Use of Omniflow® II in Infected Vascular Grafts with Femoral Anastomotic Dehiscence

Outcomes of Omniflow® II prosthesis used for revascularization in the femoral tract both in infected and non-infected setting

BACKGROUND

Evidence regarding the outcomes of Omniflow® II prosthesis in peripheral arterial revascularization at different anatomical sites and for different indications is scarce. Therefore, the aim of this study was to evaluate the outcomes of the Omniflow® II used at various positions within the femoral tract both in infected and non-infected setting.

METHODS

Patients who underwent reconstructive lower leg vascular surgery with implantation of an Omniflow® II from 2014 until 2021 at five medical centers were retrospectively included (N.=142). Patients were subdivided into the following categories: femoro-femoral crossover (N.=19), femoral interposition (N.=18), femoro-popliteal (above-the-knee [N.=25; AK] or below-the-knee [N.=47; BK]), and femoro-crural bypass grafts (N.=33). Primary outcome was primary patency and secondary outcomes included primary assisted patency, secondary patency, major amputation, vascular graft infection, and mortality. Outcomes were compared according to different subgroups and the surgical setting (infected versus non-infected).

RESULTS

The median follow-up was 35.0 (17.5-54.3) months. Three years primary patency of 58% was observed for femoro-femoral crossover bypass, 75% for femoral interposition graft, 44% for femoro-popliteal above-the-knee bypass, 42% for femoro-popliteal below-the-knee bypass, and 27% in the femoro-crural position (P=0.006). Freedom from major amputation at three years were 84% for femoro-femoral crossover bypass, 88% for femoral interposition bypass, 90% for femoro-popliteal AK bypass, 83% for femoro-popliteal BK bypass, and 50% for femoro-crural bypass (P<0.001).

CONCLUSIONS

This study demonstrates the safety and feasibility of the use of Omniflow® II for femoro-femoral crossover-, femoral interposition-, and femoro-popliteal (AK and BK) bypass. Omniflow® II seems to be less suitable for femoro-crural bypass with a significantly lower patency compared to other positions.

A systematic review and meta-analysis of the use of the Omniflow II biosynthetic graft for aortic reconstruction

OBJECTIVE

Despite the improvements in xenogeneic grafts and surgical techniques, management of aortic graft infection has remained challenging. The optimal graft material has remained controversial, with high rates of reinfection using prosthetic grafts and a limited time for venous harvest in an emergent setting. Recent studies have highlighted an increase in the use of Omniflow II biosynthetic vascular grafts (LeMaitre Vascular, Burlington, MA) for aortic reconstruction. The primary aim of the present study was to review the key outcomes for the Omniflow II graft in terms of reinfection and complications.

METHODS

The National Healthcare Service healthcare databases advanced search function was used to search nine databases for the search term "Omniflow." The present study complied with the PRISMA (preferred reporting items for systematic review and meta-analysis) statement. Eligible studies related to aortic graft infection or in situ aortic reconstruction were selected in accordance with prespecified eligibility criteria and included for review. Data on the surgical technique, comorbidities, graft reinfection, mortality, and complications were combined. The data were analyzed using Stata/MP, version 17 (StataCorp, College Station, TX), and the probabilities were pooled using a DerSimonian and Laird random effects model with Freeman-Tukey arcsine transformation.

RESULTS

Six studies with 60 patients (44 men; age range, 29-89 years) were included. Of the 60 patients, 25 had undergone surgical reconstruction because of early graft infection (<4 months after the index procedure), 24 for late graft infection, and 3 because of mycotic aneurysms. Eight high-risk patients had undergone surgical reconstruction for prevention of an initial graft infection. Staphylococcus aureus, Escherichia coli, and S. epidermis were the most common organisms. Early mortality was 8.83% (95% confidence interval [CI], 1.12%-20.53%), and late mortality was 18.49% (95% CI, 5.51%-35.34%). Follow-up varied from 9 months to 2 years. No graft rupture or graft degeneration had occurred during follow-up. However, 6.2% (95% CI, 0.39%-15.81%) had experienced early graft occlusion, and 3.83% (95% CI, 0.00%-16.34%) had developed early graft stenosis. Two cases of postoperative reinfection were reported. The freedom from reinfection was 97.71% (95% CI, 87.94%-100.00%).

CONCLUSIONS

Use of the Omniflow II graft for aortic reconstruction is a feasible alternative with acceptable mortality and low reinfection rates. However, there is a risk of limb occlusion. Although these studies were of low quality, the Omniflow II graft shows promise in this difficult patient cohort, especially when bifurcated reconstruction is required.

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.

Early Graft, Limb and Mortality Outcomes from the Omniflow II Bio-Synthetic Graft

BACKGROUND

Omniflow II biosynthetic grafts are a commonly used alternative to autologous grafts in vascular bypass procedures. They are chosen for their purported resilience to infection, often in instances of existing graft failure or infection. We examined the short term, 1-3 year outcomes of Omniflow grafts in terms of patency, limb survival and mortality in a sample of 24 individuals.

METHODS

This is a single centred retrospective study of Omniflow II grafts implanted between September 23, 2015 and April 05, 2018 in our department. It includes grafts in all anatomical locations. Primary outcome measures were overall patient survival and time to this, primary graft patency (patency with no intervention) and then limb survival at 1 and 3 years. Kaplan-Meier survival analysis was plotted for the 3 primary outcome measures.

RESULTS

A total of 24 grafts from 24 individuals were included with mean age 71.4 ± 11.7. We included 5 female and 19 male patients. The commonest indication was rest pain/claudication (N = 8) followed by graft occlusion (N = 6). Femoro-popliteal bypass (N = 13) and Femoro-distal bypass (N = 5) were the commonest procedures. Kaplan-Meier survival analysis demonstrated that 1 and 3-year primary patency rates were 54.2% and 37.5% respectively with Limb survival probability of 75% at 1 year and 70.8% at 3 years. These rates were all considerably lower than those found in previous comparative studies. Mortality however, compared favourably with 1 and 3-year survival probability 91.7% and 87.5% on average 296 days (range 95-451 days) after graft implantation.

CONCLUSIONS

We found that rates of primary patency and limb salvage for this graft type were markedly lower than in comparable studies. Further work in the form of a RCT is indicated.

Midterm outcome of biosynthetic collagen prosthesis for treating aortic and peripheral prosthetic graft infections

OBJECTIVES

To report the midterm outcomes of treating prosthetic peripheral and aortic graft infections using a biosynthetic collagen prosthesis in a tertiary vascular center.

METHODS

A retrospective analysis of all patients with prosthetic peripheral and aortic graft infections who underwent in situ reconstruction using a biosynthetic collagen prosthesis between March 2015 and November 2020 was conducted. Perioperative and midterm outcomes were analyzed.

RESULTS

A biosynthetic collagen prosthesis was used in 19 patients (14 males, median age 66 years) to reconstruct the femoral artery (n = 6), iliac artery (n = 1), and infrarenal aorta (n = 12). All patients were treated for a prosthetic vascular graft infection. The median follow-up period was 26.6 months (range 1-66 months). The 30-day graft failure rate was 15.7% (n = 3), leading to a major amputation in one patient (5.3%). All grafts were occluded aortofemoral reconstructions in patients with occluded superficial femoral artery and were treated by immediate thrombectomy. The 30-day mortality rate was 5.3% (n = 1), and survival after 3 years was 63.2%. The reinfection rate was 5.3% (n = 1). At 13.6 months, the occlusion of a femoral graft was detected in 5.3% (n = 1) and was treated with a new interposition graft. We observed no graft rupture or degeneration during follow-up.

CONCLUSIONS

Although results of in situ repair with autologous vein seem to be superior with little or none reinfection and low number of occlusions, biosynthetic collagen prostheses show acceptable midterm outcomes in terms of graft occlusion and mortality after prosthetic peripheral and aortic graft infections. Similar to other xenogenous materials, the reinfection rate is low with this prosthesis. With regard to immediate availability and easy handling, the use of a biosynthetic collagen prosthesis might be favorable compared to other replacement materials while treating prosthetic graft infections.