Adv Pediatr Surg.  2020 Jun;26(1):15-22. 10.13029/aps.2020.26.1.15.

Analysis of Ultrasonic Parameters of Pylorus in Idiopathic Hypertrophic Pyloric Stenosis Patients: A Retrospective Study

• Sim J
• Hong J

• KMID: 2525493
• DOI: http://doi.org/10.13029/aps.2020.26.1.15

Abstract

Purpose
Pyloric muscle thickness (PMT) equal to or greater than 4 mm and canal length equal to or greater than 15 mm are used to be widely accepted for diagnosis of idiopathic hypertrophic pyloric stenosis (IHPS). However, up to 25% of IHPS patients show ultrasonic parameters discordant to current diagnostic criteria. The authors tried to look if previously suggested criteria could be applied to the IHPS patients of a single center and find new concepts by analyzing the ultrasonic parameters and patient characteristics. Method: Medical records and ultrasonography (US) of 131 IHPS patients who received pyloromyotomy from 1994 to 2016 were reviewed. All presented with characteristic clinical symptoms. The patients were divided into 2 groups according to their eligibility for current criteria used in the authors' institution, as discordance group (n=32) and concordance group (n=99). Baseline characteristics were reviewed, and ultrasonic parameters were measured, and then the volume of pylorus was estimated by calculation using the measured parameters.
Results
The proportion of neonates was greater and the mean postconceptional age was younger in Discordance group than that of Concordance group at the time of US examination. Average weight at the time of US were lighter in discordance group than those of concordance group, as well. Also, mean pyloric volume (PV) and proportion of PMT/pyloric diameter were lesser in discordance group (1.72±0.49 mL vs. 2.98±0.87 mL and 31.87%±3.24% vs. 35.06%±3.61%, p<0.001), while mean luminal volume was similar in both groups. Postconceptional age and being neonate were significant variables for PV after multivariate linear regression (R ² =0.390).
Conclusion
The calculated PV of IHPS patients was strongly related to their postconceptional age, and it suggested that the diagnostic criteria may differ according to the patients' sizes and the time of their diagnoses. Future diagnostic criteria for IHPS should be applicable even with the dynamic nature of the patients.

Keyword

Hypertrophic pyloric stenosis; Ultrasonography; Pylorus; Neonate