A nomogram risk assessment model to predict the possibility of type II endoleak-related re-intervention after endovascular aneurysm repair (EVAR)

This study aimed to develop and validate a novel nomogram risk assessment model to predict the possibility of type II endoleak (T2EL)-related re-intervention. The data of 455 patients with abdominal aortic aneurysms who underwent elective endovascular aneurysm repair (EVAR) procedures between January 2018 and December 2021 at our single center were retrospectively reviewed. Following the implementation of exclusion criteria, 283 patients were finally included and divided into T2EL-related re-intervention (n = 42) and non-T2EL (n = 241) groups. The overall T2EL-related re-intervention rate for 283 patients was 14.8% (42/283). Using multivariate analysis, significant risk factors for re-intervention included age (OR, 1.172; 95% CI, 1.051-1.307; P = 0.004), smoking (OR, 13.418; 95% CI, 2.362-76.215; P = 0.003), diameter of inferior mesenteric artery (IMA) (OR, 21.380; 95% CI, 3.060-149.390; P = 0.002), and number of patent lumbar arteries (OR, 9.736; 95% CI, 3.175-29.857; P < 0.001). The discrimination ability of this risk-predictive model was reasonable (concordance index [C-index] = 0.921; 95% CI, 0.878-0.964). The Hosmer-Lemeshow goodness of fit test was performed on the model, and the chi-square value was 3.210 (P = 0.920), presenting an excellent agreement between the model-predicted and observed values. The receiver operating characteristic (ROC) curve identified that the risk thresholds of re-intervention were a diameter of > 2.77 mm for the diameter of the inferior mesenteric artery and a proportion of < 45.5% for thrombus volume in the aneurysm sac. This novel nomogram risk assessment model for predicting the possibility of patients' T2EL-related re-interventions after EVAR should be helpful in discriminating high-risk patients. Two novel risk thresholds may imply a higher possibility of T2EL-related re-intervention after EVAR.