PYLORIC STENOSIS: A RETROSPECTIVE STUDY OF AN AUSTRALIAN POPULATION

INTRODUCTION: Infantile hypertrophic pyloric stenosis (IHPS) is a common cause of nonbilious vomiting in infants. The “classic” presentation is one of a firstborn boy who is aged 2 to 8 weeks and has projectile vomiting; palpable olive, visible peristalsis; and hypochloremic metabolic alkalosis. With increased awareness of the condition and readily available ultrasonographic diagnosis, classic presentations may be becoming less common. OBJECTIVE: We sought to describe the epidemiology, clinical features, and outcomes of children with IHPS at our institution. METHODS: We conducted a retrospective case review of all cases of IHPS that presented to our tertiary pediatric hospital in an 11-year period. RESULTS: The inclusion criteria were met by 330 children with confirmed IHPS. A total of 84% of patients were male, and 19% were born preterm. Preterm infants tend to present later, reflecting postmenstrual age. The median age at presentation was 36 days (range: 7–218 days) with mean symptom duration of 11 days (range: 1–95 days). Whereas 87% of patients had at least 1 classic finding on history or examination, only 14% had the classic triad. Elevated bicarbonate was present in 61% of blood samples, whereas hypochloremia was found in only 29%. Ultrasound confirmed the diagnosis in 89%. Surgical techniques were similar in outcome, except that incomplete pyloromyotomy was more common with the laparoscopic approach compared with the periumbilical approach (6% vs 1%). CONCLUSIONS: IHPS occurs more frequently in boys and infants who were born preterm. It commonly presents without the full spectrum of classic findings. Given the availability of ultrasound diagnosis, IHPS should be considered in infants with any 1 of these findings.