Nomogram for predicting intolerable postoperative early enteral nutrition following definitive surgery for small intestinal fistula: a cohort study

Background: This study was designed to develop and validate a nomogram for predicting intolerable early enteral nutrition (EEN) following definitive surgery (DS) for small intestinal fistula. Methods: A total of 377 patients, recruited from January 2016 to September 2023, was randomly allocated into development ( n =251) and validation ( n =126) groups in a 2:1 ratio. Risk factors were identified using the nomogram. Its performance was assessed based on calibration, discrimination, and clinical utility, with validation confirming its effectiveness. Results: Of the 377 patients, 87 (23.1%) were intolerant to EEN, including 59 (23.1%) in the development cohort and 28 (22.1%) in the validation cohort ( P =0.84). Four factors were identified as predictive of intolerable EEN: severe abdominal adhesion, deciliter of blood loss during DS, human serum albumin (Alb) input >40 g during and within 48 h post-DS, and the visceral fat area (VFA)/total abdominal muscle area index (TAMAI) ratio. The model demonstrated excellent discrimination, with a C-index of 0.79 (95% CI: 0.74–0.87, including internal validation) and robust calibration. In the validation cohort, the nomogram showed strong discrimination (C-index=0.77; 95% CI: 0.64–0.87) and solid calibration. Decision curve analysis affirmed the nomogram’s clinical utility. Conclusion: This research introduces a nomogram that enables the individualized prediction of intolerable EEN following DS for small intestinal fistula, demonstrating a possible clinical utility.