Narrow portion of the terminal choledochus is a cause of upstream biliary dilatation in patients with anomalous union of the pancreatic and biliary ducts

LncRNA-mRNA coexpression analysis reveals distinct pathogenic mechanisms for subtypes of congenital biliary dilatation

BACKGROUND/PURPOSE

Congenital biliary dilatation (CBD) is a bile duct malformation often associated with pancreaticobiliary maljunction. Different subtypes of CBD have been noted for clinical differences, but their pathogenic mechanisms are unclear.

METHODS

To elucidate the genetic basis of CBD, we performed lncRNA and mRNA sequencing and bioinformatic analysis on 18 cystic and 18 fusiform CBD samples.

RESULTS

We identified differentially expressed mRNAs and lncRNAs between the two types of CBD, and constructed coexpression modules that correlated with clinical characteristics of CBD using weighted gene coexpression network analysis. We found that the brown module was the highest positive correlation with fusiform CBD (R = 0.67, p = 7.9e-6) and contained the most genes. We then built a lncRNA-mRNA coexpression network to identify potential target genes of lncRNAs in CBD, and a protein-protein interaction network to investigate the hub genes from the target genes and the brown module. Finally, we performed enrichment analyses and found differences between cystic and fusiform CBD in hepatobiliary system development, liver and pancreas development involving hub genes ONECUT1 and HNF1B that could be regulated by corresponding lncRNAs.

CONCLUSION

Our study suggests that lncRNAs may modulate pancreaticobiliary duct development differently in cystic and fusiform CBD, providing new insights for etiology studies and clinical treatment.

Establishment and validation of a predictive nomogram for the risk of premalignant lesions in children with choledochal cyst

BACKGROUND

Choledochal cyst (CDC) increases the risk (2.5%-30%) of malignancy. Metaplasia and dysplasia have been recognized as premalignant lesions among CDCs. This study aimed to evaluate the risk factors of metaplasia and dysplasia in CDC children.

METHODS

Two hundred and ten CDC children who underwent cyst excision and Roux-en-Y hepaticojejunostomy at our institution between July 2020 and November 2021 were included and randomly divided into the training set and validation set. Univariate and multivariate logistic regression analysis were used to identify independent risk factors of premalignant lesions in the training set and build a predictive nomogram. The performance and discriminatory abilities of the nomogram were further assessed and validated in the validation set.

RESULTS

Of the 210 CDC children, 78 (37.1%) patients developed premalignant lesions. Age (OR, 1.011, 95%CI, 1.000-1.022, P = 0.046), symptoms duration (OR, 1.021, 95%CI, 1.001-1.042, P = 0.036), cyst diameter (OR, 1.737, 95%CI, 1.328-2.273, P < 0.001), recurrent attacks of biliary pancreatitis (OR, 3.653, 95%CI, 1.205-11.076, P = 0.022), and biliary operation history (OR, 5.860, 95%CI, 1.268-27.084, P = 0.024) were identified as independent risk factors. Based on these predictors, a predictive nomogram was generated. The AUC of the nomogram was 0.873 in the training set and 0.793 in the validation set, indicating that it was robust and well calibrated.

CONCLUSIONS

A novel nomogram to the individualized risk of premalignant lesions in CDC children was successfully built, on the basis of age, symptoms duration, cyst diameter, recurrent attacks of biliary pancreatitis, and biliary operation history. This nomogram, combined with the final pathological results, can help clinicians to develop more efficient follow-up strategies for the high-risk children with CDC.

Transabdominal Ultrasound Evaluation of Pancreaticobiliary Maljunction in Children

ABSTRACT

The development of high-frequency ultrasound made the diagnosis of pancreaticobiliary maljunction (PBM) possible. However, no study has been performed to clarify the sensitivity and specificity of transabdominal ultrasound (TAUS) in the diagnosis of PBM. The purpose of this study was to evaluate the accuracy of TAUS in the diagnosis of pediatric PBM and to assess factors that may influence the accuracy of ultrasound. This was a prospective study and 43 patients with suspected PBM were enrolled. All of these patients underwent TAUS examination to detect the pancreaticobiliary ductal union. Final diagnoses were determined by endoscopic retrograde cholangiopancreatography or intraoperative cholangiography. Sensitivity and specificity were calculated. Fisher exact test was used to analyze the difference of sonographic features between false-negative group and true-positive group. Transabdominal ultrasound demonstrated 77.4% (95% confidence interval, 58.5%-89.7%) sensitivity and 100% (95% confidence interval, 69.9%-100%) specificity for PMB diagnosis. In the false-negative group, infant patients (71.4% vs 16.7%, P = 0.012), cystic dilatation of the common bile duct (CBD) (71.4% vs 16.7%, P = 0.012), and stenosis of the distal CBD (71.4% vs 16.7%, P = 0.012) were more frequently observed than in the true-positive group. On the other hand, the true-positive group showed a higher incidence of protein plugs than the false-negative group (62.5% vs 0%, P = 0.007). Transabdominal ultrasound may serve as a potential alternative detection modality for pediatric patients with suspected PBM. Nondetection of the anomaly may be attributed to factors, such as younger age, cystic dilatation of the CBD, and stenosis of the distal CBD.

Congenital pancreaticobiliary anomalies in an urban medical center in the United States

Background and Aim

Pancreaticobiliary anomalies are rare and often present with cryptic signs and symptoms, thus delaying appropriate treatment.

Methods

Endoscopic retrograde cholangiopancreatography (ERCP) was used to define pancreaticobiliary anomalies. A retrospective review was performed of 5522 ERCPs conducted at a tertiary care center from 1972 to 2015.

Results

There were 249 (4.5%) patients with pancreaticobiliary anomalies, including 179 patients with pancreas divisum (PD), 44 patients with choledochal cyst (CC) (Todani's classification Type I: extrahepatic cyst 31, Type III; choledochocele 9, Type V: Caroli's disease 4), 20 patients with anomalous pancreaticobiliary ductal union (APDU), and 6 patients with other abnormalities. Of 179 patients with pancreas divisum, 8 (4.5%) required minor sphincterotomies for multiple unexplained acute pancreatitis. Of the 31, 15 (48%) Type I CC patients underwent an operation. In patients with Type III CC (choledochocele), seven of the nine were treated by endoscopic sphincterotomy, and two patients were treated by surgery. Four patients with Type V CC (Caroli's disease) were managed nonoperatively. Of the 20 patients with APDU, 8 (40%) required operative intervention. Six patients were found to have other anomalies: two with pancreas bifidum, one with a duplication of the gallbladder, one with a cystic duct diverticulum, one with an annular pancreas, and one with an abnormal cystic duct origin. These patients were treated based on their etiology.

Conclusion

Pancreaticobiliary anomalies are rare and can be defined using ERCP. The appreciation of these abnormalities is important for the proper diagnosis and treatment of these rare biliary and pancreatic disorders.

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.

Congenital biliary dilatation may consist of 2 disease entities

BACKGROUND/PURPOSE

This study aims to establish the possible mechanisms of pathogenesis of congenital biliary dilatation and to classify the disease accordingly.

METHODS

Radiologic features of congenital biliary dilatation and pancreaticobiliary malunion in 107 affected children were examined and correlated with laboratory results. Relative lengths/diameters were calculated to provide comparison between children of different ages. Intraluminal pressures of common bile duct (CBD) were measured intraoperatively.

RESULTS

The minimal relative diameters of distal CBD negatively correlated with the maximal relative diameters/lengths of dilated CBD, the maximal relative diameters of common hepatic duct, and left/right hepatic ducts. The intraluminal pressure in patients with a stenotic distal CBD (stenotic group) was significantly higher than that in patients with a nonstenotic distal CBD (nonstenotic group). The narrower the distal CBD, the more deranged the liver function. Conversely, serum/bile amylase levels were more elevated in the nonstenotic group. Common channel protein plugs were only found in the nonstenotic group, whereas common hepatic duct strictures, intrahepatic duct dilatations, and calculi were detected more frequently in the stenotic group.

CONCLUSION

We propose to categorize congenital biliary dilatation into 2 subgroups: (1) cystic type with stenotic distal CBD associated with deranged liver function and common hepatic duct stricture and (2) fusiform type with nonstenotic distal CBD associated with pancreatitis and common channel protein plugs. Different underlying pathologies of each group require different operative strategies.

Choledochal cysts: differences between pediatric and adult patients

Choledochal cysts in children and adults are believed to be different, but direct comparison between them is lacking in the literature. This study was aimed to identify the clinicopathological differences between 42 children and 59 adults with choledochal cyst treated by same surgeons at the Cathay General Hospital. The mean follow-up period was 8.9 years. The result showed that the female-to-male ratios were 1.5:1 in pediatric patients and 4.9:1 in adult patients. Compared with adults with choledochal cyst, the pediatric patients presented more abdominal mass (52.4% vs 21.2%, P = 0.002) and less abdominal pain (76.2% vs. 98.0%, P = 0.002), are more frequently associated with anomalous pancreaticobiliary ductal union (85.7% vs. 59.6%, P = 0.005) and sudden severe stenosis of terminal choledochus (76.2% vs. 42.3%, P = 0.001), are less commonly associated with choledocholithiasis, are not associated with malignant transformation (0% vs 21.2%), and have fewer perioperative and long-term complications. Nevertheless, patients who received total excision had fewer surgical complications in both groups. This result shows that choledochal cysts in pediatric and adult patients are different in clinicopathological manifestations, prognosis, and the underlying abnormalities of the pancreaticobiliary system, suggesting that patients with choledochal cyst should be managed according to these differences.