Sonographic diagnosis of hypertrophic pyloric stenosis: preliminary experience

The value of ultrasound diagnosis for suspicion of infantile hypertrophic pyloric stenosis (HPS) was assessed in three consecutive years using ultrasound measurement of pyloric muscle thickness (PMT), pyloric diameter (PD) and pyloric length (PL) in Tikur Anbessa Hospital which is a tertiary referral and teaching hospital. Among all patients 39 patients (36 males and 3 females) had Infantile Hypertrophic Pyloric Stenosis confirmed by surgery, with male to female ratio of 12:1. Ultrasound correctly diagnosed all of the cases. Sixty- six patients were negative by Ultrasound, Barium meal studies and clinical follow up. The mean Pyloric Muscle Thickness (4.46 Vs 1.81), Pyloric Length (19.1 Vs 11.55) and Pyloric Diameter (14.05 Vs 8.4) between patients with and with out pyloric stenosis were significantly different (p < 0.05). A PMT of 3 mm and above was observed in all cases of HPS, and was never observed in the absence of HPS (100% sensitivity and specificity). A pyloric muscle thickness of 3 mm and above is recommended as a diagnostic cutoff and upper gastrointestinal series (UGIS) can be reserved for those who might fall in the grey zone (i.e. PMT of 2-3 mm).