From clinical trials to clinical practice: 612 cases treated with the Powerlink stent-graft for endovascular repair of AAA.
OBJECTIVE
Most endovascular stent-grafts in endovascular aortic aneurysm repair (EVAR) are designed to deploy from the renal artery level down to the iliac level. The Powerlink device (Endologix Inc, Irvine, Calif) can be deployed from the iliac level up to the renal artery level. The aim of this study was to summarize our clinical experience of EVAR using the Powerlink device.


METHODS
The fully-supported unibody bifurcated Powerlink stent graft was deployed sitting onto the abdominal aortic bifurcation (termed anatomical fixation), a proximal long cuff with or without Palmaz stent may follow the above procedure if necessary. We applied this strategy in most of our cohort. The data of 612 eligible abdominal aortic aneurysm (AAA) patients underwent endovascular repair between 1999 and 2008 using the Powerlink System at our institution were analyzed. Meanwhile, the US and French clinical trials results were enrolled for comparison.


RESULTS
Among the 612 patient cohort, 99 cases (16%) completed between 1999 and 2004 had the endograft deployed from the renal artery downward. The remaining 513 cases (84%) completed afterwards had the bifurcated stent graft deployed onto the native bifurcation. Among the 513 cases, 146 cases (28%) were deemed as challenging anatomy with short or angulated neck. Technical success was achieved in 98.5% of patients (603/612). Intraoperative conversion occurred in 9 patients, 8 of which were due to delivery access failure and 1 due to rupture. Intraoperative complications included iliac or femoral patching in 5.1% of patients and iliac-femoral graft interposition in 0.3% of patients. Perioperatively, 3 deaths occurred, 2 limb occlusions were encountered. After 30 days and through current follow-up (mean: 5.2 years; maximum: 9.5 years), 1 rupture and 7 migrations occurred, all of which were in patients in whom the device was fixed at the level of the renal arteries. The rates of late conversion in the renal fixation and anatomical fixation groups were 4.0% and 1.9%, respectively. Likewise, the cumulative rates of type I proximal endoleak in the renal fixation and anatomical fixation groups were 5.0% and 1.2%, and respectively. Cumulative rates of all-cause mortality, limb occlusion, and type II endoleak were similar among implant groups. Remarkably, no stent fracture, graft disruption, or type III or type IV endoleak has been observed in any patient to date. Through current follow-up, 96% of patients are free from aneurysm sac diameter increase.


CONCLUSIONS
Results from multiple clinical trials and our clinical practice proved that the Powerlink device is simple to implant, effective to endovascular repair, durable to mid- and long-term follow up. The implanting technique of combination of an anatomically-fixed unibody Powerlink device and proximal extension sealing leads to a superior outcome, even in challenging anatomy cases deemed unsuitable for endovascular repair. With this intuitive approach, migration and the associated sequelae were virtually eliminated.
Qu
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Department of Vascular Surgery, Changhai Hospital, Second Military Medical University, Shanghai, China.
Raithel
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