Spiral Flow Technology a year on: Results of the North American experience

Presented at the 36th Charing Cross International Symposium April 2014, London, UK Hosam El Sayed, MD, Assistant Professor of Cardiovascular Surgery, Methodist DeBakey Heart and Vascular Center, Houston, Texas, USA.

Introduction

Prosthetic graft failure is a normal tissue response to an abnormal flow environment. Endothelial cells at the anastomosis are sensitive to non-laminar flow environment (turbulence, stagnation, low shear stress, increased oscillatory index). These cells respond by signalling neo-intimal hyperplasia thus promoting failure. Results with prosthetic AV access grafts are far from ideal. We decided to use the Spiral flow graft for AV access based on early encouraging reports.

Patients and methods

This is a retrospective review of all cases that had Spiral Flow graft placement for AV access in the upper extremities.

From January, 2012 – January, 2014, 38 Spiral Flow™ AV Access Grafts (Vascular Flow Technologies Ltd) were placed in 37 patients.

The mean age was 61 years (range 42-88 years); 47% (18) were male. Patients presented with the following comorbidities: Diabetes: 25 (66%); Hypertension: 33 (87%); CAD: 8 (21%); CHF: 7 (18%); CVA: 7 (18%); PVD: 8 (21%).

Grafts were implanted as: Upper arm: 24; Forearm: 11; Chest wall: 3

Results

The mean follow-up was nine months. 15 patients completed 12 months follow up. There are 20 grafts (53%) currently in use. Three grafts were removed for infection, 3 grafts were ligated for severe steal and 1 graft was ligated for severe arm swelling. Seven patients are deceased, all with their grafts patent.

Complications were as follows: Graft infection: 3 (8%); Significant Steal: 3 (8%); Thrombosis: 7 (18%); Venous stenosis: 3 (8%); Seroma: 4 (10%); Wound complications: 3 (7%); Venous hypertension: 7(18) and Pseudo-aneurysm: 0

Overall patency (%) results at 12 months are as follows:

Primary AssistedSecondary
81% ± 983% ± 9

Conclusions

Spiral Flow Grafts are a valid and successful option for AV access. Early results are encouraging and tend to be better compared to standard straight ePTFE and heparin bonded grafts.

This may be explained on the basis of improved hemodynamics created by the spiral laminar flow.