Long-term patency of a RaK collagen vascular prosthesis – single centre results during a 10 year follow-up

Abstract

Abstract:The aim of this retrospective study was to evaluate the results of vascular operations based on the RaK prostheses, with a particular attention paid to their long-term patency. The study included 105 patients who were operated on in the period from 1992 to 1996. Vascular surgery was performed in the aortofemoral area and the underlying diagnoses were Leriche syndrome, asymptomatic abdominal aortic aneurysm, iliac artery stenosis or occlusion and symptomatic abdominal aortic aneurysm. During the mean follow-up time of 96 months (range 28-144), 8 patients (7.6 %) were lost to follow-up and 23 patients (21.9 %) died. At 12, 36, 60 and 120 months after surgery, the prostheses were patent in 99 %, 98 %, 93 % and 89 % of the patients, respectively. It is concluded that the RaK collagen prosthesis is the device of high quality and parameters comparable with the other types of knitted vascular prostheses currently used (Tab. 3, Fig. 4, Ref. 17 The number of different kinds of vascular prostheses that are produced today is enormous. The basic groups are distinguished according to the production technology and, to a certain extent, to the characteristic features of the prostheses -the most frequent prostheses used in vascular surgery are knitted dacron prostheses and prostheses made of an expanded polytetrafl uorethylen (ePTFE).The wall of knitted prostheses is made of synthetic fi bres, most often polyester. The gradual development has led to a compromise between the porosity necessary for anchoring the internal layer of fi brin, which is gradually being deposited, and the possibility of an effi cient preclotting of the prosthesis. On the other hand, a disadvantage of the prostheses that are too tightly knitted is a worse healing process and more diffi cult suturing. The last stage in the development of knitted prostheses is characterised by prostheses whose walls have been impregnated with collagen, gelatine or albumin during the manufacturing process. This fact ensures wall impermeability and, therefore, a minimal blood loss during implantation. Good healing is made possible by means of the gradual absorption of an artifi cially applied collagen layer (1, 2).At the Second Department of Surgery at St. Anne´s University Hospital in Brno, vascular surgery has a long tradition and has included cooperation with the producer (Výzkumný ústav pletařský Brno, Hosiery Research Institute Brno) in the research and development of synthetic grafts. At present, knitted prostheses impregnated with collagen are applied to the whole length of the abdominal aorta and iliac arteries as far as the inguinal ligament (Fig. 1). When the run-off is suffi cient and it is not possible to use an autologous venous graft, they are also used in the femoropopliteal area above the knee joint.The aim of this retrospective study was to evaluate clinical experience with this type of vascular prosthesis and to compare some relevant parameters (especially long-term patency) with the results obtained by other researchers. Materials and methodsIn ou...

Biodegradable Polymers as Drug Delivery Systems for Bone Regeneration

“…There has been considerable research into biologically derived materials that exhibit excellent biocompatibility and biological safety [38]. In particular, collagen is used as a biomaterial in many clinical applications, such as artificial skin [39], hemostatic agents [40], contact lenses [41], and vascular prosthesis [42].…”