Nomogram for Predicting the Probability of Permanent Stoma after Laparoscopic Intersphincteric Resection.

purposeThe purpose of this study was to determine the risk factors for the development of a permanent stoma in laparoscopic intersphincteric resection (LS-ISR) for ultralow rectal adenocarcinoma and to develop and validate a prediction model to predict the probability of permanent stoma after surgery.

methodsA primary cohort consisting of 301 consecutive patients who underwent LS-ISR was enrolled in this study. Multivariable logistic regression analysis was used to identify risk factors and develop the nomogram. The performance of the nomogram was assessed with respect to its calibration, discrimination, and clinical usefulness. An independent validation cohort contained 91 consecutive patients from January 2012 to January 2019.

resultsThe permanent stoma rate was 11.3% (34/301) in the primary cohort and 18.7% (17/91) in the validation cohort. Multivariable analysis revealed that nCRT (OR, 3.195; 95% CI, 1.169-8.733; P=0.024), ASA score of 3 (OR, 5.062; 95% CI, 1.877-13.646; P=0.001), distant metastasis (OR, 14.645; 95% CI, 3.186-67.315; P=0.001), and anastomotic leakage (OR, 11.308; 95% CI, 3.650-35.035; P<0.001) were independent risk factors for permanent stoma, and a nomogram was established. The AUCs of the nomogram were 0.842 and 0.858 in the primary and validation cohorts, respectively. The calibration curves showed good calibration in both cohorts. Decision curve analysis demonstrated that the nomogram was clinically useful.

conclusionWe developed and validated a nomogram for ultralow rectal adenocarcinoma patients who underwent LS-ISR, and the nomogram could help surgeons identify which patients are at a higher risk of a permanent stoma after surgery.