Egorova Natalia, Giacovelli Jeannine K, Gelijns Annetine, Greco Giampaolo, Moskowitz Alan, McKinsey James, Kent K Craig
Department of Health Policy, Mount Sinai School of Medicine, New York, NY 10029, USA.
J Vasc Surg. 2009 Dec;50(6):1271-9.e1. doi: 10.1016/j.jvs.2009.06.061. Epub 2009 Sep 26.
Endovascular aneurysm repair (EVAR) is commonly used as a minimally invasive technique for repairing infrarenal aortic aneurysms. There have been recent concerns that a subset of high-risk patients experience unfavorable outcomes with this intervention. To determine whether such a high-risk cohort exists and to identify the characteristics of these patients, we analyzed the outcomes of Medicare patients treated with EVAR from 2000-2006.
We identified 66,943 patients who underwent EVAR from Inpatient Medicare database. The overall 30-day mortality was 1.6%. A risk model for perioperative mortality was developed by randomly selecting 44,630 patients; the other one third of the dataset was used to validate the model. The model was deemed reliable (Hosmer-Lemeshow statistics were P = .25 for the development, P = .24 for the validation model) and accurate (c = 0.735 and c = 0.731 for the development and the validation model, respectively).
In our scoring system, where scores ranged between 1 and 7, the following were identified as significant baseline factors that predict mortality: renal failure with dialysis (score = 7); renal failure without dialysis (score = 3); clinically significant lower extremity ischemia (score = 5); patient age >or=85 years (score = 3), 75-84 years (score = 2), 70-74 years (score = 1); heart failure (score = 3); chronic liver disease (score = 3); female gender (score = 2); neurological disorders (score = 2); chronic pulmonary disease (score = 2); surgeon experience in EVAR <3 procedures (score = 1); and hospital annual volume in EVAR <7 procedures (score = 1). The majority of Medicare patients who were treated (96.6%, n = 64,651) had a score of 9 or less, which correlated with a mortality <5%. Only 3.4% of patients had a mortality >or=5% and 0.8% of patients (n = 509) had a score of 13 or higher, which correlated with a mortality >10%.
We conclude that there is a high-risk cohort of patients that should not be treated with EVAR because of prohibitively high mortality; however, this cohort is small. Our scoring system, which is based on patient and institutional factors, provides criteria that can be easily used by clinicians to quantify perioperative risk for EVAR candidates.
血管内动脉瘤修复术（EVAR）是治疗肾下腹主动脉瘤常用的微创技术。最近有人担心一部分高风险患者接受这种干预后会出现不良后果。为了确定是否存在这样的高风险人群并识别这些患者的特征，我们分析了2000年至2006年接受EVAR治疗的医疗保险患者的治疗结果。
我们从住院医疗保险数据库中识别出66943例接受EVAR治疗的患者。总体30天死亡率为1.6%。通过随机选择44630例患者建立围手术期死亡率风险模型；数据集的另外三分之一用于验证该模型。该模型被认为是可靠的（开发模型的Hosmer-Lemeshow统计量P = 0.25，验证模型的P = 0.24）且准确的（开发模型和验证模型的c值分别为0.735和0.731）。
在我们的评分系统中，评分范围为1至7分，以下因素被确定为预测死亡率的重要基线因素：接受透析的肾衰竭（评分 = 7）；未接受透析的肾衰竭（评分 = 3）；具有临床意义的下肢缺血（评分 = 5）；患者年龄≥85岁（评分 = 3），75 - 84岁（评分 = 2），70 - 74岁（评分 = 1）；心力衰竭（评分 = 3）；慢性肝病（评分 = 3）；女性（评分 = 2）；神经系统疾病（评分 = 2）；慢性肺病（评分 = 2）；医生进行EVAR手术经验<3例（评分 = 1）；医院每年进行EVAR手术量<7例（评分 = 1）。接受治疗的大多数医疗保险患者（96.6%，n = 64651）评分为9分或更低，这与死亡率<5%相关。只有3.4%的患者死亡率≥5%，0.8%的患者（n = 509）评分为13分或更高，这与死亡率>10%相关。
我们得出结论，存在一组高风险患者，由于死亡率过高不应接受EVAR治疗；然而，这组人群规模较小。我们基于患者和机构因素的评分系统提供了临床医生可轻松用于量化EVAR候选患者围手术期风险的标准。
