Association between perioperative metabolic disorders and disease time course with pyloric morphological characteristics in infants with infantile hypertrophic pyloric stenosis

OBJECTIVE: To identify risk factors for perioperative metabolic disorders in infants with infantile hypertrophic pyloric stenosis (IHPS) and examine their associations with disease time course and ultrasound-measured pyloric morphology. METHODS: In this retrospective cohort study, consecutive surgical IHPS patients (2019-2025) were included. Data on demographics, disease timeline (age at onset, age at surgery), and preoperative ultrasound parameters (pyloric muscle thickness, canal length) were collected. Univariate and multivariate logistic regression identified independent risk factors, and a decision tree prediction model was developed. RESULTS: Among 323 infants, 43.7% had preoperative metabolic disorders. Multivariate analysis identified independent risk factors: age at surgery (per 1 week delay, aOR = 1.438), pyloric muscle thickness (per 1 mm increase, aOR = 1.408), pyloric canal length (per 1 mm increase, aOR = 1.614), and pyloric index (per 10-unit increase, aOR = 1.671). In the decision tree model, pyloric canal length showed the highest predictive importance (100%), with > 20.75 mm as the primary split point. The model achieved 87.9% accuracy and 90.1% sensitivity. CONCLUSION: Perioperative metabolic disorders in IHPS reflect both obstruction duration and pyloric structural changes. Pyloric canal length is a potentially valuable imaging predictor. The preliminary threshold of > 20.75 mm may serve as a high-risk warning for metabolic disorders; combined with metabolic laboratory assessment, it could help optimize preoperative management and surgical timing.