The use of a low-profile stent graft with a polymer ring sealing technology combined with bare renal stent (vent technique) in patients with juxtarenal aneurysm not eligible for open surgery and fenestrated endograft

Abstract

ObjectiveIn cases of juxtarenal abdominal aortic aneurysm (jAAA), endovascular aneurysm repair (EVAR) involves the use of custom-made fenestrated stent grafts, which usually need large-diameter access vessels, superior costs, and a certain time between graft planning and delivery. We report our preliminary experience using the bare renal stent technique (called vent) in combination with the ultralow-profile stent graft Ovation (Endologix, Irvine, Calif) to seal jAAAs in patients evaluated to be unfit for open surgery and not suitable for fenestrated endograft. MethodsA single-center retrospective review of jAAAs treated by Ovation vent technique from January 2015 to December 2018 was conduced. The vent procedure consisted of a modified, off-label deployment of the sealing ring of the ultralow-profile Ovation stent graft close to renal orifices in combination with short bare-metal stents. The exclusion criterion was a diameter >31 mm at the level of the lowest renal artery. Early technical and clinical results, estimated midterm survival, renal artery patency, freedom from type IA endoleak, freedom from reintervention, and freedom from neck enlargement (>2 mm) were reported. ResultsOverall, 38 patients had jAAA and were considered unfit for open repair and not eligible for fenestrated EVAR. The proximal neck was <5 mm in all cases (mean, 3.3 ± 1.2 mm). Vent renal stents were implanted bilaterally in 16 patients. Primary technical success was 94.7% (36/38), with satisfactory cannulation of all renal arteries and sealing of the aneurysm in all but two cases because of type IA endoleaks that were treated immediately with success. Primary clinical success at 1 month was 100%. During a median follow-up period of 22.4 ± 3.6 months (range, 1-46 months), no abdominal aortic aneurysm-related deaths occurred, and no patient was lost to follow-up. The survival curve at 1 year and 2 years was, respectively, 96.4% and 91.6% (standard error, 0.57%). There were no cases of neck dilation or endograft migration. Freedom from reintervention at 12 months and 24 months was 100% and 89.5%, respectively (standard error, 0.7%); freedom from type IA endoleak was 100% and patency of the renal artery was 100% at 2 years. ConclusionsThe described technique includes the use of a low-profile stent graft with a polymer ring sealing technology combined with bare renal stents that are not competing for the same room. This early experience shows that the vent technique is safe and feasible and increases the range of treatment of those patients with jAAA who are unfit for open repair and for fenestrated EVAR because of several anatomic constraints.