Spontaneous extrusion of peritoneal catheter of ventriculoperitoneal shunt through the intact abdominal wall: Report of two cases.

Among the various complications associated with ventriculoperitoneal shunt (VPS) surgery, migration of the peritoneal catheter is one of the rarest complications. We report two cases of spontaneous extrusion of the peritoneal portion of the VPS through the intact abdominal wall at an area unrelated to the surgical incision. Both were conscious and had no neurological deficits. There were no signs of infection. The peritoneal end of the shunt was removed through the abdomen. Shunt revision was performed. The patients were discharged 8 days after the revision without any complications. At 6-month follow-up, both of them are doing well. Possible mechanisms of abdominal wall perforation are discussed. Pulling the extruded peritoneal end through abdominal wall decreases the possibility of infection and is probably the best way of management.

Introduction

Ventriculoperitoneal shunt (VPS) surgery is the commonly used technique for the management of hydrocephalus in pediatric cases. A high range of complications has been reported following this procedure, which are troublesome either to the surgeon or to the patient. The most common complications are shunt infection and obstruction due to the VPS device. Extrusion of the peritoneal end of the shunt through intact abdominal wall is extremely rare and few cases have been reported in the literature.[12] We are reporting two such rare cases of spontaneous extrusion of the peritoneal catheter through the intact abdominal wall.

Case Reports

Case 1

A 7-month-old female baby was admitted to Neurosurgical Department of S.C.B. Medical College and Hospital with the VPS catheter's distal end protruding through the intact abdominal wall [Figure 1]. Three months earlier, she had undergone an installation of a medium-pressure VPS for posttraumatic hydrocephalus. One week prior to her current admission, her mother noticed a painless, small blister, and erythema on the upper abdominal wall, which eroded and gave way to protrude a part of the peritoneal catheter.

Figure 1

Spontaneous extrusion of the distal peritoneal catheter through the intact abdominal wall

Case 2

A 14-year-old boy presented with extrusion of peritoneal end of the VPS catheter through the intact abdominal wall [Figure 2]. Eight years back, he had undergone medium-pressure VPS surgery for hydrocephalus caused by posterior fossa pilocytic astrocytoma. Five days prior to his current admission, he noticed erosion of the upper abdominal wall, through which a part of the peritoneal catheter extruded out.

Figure 2

Extruded peritoneal end of the ventriculoperitoneal shunt catheter through intact abdominal wall

On admission, both of them were conscious and had no neurological deficits. In both cases, physical examination showed an old scar on the right upper abdomen. The peritoneal catheter protruded from the upper abdominal wall near the epigastrium away from the previous surgical incision.

Laboratory examinations were essentially within normal limit. After abdominal ultrasonography (USG) did not show any signs of intra-abdominal pathology, the shunts were removed immediately. The peritoneal catheter was disconnected from the valve chamber by a small skin incision placed behind the ear under local anesthesia and was pulled out from the abdominal wall. Broad-spectrum antibiotic treatment was started. CSF culture was negative. Computed tomography (CT) of the head revealed dilated ventricles on the postoperative day 3. A new VP shunt was put on the opposite side. A postoperative CT showed that the size of the ventricles had decreased. The patients were discharged after 8 days with the advice for periodical checkups. At 6-months follow-up, both are doing well.

Discussion

There have been a number of reports of complications relating to the peritoneal section of VPS.[3] Among them, perforation by the peritoneal catheter was reported to have occurred in the vagina, intestine, umbilicus, and the surgical scar of the abdominal wall.[3] Others are transoral[4] or transanal protrusion,[5] extrusion through the scrotum,[6] and formation of abdominal pseudocyst,[7] etc., Spontaneous extrusion of the distal peritoneal catheter through the intact abdominal wall is very rare.[1] The sharp tip at the distal end of the catheter is blamed for higher complication rates. So, we advocate to use a soft noncutting distal tipped catheter.

Various hypotheses have been put forward regarding causes of spontaneous extrusion of the peritoneal catheter through the intact abdominal wall or chest wall.[18] Etiology of early extrusion of the shunt may include focal wound dehiscence and infection, while delayed presentation may be attributed to ischemic necrosis of dermis overlying shunt components.[8] Other factors that may contribute to shunt extrusion include poor host immunity, factors related to surgical technique, and bioreactivity of shunt components.[8] Superficial peritoneal shunt catheter placement can also cause extrusion of the shunt catheter.[9] It is therefore advised that the trocar should not be used, and the distal shunt should be placed under direct vision.

The shunt can be removed directly without laparotomy only if one is sure that there is no evidence of either abdominal abscess formation or peritonitis. Laparatomy is indispensable in peritonitis cases.[10] Meningitis or ventriculitis secondary to retrograde migration of bacteria should be treated according to the culture-antibiogram results. The cardinal factors preventing mortality are early diagnosis and appropriate treatment. If spontaneous extrusion of the distal peritoneal catheter through the intact abdominal wall is encountered, prophylactic antibiotics should be started without delay and the shunt should be removed completely.

We suggest that the firm tip of the catheter coupled with its movements with respiration produced a hammer effect and eroded the abdominal wall caused local inflammation, and then extruded through the skin. Disconnection of the peritoneal catheter from the chamber and pulling out the extruded catheter through the abdominal wall is suggested as a simple and effective method of removal of the shunt.