瘤颈角度对腹主动脉瘤腔内修复术后支架位移的影响

Effects of Aneurysmal Neck Angle on Stent Displacement after Endovascular Repair of Abdominal Aortic Aneurysm

目的研究瘤颈角度对腹主动脉瘤腔内修复术后支架位移的影响。方法选用28名患者CT影像分别建立术前腹主动脉瘤(abdominal aortic aneurysm,AAA)模型、术后两次随访(postoperative follow-up)AAA模型和覆膜支架模型,并根据术前瘤颈角度将模型分为非严重成角组(n=14)和严重成角组(n=14)。测量每个模型的几何形态,分析手术前后AAA几何参数、术后支架位移变化。通过血流动力学模拟计算术后第1次随访模型的位移力。结果两组患者在瘤长度、最大直径、位移力、瘤颈长度变化和瘤体积变化有明显差异(P<0.05)。支架重心位移和近端位移无显著差异(P>0.05)。在内漏发生情况上,未严重成角组中有2例,严重成角组中有4例(P>0.05)。结论严重的瘤颈成角可导致支架位移力显著增加以及近端锚固区减小,进而增加支架位移发生的可能性。建议在临床方面医生应加强对严重瘤颈成角患者的术后随访,警惕远期内漏的发生。

Objective To study the effects of aneurysmal neck angle on stent displacement after endovascular repair of abdominal aortic aneurysm(AAA).Methods The CT images of 28 patients were selected to establish preoperative AAA model,postoperative AAA model and covered stent model respectively,and the models were divided into non-severe angulation group(n=14)and severe angulation group(n=14)according to the preoperative angle of tumor neck.The geometric shape of each model was measured,and the changes of AAA geometric parameters and postoperative stent displacements before and after surgery were analyzed.The displacement force of the model during the first follow-up was calculated by hemodynamic simulation.Results Significant differences were found in tumor length,maximum diameter,displacement force,tumor neck length and tumor volume between two groups of patients(P<0.05),while there was no significant difference between COG(the center of gravity)displacement and proximal displacement(P>0.05).For the incidence of internal leakage,there were 2 cases in non-severe angulation group and 4 cases in severe angulation group(P>0.05).Conclusions Severe neck angulation can lead to a significant increase in support displacement force and decrease in proximal anchorage zone,and thus increase the possibility of support displacement.It is suggested that doctors should strengthen postoperative follow-up for patients with severe neck angulation and be vigilant of the occurrence of long-term internal leakage in clinic.