Swaelens Charles, Poole Robert J, Torella Francesco, McWilliams Richard G, England Andrew, Fisher Robert K
Liverpool Vascular and Endovascular Service, Royal Liverpool University Hospital, Liverpool, UK
School of Engineering, University of Liverpool, UK.
J Endovasc Ther. 2016 Apr;23(2):297-301. doi: 10.1177/1526602816631106. Epub 2016 Feb 11.
To examine the changes in distraction force following relining of a conventional abdominal aortic stent-graft with a type IIIb endoleak using the Nellix endovascular sealing device compared to a unilateral stent-graft.
Relining is often used to repair type IIIb endoleaks, but the consequences to graft stability are unknown. A mathematical model was constructed based on pressure and volume flow through the stent-grafts, incorporating recognized distraction force equations. Steady flow was presumed at peak systolic pressures to calculate the maximum distraction force, with gravity ignored. Distraction forces for 28- to 36-mm-diameter stent-graft bodies with 16-mm limbs were calculated and compared to forces following relining with single and double Nellix devices or the Renu unilateral device.
Distraction forces for the 28-, 32-, and 36-mm stent-grafts prior to relining were 5.99, 10.21, and 14.99 N, respectively. Similar forces were reported after relining with bilateral Nellix devices (5.86, 10.08, and 14.86 N, respectively). However, use of a unilateral Nellix increased the distraction forces to 9.92, 14.14, and 18.92 N, respectively. These were comparable to the increase observed after relining with a Renu unilateral stent-graft (9.87, 14.09, and 18.86 N, respectively). The proportional increase in distraction force for a unilateral relining ranged from 26% to 66%, with the greatest increase noted in the smaller diameter main bodies.
Relining a stent-graft with a type IIIb endoleak using bilateral Nellix devices does not increase the distraction force. However, a unilateral Nellix device or the Renu system could theoretically increase the distraction force by up to 66%, potentially risking migration and type Ia endoleak. In clinical practice, these results suggest that a relining with bilateral Nellix may have benefits over the Renu unilateral stent-graft.
比较使用Nellix血管内封堵装置对伴有Ⅲb型内漏的传统腹主动脉覆膜支架进行内衬修复后与单侧覆膜支架相比，牵张力量的变化。
内衬修复常用于修复Ⅲb型内漏，但对移植物稳定性的影响尚不清楚。基于通过覆膜支架的压力和体积流量构建了一个数学模型，并纳入了公认的牵张力量方程。假定在收缩压峰值时为稳定流，以计算最大牵张力量，忽略重力因素。计算了直径为28至36毫米、肢体为16毫米的覆膜支架主体的牵张力量，并与使用单个和双个Nellix装置或Renu单侧装置进行内衬修复后的力量进行了比较。
内衬修复前，28毫米、32毫米和36毫米覆膜支架的牵张力量分别为5.99牛、10.21牛和14.99牛。使用双侧Nellix装置进行内衬修复后报告了类似的力量（分别为5.86牛、10.08牛和14.86牛）。然而，使用单侧Nellix会使牵张力量分别增加到9.92牛、14.14牛和18.92牛。这些与使用Renu单侧覆膜支架进行内衬修复后观察到的增加情况相当（分别为9.87牛、14.09牛和18.86牛）。单侧内衬修复时牵张力量的比例增加范围为26%至66%，在较小直径的主体中增加最为明显。
使用双侧Nellix装置对伴有Ⅲb型内漏的覆膜支架进行内衬修复不会增加牵张力量。然而，单侧Nellix装置或Renu系统理论上可使牵张力量增加高达66%，可能存在移位和Ia型内漏的风险。在临床实践中，这些结果表明，与Renu单侧覆膜支架相比，双侧Nellix内衬修复可能具有优势。
