Division of Vascular and Endovascular Surgery, Department of Surgery, Johns Hopkins Bayview Medical Center, Baltimore, Md.
Division of Vascular and Endovascular Surgery, Department of Surgery, Johns Hopkins Bayview Medical Center, Baltimore, Md.
J Vasc Surg. 2018 Mar;67(3):760-769. doi: 10.1016/j.jvs.2017.07.114. Epub 2017 Sep 21.
Many studies have found that preoperative aneurysm anatomy can determine the postoperative complication rates for endovascular aneurysm repair (EVAR). With continual improvement in endograft technology, patients with challenging anatomy are increasingly able to undergo successful treatment with EVAR. This study aimed to quantify the influence of proximal neck anatomy on contemporary outcomes in a cohort of abdominal aortic aneurysm patients with highly angulated aneurysm necks.
The study included 205 patients originally enrolled in the Prospective Aneurysm Trial: High Angle Aorfix Bifurcated Stent Graft (PYTHAGORAS) trial, the largest study to date to enroll patients with aortic aneurysm neck angles >60 degrees. Anatomic parameters included measurements of the proximal aneurysm neck as well as seal zones modeled in preoperative computed tomography scans. Follow-up up to 5 years postoperatively was available, for which stent-related complications (defined as sac expansion, stent migration, and type Ia endoleak) were assessed. Predictive anatomic parameters were assessed by Cox regression models, and a final multivariate model was created to predict complications. The cohort was also stratified by neck diameter for further comparison of complication rates.
Of 205 patients enrolled in the trial, 67 stent-related complications occurred in 36 patients (17.6%) at 5 years after EVAR. Median follow-up was 48 months. Demographic and medical comorbidities did not predict risk of complications, nor did proximal neck length or neck angle. Independent predictors of post-EVAR complications included increasing proximal neck diameter (hazard ratio, 1.14; 95% confidence interval, 1.03-1.27; P < .05) and decreasing seal zone inner curve length (hazard ratio, 1.03; 95% confidence interval, 1.01-1.06; P < .05), which yielded a fair discriminatory utility (concordance, 0.67). Stratification by median neck diameter of 22.5 mm yielded two groups; patients with larger aortic necks (mean diameter, 24.8 ± 2.1 mm) had a 21.8% complication rate vs 12.6% in patients with smaller necks (mean diameter, 20.1 ± 1.6 mm; P < .05).
Proximal aortic neck diameter and the seal zone inner curve length were found to be the best predictors of complications related to Aorfix (Lombard Medical, Oxfordshire, United Kingdom) in this population with highly angulated neck anatomy. Modeled seal zones are better able than traditional measurements to capture the limitations of a short, angled neck. These findings may inform preoperative risk stratification and planning in patients with hostile aortic neck anatomy undergoing EVAR.
许多研究表明,术前动脉瘤解剖结构可决定血管内动脉瘤修复术(EVAR)的术后并发症发生率。随着腔内移植物技术的不断改进,越来越多具有挑战性解剖结构的患者能够成功接受 EVAR 治疗。本研究旨在定量评估腹主动脉瘤患者具有高度成角动脉瘤颈部的近端颈部解剖结构对当代结局的影响。
该研究纳入了 205 名最初参加前瞻性动脉瘤试验:高角度 Aorfix 分叉支架移植物(PYTHAGORAS)试验的患者,这是迄今为止纳入主动脉瘤颈部角度>60 度患者的最大研究。解剖学参数包括近端动脉瘤颈部的测量以及术前计算机断层扫描模型中的密封区。术后随访长达 5 年,评估支架相关并发症(定义为囊扩张、支架移位和 I 型内漏)。通过 Cox 回归模型评估预测解剖参数,并创建最终的多变量模型来预测并发症。该队列还按颈部直径进行分层,以进一步比较并发症发生率。
在试验中纳入的 205 名患者中,36 名患者(17.6%)在 EVAR 后 5 年内发生了 67 例支架相关并发症。中位随访时间为 48 个月。人口统计学和合并症并不能预测并发症风险,近端颈部长度或颈部角度也不能预测。支架后并发症的独立预测因素包括近端颈部直径增大(风险比,1.14;95%置信区间,1.03-1.27;P<.05)和密封区内曲线长度减小(风险比,1.03;95%置信区间,1.01-1.06;P<.05),这产生了良好的判别能力(一致性,0.67)。以 22.5mm 的中位颈部直径分层,得到两组;颈部较大的患者(平均直径 24.8±2.1mm)的并发症发生率为 21.8%,而颈部较小的患者(平均直径 20.1±1.6mm)的并发症发生率为 12.6%(P<.05)。
在具有高度成角颈部解剖结构的人群中,发现近端主动脉颈部直径和密封区内曲线长度是与 Aorfix(英国牛津郡隆巴德医疗公司)相关并发症的最佳预测因素。模型化的密封区比传统测量更能捕捉到短而成角的颈部的局限性。这些发现可能为具有敌对主动脉颈部解剖结构的患者进行 EVAR 提供术前风险分层和规划依据。