title: Experimental replacement of the inferior vena cava: factors affecting patency.
abstract: To evaluate factors influencing graft patency in the venous system, we replaced the inferior vena cava (IVC) in 50 dogs. Expanded polytetrafluoroethylene ( ePTFE ) grafts with external support were implanted into 32 animals while autogenous, spiral jugular vein grafts were used to replace the IVC in 18 dogs. 111In-labeled autologous platelets and 125I-labeled canine fibrinogen were utilized to evaluate early thrombus formation. A distal arteriovenous (AV) fistula significantly (P less than 0.05) decreased both platelet and fibrin deposition on ePTFE grafts 3 hours following implantation. Patency rate of 12 ePTFE grafts with a temporary AV fistula was higher (75%) than that of grafts without fistula (25%) at 3 months (P less than 0.05). Spiral vein grafts with fistula showed 91% patency at 3 months; without fistula patency was only 67%. Venograms confirmed patency in five grafts followed up to 6 months. Antiplatelet therapy resulted in 100% patency in ePTFE and vein grafts during its administration, and vein grafts maintained patency after discontinuation of antiplatelet treatment. Spiral vein grafts showed no decrease in cross-sectional area at 3 months, while the cross-sectional area of ePTFE grafts decreased significantly (59%). Distal AV fistula decreases platelet and fibrin deposition leading to early occlusion in ePTFE grafts and produces excellent patency in spiral vein grafts. Antiplatelet therapy appears to further improve patency.
mesh_terms: D000818:Animals; D001166:Arteriovenous Shunt, Surgical; D001807:Blood Vessel Prosthesis; D004285:Dogs; D005260:Female; D006493:Heparin / Q000008:administration & dosage; D007052:Ibuprofen / Q000008:administration & dosage; D007601:Jugular Veins / Q000637:transplantation*; D011138:Polytetrafluoroethylene; D011183:Postoperative Complications; D012039:Regional Blood Flow; D013927:Thrombosis / Q000209:etiology; D014682:Vena Cava, Inferior / Q000601:surgery*
chemical_list: D011138:Polytetrafluoroethylene; D006493:Heparin; D007052:Ibuprofen