261 patients shunted for typical hydrocephalus (48.7% male; age = 50.7 ± 21.7) and 93 patients for NBI hydrocephalus (72.0% male; age = 41.8 ± 13.2). For patients with typical hydrocephalus, 29.5% required ≥1 shunt revision, compared with 64.5% with NBI hydrocephalus (P < 1E-5). Of those with malfunction, NBI shunts required more revision operations (median = 3.0; max = 21) than typical shunts (median = 2.0; max = 6; P < 0.05). The censored median time to shunt failure for NBI hydrocephalus was 26.9 months and was not reached for typical etiologies by 180 months. Multivariate analysis showed shunts for NBI hydrocephalus were significantly more likely to fail (hazard ratio = 2.25; 95% confidence interval = 1.58-3.19). A distal pseudocyst was implicated in 30.0% and 2.6% of shunt failures for NBI and typical hydrocephalus, respectively (P < 1E-5). Sixteen (26.7%) NBI shunt failures required revision to lower-resistance systems compared to 6 (7.8%) typical failures (P < 0.05).
Conclusions: Shunts placed for hydrocephalus secondary to nonbacterial infections are complicated by significantly higher rates of malfunction. These patients are prone to develop distal abdominal pseudocysts and often require revision to low-resistance systems 1).
Patients presenting with ventriculoperitoneal shunt (VPS)-related sterile abdominal pseudocysts treated at two institutions between 2013 and 2018 were included. Patients who had undergone abdominal surgery or shunt revisions within a 12-month period preceding presentation were excluded. Information was collected regarding clinical characteristics; hospital course, including surgical intervention(s); and any subsequent complications. Special attention was given to the eventual surgery after pseudocyst resolution, including the use of laparoscopy for peritoneal catheter placement, distal shunt conversion (i.e., in the atrium or pleural cavity), endoscopic third ventriculostomy, or shunt removal. The timing and nature of any subsequent shunt failures were also noted.
Twenty-eight patients met the study criteria, with a mean age of 10 years. The most common etiology of hydrocephalus was intraventricular hemorrhage of prematurity. All shunts were externalized at presentation. One shunt was removed without subsequent internalization. Distal catheters were re-internalized back into the peritoneal cavity in 11 patients (laparoscopy was used in 8 cases). Fourteen shunts were converted to a ventriculoatrial shunt (VAS), and two to a ventriculopleural (VPlS). Two VPSs failed due to a recurrent pseudocyst. The total all-cause failure rates at 1 year were as follows: 18% for VPSs and 50% for VASs.
Following treatment of a VPS-related sterile abdominal pseudocyst, laparoscopy-assisted placement of the distal catheter in the peritoneum is a viable and safe option for select patients, compared to a VAS or VPlS 2).
One hundred thirty-eight patients were treated for hydrocephalus, and 112 patients received a peritoneal catheter during the follow-up. An APC was diagnosed in 14 (12.5%) patients, and 28 revisions were needed for its treatment. The rate of shunt infection in patients with APC was 50%, but bacterial examination of the pseudofluid culture revealed infection in only 3 patients. Age at first surgical procedure, type of first surgical procedure, and etiology of hydrocephalus were not associated with APC diagnosis. APC recurred in 4 patients. These patients had a catheter repositioning directly into the peritoneum as first surgical treatment. No recurrences were observed in patients with shunt externalization or replacement of the peritoneal catheter.
An APC is a major long-term complication after ventriculoperitoneal shunt treatment. Although a sterile inflammatory response cannot be excluded completely, our results favor the hypothesis of low-level shunt infection. In both cases, the surgical consequences are the same. An infected APC should be treated as a shunt infection. Uninfected patients can be treated with shunt externalization and replacement of only the peritoneal catheter 3).
In a retrospective analysis of 4 cases diagnosed to have abdominal pseudo cyst following VP shunt between 2008 and 2013. All the four cases were suspected clinically and diagnosis was confirmed by abdominal ultrasonography.
In three patients, the cyst was multilocular and of varying size. Fourth one had a unilocular cyst at the lower end of VP shunt. All the four patients had features of varying degree raised intracranial pressure and a two patients had abdominal signs also. All the patients needed open exploration. Cyst fluid was drained and partial to complete excision of the cyst was done along with the repositioning of the shunt in abdominal cavity in three patients and exteriorization of shunt in one patient. Patients were followed for any further complication over a period of 1-year 4).
Four unique cases of abdominal pseudocyst formation. The first patient initially presented with a right upper quadrant pseudocyst. Shunt was externalized and the distal end was revised with placement of catheter on the opposite side. He developed another pseudocyst within 5 months of shunt revision and developed another shunt failure.
The second patient had a history of shunt revisions and a known pseudocyst, presented with small bowel obstruction, and underwent laparotomy for the lysis of adhesions with improvement in his symptoms. After multiple readmissions for the same problem, it was thought that the pseudocyst was causing gastric outlet obstruction and his VP shunt was converted into a ventriculopleural shunt followed by percutaneous drainage of his pseudocyst.
The third patient developed hydrocephalus secondary to cryptococcal meningitis. He developed abdominal pain secondary to an abdominal pseudocyst, which was drained percutaneously with relief of symptoms.
The fourth patient had a history of multiple shunt revisions and a previous percutaneous pseudocyst drainage that recurred with cellulitis and abscess secondary to hardware infection.
Abdominal pseudocysts are a rare but important complication of VP shunt placement. Treatment depends on etiology, patient presentation, and clinical manifestations. Techniques for revision include distal repositioning of peritoneal catheter, revision of catheter into pleural space or right atrium, or removal of the shunt completely 5).
A 31-year-old female, in which a large abdominal pseudocyst was developed 1 year after insertion of a ventriculoperitoneal shunt for hydrocephalus. The abdominal CT scan and the ultrasonographical evaluation of the abdomen showed a well defined, cystic mass lesion with a volume of 50 cm3, in the recessus hepato-renal. The peritoneal tip of the shunt was located within the mass lesion. A distal externalization of the peritoneal catheter without excision of the pseudocyst was performed. Cerebrospinal fluid culture demonstrated a Staphylococcus epidermidis infection and adequate antibiotic treatment was administrated. The previous symptoms improved 4 weeks later and a new catheter was placed intraperitoneally in a different quadrant. The postoperative course was uneventful. They suggest that chronic inflammation or subclinical peritonitis is a predisposing factor for this complication 6).
64 cases of APC were found in 36 patients. The records were then reviewed for the presence of infection, history of necrotizing enterocolitis, prior abdominal surgery, and treatment performed. Of the cases of APC, 46 were primary and 18 were recurrent. A history of prior abdominal surgery other than shunt revision was found in 47% of patients and a history of necrotizing enterocolitis was found in 19% of patients. The average number of prior shunt revisions was 4.1 per patient. Shunt infection as defined by positive cultures of either cerebrospinal fluid or abdominal fluid was present in only 23% of cases of APC. A history of prior shunt infection was present in 30% of patients. Infection was treated by shunt removal, external ventricular drainage, and appropriate antibiotics. After the infection was cleared or if no infection was present, treatment consisted of: (1) repositioning the distal catheter into the peritoneum, (2) repositioning the distal catheter into the pleural space, the atrium, or the gallbladder, (3) exploratory laparotomy with lysis of adhesions and repositioning the peritoneal catheter, (4) APC aspiration only, or (5) shunt removal or disconnection. Because of the complexity of APC management, we analyzed the outcomes of our cases and outlined an algorithm to simplify this process 7).
Rainov et al., report on 14 cases of sonographically diagnosed abdominal pseudocysts, an incidence of pseudocyst formation of 4.5%. The most common presentation of the paediatric patients is with symptoms of elevated intracranial pressure and abdominal pain, whereas the adults have predominantly local abdominal signs. Diagnosis is readily made with ultrasonography. Predisposing factors for pseudocyst formation are multiple shunt revisions and infection. Microscopically, the pseudocysts consist of fibrous tissue without epithelial lining. The treatment involves surgical removal of the catheter with or without excision of the pseudocyst wall and placement of a new catheter intraperitoneally in a different quadrant or an intra-atrial shunt. Recurrences are rare, especially under appropriate medical treatment of infection. In this series, microbiologically proven infection was present in 30% of the cases 8).
Five cases of children with abdominal complications of VP shunts (four pseudocysts and one umbilical granuloma with spontaneous drainage of CSF) 9).