Platelet reactivity in human aortic grafts: A prospective, randomized midterm study of platelet adherence and release products in Dacron and polytetrafluoroethylene conduits

Abstract

Platelet-related phenomena at the blood-surface interface of randomly placed knitted Dacron (n = 6) and polytetrafluoroethylene (ePTFE) (n = 6) interposition aortic grafts were studied in patients undergoing abdominal aortic aneurysmectomy. Luminal accumulation of platelets was assessed by infusing indinm-lll-oxine (400 ~Ci) labeled autologous platelets and imaging grafts at 1 week, 3 months, and 6 months after surgery. Image analysis included an indium ratio technique (comparing aortic graft radioactivity to that of an lilac artery) and a red blood cell technetium subtraction technique (excluding blood pool radioactivity from graft radioactivity, with the heart or iliac artery serving as reference regions). Plasma levels of [3-thromboglobulin and platelet factor 4 were correlated with platelet accumulations on the aortic prostheses. Differences in graft radioactivity or platelet-release products were not evident 1 week after surgery. Three months after implantation, Dacron and ePTFE conduits exhibited 87% and 47% (p < 0.05) more radioactivity with the indium ratio technique than the iliac artery. Similary, increased Dacron compared with ePTFE graft radioactivity was noted using technetium subtraction techniques: 71% vs 30% with a heart reference and 26% vs 11% with an iliac artery reference, respectively. Increases in graft radioactivity correlated with increases in both plasma I~-thromboglobulin and platelet factor 4 at 3 months (r = 0.6 to 0.9; p < 0.05 to 0.001 depending on the imaging technique used). At 6 months, differences did not persist. In fact, technetium subtraction techniques suggested less Dacron conduit reactivity. It is speculated that differences in platelet accumulation and activation associated with different graft substrates may prove clinically important.

Prospective randomized study of carotid endarterectomy with polytetrafluoroethylene versus collagen-impregnated Dacron (Hemashield) patching: Perioperative (30-day) results

“…Studies have shown increased platelet deposition on both PTFE and knitted Dacron, with a greater deposition on knitted Dacron. 27 In conclusion, CEA with a Hemashield patch has a higher incidence of perioperative strokes, carotid thrombosis, and 50% or more early restenosis than CEA with PTFE patching. However, the mean hemostasis time is higher for PTFE patching than for Hemashield patching.…”

New assessment of platelet deposition in small caliber vascular prostheses using technetium-99m apcitide scintigraphy in rabbit model

“…Traditional methodology of the investigation of platelet deposition in the field of small caliber vascular prostheses is 111 In-platelet scintigraphy. There are many studies of acute thrombus, platelet deposition and antiplatelet medication with 111 In-platelet scintigraphy in clinical and experimental applications( [1][2][3] ). We also studied platelet deposition of fibrin-coated small caliber vascular prostheses that we used in the present study recently( 5;13 ).…”

“…The platelet deposition is traditionally assessed with Indium-111 ( 111 In) platelet scintigraphy( [1][2][3] ). This methodology is considered to be a useful technique to detect platelet deposition of the luminal surface of vascular grafts.…”

Blood Platelet Accumulation in a Dacron Graft Implanted in a Patient with Abdominal Aorta Aneurysm: Quantitative Scintigraphic Assessment Using Indium-111 Labeled Platelets - Case Report*

“…Scintigrams obtained using Indium-111 labeled autologous blood platelets performed more than a year after AAA surgical repair, which are described in (13,14), demonstrated blood platelet accumulation in the vascular graft, but determination of platelet number in the peripheral blood was not performed and coagulation and fibrinolysis activation markers were not measured.…”

“…Scintigraphic examination using autologous blood platelets labeled with Indium-111 provides direct evidence for blood platelet consumption in the vascular graft (12,13,14). After obtaining informed consent, this study was performed according to the described procedures (12).…”