Dynamic changes in the aggregate index of systemic inflammation (ΔAISI) predict postoperative complications following ileostomy closure in rectal cancer patients.

BACKGROUND

Ileostomy closure following rectal cancer surgery is generally considered a low-risk procedure; however, postoperative complications remain clinically relevant. Reliable and easily accessible biomarkers for predicting these complications are lacking. This study aimed to evaluate the predictive value of dynamic changes in the aggregate index of systemic inflammation (ΔAISI) for postoperative complications following ileostomy closure.

METHODS

This retrospective cohort study included 137 patients who underwent curative rectal cancer surgery with diverting ileostomy followed by ileostomy closure between January 2015 and March 2026. Inflammatory and nutritional markers were recorded prior to primary surgery and before ileostomy closure. ΔAISI was calculated as the difference between these two time points. Comparisons were performed using the Mann-Whitney U test and chi-square test. Receiver operating characteristic (ROC) curve analysis and multivariate logistic regression were conducted to evaluate predictive performance.

RESULTS

Postoperative complications occurred in 23 patients (16.8%). No significant differences were observed in inflammatory markers measured before primary surgery. In contrast, several inflammatory markers measured prior to ileostomy closure were significantly associated with postoperative complications. Among the evaluated indices, ΔAISI demonstrated good discriminative ability (AUC: 0.755, 95% CI: 0.628-0.882, p < 0.001). In multivariate analysis, high ΔAISI remained an independent predictor of postoperative complications (OR: 4.13, 95% CI: 1.41-12.03, p = 0.009).

CONCLUSION

ΔAISI is a promising and independent predictor of postoperative complications following ileostomy closure in rectal cancer patients. Both pre-closure AISI and ΔAISI demonstrated good predictive performance, whereas AISI measured before primary surgery showed poor discrimination. These findings suggest that inflammatory status immediately before ileostomy closure may serve as a clinically useful biomarker for perioperative risk stratification.