Sterile cerebrospinal fluid ascites, hydrothorax and hydrocele as a complication of ventriculoperitoneal shunting in an elderly patient

Background

A ventriculoperitoneal (VP) shunt is the most frequently used treatment for hydrocephalus. Approximately 20 947 shunts were inserted between 2004 and 2013 in the UK and Ireland.1 Despite the frequency of VP shunt placements, complications are relatively common, occurring in 11%–25% of patients, with shunt obstruction and infection being the most common causes of shunt failure.2 Sterile cerebrospinal fluid (CSF) ascites is a rare complication of VP shunt for which a literature review revealed 65 cases in English. Of these cases, the vast majority are of paediatric cases, with only one known reported case of an elderly patient above the age of 65.3 We present a case of sterile CSF Ascites in an elderly man complicated by bilateral pleural effusion and bilateral hydrocele which was diagnosed by ligation of VP shunt.

Case presentation

An 89-year-old patient presented with abdominal distension for the past year. He has a history of gastritis, duodenal erosion, percutaneous endoscopic gastrostomy (PEG) tube placement for oesophageal dysmotility and normal pressure hydrocephalus for which a VP shunt was placed in 2009. He underwent PEG tube placement in 2017 for oesophageal dysmotility. A CT of his abdomen completed a few months after this operation showed a small amount of ascites proximal to his right VP shunt and a right pleural effusion. He underwent a midline incisional hernia repair in 2019 and was readmitted to an external hospital 3 months after for abdominal and scrotal bloating. At that time, he was found to have large abdominal ascites, small bilateral hydrocele and bilateral pleural effusions. Given the patient’s history of torsemide for chronic lymphedema in his legs, he was discharged on an increased dose of torsemide. The patient presented to our hospital 6 months after with reports of worsening abdominal bloating and bilateral scrotal swelling, despite his increased dose of torsemide.

Investigations

CT of the abdomen and pelvis showed massive ascites (figure 1). Ultrasound of his scrotum showed moderate bilateral hydroceles (figure 2). Chest X-ray showed small bilateral layering pleural effusions (figure 3). Paracentesis was completed, removing 2.7 L of clear yellow ascitic fluid with a total protein of 2.5 g/dL, albumin of 1.5 g/dL, glucose of 155 mg/dL and a serum-ascites albumin gradient of 1.3. His blood albumin level was 2.8 g/dL. The normal reference range for blood albumin is 3.5–5.2 g/dL, but it would be expected to be lower for elderly patients. No leucocytes or organisms were isolated from culture and cytology did not show malignancy. A Doppler liver showed no evidence of portal or hepatic thrombosis. CT and ultrasound of the abdomen did not show any signs of liver cirrhosis or metastasis. An echocardiogram showed a left ventricle ejection fraction of 55% and grade 1 dysfunction. Urinalysis was negative for proteinuria, glucosuria or haematuria. The patient’s abdomen gradually reaccumulated fluid, and a repeat paracentesis was done 10 days later, drawing another 1.6 L of similar clear yellow fluid.

Differential diagnosis

The most common cause of ascites is liver cirrhosis in the setting of portal hypertension (accounting for 85% of ascites), which was ruled out in this patient given his lack of alcohol use, normal liver function enzymes and non-significant abdominal CT and ultrasound findings. Malignant ascites (accounting for 10% of cases) was ruled out given his negative cytology, negative signs of metastases on imaging and lack of suggestive symptoms such as fatigue or recent weight loss. Other causes including heart failure, nephrotic syndrome and infection were also ruled out with normal findings on echocardiogram, urinalysis and ascitic fluid culture.

Given his history of repeated abdominal surgeries and timing of the ascites accumulation around the time of those surgeries, CSF ascites due to peritoneal irritation was considered.

Treatment

Neurosurgery was consulted and determined there was no stable site for replacement of shunt given the patient’s age and comorbidities. A decision was made to ligate the shunt with the option of reversing the ligation should the patient develop neurological symptoms. The procedure was completed under local anaesthesia at the bedside. The shunt catheter was accessed inferior to the clavicle where it was easily palpated below the skin and was ligated via knots by two silk sutures. Shunt ligation would verify whether the patient’s ascites source was from the VP shunt and also act as a potential long-term minimally invasive treatment.

Outcome and follow-up

The patient’s follow-up abdominal ultrasound and chest X-ray 1 month after discharge showed resolution of the ascites and pleural effusion (figures 3 and 4). The patient also stated that his scrotal swelling had improved significantly. However, he noted he had worsening of his chronic headaches after shunt ligation. CT of his head did not reveal any changes (figure 5) but given the patient’s headache and his desire to reopen his shunt, his VP shunt was reopened. The patient was readmitted 2 months following reopening of his shunt for generalised weakness. A CT scan of his abdomen at the time revealed reaccumulation of a moderate amount of ascites and bilateral pleural effusions (figure 6). The patient stated at the time that his stomach did feel bloated, but it had not been uncomfortable enough that he would want a paracentesis completed. On follow-up 7 months after shunt reopening, the patient reinforced that while he had experienced chronic abdominal bloating, it had not bothered him enough to desire a repeat therapeutic paracentesis.