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

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.

Ovine Biosynthetic Grafts for Aortoiliac Reconstructions in Nonsterile Operative Fields

Background Prosthetic vascular grafts placed surgically or via endovascular techniques can be subject to the risk of life-threatening graft infections. The Omniflow II vascular prosthesis is a biosynthetic graft that was reported to have favorable properties in resisting infections. Materials and Methods We retrospectively reviewed our 3 years' experience of using the Omniflow II prostheses for aortoiliac reconstructions in patients considered to carry a substantial risk of subsequent prosthetic graft infections (prevention group) as well as in patients with actively infected prosthetic vascular grafts (treatment group). Results Aorto-bi-iliac (n = 4) and aortobifemoral (n = 12) vascular reconstructions were performed using bifurcated Omniflow II prostheses in nine patients in the prevention group and seven patients in the treatment group. During mean follow-up of 28.6 ± 17.2 months, there was one case of graft infection (6.3%) and graft thrombosis (6.3%) with subsequent successful thrombectomy. Early and late surgical revisions were required in eight (50%) and two (12.6%) patients, respectively. All graft prostheses were patent at last follow-up. Conclusion Using bifurcated Omniflow II vascular prostheses in patients with or at a high risk of vascular graft infection is advisable, and is associated with acceptable reinfection and patency rates.

Late hematogenous seeding and infection of a femoropopliteal Omniflow II bypass

Introduction Omniflow II is promoted as an infection-resistant vascular graft. It is used to treat vascular graft infection; nevertheless, early graft infection has been reported. Report: A 71-year-old patient was treated with an Omniflow II bypass for a non-healing diabetic foot ulcer. Seven months postoperatively, late infection occurred secondary to hematogenous spread from a persistent foot infection. Conclusion We report on the first case of late infection of an Omniflow II vascular graft caused by hematogenous spread. Despite promising results of the Omniflow II graft in the treatment of vascular graft infection, late infection may not be avoided.

Biosynthetic vascular graft: a valuable alternative to traditional replacement materials for treatment of prosthetic aortic graft infection?

Background and Aims: To report the experience of a tertiary vascular surgery center using Omniflow II® biosynthetic vascular grafts for treatment of prosthetic aortic graft infection. Materials and methods: Retrospective analysis of all patients with prosthetic graft infections who underwent in situ aortic reconstruction using Omniflow II® grafts or other conduits between March 2015 and May 2017. Early and late mortality, perioperative complications, and reinfection rate were analyzed. Results: Sixteen patients (14 males, median age 68.5, range 57–89) with prosthetic aortic graft infection were treated at our center. Eight patients received an Omniflow II® biosynthetic graft, two patients silver-triclosan coated grafts, three patients bovine pericardial tube grafts, and three patients composite bovine pericardial tube grafts with Omniflow II® graft extensions. Perioperative complications occurred in seven patients (43.8%). Early mortality rate was 18.7% (n = 3). In addition, four patients died during follow-up after a median of 11 months (range 0–34 months). We did not observe any reinfections. Bypass grafts were patent in all patients. No major limb amputations were performed during follow-up. Conclusion: Treatment of prosthetic aortic graft infection with Omniflow II® vascular grafts is feasible. Graft material seems to have an excellent resistance to infection and might be a valuable alternative to traditional replacement materials. Especially long-term durability has to be continuously monitored and documented.

Susceptibility of Vascular Implants to Colonization in vitro by Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis and Pseudomonas aeruginosa

We compared association of Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa and Enterococcus faecalis with nine vascular implants after co-culture. Vascular implants were composed of various materials such as warp knitted polyester (with or without gelatin and silver ions), expanded polytetrafluoroethylene and biological materials – surface treated porcine pericardial patch and Omniflow II. The lowest overall number of associated bacteria was detected for polytetrafluoroethylene implants and porcine pericardial patch. The highest overall number of associated bacteria was detected for Omniflow II implant. The major source of variation, i.e. primary factor influencing colonization, is the implant type (56.22%), bacterial species is responsible for only 1.81%, and interaction of those two factors – 13.09% of variation.

The Usefulness of Biosynthetic Vascular Graft Omniflow II and Autologous Veins for the Treatment of Massive Infection of Dacron Vascular Graft with Enterococcus faecalis HLAR

Infections of vascular grafts are the most severe complications in vascular surgery. We present the case of a 73-year-old male with infection of a dacron prosthesis with a strain of Enterococcus faecalis. The patient was treated with replacement of a full prosthesis with a combined graft constructed from Biosynthetic Vascular graft Omniflow and autologous veins. This graft is recommended for implantation in patients with a higher risk of infection. Our case is one of the first reported usage of this kind of graft in the aortic region and in a 2 years observation period no recurrence of infection was observed.