Journal of Indian Association of Pediatric Surgeons Medknow Publications on behalf of the Indian Association of Pediatric Surgeons ISSN: 0971-9261 EISSN: 1998-3891 Vol. 12, Num. 4, 2007, pp. 214-217

Journal of Indian Association of Pediatric Surgeons, Vol. 12, No. 4, October-December, 2007, pp. 214-217

Original Article

Abdominal cerebrospinal fluid pseudocysts in patients with ventriculoperitoneal shunts: 30 years of experience*

Sanal M, Laimer E, Haussler B, Hager J

Department of Pediatric Surgery, University of Innsbruck, 6020
Correspondence Address:Department of Pediatric Surgery, University of Innsbruck, Anichstr. 35 - 3N, Innsbruck - 6020, alimsanal@mail.com

Code Number: ip07069

Abstract

Keywords: Abdominal pseudocyst, Children, Hydrocephalus, Ventriculoperitoneal shunt malfunction

Introduction

At present, ventriculoperitoneal drainage of the cerebrospinal fluid (CSF) is the preferred treatment of hydrocephalus in children. Although this is the preferential method, it is not free from complications. ^[1],[2],[3] Abdominal pseudocyst formation is an infrequent complication and is characterized with signs of shunt malfunction and/or abdominal symptoms.

Within the last 30 years, 392 children who had hydrocephalus with various etiologies received a VP shunt. Abdominal CSF pseudocysts developed in eight patients. Five of them had recurrences over a period of 2 months to 3 years.

The treatment consists of the excision of the cyst, external drainage and then reconstruction of the entire shunt system.

Materials and Methods

Results

Eight out of 392 hydrocephalic patients developed abdominal CSF pseudocysts and were treated by laparotomy. Cyst excision, externalisation of the catheter and antibiotic therapies have been carried out.

In five children (RP, SK, AB, BR and FV), a recurrence developed over a period ranging between 2 months and 3 years. The recurrences were similarly managed by excision, shunt externalisation and antibiotic therapy [Table - 1].

The blood and CSF analysis are summarised in [Table - 2]. The CSF cell count and the glucose concentration were in normal range in all the cases.

In four children, the blood analysis were normal whereas the other four showed elevated CRP and there was no relationship between bacterial growth and elevated CRP [Table - 2].

The cyst formation was confirmed by abdominal ultrasound. Laparotomy was performed in all the cases. During laparotomy, cyst excision and externalisation of the catheter was conducted. The peritoneum and intestinal serosa localised around the tip of the peritoneal catheter were hyperaemic and oedematous in all the patients [Figure - 1].

The aerobic and anaerobic culture of the tip of the peritoneal catheter revealed that in five cases, the following bacterial growths were found: Propionibacterium acnes , Streptococcus viridans , Enterococcus faecalis , Staphylococcus albus , Staphylococcus aureus and Coagulase-Negative Staphylococcus [Table - 1].

Discussion

The ventriculoperitoneal drainage of the CSF is presently the preferred treatment for hydrocephalic children; however, still there are complications. Abdominal pseudocyst formation with signs of shunt malfunction and/or abdominal symptoms is very infrequent, but they are important complications. ^{[2],[3],[4],[5],[6]} In the literature, the incidence of the formation of CSF pseudocyst ranged between 2 and 5%. Rainov described an incidence of 4.5%. ^[6] In our series, we observed an incidence of pseudocyst formation of 2.04%.

In young patients, the main symptoms are abdominal pain and the signs of elevated intracranial pressure, whereas the adult patients with a VP shunt present in the first instance with local abdominal signs. ^[6],[7] In our patient population, we observed only a 4-year-old girl who primarily presented with abdominal symptoms such as abdominal pain and diarrhoea. The other children presented with symptoms of elevated intracranial pressure, as described in literature.

The term "pseudocyst" is used when the cyst is without epithelium and its walls consist of intestinal serosa and peritoneum. ^{[4],[7],[8],[9],[10]} As in other reported cases, the pathological examination showed chronic inflammation and a possible foreign body reaction.

There are many speculations about the etiology of the abdominal CSF pseudocyst formation; However, to date no clear reasons could be found. ^[5]

We assume that the "pseudocysts" are caused by the chronic irritation of the peritoneum and also a foreign body reaction could become important. The reaction of the peritoneum and the intestinal serosa is apparently noninfectious but a poorly understood inflammatory process. ^[6],[8],[10] In our patients, this inflammatory process was particularly located around the tip of the peritoneal catheter. The pseudocysts were histologically examined. Histological evaluation showed typical signs of pseudocysts with a cyst wall without epithelium and its walls comprise intestinal serosa, peritoneum and granulation tissue. In some supplements, fibrosis on the cyst wall and histiocytosis were observed.

An inflammatory reaction due to the starch granules from the surgical gloves has been discussed. There is a report with reference to silicon allergy; however, these children had recurrent skin breakdown over the shunt tract without any abdominal symptoms. ^[11] Since 1986, we are using latex-free gloves while inserting a VP shunt or excising pseudocysts in patients.

The cysts can be easily detected by ultrasound. In our studies, the intraabdominal cysts were located by ultrasound [Figure - 2].

The operative management of the CSF pseudocyst comprises cyst excision and externalisation of the catheter. After appropriate antibiotic therapy, the catheter can be replaced into the peritoneal cavity; moreover, the transfer to a ventriculoatrial system is possible. ^{[4],[5],[6],[7],[9]}

Many authors accept this schedule and agree with the concept that distal catheter can be replaced in almost all cases in the peritoneal cavity after adequate treatment with the externalisation of the catheter and antibiotic therapies. ^{[4],[7],[8],[9]}

The excision of the pseudocysts had been carried out in all our cases. The excision of the cyst is complicated; therefore, it is essential to operate it very meticulously. After the externalisation of the catheter, we favour to insert a VP shunt to protect the heart from an overload that could be caused by a fairly long term of the ventriculoatrial shunt system.

The literature search revealed that there are different outcomes of the excision of pseudocysts. In some studies, the recurrence is very rare whereas other authors described several cases. ^{[4],[6],[7],[8]} In our study, we have a large number of relapses of pseudocysts. Five patients had recurrences over a period of 2 months to 3 years.

There are few reports in the literature that show the sterile culture of the CSF and the tip of the distal catheter. ^[4],[7] In case of an infection, Staphylococcus epidermidis or Propionibacterium acnes could be detected. ^{[6],[7],[8],[10],[12],[13]} In order to distinguish between an infected and a noninfected pseudocyst, it is important to be aware of the fact that Staphylococcus epidermidis grows slowly and requires prolonged incubation. ^[4],[7],[10]

Prolonged aerobic and anaerobic cultures should be performed to detect any organism. In our series, Streptococcus viridans , Enterococcus faecalis , Coag. Neg. Staphylococcus , Staphylococcus albus , Staphylococcus aureus and Propionibacterium acne s in the distal catheter tip could be detected [Table - 2].

One of our patients, a 4-year-old girl (TV), showed predominant abdominal symptoms such as high fever (39-39.5°C), abdominal pain and diarrhea. During her operation, we could observe inflammatory reactions along the abdominal catheter, and the thickening of the peritoneum could be established [Figure - 3].

The hematological signs of infection such as high CRP and leucocytosis could be shown only in four cases. The relationship between the bacterial growth and a high level of CRP could not be found [Table - 2].

In all cases, the spinal protein, CSF cell count and glucose concentrations were normal. The follow-up over a period of 3-7 years did not show any recurrence and no other complications were developed. In all our cases, the same operation technique were performed: cyst excision, externalisation of the catheter followed by appropriate medical antibiotic therapy over a period of of 10 to 15 days. A new VP shunt is placed after getting two sterile consecutive CSF cultures.

References

Copyright 2007 - Journal of Indian Association of Pediatric Surgeons

The following images related to this document are available:

Photo images