Transoral extrusion of the ventriculo-peritoneal shunt: A case report and review of literature.

There are several case reports of complications of ventriculo-peritoneal shunt. Extrusion of the peritoneal end of the shunt through mouth is extremely rare. There are few case reports. We are reporting one such case. A 1-year male child was admitted with the peritoneal end of ventriculo-peritoneal shunt coming out through mouth since 6 hours after an episode of vomiting. He was conscious and had no neurological deficits. The anterior fontanelle was depressed. There was no infection. The peritoneal end of the shunt was removed through the mouth. Shunt revision was performed. The patient was discharged 10 days after the revision without any complications. At 1-year follow-up the patient is doing well. Possible mechanisms of bowel perforation are discussed. Pulling the peritoneal end through mouth is probably the best way of management as small spontaneous gut perforation seals off spontaneously. It also decreases the possibility of infection, other morbidities, and hospital stay.

Introduction

Ventriculo-peritoneal (VP) shunting of cerebrospinal fluid (CSF) is a standard procedure for the management of hydrocephalus. Several reports are available about various abdominal complications of VP shunt. The common complications are infection of the shunt, malfunction due to blockage, disconnection, migration, and shunt failure. Other complications reported in the literature include intestinal perforation, CSF ascites, inguinal hernia, and intestinal volvulus. Extrusion of the peritoneal end of the shunt through mouth is extremely rare and few cases have been reported in the literature.[1-8] We are reporting one such rare case of transoral extrusion of the peritoneal catheter.

Case Report

A 1-year, malnourished male child was admitted in our hospital with chief complaint of protrusion of a white tube from mouth since 6 hours. Ventriculo-peritoneal shunt was done for congenital hydrocephalus in some other institution 8 months back. A tube came out from the mouth after a bout of vomiting [Figure 1]. On examination there was cerebrospinal fluid (CSF) coming out from the peritoneal end which increased on pressing the chamber. There was no distention, tenderness, organomegaly or lump palpable in the abdomen. The child was neither excessively crying nor irritable. He was conscious with spontaneous eye opening, had no neurological deficits, and the anterior fontanelle was depressed. There was no evidence of inflammation along the shunt tract. The cerebrospinal fluid study was normal. There was no evidence of peritonitis or meningitis. Ultrasound of the abdomen was normal. The fixation stitch of the proximal end of the catheter was cut by the incision behind the ear and the shunt assembly was cut distal to valve. The ventricular end along with valve was removed through incision behind the ear. Removal of valve from incision behind ear helps in easy removal of the peritoneal tube and also eliminates risk of enlarging gut opening by a comparatively large diameter valve portion of the catheter. The peritoneal end of the shunt was then removed per orally. The patient was kept nil orally for 2 days to look for any evidence of gut perforation. He was then allowed orally and was accepting oral feeds well. Anterior fontanelle started bulging with clinical evidence of raised intracranial pressure. Revision VP shunt was done under antibiotic coverage on the opposite side. The patient was discharged on the 10th postoperative day without any complications. At 1-year follow-up the patient is doing well.

Figure 1

Photograph of the patient showing the peritoneal end of ventriculo-peritoneal shunt coming through the mouth

Discussion

Ventriculo-peritoneal shunt is the most common operation performed in the treatment of hydrocephalus. Complications related to VP shunt are common. Malfunction of the shunt after initial placement occurs in approximately 25–35% of patients at 1 year, and 70–80% of patients require at least one revision at some point in their lives.

The incidence of shunt-related abdominal complications has been reported to be from 5% to 47%. Bowel perforation is a rare complication of shunt placement, occurring in less than 0.1–0.7% of cases,[9] out of which nearly half are diagnosed after removal of the catheter. Perforation of every possible hollow viscus[10] has been reported. These include the colon, stomach, small bowel, urinary bladder, perforation of the fallopian tube with vaginal discharge. Protrusions of the shunt tube through the inguinal canal, perforation of umbilicus, and scrotum have been reported. Few cases of transoral extrusion of VP shunt have been reported in the literature.

Possible mechanisms of spontaneous late gut perforation have been explained in the literature. The exact pathophysiology of late perforation is difficult to establish. The majority of cases in the literature had a delayed presentation after surgery, which suggests a chronic inflammatory process rather than a traumatic event.[10] It has been proposed that the tip of the catheter adheres to and then erode the intestinal wall due to continuous friction at the site of contact.[11] Another mechanism proposed is the perforation of gut by a chronic irritative process in which the catheter adheres to the serosal surface of the bowel by way of foreign body reaction,[112] related to silicone allergy.[13] The repeated pressure on the fixed point slowly produces an ulcer and eventually a perforation.[112] Some authors believe that bowel perforation may be the result of occult shunt infection caused by intraoperative contamination.[10] The infected shunt is rejected through the perforated bowel like an infected foreign body. The predisposing factors for bowel perforation, reported in the literature, are age, male gender, malnutrition, poor general condition, length and type of catheter, previous abdominal operation, infection,[112] and silicone allergy from foreign body reaction.[13] Of these factors, age stands out as the main risk factor for bowel perforation[1] and this has been attributed to weaker intestinal musculature and stronger intestinal peristaltic activity in children.[1] Stiff, hard tipped, sharp, or spring coiled peritoneal catheters are more likely to perforate.

Transoral protrusion of VP shunt is rare.[1-8] Normally the catheter is propelled distally by peristalsis after perforation of bowel. The catheter has to move against the normal peristalsis and also cross the gastro-oesophageal junction and the oesophagus to come out from the mouth. In a case reported by Shridhar et al.,[6] the probable mechanism of bowel perforation was infection, which led to inflammation and adherence of the tube to the proximal gut. Odebode[4] reported that probably the perforation was due to a chronic irritative process in which the catheter adheres to the serosal surface of the bowel by way of foreign body reaction related to silicone allergy. Infection in the Odebode case resulted in shunt rejection due to infected foreign body reaction. Low et al.,[5] in their case, postulated that bowel perforation was due to chronic inflammation and infection. The possible mechanism in our case was a chronic irritation by the catheter tip to the serosal surface of the bowel. This chronic irritation resulted in perforation of bowel. The forceful episode of vomiting was responsible for antiperistaltic movement of the shunt and shunt came out from the mouth. Predisposing factors in our case were age, male gender, mal nourish status, and vomiting.

Management of bowel perforation generally is an emergency.[1] Park et al.[1] did laparoscopic exploration for the tube removal, Odebode[4] performed laparotomy for tube removal and primary repair of bowel, Kothari et al.[3] pulled out the shunt through the incision behind the ear, and Murali et al.[7] and Low et al.[5] removed the peritoneal end by gently pulling the tube through the mouth. We also removed the peritoneal end through the mouth. There were no postoperative complications in any of these three cases removed through mouth.[57]

There could be three ways to remove peritoneal catheter in transoral extrusion of VP shunt. A major laparotomy is probably unnecessary as the opening in the bowel is small and seals off spontaneously.[1] The peritoneal end can be removed through the incision behind the ear. Pulling the extruded peritoneal end in a retrograde manner can result in increased chances of infection. In this method there is always a theoretical risk of infection as the peritoneal end is exposed to atmosphere and the contaminated gut. This was seen in Kothari et al.'s[3] report. In the third method incision is given behind the ear, and peritoneal and ventricular ends are disconnected. The ventricular end is removed from retro-auricular incision. The peritoneal end is removed through the mouth by gentle pull. This method reduces the chances of infection as there is no contact of the contaminated tube to the peritoneum or the shunt tract. There was no infection in Park et al.'s,[1] Murali et al.'s,[7] and the present case.

Conclusion

Transoral migration of VP shunt is very rare. Pulling the peritoneal end through mouth is probably the best way of management in such cases as small spontaneous late gut perforation seals off spontaneously and decreases the possibility of infection, morbidity, and hospital stay.