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 . extrusion of the peritoneal end of the shunt through intact abdominal wall is extremely rare and few cases have been reported in the literature . we are reporting two such rare cases of spontaneous extrusion of the peritoneal catheter through the intact abdominal wall . 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 . spontaneous extrusion of the distal peritoneal catheter through the intact abdominal wall 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 . 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 , the peritoneal catheter protruded from the upper abdominal wall near the epigastrium away from the previous surgical incision . 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 . computed tomography ( ct ) of the head revealed dilated ventricles on the postoperative day 3 . the patients were discharged after 8 days with the advice for periodical checkups . at 6-months follow - up 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 . 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 . 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 , the peritoneal catheter protruded from the upper abdominal wall near the epigastrium away from the previous surgical incision . 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 . computed tomography ( ct ) of the head revealed dilated ventricles on the postoperative day 3 . the patients were discharged after 8 days with the advice for periodical checkups . at 6-months follow - up there have been a number of reports of complications relating to the peritoneal section of vps . 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 . others are transoral or transanal protrusion , extrusion through the scrotum , and formation of abdominal pseudocyst , etc . , spontaneous extrusion of the distal peritoneal catheter through the intact abdominal wall is very rare . the sharp tip at the distal end of the catheter is blamed for higher complication rates . various hypotheses have been put forward regarding causes of spontaneous extrusion of the peritoneal catheter through the intact abdominal wall or chest wall . 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 . other factors that may contribute to shunt extrusion include poor host immunity , factors related to surgical technique , and bioreactivity of shunt components . 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 . . meningitis or ventriculitis secondary to retrograde migration of bacteria should be treated according to the culture - antibiogram results . 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 .
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 .