Experimental study of a new open stent for vessel banding in a swine model: long-term results

Aims. A new stent was designed, conceived for being placed externally around blood vessels to perform vessel banding in a much simple and fast way. In fact it requires the dissection of a single segment of the aortic wall, as its mechanical features allow it to slide on the tunica adventitia. After previous tests (ex vivo and in vivo test), the new stent has been evaluated in vivo long-term study. Methods. In female pig of average weight of 60 kg, after placement of endoprosthesis in infrarenal abdominal aorta, immediately below renal arteries, aortic banding was performed with new stent at the level of each end of endoprosthesis, identified under fluoroscopic guidance. Pigs were followed up for six months, and acetylsalicylic acid was administrated: 100 mg once a day. After six months, histological evaluation of explanted abdominal aorta was performed. Results. New stent made the aortic banding simple and fast. Postoperative course was uneventful. Histological results were similar to previous 10-week survival tests and not damages of aortic wall were observed. Conclusion. Positive outcome of three last long-term survival tests, as of all those ex vitro and in vivo tests previously performed, makes conceivable further scientific investigation and trials.