Percutaneous placed bioprosthetic venous vaive in the treatment of deep vein reflux: Animal experiments and clinical trials

Objective: To evaluate the efficiency of percutaneously placed bioprosthetic bicuspid venous valve (BVV) in the treatment of deep vein insufficiency in animal experiments and clinical trials. Methods: BVV was made of two pieces of lyophilized porcine small intestinal submucosa(SIS) which were attached to a stent frame. Three kinds of BVVs (BVV1, BVV2, BVV3) was developed using different kinds of stent frames and different methods of attachment. BVV1, BVV2 and BVV3 were percutaneously placed into ovine's jugular veins acrossed the nature valves. Ascending and descending angiography were performed before and after BVVs placement. The patency of veins and the function of valves was evaluated during 5 weeks to 6 months follow-up. In clinical trial, BVV1 and BVV3 were percutaneously placed into 3 and 15 patients with chronic venous insufficiency (CVI) respectively. The patency of veins and the function of valves was also evaluated during 1 to 3 years' follow-up. Results: In animal experiment, BVV1, BVV2, and BVV3 were placed to 24, 26 and 12 ovine's jugular veins respectively. During 5 weeks to 6 months follow-up period, 22 (88.0%), 24(92.3%) and 12 of the BVVs exhibited good function. Endothelium of both surfaces of SIS leaflets was complete in approximately 3 months. SIS was gradually reabsorbed and replaced by the host's own cells. Three BVV1 were placed into 3 patients with CVI. At the third year's follow-up, symptoms relieved in 2 cases and no change of clinical symptoms was found in 1 patient. BVV3 were percutaneously placed into 15 patients with advanced symptomatic CVI. At one month and 3 months' follow-up after BVV3 placement, all BVV3 functioned well. However, BVV3 were flexible and functioned well in only 4 cases at 1 year's follow-up. Intravascular ultrasound revealed thickened rigid cusps with valve leakage of different levels and no symptom resolved in 11 cases. Conclusions: Percutaneous implantation of bioprosthetic BVV is a promising method in the treatment of CVI. Intimal hyperplasia is an important factor which damages long-term durability and flexibility.