Ultrasound Value in the Early Diagnosis and Exclusion of Idiopathic Hypertrophic Pyloric Stenosis: 10 Years Experience at Babylon Governorate

Abstract

Background: Idiopathic Hypertrophic Pyloric Stenosis (IHPS) is one of the most common surgical conditions of early infancy, presenting in 1.5 to 4 per 1000 live births. Despite this high prevalence, the precise etiology remains poorly understood. The diagnosis is made primarily with history and physical examination. Projectile, non-bilious vomiting is the classic presentation of an infant with IHPS. The typical physical exam findings include visible peristaltic waves and palpation of the olive mass in the upper abdomen. In the absence of a palpable mass, an upper gastrointestinal (UGI) barium study or ultrasonographic evaluation will usually make the diagnosis. Ultrasound is the preferred modality to diagnose IHPS. Demonstration of pyloric muscle thickness of 3.5 mm to 4 mm or more and pyloric channel length of 16 mm or more increases the specificity of the ultrasound to 100%. Objectives: This prospective study aims to evaluate the ultrasonographic accuracy in the diagnosis and exclusion of Idiopathic Hypertrophic Pyloric Stenosis in infants presenting with non-bilious vomiting and no palpable pyloric mass, suspected to have IHPS. Patients and Methods: Prospective study carried out between June 2006 and June 2016 at Babylon Maternity and Pediatric Teaching Hospital. One hundred forty-six (146) infants suspected of having IHPS presenting with nonbilious vomiting and no palpable pyloric (olive) mass were enrolled in this study. All infants sent for abdominal ultrasound examination. The sonographic findings categorized as positive and negative IHPS. Surgery done for patients as indicated according to diagnostic positive criteria and the operative findings compared to ultrasound findings. Results: Sixty-nine (69) infants with positive ultrasound criteria underwent surgery and the diagnosis was confirmed intra-operatively for (67) patients, while negative for (2) infants. In (77) infants with negative ultrasound criteria, the diagnosis of IHPS excluded for (75) patients, and all observed and treated conservatively as pylorospasm or chalasia (Gastro-esophageal reflux), only 2 patients then need pyloromyotomy. About 88% of patients with positive ultrasound criteria (69) diagnosed from third to sixth week of age and about 12% of patients in this study were diagnosed later. Sensitivity and the Specificity of ultrasound to confirm the diagnosis of (IHPS) in this study were 97.1% and 97.4% respectively. Conclusion: Ultrasonography is the investigation of choice for early diagnosis of IHPS before significant fluid and electrolyte imbalance occur. It is cost effective, rapid, harmless, non-invasive procedure mostly available and easy to perform. It’s the method of choice for both diagnosis and exclusion of pyloric stenosis. Indication for surgical interference could safely be based on positive ultrasound result.