Factors enhancing risk of limb loss after revascularization

Factors enhancing risk of limb loss after surgical revascularization

Factors enhancing risk of limb loss after revascularization are:

1. Infrainguinal bypass using prosthetic material
2. Bypass below the knee
3. Use of suboptimal conduit
4. Poor arterial runoff
5. Extensive lesion

Project of Ex Vivo Vein Graft Engineering via Transfection III (PREVENT III) randomized trial database included 1404 lower extremity vein graft operations performed exclusively for critical limb ischemia [1]. Black race and female gender were found to have poorer outcome on 1 year ultrasound evaluation of vein grafts. They also noted that black women are at particularly high risk.

PREVENT III dataset along with a multicenter registry having 716 patients were analyzed by Andres Schanzer , Jessica Mega, Judith Meadows, Russell H Samson, Dennis F Bandyk and Michael S Conte [2]. They used 5 significant predictors of risk to predict amputation free survival and designed a score (PIII risk score). The predictors were:

1. Dialysis dependency
2. Tissue loss defined as non healing ulcer or gangrene
3. Age 75 years or more
4. Hematocrit 30 or less
5. History of advanced coronary artery disease

In the PIII risk score for critical limb ischemia, dialysis had 4 points, tissue loss 3 points, age 75 or more had 2 points, hematocrit 30 or less had 2 points and advanced coronary artery disease had one point.

Measures to prevent limb loss after surgical revascularization

When these risk factors are noted, antithrombotic therapy can be intensified by adding either rivaroxaban or warfarin to aspirin. Another option is to give dual antiplatelet therapy. While intensifying therapy, risk of limb loss should be weighed against the potential bleeding risk in each individual. Triple therapy with two antiplatelet agents and one anticoagulant is better avoided in view of high bleeding risk.

References

1. Nguyen LL, Hevelone N, Rogers SO, Bandyk DF, Clowes AW, Moneta GL, Lipsitz S, Conte MS. Disparity in outcomes of surgical revascularization for limb salvage: race and gender are synergistic determinants of vein graft failure and limb loss. Circulation. 2009 Jan 6;119(1):123-30.
2. Andres Schanzer , Jessica Mega, Judith Meadows, Russell H Samson, Dennis F Bandyk and Michael S Conte. Risk stratification in critical limb ischemia: derivation and validation of a model to predict amputation-free survival using multicenter surgical outcomes data. J Vasc Surg. 2008 Dec;48(6):1464-71.