choledochal cyst ( cc ) is a congenital dilatation of the extrahepatic and/or intrahepatic bile duct , and is commonly associated with pancreaticobiliary maljunction . cyst excision combined with hepaticoenterostomy ( hepaticoduodenostomy or hepaticojejunostomy ) has become the standard procedure for children with choledochal cyst [ 13 ] . the majority ( over 8590% ) . however , 610% of patients need reoperative surgery due to severe postoperative complications , including bile leakage , anastomotic stricture , intrahepatic cholelithiasis , recurrent pancreatitis , adhesive bowel obstruction , and malignancy . the aim of this study was to review our experience with 18 patients who underwent reoperation over the past 20 years . between january 1995 and december 2014 , 275 children with cc were diagnosed and surgically treated in 2 tertiary hospitals ( children s hospital of shanghai jiao tong university and children s hospital of fudan university ) . cysts were categorized according to todani s classification : type ia ( n=176 ) , type ic ( n=64 ) , type iii ( n=1 ) , type iv - a ( n=33 ) , and type v ( n=1 ) . the study was approved by the institutional review board and the ethics board of children s hospital of shanghai jiao tong university and children s hospital of fudan university . written informed consents were obtained from the parents . regular follow - up was carried out by phone or interview in our clinics by an experienced surgeon ( y. wu ) . in this study , procedures performed after primary surgery , such as percutaneous peritoneal drainage ( n=2 ) and gastroscopy ( n=1 ) , were excluded . the medical records of 18 patients who underwent reoperation were retrospectively analyzed , including sex , cyst type , initial procedure , age at time of primary surgery and reoperation , clinical presentations , lab and imaging findings , indications for reoperation , intraoperative findings , and type and results of reoperation . spss 17.0 software package ( spss inc , chicago , il ) was used for statistical analysis . differences in frequency distribution were compared using the  test or fisher s exact test . a p - value of less than 0.05 was considered significant ( =0.05 , two - tailed ) . initial operation was performed by open or laparoscopic cyst excision and end - to - side hepaticojejunostomy using a 30- to 40-cm roux limb without additional anti - reflux procedure . enteric drainage ( roux - en - y cystojejunostomy ) was abandoned after january 1995 . twelve children ( 8 type ia , 4 type ic ) were lost to follow - up . of the remaining 263 patients , 43 children developed early ( less than 30 days , n=18 ) or late ( greater than 30 days , n=25 ) postoperative complications . eighteen ( 6.8% , 15 females ) children required surgical intervention ( table 1 ) . they underwent definitive primary surgery ( 16 open , 2 laparoscopic ) at the median age of 6 years ( range , 11 months to 11 years ) . diagnostic workup before reoperation was carried out , including thorough history - taking , meticulous clinical examination , lab and radiological studies ( abdominal x - ray film , ultrasonography , computed tomography ( ct ) , and magnetic resonance cholangiopancreatography ( mrcp ) . the median time interval from primary surgery to reoperation was 19.5 months ( range , 3 days to 8 years ) . abdominal pain , there was no significant difference in reoperation rate between open and laparoscopic procedure ( 7.5% , 16/212 ; 3.9% , 2/51 ; p=0.539 ) . two early postoperative complications required surgery due to anastomotic bile leakage ( 1 case ) and intussusception ( 1 case ) ( table 2 ) . a 38-month - old girl presented with fever and abdominal pain 6 days after the primary procedure . a ct scan showed perihepatic fluid collection and eventration of the diaphragm on the right side ( figure 1 ) . an 11-month - old girl , vomiting developed 3 days after primary surgery and intussusception was diagnosed by ultrasonography and ct scan ( figure 2 ) . other early complications were managed conservatively with good results , including wound infection ( n=4 ) , wound dehiscence ( n=1 ) , gastrointestinal bleeding ( n=2 ) , chylous ascites ( n=3 ) , acute pancreatitis with pancreatic juice leakage ( n=1 ) , anastomotic leakage ( n=2 ) , and intra - abdominal infection or abscess formation ( n=3 ) . twenty - five late complications occurred and 16 of these patients underwent relaparotomy ( table 3 ) , including intrahepatic bile duct stenosis with stones ( n=3 ) , anastomotic stricture with or without stone formation ( n=5 ) , intrapancreatic cyst remnant ( n=4 ) , adhesive bowel obstruction ( n=3 ) , and internal hernia formation ( n=1 ) . postoperative cholangeitis occurred significantly more often in type iv - a than in type i patients ( 27.2% , 9/33 ; 1.3% , 3/228 ; p<0.001 ) . stenosis of the intrahepatic bile duct and calculus formation developed in 3 type iv - a patients ( figure 3 ) . the time interval between the initial surgery and the first identification of intrahepatic stones ranged from 21 months to 7 years . intrahepatic stenosis occurred near the orifice of the left hepatic duct in all 3 children . organisms cultured from the bile were reported : escherichia coli ( 2 cases ) and negative culture ( 1 case ) . the stenotic bile duct was incised from the hepatic hilum to the dilated segment and irrigated via a catheter . then a wide oblique anastomosis was performed . anastomotic stricture was identified in 5 patients ( 3 type iv - a , 1 type ia , and 1 type ic ) ( figure 4 ) . symptoms of cholangitis , including abdominal pain , high fever , and jaundice , were observed . the stricture including the proximal hepatic duct and jejunal wall was excised en bloc , stones were removed , and intrahepatic bile ducts were lavaged with normal saline . then a redo hepaticojejunostomy was performed . postoperative pancreatitis with or without stone formation was detected in 4 patients ( 2 type iv - a , 1 type ia , and 1 type ic ) after a median follow - up period of 9.5 months ( range , 4 months to 50 months ) . elevated serum amylase levels ( 726250 u / l ) were detected in all 4 children . ultrasonographic examination and ct scan of the abdomen revealed dilated residual cysts in the head of pancreas ( figure 5 ) . radical excision of the dilated cystic remnant was completed in 4 children ( with 1 needing an additional pancreaticojejunostomy procedure due to significant pancreatic duct dilatation ) . it is important to keep the pancreatic parenchyma and duct intact during choledochal remnant dissection . one girl developed acute bowel obstruction due to internal herniation through the mesenteric defect 2 months after primary surgery . of the 8 children with adhesive intestinal obstructions , 3 underwent surgical interventions and 5 were treated medically . the median follow - up period after reoperation was 6 years ( range , 1 year to 13 years ) . wound infection developed in 2 patients and was managed by changing the dressing , and the other 16 patients recovered uneventfully . complete cyst excision with biliary reconstruction is the treatment of choice for choledochal cyst . understanding the pathophysiology and anatomy of cc is crucial for successful management . despite recent advances in surgical techniques and peri - operative management , early and late complications are not rare in children , while postoperative complications are more common in adults . reoperation is required in less than 10% of pediatric patients and remains a great challenge to pediatric surgeons . the rate of reoperation in this study was about 6.8% , which is similar to other reports from japan and uk . anastomotic bile leakage is thought to be caused by surgical inexperience and severe inflammation . in some cases , the diagnosis of bile leakage is difficult and delayed because the symptoms are nonspecific . imaging findings of ultrasonography and ct can not be differentiated from other causes of postoperative intra - abdominal fluid collection . some patients might succumb to the subsequent damage , such as septicemia and septic shock . reported gadobenate - enhanced mr cholangiography can be used to diagnose and accurately localize the site of bile leakage noninvasively . the leakage can be repaired by a circumferential buried suture around the anastomotic site , peritoneal lavage , and effective drainage . postoperative intussusception may develop after a variety of abdominal operations . the majority ( 87.2% ) of them were small bowel intussusceptions ( jejuno - jenual , jejuno - ileal , or ileo - ileal ) . therefore , intussusception , although very rare , should be considered , in addition to adhesive ileus and bowel twist . based on our experience , unrecognized primary bile duct stenosis , residual debris , and anastomotic stricture are the main causes of postoperative cholangitis . in the present study , 4 of the 12 patients with cholangitis responded to antibiotics treatment , and biochemical liver dysfunction normalized . intrahepatic bile duct dilatations of type iv - a always accompany a downstream ductal stenosis , frequently around the hepatic hilum . interestingly , tsuchida et al .   found that 40% of patients developed postoperative intrahepatic cholelithiasis among patients with dilated intrahepatic ducts and downstream stenosis , while only 2% occurred in patients without any dilatation of the intrahepatic bile ducts . therefore , it is clinically meaningful to detect the intrahepatic bile ductal stricture however , it can be very difficult to distinguish between type i and type iv - a preoperatively in some cases . excision of the cyst , ductoplasty , and wide hepaticoenterostomy at the hilum may be imperative to prevent bile stasis , recurrent cholangitis , stone formation , and biliary carcinoma . it is also important to perform endoscopic examination and wash out debris or stones from the dilated intrahepatic bile duct during cyst excision . liver resection has been performed in adult patients with type iv - a cc , but it is too aggressive for infants and children . reported hepaticojejunostomy at hilum combined with intrahepatic cystojejunostomy ( double anastomoses ) was an attractive alternative procedure for more upstream intrahepatic ductal cyst . in terms of anastomotic stricture , improvement of surgical skills , preservation of blood supply , no or mild inflammation of cyst wall , and construction of a wide ( larger than 1 cm ) and tension - free stoma are key factors to reduce anastomosis - related complications . there should be no delay in surgical or endoscopic intervention once the biliary obstruction develops postoperatively , but a great deal of planning and a thoughtful workup are required . kim et al .   reported that percutaneous transhepatic cholangioscopy with stone removal and balloon dilatation was useful in 7 adult patients with anastomotic stricture . recently , ono et al .   successfully treated pediatric patients with intrahepatic bile duct stones using double - balloon enteroscopy ( via the limb of the roux - en - y reconstruction ) . reported that the incidence of pancreatitis after cyst excision was about 4.2% . in this study , complete resection of the distal portion of the cyst , removal of debris and protein plugs in the long common channel and pancreatic duct , and correction of anomalous arrangement of the pancreaticobiliary duct junction are essential to minimize pancreatic complications after the operation . reported that intraoperative ureteroscopy during laparoscopic excision of cc was successfully used to more accurately dissect the intrapancreatic cyst . however , a fine - caliber endoscope is not available in our institutes , so we instead use a flexible catheter to irrigate the common channel . thus , radical excision of the residual cyst is strongly advocated . in some unusual cases with pancreatic duct stenosis and upstream dilatation , pancreaticojejunostomy ( puestow procedure ) adhesions after intra - abdominal surgery are common and are a major cause of small bowel obstruction . patients should be closely observed for any sign of deterioration after initial management . in the absence of clinical improvement , observation longer than 48 h carries a greater risk of bowel necrosis and bowel resection . furthermore , it is necessary to pay particular attention to the length and placement of the roux loop during biliary reconstruction . although there was no subsequent biliary malignancy documented in this series , long - term surveillance remains mandatory for patients with cc . the main limitations of this study are its retrospective design and small number of patients . detection and correction of the intrahepatic bile duct stenosis , and a wide hepaticojejunostomy ( with ductoplasty when necessary ) are essential to prevent cholangitis , anastomotic stricture , and calculus formation . moreover , complete cyst excision , including the intrapancreatic portion , should be strongly recommended .
backgroundcomplete cyst excision with biliary reconstruction is the treatment of choice for choledochal cyst ( cc ) . 
 the aim of this article is to review our experience in patients who underwent reoperation between january 1995 and december 2014.material/methodsthe records of 18 patients ( female / male , 15/3 ) were retrospectively analyzed including age , sex , cyst type , initial procedure , lab and imaging findings , indications for reoperation , intraoperative findings , and results of reoperation . 
 the median follow - up period was 6 years.resultsthe rate of reoperation in this study was about 6.8% . 
 eighteen patients ( 7 type ia , 2ic , 9 iv - a ) developed severe postoperative complications and required surgical intervention . 
 the median time interval from primary surgery to reoperation was 19.5 months ( range , 3 days to 8 years ) . 
 two early complications required surgery due to anastomotic bile leakage and intussusception . 
 sixteen late complications occurred , including 3 intrahepatic bile duct stenosis with calculi , 5 anastomotic strictures with / without stones , 4 intrapancreatic cyst remnants , 3 adhesive bowel obstructions , and 1 internal hernia . for patients with persistent dilatation of the intrahepatic bile duct or anastomotic stricture , removal of stones and 
 revision of hepaticojejunostomy were performed , with additional hepatic ductoplasty when necessary . 
 radical excision of the dilated cystic remnant in the head of pancreas was performed in 4 patients , with 1 needing additional pancreaticojejunostomy procedure . 
 no deaths occurred . 
 sixteen patients recovered uneventfully after reoperation , and 2 wound infections developed.conclusionsa wide hepaticojejunostomy with / without ductoplasty is essential to prevent cholangitis , anastomotic stricture , and calculi formation . 
 complete cyst excision , including the intrapancreatic portion , should be meticulously pursued .