Anastomotic stenting in a porcine aortoiliac graft model

The purpose of the study was to evaluate the feasibility of anastomotic stent application in a porcine aortoiliac graft model. In a total of 10 pigs, a polytetrafluoroethylene aortobi-iliac graft was implanted through a midline abdominal incision. The lower edge of the iliac vessel was graft-inverted about 1 mm to produce irregularities at the downstream anastomosis. After transverse graft incision, six stainless-steel stents, six poly-L-lactic acid (PLLA) stents and four PLLA stents with 10% polycaprolactone (PCL) were implanted at the iliac anastomotic site using a 6 mm balloon dilatation catheter. Four anastomotic sites were left untreated. After two weeks, the patency of graft limbs was evaluated by contrast-enhanced computed tomography (CT). Both metal and polymeric stent designs provided adequate flexibility to manoeuvre across the anastomotic site for expansion in the chosen position. After deployment, the stent-arterial wall contact was complete on a macroscopic view. On CT scan, all metal and PLLA-stented graft limbs were free of stenosis, whereas all PLLA/PCL stents were occluded. The non-stented graft limbs showed a stenosis of 50-70%. In summary, this model is feasible to assess preclinically the deployment and patency rate of an anastomotic stent and to test future stent developments.