Factors enhancing risk of limb loss after surgical revascularization
Factors enhancing risk of limb loss after revascularization are:
Infrainguinal bypass using prosthetic material
Bypass below the knee
Use of suboptimal conduit
Poor arterial runoff
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 . 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 . They used 5 significant predictors of risk to predict amputation free survival and designed a score (PIII risk score). The predictors were:
Tissue loss defined as non healing ulcer or gangrene
Age 75 years or more
Hematocrit 30 or less
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.