Beck Adam W, Goodney Philip P, Nolan Brian W, Likosky Donald S, Eldrup-Jorgensen Jens, Cronenwett Jack L
Dartmouth-Hitchcock Medical Center Department of Surgery, Section of Vascular Surgery, Lebanon, NH, USA.
J Vasc Surg. 2009 Apr;49(4):838-43; discussion 843-4. doi: 10.1016/j.jvs.2008.10.067.
Benefit of prophylactic abdominal aortic aneurysm (AAA) repair requires sufficient survival to overcome operative risk. Since death within 1 year of elective open or endovascular (EVAR) infrarenal AAA repair likely indicates ineffective treatment, we developed a prediction model for 1-year mortality to aid clinical decision-making.
We used a prospective registry of 1387 consecutive patients who had undergone elective AAA repair from 2003 to 2007 by 50 surgeons from 11 hospitals in Northern New England. Cox proportional hazards were used to analyze potential risk factors for 1-year mortality, including medical comorbidities, aortic clamp site, preoperative risk factor modification (eg, beta-blockade), and aneurysm diameter.
Thirty-day and 1-year mortality after open repair (n = 748) was 2.3% and 5.8%, and after EVAR (n = 639) was 0.5% and 5.7%, respectively. Factors associated with death within 1-year after open repair were: age >/= 70 (P = .007; hazard ratio [HR] 2.9, 95% confidence interval [CI] 1.3-6.3), history of chronic obstructive pulmonary disease (COPD) (P < .0001; HR 3.6, 95% CI 1.9-7.0), chronic renal insufficiency (creatinine >/= 1.8) (P = .008; HR 2.8, 95% CI 1.3-6.2) and suprarenal aortic clamp site (P < .0001; HR 3.8, 95% CI 1.9-7.5). Depending on the number of risk factors present, predicted 1-year mortality after open repair varied from 1% in patients with no risk factors to 67% in patients with four risk factors. Our model demonstrated excellent correlation between observed and expected deaths (r = 0.97). For EVAR, identified risk factors for death within 1 year included a history of congestive heart failure (CHF) (P = .002; HR 3.2, 95% CI 1.6-6.5), and aneurysm diameter >/=6.5 cm (P = .04 95% CI 1.0-4.8). Depending on the number of risk factors present, predicted mortality ranged from 3.6% to 23%. A model using CHF and aneurysm diameter correlated well with actual mortality rates, with an observed to expected ratio of 0.96.
Predictors of 1-year mortality can identify patients less likely to benefit from elective AAA repair. These factors differ for open repair vs EVAR and should be considered in individual patient decision-making. Our EVAR model had less impact on 1-year survival, even if CHF and large AAA diameter were present. However, a combination of age, COPD, renal insufficiency, and need for suprarenal clamping have significant impact on 1-year mortality after open AAA repair. Consideration of these variables should assist decision-making for elective AAA repair, especially in borderline cases.
预防性腹主动脉瘤（AAA）修复的益处需要足够的生存期以克服手术风险。由于择期开放性或血管腔内修复术（EVAR）治疗肾下腹主动脉瘤后1年内死亡可能表明治疗无效，我们开发了一种1年死亡率预测模型以辅助临床决策。
我们使用了一个前瞻性登记数据库，纳入了2003年至2007年期间新英格兰北部11家医院的50名外科医生连续收治的1387例行择期AAA修复术的患者。采用Cox比例风险模型分析1年死亡率的潜在危险因素，包括内科合并症、主动脉阻断部位、术前危险因素调整（如β受体阻滞剂使用情况）以及动脉瘤直径。
开放性修复术（n = 748）后30天和1年死亡率分别为2.3%和5.8%，EVAR术后（n = 639）分别为0.5%和5.7%。开放性修复术后1年内死亡相关因素包括：年龄≥70岁（P = 0.007；风险比[HR] 2.9，95%置信区间[CI] 1.3 - 6.3）、慢性阻塞性肺疾病（COPD）病史（P < 0.0001；HR 3.6，95% CI 1.9 - 7.0）、慢性肾功能不全（肌酐≥1.8）（P = 0.008；HR 2.8，95% CI 1.3 - 6.2）以及肾上主动脉阻断部位（P < 0.0001；HR 3.8，95% CI 1.9 - 7.5）。根据存在的危险因素数量，开放性修复术后预测的1年死亡率从无危险因素患者的1%到有4个危险因素患者的67%不等。我们的模型显示观察到的死亡与预期死亡之间具有良好的相关性（r = 0.97）。对于EVAR，确定的1年内死亡危险因素包括充血性心力衰竭（CHF）病史（P = 0.002；HR 3.2，95% CI 1.6 - 6.5）以及动脉瘤直径≥6.5 cm（P = 0.04，95% CI 1.0 - 4.8）。根据存在的危险因素数量，预测死亡率范围为3.6%至23%。使用CHF和动脉瘤直径的模型与实际死亡率相关性良好，观察值与预期值之比为0.96。
1年死亡率预测指标可识别出不太可能从择期AAA修复术中获益的患者。这些因素在开放性修复术与EVAR之间有所不同，在个体患者决策时应予以考虑。即使存在CHF和较大的AAA直径，我们的EVAR模型对1年生存率的影响较小。然而，年龄、COPD、肾功能不全以及肾上阻断需求的综合因素对开放性AAA修复术后1年死亡率有显著影响。考虑这些变量应有助于择期AAA修复术的决策，尤其是在临界病例中。
