Omniflow II biosynthetic grafts versus expanded polytetrafluoroethylene grafts for infrainguinal bypass surgery. A single-center retrospective analysis

Abstract

Introduction: The aim of this study is to evaluate the outcome of Omniflow II biosynthetic vascular grafts as compared to synthetic expanded polytetrafluoroethylene (ePTFE) grafts in infrainguinal bypass surgery.

Methods: A single-center, retrospective, observational study was performed reviewing patients with critical limb ischemia who underwent infrainguinal bypass surgery between 2014 and 2018. Patients characteristics, graft characteristics, and treatment outcomes were collected. Patency rates were compared using Kaplan-Meier estimates.

Results: Sixty bypasses were performed in 57 patients. For above-knee surgery, six were Omniflow and 13 were synthetic. For below-knee surgery, 19 were Omniflow and 22 were synthetic. Patient characteristics between groups were similar. However, American Society of Anesthesiologists (ASA) classification scores were higher in the Omniflow group as compared to ePTFE (88% was ASA 3 or higher versus 60%; p = 0.018). Furthermore, wound, ischemia, and foot infection (WIfI) composite scores were higher in the Omniflow group (p = 0.0001). There was a trend toward more active infection at time of surgery in the Omniflow group (40 vs 22.9%, p = 0.15). At 1 year, primary patency rates were 60.0% versus 46.9% for above-knee Omniflow versus ePTFE grafts, respectively (p = 0.72). Secondary patency rates were 80.0% versus 82.5% (p = 0.89), and limb salvage rates were 83.3% versus 100% (p = 0.14). For below-knee surgery, 1- and 2-year primary patency rates in Omniflow versus ePTFE grafts were 36.0% versus 41.8% (p = 0.60) and 36.0% versus 31.1% (p = 0.87). Secondary patency rates were 66.8% versus 75.2% at 1 year (p = 0.53) and 58.8% versus 48.3% (p = 0.77) at 2 years. Below-knee limb salvage rates for Omniflow versus ePTFE after 2 years were 88.0% versus 68.3% (p = 0.28), respectively. Aneurysmal degeneration occurred in 2/25 (8%) in the Omniflow group and 0/35 (0%) in the ePTFE group. Bypass infections occurred in 2/25 (8%) in the Omniflow group and 0/35 (0%) in the ePTFE group (p = 0.09).

Conclusion: Omniflow bypasses were more commonly implanted in patients with higher limb infection rate as confirmed with a higher adapted WIfI score. A trend toward a higher infection rate of Omniflow grafts was observed but not statistically significant. Graft infection rates were relatively low and treatable with antibiotics. No significant difference in graft performance was observed. The choice between the two studied grafts remains based on surgeon's preference.

Keywords: Omniflow; biosynthetic graft; expanded polytetrafluoroethylene; femoro-popliteal bypass; peripheral arterial disease.