Modified polytetrafluoroethylene: Indium 111-labeled platelet deposition on carbon-lined and high-porosity polytetrafluoroethylene grafts

Abstract

Platelet accumulation on carbon-lined (CL) and high-porosity (Ill') polytetrafluoroethylene (PTFE) grafts was investigated in vivo. In experiment l, 20 CL grafts and 20 control PTFE grafts, each 5 cm in length and 4 mm in diameter, were interposed into both carotid and femoral arteries of 10 dogs. In experiment 2, 12 lip grafts (90 Itm mean internodal distance) and 12 control PTFE grafts were implanted in six dogs. Indium Ill-labeled platelets were injected intravenously and the grafts were retrieved 48 hours later. Radioactivity of the grafts and a control segment of the carotid artery was counted. A graft platelet accumulation index (GPAI) was calculated as the ratio of emission from the graft compared to that from the control segment. The GPAI of the CL graft was significantly less than the GPAI of the control graft in both the carotid (control 29.7 ± 5.46, CL 22.3 ± 6.55; n = 9 [p < 0.05]) and the femoral arteries (control 30.7 ± 9.65, CL 22.0 ± 6.59; n = 9 [p < 0.05]). There was no significant difference in GPAI between the control and HP grafts in the carotid arteries (control 30.6 ± 11.8, HP 31.5 ± 9.71; n = 6) and in the femoral arteries (control 31.5 ± 7.88, HP 34.0 ± 4.97; n = 6). Carbon linin~ decreases platelet accumulation on PTFE grafts in the early postoperative period, and HP grafts do not exhibit increased platelet uptake. (J V/ksc SURG 1992;16:643-50.)

Long-term complication and patency rates of Vectra and IMPRA Carboflo Vascular Access Grafts with aggressive monitoring, surveillance and endovascular management

“…Carbon particles are permanently integrated into the ePTFE material and are uniformly distributed through 25% of the wall. Animal studies have demonstrated that compared with standard PTFE grafts, carbon lining significantly decreases platelet accumulation, 8 and deposition by a factor of six. 9…”

“…1,3 Rheolytic thrombectomy using the AngioJet device (Possis Medical Inc, Minneapolis, MN, USA) and a specially designed catheter (AVX or DVX) was performed for graft occlusion followed by angioplasty (±stenting) of the anatomical lesion (arterial anastomosis, graft, venous outflow, draining or central veins) responsible for the thrombotic event. 8,9 Isolated angioplasty (±stenting) of the anatomical lesion (arterial anastomotis, intragraft, venous outflow, draining or central veins) was performed for failing grafts.…”

An immediate access dialysis graft designed to prevent needle-related complications: Results from the initial pre-clinical studies

“…4–10 To a lesser extent, companies have attempted to reduce graft clotting by altering the luminal surface of the graft and to improve upon post-dialysis bleeding, and they have made attempts to alter the graft structure and materials. 11–16…”

Graft thrombosis in small diameter vascular prosthesis: A laboratory model

“…Carbon coating has been shown to decrease the thrombogenicity of Dacron grafts in vitro and in vivo [7]. Experimental data reported excellent results with carbon-lined PTFE grafts in a dog model using both carotid and femoral arteries [7,8] in a limited number of animals [t0]. The in vivo technique for detection of deposition of platelets and the formation of thrombus on PTFE grafts was developed and quantitated with 11~Indium-labeled autologus platelets according to the method described by Dewanjee et al, and modified in our laboratory by location of platelet deposition from [9][10][11] the scintiphotos using gamma-camera.…”