BACKGROUND AND OBJECTIVES Benchmarks represent the best possible outcome and help to improve outcomes for surgical procedures. However, global thresholds mirroring an optimal and reachable outcome for microsurgical clipping of unruptured intracranial aneurysms (UIA) are not available. This study aimed to define standardized outcome benchmarks in patients who underwent clipping of UIA. METHODS A total of 2245 microsurgically treated UIA from 15 centers were analyzed. Patients were categorized into low- ("benchmark") and high-risk ("nonbenchmark") patients based on known factors affecting outcome. The benchmark was defined as the 75th percentile of all centers' median scores for a given outcome. Benchmark outcomes included intraoperative (eg, duration of surgery, blood transfusion), postoperative (eg, reoperation, neurological status), and aneurysm-related factors (eg, aneurysm occlusion). Benchmark cutoffs for aneurysms of the anterior communicating/anterior cerebral artery, middle cerebral artery, and posterior communicating artery were determined separately. RESULTS Of the 2245 cases, 852 (37.9%) patients formed the benchmark cohort. Most operations were performed for middle cerebral artery aneurysms (53.6%), followed by anterior communicating and anterior cerebral artery aneurysms (25.2%). Based on the results of the benchmark cohort, the following benchmark cutoffs were established: favorable neurological outcome (modified Rankin scale ≤2) ≥95.9%, postoperative complication rate ≤20.7%, length of postoperative stay ≤7.7 days, asymptomatic stroke ≤3.6%, surgical site infection ≤2.7%, cerebral vasospasm ≤2.5%, new motor deficit ≤5.9%, aneurysm closure rate ≥97.1%, and at 1-year follow-up: aneurysm closure rate ≥98.0%. At 24 months, benchmark patients had a better score on the modified Rankin scale than nonbenchmark patients. CONCLUSION This study presents internationally applicable benchmarks for clinically relevant outcomes after microsurgical clipping of UIA. These benchmark cutoffs can serve as reference values for other centers, patient registries, and for comparing the benefit of other interventions or novel surgical techniques.

中文翻译：

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未破裂颅内动脉瘤显微外科夹闭的全球结果：2245 例病例的基准分析。

背景和目标 基准代表了可能的最佳结果，有助于改善外科手术的结果。然而，反映未破裂颅内动脉瘤（UIA）显微手术夹闭的最佳且可达到的结果的全局阈值尚不可用。本研究旨在为接受 UIA 夹闭术的患者定义标准化结果基准。方法 对来自 15 个中心的 2245 例经显微手术治疗的 UIA 进行了分析。根据影响结果的已知因素，将患者分为低风险（“基准”）和高风险（“非基准”）患者。该基准被定义为给定结果的所有中心中位数分数的 75%。基准结果包括术中（例如手术持续时间、输血）、术后（例如再次手术、神经状态）和动脉瘤相关因素（例如动脉瘤闭塞）。分别确定前交通/大脑前动脉、大脑中动脉和后交通动脉动脉瘤的基准截止值。结果 在 2245 例病例中，852 例（37.9%）患者构成基准队列。大多数手术针对大脑中动脉动脉瘤（53.6%），其次是前交通动脉瘤和大脑前动脉瘤（25.2%）。根据基准队列的结果，确定了以下基准临界点：良好的神经学结果（改良Rankin量表≤2）≥95.9%，术后并发症率≤20.7%，术后住院时间≤7.7天，无症状卒中≤3.6% ，手术部位感染≤2.7%，脑血管痉挛≤2.5%，新发运动障碍≤5.9%，动脉瘤闭合率≥97.1%，1年随访：动脉瘤闭合率≥98.0%。24 个月时，基准患者在改良 Rankin 量表上的得分高于非基准患者。结论 本研究提出了 UIA 显微手术夹闭后临床相关结果的国际适用基准。这些基准截止值可以作为其他中心、患者登记处的参考值，并用于比较其他干预措施或新颖手术技术的益处。