Circumferential degree of tibial artery calcification is associated with infrapopliteal endovascular revascularization outcomes in patients with chronic limb-threatening ischemia

Background: Tibial artery calcification (TAC) is correlated with an increased risk of amputation and mortality in patients with chronic limb-threatening ischemia (CLTI). The association between calcification characteristics and adverse limb events of CLTI. However, it has not been assessed. This study aims to assess the relationship between the characteristics of TAC based on computed tomography angiography (CTA) scans and postoperative outcomes in patients with CLTI undergoing infrapopliteal endovascular therapy.Methods: This was a retrospective study of patients who underwent infrapopliteal endovascular revascularization for CLTI and had a preoperative CTA scan. Based on CTA, TAC was divided into the following categories: annularity, thickness, continuity and severity. Cox regression models using generalized estimating equations were performed to assess the relationship between calcification characteristics and postoperative outcomes. The outcomes evaluated were the occurrence of all cause mortality (ACM) and unplanned amputation.Results: Among the 148 patients undergoing endovascular, there were 50 (33.8%) patients died and 26 (17.6%) patients underwent unplanned amputation. Annular calcification was more common in the ACM group than in the non-ACM group. No significant differences were found between the two groups with regard to the probability of calcification in the thickness and the continuity (P>0.05). Patients in the unplanned amputation group had significantly annular, thin and continuity calcifications (P<0.05) than those in the non-unplanned amputation group. The presence of annular calcification was an independent predictor of ACM (hazard ratio (HR), 3.186; 95% confidence interval (CI), 1.781-5.702; P<0.001) and unplanned amputation (HR, 3.739; 95% CI, 1.707-8.191; P<0.05).Conclusions: Among patients with CLTI, the occurrence of annular calcification in the tibial artery are related to a greater chance of ACM and unplanned amputation in the postoperative period. The circumferential degree of TAC of the operated limb can be considered as a marker of clinical prognosis in this group of patients.