Ultrasound diagnosis of hypertrophic pyloric stenosis – Time to change the criteria

Abstract

Introduction Ultrasound is the examination of choice for the diagnosis of hypertrophic pyloric stenosis (HPS). A correct diagnosis is dependent on the technique and measurement accuracy. However, in the world literature there is a wide range of values suggested for the diagnosis of this condition. The current minimum measurements used to diagnose HPS seem excessively large, and therefore, we set out to redefine these values. Methods A retrospective study was performed on 607 patients (615 scans) being investigated for HPS. The length and transverse diameter of the pyloric canal, and thickness of the pyloric muscle were measured. All results were correlated with clinical and surgical findings. Results In this study, the muscle thickness in the normal group was <2.0 mm than in HPS infants having a muscle thickness of 2.0–5.0 mm. All the pyloric canal lengths in the normal group were <5.0 mm than in those with HPS having a length of 10.0–24.0 mm. The transverse diameters ranged from 6.0 to 11.0 mm in the normal group compared with those with HPS having a diameter between 8.0 and 16.0 mm. Conclusions The current criteria for sonographic diagnosis of HPS should be redefined. The canal length is the single most important discriminator, with a clear separation between normal and abnormal. The commonly used 16.0‐mm measurement is too long and should be reduced to 10.0 mm (without the risk of false positives). In many cases, the muscle thickness in those with HPS is as low as 2.0 mm, considerably less than the 3.0 mm that is currently used. The transverse diameter is not a useful discriminator for HPS. The use of current values will delay the diagnosis and timely treatment of this condition.

Ultrasound evaluation of the stomach and pylorus in the neonate and baby

“…The normal thickness of the pyloric muscle is less than 2.0 mm. 27 Elongation of the canal is readily apparent in a longitudinal view (Figure 9), while thickening of the circular muscle is best demonstrated in a transverse view (Figure 10). These patients typically present at approximately 4 or 5 weeks of age with a history of increasing vomiting after feeds, frequently projectile.…”

“…HPS, also known as idiopathic HPS but usually abbreviated to pyloric stenosis, is a condition in which there is lengthening of the pylorus and hypertrophy of its circular and, to a lesser degree, longitudinal muscle fibres, resulting in compromise of the pyloric canal and outlet obstruction of the stomach. 26 The length of a normal pylorus is 4.6 mm or less 27 (Figure 7).…”

Ultrasound research – Sometimes you win, sometimes you lose

“…In another large clinical cohort, Piotto et al 3 present their data, suggesting that the pyloric muscle reference values used as part of the workup for hypertrophic pyloric stenosis may be outdated and, indeed, incorrect, which can lead to delays in diagnosis. The published reference values have not changed much in three decades, yet ultrasound techniques and imaging quality have surged ahead, so this is not surprising that measurement thresholds have changed.…”

“…In another large clinical cohort, Piotto et al 3 . present their data, suggesting that the pyloric muscle reference values used as part of the workup for hypertrophic pyloric stenosis may be outdated and, indeed, incorrect, which can lead to delays in diagnosis.…”

“…Srigandan et al 1 present real-world evidence of the application of attenuation imaging (ATI) to diagnose hepatic steatosis beyond hepatorenal index, which is an older technique. Ferraioli et al 2 showed in 2019 that this ATI was very promising in a pilot study under carefully controlled conditions, and Srigandan et al 1 found that when this was applied to their clinical cohort, in usual clinical practice, it also outperformed the hepatorenal index.In another large clinical cohort, Piotto et al 3 present their data, suggesting that the pyloric muscle reference values used as part of the workup for hypertrophic pyloric stenosis may be outdated and, indeed, incorrect, which can lead to delays in diagnosis. The published reference values have not changed much in three decades, yet ultrasound techniques and imaging quality have surged ahead, so this is not surprising that measurement thresholds have changed.…”