Anal extrusion of a ventriculo peritoneal shunt tube: Endoscopic removal

Abstract

We describe the extrusion of a ventriculo peritoneal shunt tube from the anus into a 6-year-old boy following the placement of a ventriculo peritoneal shunt for postoperative periventricular tumor-induced hydrocephalus. He was admitted with a complaint of extrusion of a tube through anus on and off during bowel evacuation. He was evaluated with an X-ray of the abdomen which was showing a coiled tube in descending and sigmoid colon, confirmed by sigmoidoscopy. The proximal end was exposed for external ventricular drainage and distal end was removed endoscopically. The patient was watched for peritonitis and managed conservatively. The proximal end of the tube was removed after 5 days of external ventricular drainage and after ruling out ventriculitis and meningitis. Bowel perforation by a ventriculo peritoneal tube is a rare complication. Diagnosis is often difficult and delayed. Most of the bowel perforation is seen in young patients.

Introduction

Ventriculoperitoneal shunt is a commonly performed surgical procedure and offers good results in treatment of hydrocephalus. Various complications have been reported, including shunt infection, migration, and cerebrospinal fluid pseudocyst. The migration of the peritoneal catheter can occur into the abdominal wall, GIT, bladder, vagina, scrotum, and mediastinum. Infections like peritonitis, ventriculitis, and meningitis are other common complications. The rates of reported complications range from 24 to 47% and about 25% of these are abdominal complications. The incidence of intestinal perforation is 0.1-0.7%. However, despite its easy installation, it may lead to few serious and rare complications which warrant early recognition to avoid morbidity and mortality.

Intestinal perforation by the distal end of ventriculoperitoneal shunt is a rare complication with incidence of 0.1-0.7%. Young patients are commonly affected due to weak intestinal wall musculature which can be perforated easily by the hard tipped distal end of the tube. Another reason might be secondary, and chronic, and irritative process. Prompt recognition of this complication is warranted to avoid morbidity and mortality. Removal of the catheter by a less invasive method is advisable in the absence of infection.

Case Report

A 6-year-old male child came with a complaint of left focal seizures with 10 days history. The child was evaluated with a CT scan and MRI and was diagnosed as right frontoparietal oligodendroglioma. The child was operated on April 18, 2008 with excision of tumor. The histopatholgical examination is suggestive of oligodendroglioma grade III. In the same course of hospitalization, the child developed hydrocephalus and managed with ventriculoperitoneal shunt. The clinical and imageological conditions of the child improved after the shunt and he was discharged with advice of postoperative radiotherapy. After 4 months of surgery, the child presented with a complaint of protrusion of a shunt tube through anus with a history of 15 days on and off. On examination, the child was found to be afebrile with no meningeal and abdominal signs. The shunt tube comes out of anus with straining [Figure 1]. The child was evaluated with an X-ray of the abdomen [Figure 2] and sigmoidoscopy which shows coiling of the tube in the descending colon and sigmoid colon with perforation [Figure 3]. The CT scan of the brain showed normal size of ventricles and no pneumocephalus and recurrence of tumor [Figure 4].

Figure 1.

Plain x-ray abdomen with coiling of shunt tube in descending and sigmoid colon

Figure 2.

Clinical photograph of the patient with anal extrusion of a shunt tube

Figure 3.

Sigmoidoscopy view showing perforation of colon

Figure 4.

CT scan of the brain showing a shunt tube in a normal sized ventricle

We managed the case with separation of the proximal portion of the shunt tube from the distal portion and it was exteriorized and external ventricular drainage was connected and cerebrospinal fluid was sent for analysis. Laboratory examination of blood showed that total leukocyte count was 9200mm³ and in differential count neutrophils-62, lymphocy tes-30 and eosinophils-8. Cerebrospinal fluid examination showed nil leukocyte count and sugar level was 40 mg /dl, proteins 219 mg/dl, and chloride 123 meq/dl. Gram strain was negative and culture failed to reveal any organism.

Sigmoidoscopy found that ventriculoperitoneal shunt's distal end was perforating and migrating into the descending and sigmoid colon and it was removed endoscopically. The patient was kept nil by mouth for 48 h being on ryles tube aspiration and intravenous supplementation. External ventricular drainage and ventricular end of the shunt tube was removed after 2 days and the patient was observed for 5 days for any development of peritonitis and raised intracranial pressure features. The patient was doing well without shunt, and CT scan of the brain suggested normal ventricular size, and patient was discharged.

Discussion

Ventriculoperitoneal shunting is most commonly indicated surgical treatment of hydrocephalus; however, the complication rate is relatively high. Mostly due to infection, mechanical obstruction failure of CSF flow is observed. There are a few reports of complications that include the perforation of visceral organs mostly gastrointestinal organs. The reported incidence of bowel perforation by ventriculoperitoneal shunt is 0.1-0.7% with mortality rate as high as 15%.

Bowel perforation and anal extrusion of distal shunt tube are rare and unusual complications. The first case of anal extrusion was reported by Wilson and Bertnad in 1966.[1] Complication like these often occur after a long period following surgery, suggesting that they resulted from a chronic inflammatory process rather than a traumatic event. It has been suggested that analyzed all reports related to these complications published in 84 articles and it has been also suggested that catheter length and the presence of fibrosis around the distal end of the catheter are important factors. An interaction between a silicon tube material of the shunt tube, CSF contents (particularly proteins and glucose) and foremost immunomediators mediated in inflammatory response to infection in the peritoneum have also been proposed and published.

Nishijima et al.[2] suggested two reasons for the frequent occurrence of intestinal perforation caused by the distal end of the shunt tube. Firstly, the intestinal musculature is relatively weaker in children, and is, therefore, perforated easily by hard tip of the catheter. Secondly, the children have stronger peristaltic activity than in older patients, which makes them vulnerable to this type of injury.

It has been observed that intestinal perforation due to shunt cathetriazation can be related to a previously undergone abdominal surgery and prior abdominal infection. Davidson et al.[3] reported that malnutrition and a former abdominal surgery may increase the risk of migration due to adhesions arised from infection.

However, the exact pathogenesis of shunt tube-related organ perforation is unclear, and various mechanisms have been suggested including foreign body reaction, pressure necrosis, poor general condition with weak bowel musculature, and previous inflammations to the bowel wall that may contribute to perforation.[4–10]

In our case the predisposing cause can be malnutrition enhanced chronic irritation that might have weakened bowel wall that lead to perforation.

In view of the high mortality associated with this complication, early diagnosis of bowel perforation is essential. If the catheter left inside, then ascending infection can cause ventriculitis, meningitis, and finally sepsis by migrating intestinal flora through the catheter and its sheath, which are the possible developments. In view of this, paying attention in early diagnosis of this complication is advisable.

Conclusion

Prompt attention is advisable to recognize this complication and endoscopic removal of the shunt tube is advocated in the absence of infection to avoid major operative procedures and related morbidity and mortality.