Molded, Seamless Tubes of Polyvinyl Formalinized Sponge

Abstract
Currently among surgeons and investigators interested in vascular surgery there is a widespread interest in attempts to produce an entirely satisfactory synthetic vascular prosthesis. Most work1has been done with cloth tubes made from synthetic fibers such as Vinyon-N, nylon, Dacron, Orlon, and so forth. Although results have been generally fairly good and are improving as better products are being developed and are being used more effectively, it seems generally agreed that vascular grafts made from these cloth fabrics are not ideal and can probably be improved on. For several years one of us (Grindlay) has been investigating tissue responses to various forms of polyvinyl formalinized (Ivalon*) sponge2implanted into many sites in experimental animals and in certain sites in clinical patients. As early as 1950, he fashioned blood-vessel grafts of this material and in pilot studies implanted them in the aortas of dogs. During the past year,