Shunt trouble or something else? Diagnosing an abdominal CSF pseudocyst in a child using point-of-care ultrasound.

BACKGROUND

With increasing rates of survival amongst pre-term infants, patients with ventriculoperitoneal shunts are an increasingly common presentation to the emergency department, meaning that paediatricians must be familiar with the potential complications shunts can bring. Abdominal cerebrospinal fluid pseudocyst is a rare complication of ventriculoperitoneal shunts but remains an important cause of distal site failure in children. Irradiating imaging modalities have been traditionally relied upon in the past to help make such diagnoses, however, point of care ultrasound offers many advantages to this and presents itself as a reliable alternative.

CASE PRESENTATION: A 7-year-old girl who was born prematurely at 27 + 6 weeks and had a ventriculoperitoneal shunt inserted as an infant was brought to the Paediatric Emergency Department by her grandparents after they noticed her abdomen was distended. Her grandfather stated that he had replaced her gastrostomy recently and had unable to obtain aspirates for the past 48 h. POCUS revealed a large anechoic fluid collection with the shunt tip visible within it consistent with a CSF pseudocyst. POCUS was also able to confirm position of the gastrostomy balloon in the expected location helping to exclude malposition as a potential differential diagnosis.

CONCLUSIONS

In patients with ventriculoperitoneal shunts, POCUS can correctly identify the presence of abdominal CSF pseudocyst differentiating it from other causes of abdominal distension including gastrostomy-related complications. This case supports the role of POCUS as a safe, reliable first-line imaging tool for diagnosing CSF pseudocysts in patients with ventriculoperitoneal shunts, particularly where previous similar complications have existed.