2007 Abstracts: Duplex Surveillance Does Not Predict the Need For Reintervention Following Percutaneous Infrainguinal Revascularization

Purpose: Duplex surveillance of infrainguinal vein grafts is a widely-accepted and clinically useful practice. Vein graft occlusions are most often preceded by focal stenoses which can be identified and monitored for progression by duplex surveillance. Established peak systolic velocity (PSV) and velocity ratio (Vr) threshold criteria for vein graft stenoses at high-risk of occlusion have been developed to guide treatment. Percutaneous techniques to treat infrainguinal occlusive disease are also plagued by restenosis, at nearly double the rate for infrainguinal vein grafts. The clinical utility of duplex surveillance following infrainguinal endoluminal therapy (ELT), however, is unclear and criteria for reintervention have not been established. The purpose of this study is to evaluate the clinical utility of routine duplex surveillance following infrainguinal ELT.
Methods: Ninety consecutive patients undergoing primary infrainguinal ELT underwent duplex surveillance using a traditional vein graft surveillance algorithm. The surveillance protocol included ABI and/or toe pressure determination and femoro-popliteal duplex interrogations with determination of PSV and Vr; the tibial arteries were imaged in patients who underwent tibial artery interventions. Fifty-six (62%) patients underwent intervention for critical limb ischemia (CLI) and 34 (38%) for disabling claudication. TASC classifications were: A 19 (21%), B 30 (33%), C 20 (22%), and D 21 (23%). The distribution of interventions was as follows: 49% PTA alone, 31% PTA and stent, and 20% atherectomy.
Results: Two-year primary patency rates were 77% (TASC A & B) versus 53% (TASC C & D), p=0.014. Assisted primary patency rates at two years were 85% for TASC A & B versus 63% for TASC C &D (p=0.098). The limb salvage rate for all CLI patients was 83% at two years. Reintervention was required in 21 patients (23%), percutaneous in 13 (14%) and open bypass in 8 patients (9%). Of these patients, 8 patients required reintervention within 30 days because the initial revascularization was insufficient to heal large foot or heel wounds. Among the 21 patients that required reintervention, duplex findings were not predictive of the need for reintervention. All 21 patients who required reintervention were symptomatic (recurrent claudication, ischemic rest pain, or poor wound healing), and 71% of these patients presented with restenosis rather than occlusion of the treated segment.
Conclusions: The vast majority of patients who require re-intervention following ELT for infrainguinal occlusive disease present with restenosis and recurrent symptoms, rather than occlusion of the treated segment. ABI's and toe pressures were useful to assess the hemodynamic response following ELT, however duplex surveillance did not reliably predict which patients were likely to develop symptomatic restenosis. Unless more accurate predictors of clinically significant restenosis following infrainguinal PTA can be developed, we cannot recommend the routine use of duplex surveillance following infrainguinal ELT.