Ultrasound for infantile midgut malrotation: Techniques, pearls, and pitfalls

Midgut malrotation with volvulus is a surgical emergency with potentially devastating outcomes which include short gut syndrome necessitating long-term parenteral nutrition, overwhelming sepsis, and death. The clinical presentation is most frequently with bilious vomiting in the first days-weeks of life, which is non-specific and common. Timely imaging investigation is therefore crucial to prevent delays to diagnosis and treatment and avoid unnecessary surgical exploration in infants with non-surgical bilious vomiting. Fluoroscopic upper gastrointestinal contrast series (UGI) has been the first-line imaging modality to investigate midgut malrotation at pediatric surgical centers worldwide. However, there is a growing body of evidence to indicate that ultrasound (US) has greater diagnostic accuracy than UGI in this context. Furthermore, US offers the benefits of accessibility, portability, lack of ionizing radiation, and the ability to identify alternative diagnoses, and is beginning to attract significant attention and consideration in the literature. Over the last 3 years, we have transitioned to an "US-first" pathway for the investigation of midgut malrotation in infants with bilious vomiting. This pictorial essay illustrates our comprehensive approach, describes unique troubleshooting techniques, and highlights the variably published pitfalls we have encountered with the aim of encouraging wider adoption.