Rapid cellular luminal coverage of Dacron inferior vena cava prostheses in dogs by immediate seeding of autogenous endothelial cells derived from omental tissue: Results of a preliminary trial

Abstract

Endothelial cell seeding methods might reduce the high failure rates of venous vascular prostheses, but low flow rates in venous vascular prostheses impose a need to protect early patency and to attain early endothelial cell coverage without waiting several weeks for relatively small endothelial cell innocula from autologous veins to form confluent linings. To obtain large number of autologous endothelial cells for high-density seeding, canine omental microvascular endothelial cells were harvested by collagenase digestion and density gradient centrifugation, with yields of 1.34 +/- 0.24 (SD) X 10(6) cells/gm of omentum (N = 8 harvests). Primary culture of a subfraction from each harvest showed the cell population to be dominated by factor VIII-related antigen-positive endothelial cells with only a few nonstaining cells (estimated to be 10% or less of total cell number) visible. Freshly harvested omental cells were seeded onto double velour knitted Dacron prostheses at densities of 5 X 10(5) cells/cm2 of graft luminal surface in an autologous plasma suspension by use of prior preclotting with cell-free autologous plasma, followed by endothelial cell seeding in autologous plasma, with plasma recalcification during endothelial cell instillation. Six seeded and two control (sham-seeded) vascular prostheses 5 cm long with 10 mm inner diameter were used as inferior vena cava interposition grafts. A distal arteriovenous fistula and aspirin (300 mg) and dipyridamole (50 mg orally every day) starting 3 days before surgery were used to protect early patency of all grafts. Seeded venous vascular prostheses were explanted for study at intervals of 1,5, and 10 days after surgery (N = 2 prostheses at each time); the two control venous vascular prostheses were explanted at 10 days. All venous vascular prostheses were patent at time of removal. In seeded venous vascular prostheses, light, scanning, and transmission electron microscopy showed emergence of numerous flattened endothelial cell-like cells on the luminal surface 24 hours after surgery, followed by formation of a confluent cellular lining without adherent platelets by 5 to 10 days after surgery. Control venous vascular prostheses, in contrast, remained covered by an irregularly thickened fibrin and red cell thrombus, which sometimes encroached on the lumen. Our results suggest that (1) omental tissue can furnish endothelial cells for high-density immediate seeding of venous vascular prostheses, and (2) that the method we used to combine features of both so-called high density "seeding" and "sodding" techniques offers both more rapid prosthesis coverage than the former and shorter intraoperative times for cell attachment to prostheses than the latter.(ABSTRACT TRUNCATED AT 400 WORDS)

Cellular engineering of vascular bypass grafts: Role of chemical coatings for enhancing endothelial cell attachment

“…The cells are then washed off and collected. Centrifugation involves the mixture of fat and collagenase being centrifuged at variable speeds (WANG et al, 1990). This separates the constituents into a top fat layer, enzymatic middle and bottom of cells and red blood cells.…”

Human Blood Vessel–Derived Endothelial Progenitors for Endothelialization of Small Diameter Vascular Prosthesis

“…Endothelial cells provide a physical interface between blood and surrounding tissues and also maintain a haemostatic-thrombotic balance that regulates inflammation and angiogenesis. It is proposed that endothelialization of artificial prosthesis using autologous vascular endothelial cells would help in improving the patency rates of these grafts [6]–[8]. Furukawa et al have also shown that endothelial cell monolayers demonstrate better blood compatibility than either ePTFE or silicone sheets alone [9].…”

Tissue-Engineered Vascular Grafts for Small-Diameter Arterial Replacement

“…Pre-clotting [23,25,44,45], fibrin glue [27] or coating with fibronectin is often used before endothelial cell seeding in animal models [26,28,46]. In patients, the use of either one of the above techniques may face certain disadvantages.…”