 的治疗。在低容量中心，无症状（3.66% vs 2.77%）和有症状（7.4% vs 6.87%）患者的并发症发生率有所增加。在低容量中心接受治疗的无症状患者出现严重并发症（OR 1.26，95% CI 1.07-1.49；p = 0.007）和非常规出院（OR 1.36，95% CI 1.24-1.50；p < 0.0001）的可能性增加。在低容量中心接受治疗的有症状患者也更有可能出现严重并发症（OR 1.47，95% CI 1.07-2.02；p = 0.02）和非常规出院（OR 1.26，95% CI 1.07-1.47；p = 0.005）。低容量医院和大容量医院之间无症状（分别为 0.36% 和 0.32%）和有症状（分别为 1.06% 和 1.49%）患者的死亡率相似，而容量与无症状患者的死亡率（OR 1.06，多变量分析中，95% CI 0.67-1.65；p = 0.81）和有症状（OR 0.81，95% CI 0.43-1.54；p = 0.52）患者。结论 无论是无症状还是有症状的 CEA 患者，在低容量中心出现严重并发症和非常规出院的风险都较高。CEA 作为连续变量的分析表明，每年的截止病例数为 7 例，进一步的研究可能会确定与最低治疗量中心的预后改善相关的因素。