# Preoperative phase angle and postoperative complications in Crohn’s disease patients undergoing ileocolic resection: a retrospective cohort study

## TL;DR

This study found that lower preoperative phase angle is linked to higher risk of post-surgery complications in Crohn’s disease patients undergoing ileocolic resection.

## Contribution

The study introduces preoperative phase angle as a novel predictor of postoperative complications in Crohn’s disease patients.

## Key findings

- Lower preoperative phase angle was significantly associated with increased postoperative complications.
- Phase angle demonstrated good discrimination for predicting complications, with better performance in females.
- Elevated C-reactive protein on postoperative day 3 was also linked to increased complication risk.

## Abstract

To investigate the association between preoperative phase angle (PhA), measured by bioelectrical impedance analysis, and short-term postoperative complications in patients with Crohn’s disease (CD) undergoing ileocolic resection.

This retrospective cohort study included consecutive patients with CD who underwent ileocolic resection between April 2021 and December 2024. Baseline demographic, clinical, and nutritional data were analyzed. Univariable and multivariable logistic regression models were employed to identify predictors of postoperative complications. The discriminative ability of PhA was evaluated using receiver operating characteristic (ROC) curve analysis, with additional stratification by sex.

Among 119 patients (median age 28 years; 72.3% male; median BMI 18.0 kg/m2), 25 (21.0%) experienced postoperative complications. Mean preoperative PhA was significantly lower in patients with complications compared with those without (4.1 ± 0.5° vs 4.8 ± 0.7°, P < 0.001). In multivariable analysis, higher preoperative PhA was independently associated with reduced odds of complications (OR = 0.203, 95% CI = 0.085–0.487, P < 0.001), whereas elevated C-reactive protein on postoperative day 3 was associated with increased odds (OR = 1.017, 95% CI = 1.007–1.028, P = 0.002). PhA demonstrated good overall discrimination (AUC 0.772, 95% CI 0.657–0.863). Sex-stratified analysis revealed superior discrimination in females (AUC 0.864, 95% CI 0.689–1.000; cut-off 3.9°) compared with males (AUC 0.748, 95% CI 0.625–0.857; cut-off 4.5°).

Lower preoperative PhA values were associated with a higher risk of short‑term postoperative complications after ileocolic resection for CD. Findings support the potential incorporation of PhA into preoperative risk assessment to help identify higher‑risk patients and guide perioperative optimization.

The online version contains supplementary material available at 10.1007/s00384-025-05053-y.