Antegrade in situ fenestration of aortic stent graft: in-vivo experiments using a pig model.

Background: Short proximal neck of an abdominal aortic aneurysm is associated with risk of treatment failure during abdominal aortic repair. Important side branches, such as renal arteries, cannot be covered without serious consequences.

Purpose: To test the feasibility of preoperative fenestration of abdominal aortic stent grafts with a re-entry catheter and steerable sheath to preserve the patency of renal arteries in an animal model.

Material And Methods: Three domestic pigs were anesthetised and a stent graft placed in the abdominal aorta, covering the renal arteries. An attempt was made to fenestrate the renal arteries through the prosthesis using the Outback re-entry catheter supported by the Channel Steerable sheath. The hole that was created was dilated and stented. The specimens were visually analyzed after sacrifice.

Results: In one pig, the graft material was successfully traversed and a guide wire advanced in the renal arteries. Due to insufficient guide wire support and a poor balloon profile, dilatation of the fenestration failed. In another pig, the procedure was technically successful, but a long warm ischemia time for the left kidney caused infarction. In the third experiment, the procedure had to be discontinued due to a technical failure of the Outback device.

Conclusion: Fenestration of a stent graft with a re-entry device through a steerable sheath is technically feasible in vivo. However, without further refinement of the instrumentation, the technique cannot be recommended in elective cases of abdominal aortic repair, but if the renal arteries are covered accidentally during endovascular treatment, the technique may be a valuable salvage option if surgical revascularization is not considered as an option.