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  • Clinical Research Article
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Pyloric index: a novel nomogram predictor of metabolic alkalosis in congenital hypertrophic pyloric stenosis

Abstract

Background

Metabolic alkalosis (MA) is a common complication of congenital hypertrophic pyloric stenosis (CHPS). This study develops and validates a nomogram to predict MA probability in CHPS infants.

Methods

A retrospective study was conducted on CHPS patients at the First Affiliated Hospital of Zhengzhou University. Patients were divided into CHPS and MA-CHPS groups. Lasso and logistic regression selected predictive factors, and a nomogram was developed. Discriminative ability was assessed using the C-index with bootstrap validation. Calibration curves evaluated predictive accuracy, while decision curve analysis (DCA) assessed clinical applicability.

Results

A total of 107 cases were included in the final analysis, with 81 in the CHPS group and 26 in the MA-CHPS group. The predictive nomogram included the following factors: weight at diagnosis, symptom duration, and pyloric index (PI). The C-index of the predictive nomogram was determined to be 0.818, with a bootstrap validation (1000 resamples) yielding a corrected C-index of 0.798, indicating good discriminative ability. Calibration curves demonstrated a high degree of consistency between predicted and actual results. DCA confirmed good clinical utility.

Conclusion

We developed a nomogram to predict the probability of MA in CHPS patients, enabling early identification of poor prognosis and improving outcomes.

Impact statement

  • This study presents a novel predictive model for assessing the probability of metabolic alkalosis (MA) in congenital hypertrophic pyloric stenosis (CHPS) infants. It is the first model integrating the pyloric index (PI) as a predictive factor, alongside weight at diagnosis and symptom duration. The nomogram demonstrated strong discriminative ability and clinical utility, aiding early MA identification and improving perioperative management. By providing a practical risk stratification tool, this model enhances clinical decision-making, facilitates timely interventions, and ultimately improves outcomes for CHPS infants.

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Fig. 1: Correlation analysis between parameters.
Fig. 2: Variables selected based on LASSO regression.
Fig. 3: AUC values of key feature variables.
Fig. 4
Fig. 5: Validation of the nomogram.

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Data availability

The datasets generated during and/or analysed during the current study are available from the corresponding author on reasonable request.

References

  1. Alain, J. L., Grousseau, D. & Terrier, G. Extramucosal pyloromyotomy by laparoscopy. Surgical Endosc. 5, 174–175 (1991).

    Article  CAS  Google Scholar 

  2. Rich, B. S. & Dolgin, S. E. Hypertrophic pyloric stenosis. Pediatrics Rev. 42, 539–545 (2021).

    Article  Google Scholar 

  3. Jobson, M. & Hall, N. J. Contemporary management of pyloric stenosis. Semin. Pediatr. Surg. 25, 219–224 (2016).

    Article  PubMed  Google Scholar 

  4. Touloukian, R. J. & Higgins, E. The spectrum of serum electrolytes in hypertrophic pyloric stenosis. J. Pediatr. Surg. 18, 394–397 (1983).

    Article  CAS  PubMed  Google Scholar 

  5. Breaux, C. W. Jr, Hood, J. S. & Georgeson, K. E. The significance of alkalosis and hypochloremia in hypertrophic pyloric stenosis. J. Pediatr. Surg. 24, 1250–1252 (1989).

    Article  PubMed  Google Scholar 

  6. Ohri, S. K., Sackier, J. M. & Singh, P. Modified Ramstedt’s pyloromyotomy for the treatment of infantile hypertrophic pyloric stenosis. J. R. Coll. Surg. Edinb. 36, 94–96 (1991).

    CAS  PubMed  Google Scholar 

  7. Downey, E. C. Jr Laparoscopic pyloromyotomy. Semin. Pediatr. Surg. 7, 220–224 (1998).

    Article  PubMed  Google Scholar 

  8. Goh, D. W. et al. Plasma chloride and alkalaemia in pyloric stenosis. Br. J. Surg. 77, 922–923 (1990).

    Article  CAS  PubMed  Google Scholar 

  9. van den Bunder, F. et al. Respiratory problems owing to severe metabolic alkalosis in infants presenting with hypertrophic pyloric stenosis. J. Pediatr. Surg. 55, 2772–2776 (2020).

    Article  PubMed  Google Scholar 

  10. Nissen, M. et al. Does metabolic alkalosis influence cerebral oxygenation in infantile hypertrophic pyloric stenosis?. J. surgical Res. 212, 229–237 (2017).

    Article  Google Scholar 

  11. van den Bunder, F. et al. Perioperative hypoxemia and postoperative respiratory events in infants with hypertrophic pyloric stenosis. Eur. J. Pediatr. Surg. J. Austrian Assoc. Pediatr. Surg. [et al.] Z. fur Kinderchir. 33, 485–492 (2023).

  12. Khan, A. A., Yousaf, M. A. & Ashraf, M. Role of ultrasonography in early diagnosis of infantile hypertrophic pyloric stenosis. J. Ayub Med. Coll., Abbottabad: JAMC 26, 316–319 (2014).

    PubMed  Google Scholar 

  13. AlMaramhy, H. H. Is there a relation between pyloric muscle thickness and clinical and laboratory data in infants with hypertrophic pyloric stenosis?. Indian J. Surg. 77, 827–830 (2015).

    Article  PubMed  Google Scholar 

  14. Kim, H. J. Utility of pyloric length measurement for detecting severe metabolic alkalosis in infants with hypertrophic pyloric stenosis. Pediatr. Gastroenterol., Hepatol. Nutr. 27, 88–94 (2024).

    Article  PubMed  Google Scholar 

  15. Kaya, B. et al. Pyloric index, a new parameter: predicting perioperative prognosis in neonates with hypertrophic pyloric stenosis. Scand. J. Gastroenterol. 59, 1272–1276 (2024).

    Article  PubMed  Google Scholar 

  16. Hussain, M. Sonographic diagnosis of infantile hypertrophic pyloric stenosis- use of simultaneous grey-scale & colour doppler examination. Int. J. Health Sci. 2, 134–140 (2008).

    Google Scholar 

  17. Zaghal, A., El-Majzoub, N., Jaafar, R., Aoun, B. & Jradi, N. Brief overview and updates on infantile hypertrophic pyloric stenosis: focus on perioperative management. Pediatr. Ann. 50, e136–e141 (2021).

    Article  PubMed  Google Scholar 

  18. Westra, S. J., de Groot, C. J., Smits, N. J. & Staalman, C. R. Hypertrophic pyloric stenosis: use of the pyloric volume measurement in early US diagnosis. Radiology 172, 615–619 (1989).

    Article  CAS  PubMed  Google Scholar 

  19. van den Bunder, F., Hall, N. J., van Heurn, L. W. E. & Derikx, J. P. M. A delphi analysis to reach consensus on preoperative care in infants with hypertrophic pyloric stenosis. Eur. J. Pediatr. Surg. J. Austrian Assoc. Pediatr. Surg. [et al.] = Z. fur Kinderchir. 30, 497–504 (2020).

  20. Tutay, G. J., Capraro, G., Spirko, B., Garb, J. & Smithline, H. Electrolyte profile of pediatric patients with hypertrophic pyloric stenosis. Pediatr. Emerg. care 29, 465–468 (2013).

    Article  PubMed  Google Scholar 

  21. Bašković, M., Župančić, B., Lesjak, N. & Vukasović, I. Hypertrophic Pyloric Stenosis - Five-Year Retrospective Analysis. Acta Med. Croatica Cas. Hravatske akademije medicinskih Znan. 70, 103–106 (2016).

    Google Scholar 

  22. Ramsay, P. T. & Carr, A. Gastric acid and digestive physiology. Surgical Clin. North Am. 91, 977–982 (2011).

    Article  Google Scholar 

  23. McCauley, M., Gunawardane, M. & Cowan, M. J. Severe metabolic alkalosis due to pyloric obstruction: case presentation, evaluation, and management. Am. J. Med. Sci. 332, 346–350 (2006).

    Article  PubMed  Google Scholar 

  24. Palmer, B. F. Potassium binders for hyperkalemia in chronic kidney disease-diet, renin-angiotensin-aldosterone system inhibitor therapy, and hemodialysis. Mayo Clin. Proc. 95, 339–354 (2020).

    Article  CAS  PubMed  Google Scholar 

  25. Terano, C. et al. Incidence of and risk factors for severe acute kidney injury in children with heart failure treated with renin-angiotensin system inhibitors. Eur. J. Pediatrics 175, 631–637 (2016).

    Article  CAS  Google Scholar 

  26. Ndongo, R. et al. Infantile hypertrophic pyloric stenosis: a 4-year experience from two tertiary care centres in cameroon. BMC Res. Notes 11, 33 (2018).

    Article  PubMed  PubMed Central  Google Scholar 

  27. Feng, Z. et al. The clinical features of infantile hypertrophic pyloric stenosis in Chinese Han Population: analysis from 1998 to 2010. PloS one 9, e88925 (2014).

    Article  PubMed  PubMed Central  Google Scholar 

  28. Shaoul, R., Enav, B., Steiner, Z., Mogilner, J. & Jaffe, M. Clinical presentation of pyloric stenosis: the change is in our hands. Isr. Med. Assoc. J. : IMAJ 6, 134–137 (2004).

    PubMed  Google Scholar 

  29. Labrune, P., Myara, A., Huguet, P., Trivin, F. & Odievre, M. Jaundice with hypertrophic pyloric stenosis: a possible early manifestation of Gilbert syndrome. J. Pediatrics 115, 93–95 (1989).

    Article  CAS  Google Scholar 

  30. Hannam, S., McDonnell, M. & Rennie, J. M. Investigation of prolonged neonatal jaundice. Acta Paediatrica 89, 694–697 (2000).

    Article  CAS  PubMed  Google Scholar 

  31. Nobili, V., Alisi, A., Panera, N. & Agostoni, C. Low birth weight and catch-up-growth associated with metabolic syndrome: a ten year systematic review. Pediatr. Endocrinol. Rev. 6, 241–247 (2008).

    PubMed  Google Scholar 

  32. Bhatia, J. Fluid and electrolyte management in the very low birth weight neonate. J. Perinatol. J. Calif. Perinat. Assoc. 26, S19–S21 (2006).

  33. Ezomike, U. O., Ekenze, S. O., Amah, C. C., Nwankwo, E. P. & Obianyo, N. E. Infantile hypertrophic pyloric stenosis - our experience and challenges in a developing country. Afr. J. Paediatr. Surg. 15, 26–30 (2018).

    Article  PubMed  PubMed Central  Google Scholar 

  34. Li, J., Gao, W., Zhu, J. M., Zuo, W. & Liu, X. Epidemiological and clinical characteristics of 304 patients with infantile hypertrophic pyloric stenosis in Anhui Province of East China, 2012-2015. J. Matern. -fetal neonatal Med. J. Eur. Assoc. Perinat. Med. Federation Asia Ocean. Perinat. Societies, Int. Soc. Perinat. Obstet. 31, 2742–2747 (2018).

    CAS  Google Scholar 

  35. Peters, B., Oomen, M. W., Bakx, R. & Benninga, M. A. Advances in infantile hypertrophic pyloric stenosis. Expert Rev. Gastroenterol. Hepatol. 8, 533–541 (2014).

    Article  CAS  PubMed  Google Scholar 

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Acknowledgements

The authors are grateful to those who contributed to this study. We confirm that no Large Language Models (LLMs), including ChatGPT or similar AI-based technologies, were used in the conceptualization, writing, analysis, or editing of this manuscript. All content was independently developed, reviewed, and approved by the authors, ensuring full accountability and compliance with the journal’s authorship criteria.

Funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. The project was funded by the Key Scientific Research Projects of Henan Higher Education Institutions (No. 24A320078), the Science and Technology Research Program of Henan Province (No. 242102310256), and the Nursing Research Special Fund of the First Affiliated Hospital of Zhengzhou University (No. HLKY2023015).

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Authors and Affiliations

Authors

Contributions

F.Y.C. contributed to data curation, formal analysis, and writing of the original draft. Z.D. and D.J. contributed to supervision. C.J., Z.X., Q.X.H. contributed to methodology. W.Y.Y., W.J.Y., L.S.K., D.J. and Z.D. contributed to conceptualization, reviewing and editing, and resources. All authors approved the final manuscript as submitted.

Corresponding authors

Correspondence to Juan Ding or Da Zhang.

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The authors declare no competing interests.

Ethics approval and consent to participate

The study was conducted in accordance with the principles of the Declaration of Helsinki and approved by the Ethics Committees of the First Affiliated Hospital of Zhengzhou University (Approval Number No. 2025-KY-0737-001).

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This was a retrospective study, so the requirement for informed consent was waived.

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Fu, Y., Cheng, J., Zhou, X. et al. Pyloric index: a novel nomogram predictor of metabolic alkalosis in congenital hypertrophic pyloric stenosis. Pediatr Res (2025). https://doi.org/10.1038/s41390-025-04382-6

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