Transanal protrusion of ventriculoperitoneal shunt via appendicular perforation: A rare case report.

Perforation of abdominal viscera and protrusion of the distal end of ventriculoperitoneal shunt (VPS) through natural orifice is well known but rare complication. We report a case of a transanal protrusion of distal end of VPS through appendix perforation without any symptomatology of prior appendicitis. To the best of our knowledge, no case of such kind has been reported in literature yet. The management plan of these patients should be looked in a different way because they may have underlying inflammation of the appendix and distal end of shunt removal should be done by proper surgical exploration followed by added appendicectomy.

Introduction

Ventriculoperitoneal shunt (VPS) is a well-established cerebrospinal fluid (CSF) diversion procedure in cases of hydrocephalus. There are a lot of complications associated with this procedure and shunt extrusion via different natural orifices is one of them. Transanal and per abdomen shunt extrusion are well documented in literature while shunt extrusion via urinary bladder, vagina, uterus, gall bladder, urethra, and scrotum are sporadically reported in the literature. The distal end of shunt erodes through the wall of hollow viscera, approaches their lumen, and protrudes outside through natural orifices. The distal end of shunt protrusion depends on stiffness of shunt tip, thickness of the wall of hollow viscera, condition of the visceral wall, underlying infection, fixity of viscera, and the operative hand of the surgeon. The incidence of perforation is inversely related to the mobility of gut, and colon is the most frequently perforated viscus due to its immobility.[1]

Case Report

A 10-month-old male child presented with protrusion of shunt tubing from the anus, incidentally noticed by his parents. VPS was done 6 months back for congenital hydrocephalus. The patient had a history of excessive cry along with extrusion of shunt tube through anal orifice [Figure 1a]. CSF was trickling out through the protruded end. On clinical examination, the abdomen was soft, nontender, and bowel sounds were audible on abdominal auscultation. No signs of peritonitis were present. His developmental milestones were delayed, and rests of the neurological examinations were within normal limit. X-ray abdomen erect imaging showed no pneumoperitoneum [Figure 1b]. Computed tomography head showed dilated lateral and third ventricles. The patient was taken up for the removal of previous shunt assembly and placement of new one. At the time of distal end removal, lower end of shunt had retracted back into rectum; hence, we planned to remove that via incision at abdominal insertion point. Two incisions were given, one at the cranial end of shunt tubing, and another one at the abdominal insertion site. The shunt was divided at the abdominal insertion point, and cranial part was pulled out from cranial incision while abdominal part was pulled through the abdominal incision. The abdominal end came out with a perforated appendix. The shunt tube had perforated the appendix and entering through the perforation [Figure 2a and b]. An urgent gastrosurgery opinion was taken and urgent laparotomy via extension of same incision was performed by the gastrosurgeon. Laparotomy showed perforation at tip of appendix by tip of the shunt. After that appendicectomy was done and new shunt assembly was placed on opposite side. Postoperative period was uneventful, and patient discharged from hospital after removal of stitches and is under follow-up.

Figure 1

(a) Protrusion of the lower end of the shunt through anus, (b) a radiograph of a patient showing the course of the lower end of the shunt through a large intestine

Figure 2

(a) An intraoperative photograph showing the appendix coming out of the abdominal incision while pulling the lower end of the shunt which was perforating the appendix at the tip (black arrow), (b) the perforated appendix during appendicectomy

Discussion

VPS is most commonly used and universally accepted surgical procedure for the management of hydrocephalus in children.

A number of complications associated with this procedure are mentioned in literature with abdominal complications accounting for 10–30% of all.[2] Bowel perforation by the tip of the catheter and extrusion of the shunt through external orifices is one of them. Although this is a rare complication and have incidence rate of 0.1–0.7% only.[3] The first case of anal extrusion of distal VPS was reported by Wilson and Bertan in 1966.[4] The duration between shunt surgery and bowel perforation was found to be minimum in infants and was related with the age of the patient. Higher duration was seen in elderly age groups. The interval between shunt insertion to the protrusion of catheter from anus ranges from 2 to 20 months with an average of 6.1 months.[5] In our case, this period was 6 months. Nonenteric visceral perforation has also been sporadically reported in the literature and that includes urinary bladder, urethra, scrotum, vagina, gall bladder, and uterus.[6]

Factors associated with perforation of gut are foreign body reaction, stiff tip of shunt, thin bowel wall in pediatric patients,[67] abdominal infections, silicon allergy,[8] use of trocar for insertion of peritoneal end,[9] previous abdominal surgery, and chronic wear and tear produced by tip of the shunt.[10] Patient with per anal shunt extrusion may or may not present with abdominal peritonitis. Many patients do not present with significant abdominal symptoms because the fibrous tract formed at the perforated site usually seals the perforation and prevents spillage of fecal matter into the peritoneum, which would otherwise lead to peritonitis. Hence, the correct diagnosis may be delayed until a very later stage at which Gram-negative or anaerobic meningitis, encephalitis or ventriculitis has been fully established, leading to significant morbidity and/or mortality to the patients. Mechanism of shunt extrusion is not well-established but most accepted hypothesis is that after bowel perforation shunt tubing propels outside with sequential peristaltic movement of the gut.

In the cases of shunt extrusion through anal opening, most common site of bowel perforation is colon (70%) while in cases of oral extrusion most common site is the stomach.[11] Early diagnosis, adequate clinical, radiological and biochemical evaluation, and prompt treatment are the key to successful treatment. The standard method of treatment is the removal of the extruded shunt system, control of infection, improvement of general condition followed by CSF diversion procedure. The different available alternatives are laparotomy with the revision of the peritoneal end of shunt, conventional exploratory laparotomy and repair of bowel perforation, endoscopic localization of enterotomy site and removal of shunt, shunt removal, external diversion of CSF and use of antibiotics, and later on replacement of VPS when no infection are seen. In uncomplicated cases of shunt extrusion, shunt tubing can be removed via extruding orifice and bowel perforation can be managed conservatively while in complicated cases shunt removal is advised via a laparotomy. Appendicitis after ventriculoperitoneal shunting is a known complication but to best of our knowledge shunt extrusion via appendicular perforation is not documented in literature yet. In such cases, shunt removal via extruding orifice may be quite difficult. Theoretically, there are high possibilities of associated appendicitis which can result in the development of frank peritonitis or appendicular abscess after shunt removal through extruding orifice. Management in such type of cases is difficult and needs to be individualized. So in our opinion, such type of cases whether complicated or not should be placed in special category and shunt removal should be done via laparotomy and followed by prophylactic appendectomy.

Conclusion

Perforation of hollow viscera of abdominal cavity is uncommon complication after VPS surgery. Shunt extrusion may also occur through appendicular perforation. Such type of case should be consider in special category in which shunt removal without proper surgical exploration and added appendicectomy may be quite difficult and hazardous for the patient. Optimal management plan in such type of cases either uncomplicated or complicated is laparotomy and removal of the shunt with added appendicectomy.

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Conflicts of interest

There are no conflicts of interest.