Japanese clinical practice guidelines for congenital biliary dilatation

Differences in post-operative complications after reconstruction for congenital biliary dilatation in a single institution-Roux-en-Y hepaticojejunostomy versus hepaticoduodenostomy

BACKGROUND

The standard surgical procedure for congenital biliary dilatation (CBD) consists of excision of extrahepatic bile duct and Roux-en-Y hepaticojejunostomy (HJ). However, alternative reconstructive operations for CBD includes hepaticoduodenostomy (HD). We compared postoperative complications and therapeutic outcomes of these two operations at our institution.

METHODS

From 1981 to 2009, there were 23 traceable patients who underwent operation for CBD, They were divided into an HJ Group (n = 15) and an HD Group (n = 8). Demographic and outcome data were compared.

RESULTS

There were no significant differences in postoperative complications (cholangitis, pancreatitis, and anastomotic stenosis) and current blood test data (AST, ALT, Total Bilirubin, Direct Bilirubin, Amylase) between the two groups. Current abdominal pain and carcinogenesis were not observed in either group. Intrahepatic stones occurred in one patient in each group, both > 25 years post-operation.

CONCLUSION

HD is considered to be an acceptable reconstruction method compared to HJ, based on our results. There has been a suggestion that inadequate diversion in HD might increase the risk of cholangiocarcinoma. To date, in this series, that has not happened.

Preliminary Experiences With Robot-Assisted Choledochal Cyst Excision Using the Da Vinci Surgical System in Children Below the Age of One

The purpose of this study is to introduce our preliminary experiences with using the da Vinci surgical system to treat choledochal cysts in children under 1 year old and discuss the application of this robot-assisted surgery. We retrospectively analyzed all available clinical data of children below the age of 1 who underwent surgery for choledochal cysts using the da Vinci robotic surgical system between January 2015 and December 2020. Data collection mainly included demographic information, imaging data, perioperative details, and postoperative outcomes. Ten patients were included in this study. The average patient age was 8.5 months, and the average weight was 9.11 kg. Half of these patients suffered from abdominal pain, while 30% exhibited vomiting and 10% jaundice. Eight of them were type Ia, and two were Ic. The average operation time among the patients was 219.5 min. None of the 10 patients had to receive a blood transfusion or conversion. The average time of the patients' subsequent fluid diet was 3.28 days, and the solid diet was 3.76 days. Meanwhile, the average length of hospital stay was 7.6 days. All 10 patients recovered and were eventually discharged. We believe that the da Vinci surgical system is a safe and feasible form of treatment for choledochal cysts in children <1 year old.

Focal intrahepatic strictures: A proposal classification based on diagnosis-treatment experience and systemic review

BACKGROUND

Focal intrahepatic strictures (FIHS) refer to local strictures of the small and medium intrahepatic bile ducts. FIHS are easily misdiagnosed due to their rare incidence, and few studies have focused on the diagnosis and treatment approaches.

AIM

To propose a new classification for FIHS in order to guide its diagnosis and treatment.

METHODS

The symptoms, biochemistry results, imaging results, endoscopic examination results and initial and final diagnoses of 6 patients with FIHS admitted between January 2010 and December 2019 were retrospectively analyzed.

RESULTS

The 6 patients were diagnosed with intratubular growth-type intrahepatic cholangiocarcinoma (IG-ICC), recurrent multiple hepatocellular carcinoma (rmHCC) with bile duct tumor thrombus (BDTT), adenosquamous carcinoma (ASC), hepatolithiasis, small duct primary sclerosing cholangitis (SD-PSC) and autoimmune hepatitis (AIH). The initial and final diagnoses were not consistent in 4 patients. Hepatectomy was performed in patients with IG-ICC, ASC and hepatolithiasis according to the locations of their FIHS. Patients with rmHCC with BDTT received lenvatinib/sintilimab, while patients with SD-PSC and AIH received UDCA. We proposed the following classification system for FIHS: type I: FIHS located within one segment of the liver; type II: FIHS located at the confluence of the bile ducts of one segment or two adjacent segments; type III: FIHS connected to the left or right hepatic duct; and type IV: Multiple FIHS located in both lobes of the liver.

CONCLUSION

Our proposed classification system might help to guide the diagnosis and treatment of FIHS. Hepatectomy should be performed not only for malignant FIHS but also for benign strictures with severe secondary damage that cannot be improved by nonsurgical methods.

De novo somatic mutations and KRAS amplification are associated with cholangiocarcinoma in a patient with a history of choledochal cyst

BACKGROUND/PURPOSE

Choledochal cysts are congenital dilations of the bile ducts, and are associated with an increased risk of malignant transformation. The purpose of this study is to report the outcomes of a large series of patients with choledochal cysts and to highlight our analysis of one patient who developed malignancy after cyst resection.

METHODS

We conducted a retrospective review of patients <18 years of age with a choledochal cyst who underwent surgical resection between 1995 and 2018. Molecular testing of resected choledochal cyst specimens using the UCSF500 gene panel was performed on three patients including a 3-month-old boy and a 7-year-old girl who have remained cancer-free, and a 16-year-old girl who subsequently developed cholangiocarcinoma less than two years after resection.

RESULTS

One patient of the 48 included in our study developed cholangiocarcinoma after choledochal cyst resection. We observed de novo somatic mutations in TP53 and RBM10, and KRAS amplification in this patient's tumor.

CONCLUSIONS

In our series, the rate of malignancy after choledochal cyst resection was low. One patient developed de novo mutations in the remnant bile ducts after cyst resection. While it is a rare occurrence, the risk of malignancy following cyst resection supports the need for lifelong surveillance.

LEVEL OF EVIDENCE

IV.

Choledochal Cyst: A Retrospective Study of 30 Cases From Nepal

Introduction Choledochal cysts (CCs) are uncommon biliary lesions. Considering the evolution of imaging, we describe our experience with the presentation and management of choledochal cysts. Methods A review of the records of all patients with choledochal cyst managed in our institute were retrospectively analyzed. The study analyzed clinical presentation, diagnosis, treatment and postoperative outcomes.  Results Between 2015 and 2019, 30 CCs (male/female: 7/23) were operated. We observed more adults compared to children (17 vs. 13). The median age at surgery was 18.5 years (4-67 years). The presentation included abdominal pain (90%), pancreatitis (17%0, cholangitis (13%), and incidental diagnosis in (7%). Anomalous union of the bile duct and the pancreatic duct was seen in 17%. Two patients had synchronous cholangiocarcinoma. The cysts were classified (Todani's): I: 26; IV:3; and V: 1. The patients underwent complete excision of the cyst and Roux-en-Y hepaticojejunostomy - 27; pancreaticoduodenectomy - 1; hepaticoduodenostomy - 1; and cholecystectomy with T-tube drainage - 1 patient. The operative complications were observed in 10 (33.3%) patients: biliary leaks (four), superficial surgical site infections (four), and cholangitis (three). Only one patient developed a major complication; required re-operation for bile leak peritonitis. There was no operative mortality. One patient with cholangiocarcinoma died with the disease at three months of surgery. The remaining 29 patients are doing well at a mean follow-up of 29.5 months (12-56). Conclusion Adults CCs now far outnumber children at the time of presentation. The majority were symptomatic Todani's type I cyst. Complete cyst excision and bilio-digestive anastomosis is the best treatment for type I and IV CCs, thus eliminating the risk of malignancy with an excellent operative outcome.

Cyst Size in Fetuses with Biliary Cystic Malformation: An Exploration of the Etiology of Congenital Biliary Dilatation

PURPOSE

Our aim was the longitudinal assessment of cyst size in fetuses with biliary cystic malformation (BCM) to explore its etiology and the possibility of antenatal differentiation between biliary atresia (BA) and congenital biliary dilatation (CBD).

METHODS

We conducted a retrospective review of all patients diagnosed antenatally with BCM from 1994 to 2014 at our institutions.

RESULTS

The study cohort comprised of three patients with BA and six with CBD. There were no significant differences in the gestational age and cyst size at the first detection of BCM between the two groups. In fetuses with CBD, the cyst size steadily increased as the gestational age advanced, while it fluctuated around 1.5 cm and remained below 2.1 cm in those with BA. However, the ratio of cystic area to fetal trunk area was approximately constant due to linear fetal growth in fetuses with CBD.

CONCLUSION

Fetuses with BCM <2.1 cm in the late gestation period were more likely to have BA than CBD. Our observation of cyst enlargement with advancing gestational age in the CBD group was attributed solely to fetal growth. Biliary dilatation in fetuses with CBD and BA might be completed at the onset of BCM.

Congenital biliary dilatation in the era of laparoscopic surgery, focusing on the high incidence of anatomical variations of the right hepatic artery

BACKGROUND

The present study aimed to evaluate anatomical variations of the right hepatic artery (RHA) in patients with congenital biliary dilatation (CBD) and the appropriate approach in laparoscopic surgery for CBD.

METHODS

The medical records of 36 patients who underwent laparoscopic or open surgery for CBD from 1996 to 2018 were retrospectively reviewed. Radiological evaluation of the origin and course of the RHA in these 36 patients were compared with 195 control patients without CBD.

RESULTS

The incidence of the RHA crossing anterior to the common hepatic duct (CHD) was significantly higher in patients with CBD than in those without CBD (33% versus 10%, P = .0001). There was no intraoperative injury of the RHA, irrespective of the course of the RHA. The CHD was divided at the caudal side of the RHA in 11 of 12 patients (92%) with the anterior type of RHA, and in 13 of 24 patients (54%) with the posterior type of RHA (P = .03).

CONCLUSIONS

Patients with CBD had a higher incidence of the RHA crossing anterior to the CHD than patients without CBD. Preservation of the RHA in each situation is necessary during surgery for CBD in the era of laparoscopic surgery.

Preoperative one-stop magnetic resonance imaging evaluation of the pancreaticobiliary junction and hepatic arteries in children with pancreaticobiliary maljunction: a prospective cohort study

PURPOSE

Pancreaticobiliary maljunction (PBM) is routinely assessed by intraoperative cholangiography (IOC), whereas accompanying abnormalities in the hepatic artery are assessed by preoperative contrast multi-slice computed tomography (MSCT). We evaluated the efficiency of performing one-stop preoperative magnetic resonance imaging (MRI) for delineating the anatomy of the pancreaticobiliary junction and the hepatic artery.

METHODS

The subjects of this prospective analysis were children who underwent Roux-en-Y surgery for PBM in our institution during a recent 3-year period. Preoperative one-stop MRI was conducted using 3.0-T MRI. The efficiency of one-stop MRI was compared with that of IOC for assessing the bile duct, and with contrast MSCT for assessing the blood vessels.

RESULTS

Sixty-five children underwent one-stop preoperative MRI, which had a 100% concordance rate, versus IOC for assessing the bile duct type. Protein plugs or cholelithiasis were identified by IOC in 8 children and by one-stop MRI in 45 children (P = 0.0233). Cholangitis was not identified by IOC in any children but it was identified by one-stop MRI in 29 children. MSCT was also performed in 46 children and revealed a variant hepatic artery in 9 and cholangitis in 21. One-stop MRI had a 100% concordance rate versus MSCT.

CONCLUSION

Preoperative one-stop MRI accurately delineates the bile duct anatomy as well as the hepatic artery, cholangitis, and protein plugs in children with PBM.

Learning curve of robot-assisted choledochal cyst excision in pediatrics: report of 60 cases

BACKGROUND

Little data are available to assess the learning curve for robot-assisted surgery on choledochal cysts. The aim of this current study is to investigate the characteristics of the learning curve for robot-assisted choledochal cyst excisions using the da Vinci (SI) surgical system in pediatrics.

METHODS

A retrospectively collected database comprising all medical records of the first 60 consecutive patients undergoing a robot-assisted choledochal cyst excision and Roux-en-Y hepaticojejunostomy using the da Vinci (SI) surgical system performed by one individual surgeon was studied. Baseline information and postoperative outcomes were collected and then learning curves were analyzed using the cumulative sum (CUSUM) method. Patients were divided into two groups including group A and group B according to the cutoff points of the learning curve. Intraoperative characteristics and short-term outcomes were compared between the two groups.

RESULTS

CUSUM plots revealed that the cutoff point of the learning curve was 14 cases. Comparison of the operative time between the two groups revealed that the total operative time (203.71 ± 15.27, 171.28 ± 3.62 min, P < 0.001), docking time (23.79 ± 5.81, 14.50 ± 0.98 min, P < 0.001), and console time (151.86 ± 9.77, 129.15 ± 2.96 min, P < 0.001) were decreased significantly. The intraoperative bleeding (20.36 ± 7.46 vs. 20.43 ± 9.18, P = 0.977), time to taking water (2.89 ± 0.22 vs. 3.04 ± 0.34, P = 0.115), time to starting solids diet (3.73 ± 0.17 vs. 3.79 ± 0.26, P = 0.387), hospital stay (7.51 ± 1.12 vs. 7.54 ± 0.95, P = 0.910), and the postoperative complications did not differ significantly between the two groups.

CONCLUSIONS

The learning curve for the robot-assisted choledochal cyst excision and Roux-en-Y hepaticojejunostomy in children is 14 cases. This learning curve can be used as the basis for performance guidance during training in future.

Imaging of Pancreaticobiliary Maljunction

Pancreaticobiliary maljunction (PBM) is a congenital malformation in which the pancreatic and bile ducts join outside the duodenal wall, usually forming a long common channel. A major issue in patients with PBM is the risk of biliary cancer. Because the sphincter of Oddi does not regulate the pancreaticobiliary junction in PBM, pancreatic juice frequently refluxes into the biliary tract and can cause various complications, including biliary cancer. Most cancers arise in the gallbladder or dilated common bile duct, suggesting that bile stasis is related to carcinogenesis. Early diagnosis and prophylactic surgery to reduce the risk of cancer are beneficial. The diagnosis of PBM is made mainly on the basis of imaging findings. The development of diagnostic imaging modalities such as multidetector CT and MR cholangiopancreatography has provided radiologists with an important role in diagnosis of PBM and its complications. Radiologists should be aware of PBM despite the fact that it is rare in non-Asian populations. In this review, the authors present an overview of PBM with emphasis on diagnosis and management of PBM and its complications. For early diagnosis, the presence of extrahepatic bile duct dilatation or gallbladder wall thickening may provide a clue to PBM with or without biliary dilatation, respectively. The pancreaticobiliary anatomy should be closely examined if imaging reveals these findings. Radiologists should also carefully evaluate follow-up images in PBM patients even years after prophylactic surgery because residual bile ducts remain at risk for cancer.^©RSNA, 2020.

Classification of pancreaticobiliary maljunction and its clinical features in adults

BACKGROUND

In pancreaticobiliary maljunction (PBM), reflux of pancreatic juice and bile produces various pathological conditions in the biliary tract and pancreas. Clinical features according to the classification of PBM by confluence between the distal bile duct and the main pancreatic duct proposed in 2015 were evaluated in children.

METHODS

Clinical features and complicating diseases according to the PBM classification were evaluated in 168 adult PBM patients. Patency of Santorini duct and associated biliary carcinomas were evaluated in 123 patients.

RESULTS

Similar to children, there were significant differences in age (P < 0.01) and type of common bile duct (P < 0.01) between the groups of the classification. Unlike in children, there was no significant difference in the incidence of abdominal pain and hyperamylasemia. There were 87 associated biliary carcinomas (79 gallbladder carcinomas and eight cholangiocarcinomas). PBM patients with a cudgel-type Santorini duct, which is greater than 2 mm in diameter, did not develop biliary carcinomas, compared to 61.1% of those with other types of Santorini duct (P < 0.01).

CONCLUSIONS

Clinical features according to the PBM classification in adults were different from those in children. Although biliary carcinomas were frequently seen in adult PBM patients, none of those with a cudgel-type Santorini duct developed biliary carcinoma.

Gene expression profiling reveals upregulated FUT1 and MYBPC1 in children with pancreaticobiliary maljunction

Pancreaticobiliary maljunction (PBM) is associated with high risk of epithelial atypical growth and malignant transformation of the bile duct or gallbladder. However, overall changes in genetic expression have not been examined in children with PBM. Genome-wide expression was analyzed using peripheral blood samples from 10 children with PBM and 15 pediatric controls. Differentially expressed genes (DEGs) were identified using microarray. Bioinformatics analysis was conducted using Gene Ontology and KEGG analyses. The top 5 in the up-regulated genes in PBM were verified with qRT-PCR. Receiver operator characteristic curve analysis was conducted to evaluate the predictive accuracy of selected genes for PBM. The microarray experiments identified a total of 876 DEGs in PBM, among which 530 were up-regulated and the remaining 346 were down-regulated. Verification of the top 5 up-regulated genes (TYMS, MYBPC1, FUT1, XAGE2, and GREB1L) by qRT-PCR confirmed the up-regulation of MYBPC1 and FUT1. Receiver operating characteristic curve analysis suggested that FUT1 and MYBPC1 up-regulation could be used to predict PBM, with the area under the curve of 0.873 (95%CI=0.735-1.000) and 0.960 (95%CI=0.891-1.000), respectively. FUT1 and MYBPC1 were up-regulated in children with PBM, and could be used as potential biomarkers for PBM.

Choledochal cysts: Similarities and differences between Asian and Western countries

Choledochal cysts (CCs) are rare bile duct dilatations, intra-and/or extrahepatic, and have higher prevalence in the Asian population compared to Western populations. Most of the current literature on CC disease originates from Asia where these entities are most prevalent. They are thought to arise from an anomalous pancreaticobiliary junction, which are congenital anomalies between pancreatic and bile ducts. Some similarities in presentation between Eastern and Western patients exist such as female predominance, however, contemporary studies suggest that Asian patients may be more symptomatic on presentation. Even though CC disease presents with an increased malignant risk reported to be more than 10% after the second decade of life in Asian patients, this risk may be overstated in Western populations. Despite this difference in cancer risk, management guidelines for all patients with CC are based predominantly on observations reported from Asia where it is recommended that all CCs should be excised out of concern for the presence or development of biliary tract cancer.

Long-term outcomes after biliary diversion operation for pancreaticobiliary maljunction in adult patients

AIM

Pancreaticobiliary maljunction (PBM) with or without congenital biliary dilatation (CBD) is a risk factor for biliary tract cancer. We investigated long-term outcomes after biliary diversion operation with special reference to types of CBD.

METHODS

Subjects comprised 40 adult patients who underwent biliary diversion operation for PBM without biliary tract cancer. Group A comprised 20 patients with type Ia or Ic CBD, or non-dilated bile ducts, while group B comprised 20 patients with type IV-A CBD. The clinical findings and postoperative outcomes were compared between groups.

RESULTS

Of 40 patients, nine patients suffered from repeated cholangitis and eight of these nine patients suffered from hepatolithiasis after biliary diversion operation. Biliary tract cancer or pancreatic cancer was detected in four patients at 3 years and 2 months to 24 years after the operation. In three of these four patients, the serum concentration of carbohydrate antigen 19-9 increased before detection of carcinoma. One patient died of hepatic failure due to repeated cholangitis. The proportions of patients with repeated cholangitis, hepatolithiasis, and re-operation, and patients who died of biliary tract cancer, pancreatic cancer, or hepatic failure, were significantly higher in group B than in group A. The survival rate was significantly worse in group B than in group A.

CONCLUSIONS

Careful long-term follow-up with measurement of serum tumor markers is necessary after biliary diversion operation for PBM, especially in patients with type IV-A CBD or repeated cholangitis.

Pancreaticobiliary maljunction and congenital biliary dilatation

Pancreaticobiliary maljunction is a congenital malformation in which the pancreatic and bile ducts join outside the duodenal wall, usually forming a long common channel. Because the action of the sphincter of Oddi does not regulate the function of the pancreaticobiliary junction in patients with pancreaticobiliary maljunction, two-way regurgitation occurs. Reflux of pancreatic juice into the biliary tract is associated with a high incidence of biliary cancer. Biliary carcinogenesis in patients with pancreaticobiliary maljunction is thought to follow the hyperplasia, dysplasia, then carcinoma sequence due to chronic inflammation caused by pancreatobiliary reflux. Pancreaticobiliary maljunction is diagnosed when an abnormally long common channel is evident on imaging studies. Congenital biliary dilatation involves both local dilatation of the extrahepatic bile duct, including the common bile duct, and pancreaticobiliary maljunction. Extrahepatic bile duct resection is the standard surgery for congenital biliary dilatation. However, complete excision of the intrapancreatic bile duct and removal of stenoses of the hepatic ducts are necessary to prevent serious complications after surgery.

Robotic-assisted surgery for pediatric choledochal cyst: Case report and literature review

Our paper describes the key surgical points of pediatric choledochocystectomy performed completely by Da Vinci robotic system. A choledochocystectomy was safely carried out for a girl at our hospital, and without any complication. Then systematic literature review was done to discuss the methods of intestine surgery and intestinal anastomosis, the use of 3^rd robotic arm, the surgical safety and advantages comparing open and laparoscopic surgery. We systematically reviewed choledochocystectomy for children performed by robotic surgery. We included a total of eight domestic and foreign reports and included a total of 86 patients, whose average age was 6.3 (0.3-15.9) years; the male-to-female ratio was 1:3.5 (19:67). Seven patients experienced conversion to open surgery, and the surgery success rate was 91.9% (79/86). The average total operation time was 426 (180-520) min, the operation time on the machine was 302 (120-418) min, 11 cases used the number 3 arm, and the remaining mainly used the hitch-stitch technique to suspend the stomach wall and liver. Forty-seven patients underwent pull-through intestine and intestinal anastomosis, and 39 patients underwent complete robotic intestine surgery and intestinal anastomosis. The hospitalization time of robotic-assisted choledochocystectomy was 8.8 d. Eight patients had biliary fistula and were all cured by conservative treatment and continuous observation. One patient had anastomotic stenosis, and one patient had wound dehiscence, both cured by surgery. Choledochocystectomy for children performed by completely robotic surgery and Roux-en-Y hepaticojejunostomy is safe and feasible. The initial experience shows that this surgical approach has a clearer field than the traditional endoscopy, and its operation is more flexible, the surgery is more accurate, and the injury is smaller. With the advancement of technology and the accumulation of surgeons’ experience, robotic surgery may become a new trend in this surgical procedure.

Factors affecting the operating time for complete cyst excision and Roux-en-Y hepaticojejunostomy in paediatric cases of congenital choledochal malformation: a retrospective case study in Southeast China

OBJECTIVE

The aim of this study was to evaluate factors affecting the operating time for complete cyst excision and Roux-en-Y hepaticojejunostomy in paediatric cases of congenital choledochal malformation (CCM).

DESIGN

A 3-year retrospective study was undertaken between January 2013 and December 2015 in four centres in China.

SETTING

This involved a retrospective chart review of paediatric patients with CCM in four large hospitals in Southeast China.

PARTICIPANTS

Sixty-five paediatric patients with CCM were included in this study. We derived all available information on patient demographics, clinical characteristics, preoperative complications and surgical methods from the charts of all these patients.

INTERVENTIONS

Univariate and multivariate logistic regression analyses were used to evaluate factors significantly affecting the operating time for complete cyst excision and Roux-en-Y hepaticojejunostomy in paediatric cases of CCM.

RESULTS

Twenty-three of the 65 case surgeries were performed using laparoscopic technique, and 42 surgeries were performed by conventional open surgery. The median operating time was 215 min (range 120-430 min). The morphological subtype of CCM and the presence of cholecystitis or cholangitis were the only factors found to affect the operating time (p<0.05). Logistic regression analysis confirmed cholangitis as an independent risk factor.

CONCLUSIONS

The morphological subtype of CMM and the presence of cholecystitis or cholangitis are factors affecting the operating time for complete cyst excision and Roux-en-Y hepaticojejunostomy in paediatric cases of CCM, whereas cholangitis is an independent risk factor.

Long-term outcomes of surgery for choledochal cysts: a single-institution study focusing on follow-up and late complications

PURPOSE

The late postoperative complications of choledochal cyst (CC) surgery are serious and include intrahepatic stones and biliary carcinoma; therefore, long-term follow-up is crucial.

METHODS

The subjects of this retrospective study were patients who underwent surgery for CC at Kagoshima University Hospital between April, 1984 and December, 2016. We analyzed the operative results, early and late postoperative complications, and postoperative follow-up rate.

RESULTS

The study population comprised 110 CC patients (male/female: 33/77) with a median age at surgery of 4 years, 3 months (range 12 days-17 years). The patients underwent hepaticoduodenostomy (n = 1; 0.9%) or hepaticojejunostomy (n = 109; 99.1%). Late complications included intrahepatic bile duct (IHBD) dilatation (n = 1; 0.9%), IHBD stones (n = 3; 2.7%), and adhesive ileus (n = 4; 3.6%). There was no incidence of biliary carcinoma in this series. The rates of follow-up at our institute within 10 years of surgery and more than 20 years after surgery were 69.2% (18 of 26) and 14.5% (8 of 55), respectively.

CONCLUSIONS

The follow-up rate after definitive surgery declined with time. Late complications were observed within 20 years, but biliary carcinoma was not observed. The follow-up rate should be increased to detect late complications. Moreover, patient education on long-term follow up is essential to prevent life-threatening events after definitive surgery for CC.

Telomere length of gallbladder epithelium is shortened in patients with congenital biliary dilatation: measurement by quantitative fluorescence in situ hybridization

BACKGROUND

Congenital biliary dilatation (CBD) is a congenital malformation involving both dilatation of the extrahepatic bile duct and pancreaticobiliary maljunction. Persistent reflux of pancreatic juice injures the biliary tract mucosa, resulting in chronic inflammation and higher rates of carcinogenesis in the biliary tract, including the gallbladder. Telomeres are repetitive DNA sequences located at the ends of chromosomes. Chromosomal instability due to telomere dysfunction plays an important role in the carcinogenesis of many organs. This study was performed to determine whether excessive shortening of telomeres occurs in the gallbladder mucosa of patients with CBD.

METHODS

Resected gallbladders were obtained from 17 patients with CBD, ten patients with cholecystolithiasis without pancreatic juice reflux, and 17 patients with normal gallbladders (controls) (median age of each group of patients: 37, 50, and 53 years, respectively). The telomere lengths of the gallbladder epithelium were measured by quantitative fluorescence in situ hybridization using tissue sections, and the normalized telomere-to-centromere ratio (NTCR) was calculated.

RESULTS

The NTCRs in the CBD, cholecystolithiasis, and control groups were 1.24 [interquartile range (IQR) 1.125-1.52], 1.96 (IQR 1.56-2.295), and 1.77 (IQR 1.48-2.53), respectively. The NTCR in the CBD group was significantly smaller than that in the cholecystolithiasis and control groups (p = 0.003 and 0.004, respectively), even in young patients.

CONCLUSIONS

Our findings indicate that telomere shortening in the gallbladder mucosa plays an important role in the process of carcinogenesis in patients with CBD. These results support the recommendation of established guidelines for prophylactic surgery in patients with CBD because CBD is a premalignant condition with excessive telomere shortening.

Biliary carcinogenesis in pancreaticobiliary maljunction

Pancreaticobiliary maljunction (PBM) is a congenital malformation in which the pancreatic and bile ducts join anatomically outside the duodenal wall. Because of the excessive length of the common channel in PBM, sphincter action does not directly affect the pancreaticobiliary junction, which allows pancreatic juice to reflux into the biliary tract. According to the results of a nationwide survey, bile duct and gallbladder cancers were found in 6.9 and 13.4 % of adult patients with congenital biliary dilatation, respectively, and in 3.1 and 37.4 % of those with PBM without biliary dilatation, respectively. Biliary tract cancers develop about 15-20 years earlier in patients with PBM than in individuals without PBM; they sometimes develop as double cancers. Carcinogenesis is strongly associated with stasis of bile intermingled with refluxed pancreatic juice. Epithelial cells in the biliary tract of PBM patients are under constant attack from activated pancreatic enzymes, increased secondary bile acids, or other mutagens. This can result in hyperplastic change with increased cell proliferation activity, and in turn, oncogene and/or tumor suppressor gene mutations in the epithelia, leading to the biliary tract carcinogenesis. The carcinogenesis of biliary tract cancer accompanying PBM is considered to involve a hyperplasia-dysplasia-carcinoma sequence induced by chronic inflammation caused by the reflux of pancreatic juice into the biliary tract, which differs from the adenoma-carcinoma sequence or the de novo carcinogenesis associated with biliary tract cancers in the population without PBM. Patients with a relatively long common channel have a similar, albeit slightly lower, risk for gallbladder cancer compared with PBM patients.