Clinical ResearchMid- and Long-Term Results of the Treatment of Infrainguinal Arterial Occlusive Disease With Precuffed Expanded Polytetrafluoroethylene Grafts Compared With Vein Grafts
Introduction
Lower-extremity bypass constitutes one of the foundations for the treatment of symptomatic peripheral arterial disease. Despite advances in surgical technique, bypass graft occlusion still remains the primary problem in infrainguinal bypass grafts, especially to targets below the knee. Autologous saphenous vein remains the conduit of choice and the gold standard for long-term patency.1, 2, 3 Unfortunately, saphenous vein is desirable as a conduit for a number of surgical procedures and often has been harvested for cardiac or previous vascular procedures. Expanded polytetrafluoroethylene (PTFE) conduits offer an acceptable alternative for patients without suitable autologous conduit.2, 3, 4, 5, 6 However, although patency of PTFE grafts is reasonable to above-knee popliteal targets, below-knee (BK) popliteal and tibial artery targets have poorer patency rates.3, 4
Studies into the flow dynamics of prosthetic bypass grafts have shown that altered hemodynamic flow patterns at the distal anastomosis may contribute to decreased sheer stress and, as a result, accelerated restenosis.7, 8, 9, 10 Adjunctive procedures, such as vein cuffs, may act as a bridge at the distal anastomosis, thus altering the flow dynamics to more closely mimic the natural state and improve patency.11, 12, 13 However, vein cuffs add significantly to the bypass complexity and operative time. Based on these flow dynamic studies, precuffed expanded PTFE grafts incorporate a large hood at the distal anastomosis in an attempt to alter the hemodynamic flow, eliminating areas of low flow and reducing restenosis.14 The Bard Distaflo (Bard, Tempe, AZ) graft incorporates such a cuff and has demonstrated improved flow dynamics and reduced levels of intimal hyperplasia at the distal anastomosis in premarket studies.14, 15
Studies analyzing early patency results of the Distaflo graft demonstrated acceptable patency.15 However, long-term patency results are lacking. This study seeks to evaluate the long-term patency of the Distaflo graft and compares these with those of reversed saphenous vein grafts (rSVG).
Section snippets
Methods
A retrospective search of all infrainguinal bypasses performed at a single institution from June 2003 to December 2009 was performed. All patients undergoing revascularization to BK targets with either Distaflo grafts or rSVG were selected for analysis. The choice of conduit was solely at the discretion of the operating surgeon, and although an effort was made to use a saphenous vein if present, the operating surgeons could elect to use a prosthetic if they deemed the saphenous vein
Patient Characteristics
Review of infrainguinal bypasses identified 101 Distaflo and 47 SVG bypasses to targets below the knee. BK popliteal targets accounted for 52 (51.5%) bypasses in the Distaflo group and 16 (34%) bypasses in the SVG group. Tibial targets accounted for 49 (48.5%) bypasses in the Distaflo group and 31 (66%) bypasses in the SVG group. Both groups were similar in age, with the SVG group having a significantly higher percentage of male subjects. The most common comorbidities were hypertension,
Discussion
Autologous great saphenous vein (GSV) remains the gold standard conduit for lower-extremity bypasses, especially to targets below the knee, with superior patency rates.1, 2 However, the GSV is a highly prized conduit for any operation requiring vascular reconstruction, especially coronary bypass and previous lower-extremity bypass. Thus, the GSV has been used for other procedures in up to 40% of patients requiring lower-extremity bypass, with an additional 12% of patients having a GSV that is
Conclusion
In the BK popliteal position, Distaflo grafts offer early patency comparable with rSVG but have significantly poorer mid- and long-term patency. Secondary interventions can improve midterm patency, with overall comparable limb salvage rates at all time points. Patency and limb salvage rates of the Distaflo bypasses are similar to those of standard PTFE bypasses reported historically. In the tibial position, Distaflo graft performed significantly worse compared with vein grafts at all time
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