Endovascular Grafting in Elastase-induced Experimental Aortic Aneurysms in Dogs: Feasibility and Preliminary Results

Abstract

A new model of aortic aneurysm was developed in 12 beagles to study the feasibility of endoluminal exclusion of aortic aneurysms. After preliminary experiments in four dogs, aneurysms were induced by infusing elastase into an isolated segment of the abdominal aorta in eight dogs. To create aortic endoprostheses, a Palmaz stent was sutured onto each end of an ultrathin Dacron tube. Endoprosthesis placement was performed under fluoroscopic and intravascular ultrasonographic (US) guidance. The endoprostheses were introduced via a femoral arteriotomy, through a 12-F sheath positioned in the aorta, and then were expanded on an angioplasty catheter. Intravascular US and aortography showed aneurysms in the elastase-perfused area in the eight animals and demonstrated the exclusion of the aneurysm by the endoprostheses in six cases. Intravascular US was more accurate than aortography in demonstrating two cases of endoprosthesis dysfunction. Aneurysm formation was proportional to the loss of elastic tissue observed at histologic examination of the elastase-infused area. Macro- and microscopic examinations confirmed thrombosis of the excluded part of the aneurysm and patency of all grafts. This model and intravascular US appear helpful in exploring the feasibility of endovascular treatment of abdominal aortic aneurysm.