Global Limb Anatomic Staging System Score correlates with the clinical outcomes in chronic limb threatening ischemia patients.

Abstract

Chronic limb-threatening ischemia (CLTI) affects millions of people and causes health care burden around the globe. Global Limb Anatomic Staging System (GLASS) was proposed as a new anatomic system for integrating the complexity of threatened limb. We retrospectively classified computed tomography angiography images of threatened limbs into GLASS stages between January 2018 and April 2020. Comorbidities, limb treatments, and outcomes including amputation-free survival (AFS), reintervention and mortality were compared and the likelihood of benefit from revascularization was estimated according to GLASS. Kaplan-Meier estimate was used to determine the rates of endpoint events at 1 year. Multivariate analysis was performed to identify predictors of those outcomes. In our study, 285 threatened limbs in 263 patients were stratified including GLASS stage I disease (N.=53, 19%), stage II (N.=129; 45%) and stage III (N.=103; 36%) disease. The percentage of limbs undergoing endovascular revascularization and minor amputation increased significantly with increasing GLASS stage. On Kaplan-Meier analysis, increasing GLASS stage was associated with 1-year reduced AFS (stage I: 96.1%, stage II: 94.1%, stage III: 83.9%; log rank P=0.016). The percentage of 1-year reintervention rate in infrapopliteal GLASS grade 3-4 (15%) was significantly higher than the percentage of reintervention in infrapopliteal GLASS grade 0-2 (5%) (Log rank P=0.002). Infrapopliteal GLASS grade 3 and 4 was the independent predictor of reduced AFS. GLASS stage correlated with intensity of limb treatment and with clinical outcomes at 1 year. Infrapopliteal GLASS grade 3 and 4 independently predicted the reduced amputation-free survival.