Spiral Laminar Flow and its Influence on Graft Patency: Our Experience with the Spiral Flow Peripheral Bypass Graft in A Multicentre Retrospective Study
Spiral Laminar Flow, SLF, is the natural flow pattern found in healthy arteries. Blood leaves the left ventricle of the heart with a distinctive single spiral flow pattern and is propagated within the arterial system by the spiral configuration of the arterial luminal layers. SLF reduces static wall pressures at the intimal layer and, if destroyed, the severity of arterial disease and the tendency towards myointimal hyperplasia is greater. The Spiral Flow Peripheral Bypass Graft (Vascular Flow Technologies) reintroduces SLF at the distal anastomosis by a novel design at the distal end. To verify the advantages of this design, a series of peripheral bypass procedures using the graft were reviewed.
A retrospective multicentred, structured study of 72 patients who received the Spiral Flow Graft for peripheral bypass between February 2010 and February 2013 was performed. There were 61 males and 11 females, in which 75 bypasses were constructed; 68% were above knee and 32% were below knee. In all cases, the Fontaine Classification was 2b (severe claudication) or higher. Using duplex ultrasound and Computed Tomographic Angiography (CTA), all patients were scored as level C or D suitable for surgical revascularization according to the TASC IIb morphological stratification guidelines. In all cases the patients received general or epidural anaesthesia and antibiotic prophylaxis. Low molecular heparin was administered postoperatively out to 12 weeks.
Technical success at implantation was achieved in all 75 cases. The maximum and minimum follow-up was 38 months and 2 months respectively. There were no amputations in the limbs implanted with the Spiral Flow Graft and no cases of peri-operative bleeding or infection. There were 2 deaths due to serious comorbidities in this high-risk group of patients. Risk factors for vascular disease and indications for surgery were similarly distributed in the above knee and below knee bypasses. Primary patency rate was 85% and secondary patency 96%. 8 of 11 occlusions were successfully reopened with the use of thrombolysis, percutaneous angioplasty or open surgical revision. There were 3 permanent graft occlusions.
We implanted the Spiral Flow Peripheral Vascular Graft in 72 patients with peripheral occlusive arterial disease. The unique SLFTM technology is based on a renewed understanding of blood flow patterns in the healthy arterial system, the evidence of which is well documented. The mid-term results from this multicentre series of femoro-popliteal bypass procedures using the Spiral Flow Bypass Graft are encouraging.