Heparin-Bonded Vascular Prostheses for the Treatment of Peripheral Artery Disease

PICHON RIVIERE, A.; AUGUSTOVSKI, F.; GARCIA MARTI, S.; GLUJOVSKY, D.; ALCARAZ, A.; LOPEZ, A.; BARDACH, A.; CIAPPONI, A; SPIRA, C

Documento de Evaluación de Tecnologías Sanitarias

IECS

Año: 2012 p. 1 - 30

1668-2793

Peripheral Artery Disease (PAS) is associated with a high risk of morbidity and mortality due to cardiovascular disease. It is often asymptomatic and diagnosed at advanced stages. Most common symptoms include: Intermittent claudication, ischemic pain at rest with or without ischemic ulcer or gangrene, hair loss and cold extremities. Treatment of the disease consists in reducing the atherosclerotic risk factors, anti-platelet therapy, endovascular procedures and open surgery as in the case of bypass. The most common procedure for PAS is femoro popliteal bypass. Immediate and long-term permeability rates recommend the use of an autologous vein. If not available, vascular prostheses become an alternative. Occlusion of vascular prostheses is mainly due to technical failures in placement, vascular disease progression and intimal hyperplasia. Due to the need of improving the permeability rates, attach a safe and efficient anticoagulant such as heparin to standard prostheses is an attractive solution. Technology Different types of peripheral vascular prostheses have been used in PAS, such as autologous vein, umbilical vein, synthetic polymers, Dacron and PTFE prostheses, and most recently, the heparin-bonded vascular prosthesis. Among the latter, the most common bonding and successful technique is the Carmeda BioActive Surface (CBAS) where heparin is attached to the surface through covalent bonding thus keeping its properties. Purpose To assess the evidence available on the safety, efficacy and other aspects related to coverage polices of the use of heparin-bonding vascular prosthesis for the treatment of peripheral artery occlusion. Methods A bibliographic search was carried out on the main databases: DARE, NHS EED, on Internet general search engines, in health technology evaluation agencies and health sponsors. Priority was given to the inclusion of systematic reviews; controlled, randomized clinical trials (RCTs); health technology assessments and economic evaluations; clinical practice guidelines and coverage policies of other health systems. Results One Cochrane review, one retrospective study and one RCT published later than the review were included. Prosthesis with heparin vs. prosthesis without heparin Heparin-bound Dacron vascular prosthesis versus non-heparin-bound PTFE (polytetrafluoroethylene) vascular prosthesis One Cochrane review included 13 randomized controlled studies (n=2,313) with the purpose of comparing the primary permeability of these two types of prostheses for the treatment of femoro popliteal artery stenosis or occlusion, both in bypass above and below the knee. For the purpose of this report, only those results which include heparin-bonded prosthesis will be included. The only study comparing the primary permeability (understood as blood flow through the prosthesis which did not required reintervention), the heparin-bonded Dacron prosthesis with the non-heparin-bonded PTFE prosthesis above the knee included 179 patients. At 24 months, the heparin-bonded prostheses showed better results: heparin-bonding permeability rate of 64.15% vs. non-heparin-bonding of 50%. The benefit was only observed in those prostheses located above the knee (OR=0.60; 95% CI 0.37-0.96). Heparin-bound PTFE vascular prosthesis versus non-heparin-bound PTFE vascular prosthesis One randomized blind multicenter controlled study published in 2011, included 546 patients with femoro popliteal bypass above and below the knee with the purpose of comparing the permeability between the heparin-bonded PTFE prosthesis (Hb-PTFE, n=272) and the non-heparin-bonded PTFE prosthesis (n=274) after one year. Average follow up was 9.75 ± 3.79 months versus 10.30 ± 3.35 months respectively. Seventy nine point nine percent of the implanted PTFE prostheses retained their permeability after one year versus 86.6% of the Hb-PTFE prostheses (OR=0,627; 95% IC: 0.398-0.989; p=0.043). In the femoro popliteal bypass group, the permeability rate was higher in the Hb-PTFE group: 80.4% versus 69.6% (OR=0.515; 95% CI 0.81-0.944, p=0.030) after one-year follow up. Heparin-bonded vascular prosthesis versus autologous vein graft (AV) One retrospective study published in 2009, included 350 patients to assess primary permeability one and two years after comparing Hb-PTFE prosthesis (n=240) versus the autologous saphena vein graft (n=111). No significant differences were observed in the permeability rate one and two years after bypass above the knee, showing a 92% and 91% permeability, and 83% and 80% after two years for the heparin-bound prosthesis and the autologous vein respectively. The permeability rates below the knee were 92% and 72% after one year, and 83% and 72% after two years for heparin-bound prosthesis and autologous vein graft respectively; no significant differences were observed between both groups. Clinical Practice Guidelines In the 2011 report, the American Heart Association and the American College of Cardiology recommend to perform popliteal artery bypass both below and above the knee using an autologous vein when available, otherwise, synthetic prostheses should be considered and their use in femoral tibial bypass is discouraged. The guidelines do not specifically mention heparin-bound vascular prostheses. Conclusions Short and long-term primary and secondary permeability rates have made heparin-bound prostheses a safe and efficient choice especially in procedures carried out above the knee. Long-term randomized studies are required to determine the true relative efficacy of this prosthesis versus standard prosthesis and autologous vein bypass. At present, the autologous vein bypass is still the surgical approach of choice for PAS. Since it cannot always be carried out, mainly due to patient-related factors, synthetic heparin-bound prostheses have become a valid alternative.