BACKGROUND: To evaluate and compare the tissue response, in swine, to a biosynthetic stent-graft when implanted in both thoracic aorta and inferior vena cava. METHOD: It was used a self-expanding stainless stent, covered by segment of bovine jugular veins, processed by the method L-hydro, and delivered by Taheri-Leonhardt system (Florida, USA) . The implants were done in the descending thoracic aorta, and in the infra-renal vena cava of 10 swines. Sixty days after, the endoprosthesis were removed and analyzed under macro and microscopic view. The following parameters were analyzed: patency, incorporation to the vessel wall, type of inflammatory reaction, tissue response concerning the layer of the vessel as for the contact with the ring steel. RESULTS: All implanted stent-grafts were patent, and incorporated to the vessel wall. Six presented fibrous bars, and four presented perivascular fibrosis at the venous section. At the arterial section, only one prosthesis developed a very small stenosis, without perivascular fibrosis. We observed chronic inflammatory reaction with a foreign body granulomatous response in 100% of the samples, the medium layer was the more prevalent at the vein section, while the intima layer was more constant at the artery, venous incorporation was stronger than artery incorporation, and tissue response was enhanced in the inner contact between the vessel wall and the ring steel. CONCLUSION: The prosthesis in study presented low thrombogenicity in both systems. It was also present, larger tissue response and low biocompatibility at the venous system, and better biocompatibility at the arterial system.
Blood vessel prosthesis implantation; Stents; Jugular veins; Vena cava, inferior; Aorta thoracic; Vascular patency; Material testing; Cattle; Swine; Comparative Study
