A Systematic Review and Meta-Analysis of Heparin-Bonded Expanded Polytetrafluoroethylene Grafts for Below-The-Knee Femoral Bypass Surgery

Objectives Heparin-bonded expanded polytetrafluoroethylene (hb-ePTFE) synthetic grafts are an alternative to autologous vein grafts for surgical bypass interventions in lower limb peripheral arterial disease. However, the clinical benefits of hb-ePTFE grafts have not been reviewed systematically for patients undergoing below-knee surgical bypass. This study aimed to meta-analyze available data on the utility of hb-ePTFE in patients undergoing below-knee surgical bypass. Methods Medline, Embase, and Cochrane databases were searched, restricted to material in English with no date restriction. In addition, proceedings from relevant congresses were screened going back two years. The search was performed in December 2021. Eligible studies included prospective or retrospective comparative studies or prospective single-arm cohorts with an hb-ePTFE arm. Methodological quality was assessed with the ROBINS-I criteria. Outcomes included primary patency, amputation/limb salvage and overall survival. Clinical outcomes were expressed as event rates. Studies were compared using meta-analysis to generate a standardized mean event rate for each outcome, with its 95% confidence interval (95%CI), using a random effects model. Results Following de-duplication 10,263 records were identified, 261 were assessed at full text. No prospective comparative studies were identified. The level of evidence was uniformly low. Seventeen publications describing data from nine individual patient cohorts met the inclusion criteria. These cohorts included a total of 1,452 patients undergoing below-the-knee surgical bypass with hb-ePTFE. The primary patency rate was 78.9% [95% CI: 72.2 – 85.7%] at one year, 68.2% [95% CI: 62.8 – 73.6%] at two years, decreasing to 48.0% [95%CI: 27.3% – 68.7%] at five years. The secondary patency rate was 84.8% [95% CI: 77.0% – 92.5%] at one year and 68.9% [95% CI: 43.0% – 94.9%] at three years; the one-year limb salvage rate was 88.3% [95% CI: 79.6% – 97.1%] at one year and 79.0% [95% CI: 56.7% – 100%] at three years. Conclusion In patients undergoing below-knee bypass surgery, hb-ePTFE synthetic grafts, compared to uncoated grafts, perform well for patency and limb salvage. However, the quality of the evidence is low and well-performed randomized clinical trials are needed to inform clinical decision making on the choice of synthetic graft.