[Abdominal CSF pseudocyst recurrence in a 14-year-old patient with ventricular-peritoneal shunt]

Abdominal cerebrospinal fluid (CSF) pseudocyst is a rare complication of ventricular-peritoneal shunt (VPS) but needs to be considered in every patient with abdominal complaints or signs of intracranial hypertension (IH). The pathogenesis of pseudocysts remains unclear. Diverse predisposing factors have been proposed such as previous abdominal surgeries, multiple VPS revisions, infections, history of necrotizing enterocolitis, and nonspecific inflammatory processes. We report the case of a 14-year-old patient, known to have a VPS as intraventricular hemorrhage treatment, presenting cephalalgia, vomiting, apathy, and an indurate abdominal mass without fever. The first abdominal CSF pseudocyst diagnosis had been established 3 months earlier. Abdominal ultrasounds confirmed a large homogeneous cyst with the shunt tip within the pseudocyst. Cerebral CT revealed an increased ventricular size. An exploratory laparotomy with cyst aspiration, lysis of adhesions, excision of cystic walls, and repositioning of the peritoneal catheter was performed. No antibiotics were initiated given that the cultures were negative. Ultrasonography proved to be the method of choice in the diagnosis of VPS abdominal complications, especially CSF pseudocyst. CT can also reliably confirm the pseudocyst. In case of IH signs, a cerebral CT scan can be performed to evaluate the ventricular distension and to check the shunt position. Various methods to process the cyst have been described in the medical literature, but the recurrence rate remains elevated (25-100%). Then the probability of an infection without any clinical sign has to be considered. In case of suspected infection, the VPS is removed and replaced by an external ventricular drain. Antibiotics are started and adjusted to the results of the CSF culture. If there is no direct sign of infection, only the distal catheter is externalized and antibiotics are introduced until infection is treated. Depending on the peritoneal absorption state, the distal catheter is replaced in the abdominal cavity or in the atrium, the pleural space or the gallbladder if there is no suitable place for repositioning. If the peritoneal state allows it, a laparoscopic procedure is recommended to avoid peritoneal adhesion formation increasing the recurrence rate of CSF pseudocyst.