A prognostic model for amputation in critical lower limb ischemia

Abstract

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.

The role of amputation as an outcome measure in cellular therapy for critical limb ischemia: implications for clinical trial design

“…Meta-analysis of these trials demonstrated that patients with tissue loss have a higher amputation rate than those with rest pain (Hazard Ratio 8.650, p = 0.0513). This is further supported by a separate analysis of patients in a spinal cord trial in which those with tissue loss demonstrated a higher amputation risk (HR 2.38, p = 0.018) [ 16 ].…”

Evaluation and Treatment of Patients With Lower Extremity Peripheral Artery Disease

“…Table 3 presents the segments with their anatomic borders. Several other groups have developed complex lesion and anatomy assessment below the knee and in the pedal arch, including the angiosome concept (27,28). The PARC group recommends continued research and data capture in relevant patients with distal disease to help inform future efforts.…”

Isolated Endarterectomy of Femoral Bifurcation in Critical Limb Ischemia: Is Restoration of Inline Flow Essential?

“…In patients with nonreconstructible CLI, a higher radiological arterial disease score is significantly associated with amputation risk. 23 Al-Khoury et al 15 reported outcome following isolated CFE and suggested that patients with The TransAtlantic InterSociety Consensus (TASC) C and D SFA lesions are at increased risk of developing recurrent symptoms; however, this study included patients with both intermittent claudication and CLI. Secondly, they grouped patients based on number of patent arteries when analyzing runoff, whereas we have evaluated the level of disease in each runoff artery and based on the SVS score.…”