Pyloric stenosis: is over-reliance on ultrasound scans leading to negative explorations?

To see whether increasing use of ultrasound scans in pyloric stenosis is leading to false-positive diagnoses, and even negative laparotomies.

Over a 2-year period, 76 neonates underwent laparotomy with a preoperative diagnosis of pyloric stenosis (PS). There were 57 males and 19 females, age ranged from 10 days to 7 weeks.

Six patients proceeded straight to surgery after undergoing a test feed. The remaining 70 patients had one or more imaging investigations. Of these; 56 patients had an ultrasound only, 5 had a barium meal only while 9 patients had both investigations. Ultrasound showed evolving lesions in 2 patients. It was equivocal or falsely negative in 8 - all were diagnosed correctly after undergoing barium meals. Fifty-two patients were diagnosed correctly on ultrasound. There were, however, 3 false-positive ultrasonic diagnosis--i.e., at laparotomy the pylorus was found to be normal. One of these patients even had a "diagnostic" barium meal. The factors leading to these negative explorations are discussed.

Pyloric "tumours" can be difficult to palpate early in the evolution of the disease. Reliance upon the ultrasound appearance of the pylorus without taking into account other important diagnostic evidence will increase the risk of false-positive diagnoses and unnecessary laparotomy. The importance of clinical examination and test feed is emphasised.