Factors associated with pyloric hypertrophy severity and post-operative feeding and nutritional recovery in infantile hypertrophic pyloric stenosis

BACKGROUND: To examine factors that affect the severity of pyloric hypertrophy, post-operative feeding and nutritional recovery in infantile hypertrophic pyloric stenosis (IHPS). METHODS: Medical records of infants diagnosed with IHPS at a single tertiary center between 2009 and 2018 were retrospectively reviewed. Clinical characteristics, biochemistry data and outcome were assessed for their association with the severity of pyloric hypertrophy and post-operative recovery. Nutritional recovery was assessed using weight-for-age status improvement after surgery. RESULTS: Eighty-five patients were recruited in this study. The mean pre-operative weight-for-age percentile was 18.2. Elevated bicarbonate was positively correlated with symptom duration (p = 0.007). Pyloric muscle thickness was significantly correlated with age, weight, and symptom duration (p = 0.004, 0.003, 0.008, respectively). The mean weight-for-age percentile increased to 41.6 by post-operative weeks 6–8. Pyloric muscle thickness was negatively correlated with nutritional recovery by post-operative weeks 6–8 (p = 0.003). In multivariable analysis, pyloric length related to nutritional recovery at week 1–2 postoperatively (OR = 1.42, p = 0.030, 95% CI = 0.03–1.94), and pyloric muscle thickness related to nutritional recovery at week 6–8 postoperatively (OR = 4.08, p = 0.032, 95% CI = 1.13–14.7). CONCLUSION: Our study indicated that favorable nutritional outcome and successful weight gain was observed 6–8 weeks after surgery in children with IHPS. Pyloric muscle thickness positively correlated with age, weight, symptom duration, and favorable nutritional recovery. Serum bicarbonate showed a positive correlation with symptom duration.