In a (negative) multicenter randomized trial on management for inoperable critical lower limb ischemia, comparing spinal cord stimulation and best medical treatment, a number of pre-defined factors were analyzed for prognostic value. We included a radiological arterial disease score, modified from the SVS/ISCVS runoff score. The purpose of this analysis was to evaluate clinical factors and commonly used circulatory measurements for prognostic modeling in patients with critical lower limb ischemia. We determined the incidence of amputation and its relation to various pre-defined risk factors. A total of 120 patients with critical limb ischemia were included in the study. The integrity of circulation in the affected limb was evaluated on five levels: suprainguinal, infrainguinal, popliteal, infrapopliteal and pedal. A total radiological arterial disease score was calculated from 1 (full integrity of circulation) to 20 (maximally compromised state). We used Cox regression analysis to quantify prognostic effects and differential treatment (predictive) effects. Major amputation occurred in 33% of the patients at 6 months and in 51% at 2 years. The presence of ischemic skin lesions and the radiological arterial disease score were independent prognostic factors for amputation. Patients with ulcerations or gangrene had a higher amputation risk (hazard ratio 2.38, p = 0.018 and 2.30, p = 0.036 respectively) as well as patients with a higher radiological arterial disease score (hazard ratio 1.17 per increment, p = 0.003). We did not observe significant interactions between prognostic factors and the effect of spinal cord stimulation. In conclusion, in patients with critical lower limb ischemia, the presence of ischemic skin lesions and the described radiological arterial disease score can be used to estimate amputation risk.

aged, amputation, artery disease, article, clinical trial, controlled study, female, gangrene, hazard ratio, human, incidence, leg amputation, leg ischemia, major clinical study, male, multicenter study, peripheral arterial disease, peripheral circulation, predictive value of tests, priority journal, prognosis, proportional hazards model, radiodiagnosis, randomized controlled trial, randomized controlled trials, risk assessment, risk factor, scoring system, skin ulcer, spinal cord stimulation, therapy effect,
Vascular Medicine: the international journal of research review and clinical practice
Vasc Med
Erasmus MC: University Medical Center Rotterdam

Klomp, H.M, Steyerberg, E.W, Wittens, C.H, van Urk, H, & Habbema, J.D.F. (2009). A prognostic model for amputation in critical lower limb ischemia. Vascular Medicine: the international journal of research review and clinical practice, 14(2), 109–115. doi:10.1177/1358863X08098227