ventriculoperitoneal ( vp ) shunt is the preferred treatment for hydrocephalus . vp shunt malfunction causing elevated intracranial pressure may be due to obstruction or catheter fracture , which requires surgical intervention . the obstruction may be proximal ( pump failure ) , or distal within the peritoneum due to adhesions , cerebrospinal fluid ( csf ) pseudocysts , or catheter fracture . when distal obstruction or a catheter fracture is diagnosed , an initial laparoscopic approach may be diagnostic and therapeutic , avoiding the morbidity of a formal laparotomy . laparoscopy permits diagnostic evaluation of the peritoneum , visualization of a patent and functional catheter , and identification and retrieval of a fragmented catheter . reinsertion of the vp shunt using laparoscopy permits diagnostic evaluation , lysis of adhesions as indicated , and safe placement of the vp shunt within a satisfactory peritoneal location . we report our experience with laparoscopic assistance during vp shunt revision or insertion within the peritoneum . from january 2000 through october 2002 , a retrospective analysis was performed on the use of laparoscopy and vp shunt surgeries in children and adolescents . with the patient under general anesthesia , an infraumbilical 5-mm step port ( tyco healthcare , norwalk , ct ) is placed by using the hasson technique . using carbon dioxide ( co2 ) , a pneumoperitoneum of 10 mm hg is achieved and a 5-mm 30-degree scope is advanced through the step port into the peritoneum . with regards to the pneumoperitoneum , we do not routinely clamp the vp shunt , relying on the functioning 1-way valve in the vp shunt circuit instead . a second 5-mm step port is placed under direct visualization , either in the right or left mid abdominal wall . the second port is used as a working port for catheter retrieval , catheter positioning or repositioning , lysis of adhesions , or fenestration of csf pseudocysts . laparoscopic lysis of adhesions and fenestration of csf pseudocysts is performed using electrocautery or sharp dissection using laparoscopic scissors , or both , and the maryland dissector . placement of the distal vp shunt is performed by making a small stab incision under the costal margin and inserting a sharp groove director into the peritoneum under direct visualization . the vp shunt is then advanced into the peritoneum via the groove director and optimal positioning is achieved using a laparoscopic maryland dissector . documentation of a functional catheter is achieved by viewing csf dripping out of the catheter tip . in cases of suspected vp shunt infection , peritoneal fluid is aspirated via the 5-mm working port and sent for culture . this study was reviewed and approved by the colorado multiple institutional review board ( comirb # 04  0768 ) . indications for laparoscopic assistance were malfunctioning shunt , presumed shunt dislodgment or fracture , reinsertion after externalization , and primary shunt placement in obese patients or patients with multiple previous abdominal surgeries . one patient was converted to a ventriculopleural shunt due to an inability to achieve adequate surface area after adhesiolysis . five ( 45% ) patients had adhesiolysis with repositioning of a functional vp shunt ( figure 1 ) . three ( 27% ) patients had retrieval of a fractured catheter and reinsertion of a new vp shunt ( figure 2 ) . abdominal radiograph demonstrating a ventriculoperitoneal shunt fracture with migration of the proximal catheter out of the peritoneum . two ( 18% ) patients had laparoscopic confirmation of a functioning catheter in a satisfactory position , requiring no revision ( figure 3 ) . one ( 9% ) patient had the initial vp shunt inserted with laparoscopic assistance due to obesity . intraoperative photo demonstrating a functional ventriculoperitoneal shunt catheter with cerebrospinal fluid exiting the catheter , requiring no revision . operative time for laparoscopy ranged from 30 minutes to 60 minutes and was performed concurrently with the neurosurgery team . over a 2-year period , an initial laparoscopic approach was performed in 17 patients with a vp shunt malfunction requiring surgical intervention . we were able to safely and effectively perform laparoscopic vp shunt placement in 65% of the cases , offering these patients the advantages of laparoscopy over laparotomy . in 1 patient , the laparoscopic approach was used for the initial placement of the vp shunt because of the patient 's obesity . the remaining cases were all reoperative , accounting for the 35% conversion rate from dense adhesions . because the average patient with hydrocephalus undergoes 2.1 shunt revisions every 3 years an initial laparoscopic approach is advocated when a distal obstruction is due to adhesions or pseudocysts . laparoscopic adhesiolysis or pseudocyst marsupialization can be performed safely in most cases by using electrocautery , sharp dissection , or both . although an initial laparoscopic approach was attempted in all cases , 6 patients demonstrated dense adhesions not amenable to safe laparoscopic adhesiolysis . when distal vp shunts disconnect or fracture , their location within the peritoneum can be varied . placement of the working 5-mm port in either the right or left mid abdominal wall is opposite to the planned side of the new catheter . this allows optimal use of this working port for catheter retrieval , repositioning , or initial positioning . moreover , a proximal cause of a nonfunctioning catheter can be evaluated laparoscopically . in 2 cases , we were able to laparoscopically observe proper functioning of the shunt within the peritoneum , requiring no further revision of the intraabdominal portion of the catheter . during pneumoperitoneum , a theoretical risk exists of pressure transmission into the central nervous system . we do not routinely clamp the vp shunt and rely solely on the 1-way valve . visualization of csf dripping out of the functioning shunt confirms that the intracranial pressure exceeds our pneumoperitoneum . a pneumoperitoneum of 10 mm hg using co2appears to be safe and effective for laparoscopic procedures in these patients with vp shunts . if the adhesions are too dense or laparoscopic adhesiolysis can not be safely performed , then conversion to a formal laparotomy is warranted . laparoscopic guidance or revision of vp shunts permits direct visualization and positioning of the catheter within the peritoneum , allowing for optimal functioning . in addition , minimally invasive adhesiolysis , marsupialization of pseudocysts , and retrieval of fractured catheters can be performed safely and without the morbidity associated with a laparotomy . and given that children with vp shunts undergo frequent revisions , laparoscopy appears preferable to laparotomy . moreover
background : ventriculoperitoneal shunt is the preferred treatment for hydrocephalus . 
 known complications include infection , obstruction , and disconnection with the fractured fragment migrating in the peritoneal cavity . 
 we report 17 cases of laparoscopic evaluation and revision of ventriculoperitoneal shunts in children.methods:from january 2000 through october 2002 , we retrospectively reviewed our experience with laparoscopy and ventriculoperitoneal shunts.results:laparoscopy was performed in 17 children with a malfunctioning shunt , presumed shunt dislodgment or disconnection , reinsertion of a shunt after externalization , and primary shunt placement . 
 six patients ( 35% ) were converted to an open laparotomy due to dense adhesions . 
 eleven patients ( 65% ) underwent successful laparoscopic - assisted ventriculoperitoneal shunt placement : 5/11 ( 45% ) had lysis of adhesions or pseudocyst marsupialization with repositioning of a functional shunt , or both ; 3/11 ( 27% ) had successful retrieval of a disconnected catheter with reinsertion of a new catheter ; 2/11 ( 18% ) had laparoscopic confirmation of satisfactory placement and function , requiring no revision ; 1/11 ( 9% ) had an initial shunt placed with laparoscopic guidance due to the obesity . 
 operative time for the laparoscopic procedure ranged from 30 minutes to 60 minutes . 
 all laparoscopic procedures used 1-mm or two 5-mm ports . 
 perioperatively , no adverse neurological sequelae occurred due to the pneumoperitoneum.conclusion:laparoscopic guidance or revision of ventriculoperitoneal shunts permits ( 1 ) direct visualization of catheter insertion within the peritoneal cavity , ( 2 ) satisfactory positioning , ( 3 ) lysis of adhesions or marsupialization with catheter repositioning , or both , and ( 4 ) retrieval of fractured catheters .