Pancreaticobiliary maljunction and choledochal cysts: from embryogenesis to therapeutics aspects.

Pancreaticobiliary maljunction (PBM) and choledochal cysts (CC) are rare and little-known diseases. Several definitions have been proposed for the PBM, but the most widely accepted is an excessive length of the common pancreaticobiliary duct due to the abnormal convergence of the pancreatic and biliary ducts out of the duodenal wall. This anomaly, thought to develop during embryogenesis, is associated with a loss of regulation of the Oddi's sphincter leading to a pancreaticobiliary or biliopancreatic backflow. This reflux could be responsible, or associated with cystic dilatation of the bile ducts and biliary tract cancers, to various biliary or pancreatic events such as cholangitis or pancreatitis. For the diagnosis of PBM, magnetic resonance cholangiopancreatography has now become the gold standard as a noninvasive imaging tool. However, the main risk of PBM is the development of bile duct cancer, most often on a distended area. PBM without CC increase the occurrence of gallbladder cancer and require a preventive cholecystectomy. Surgical treatment of PBM with concomitant CC is more complex and depends on localization of the dilatation(s) as reported in the Todani's classification. This review describes the pathogenesis, embryogenesis, clinical features, investigation and management of PBM and CC.

Anatomy and embryology of the biliary tract.

Working knowledge of extrahepatic biliary anatomy is of paramount importance to the general surgeon. The embryologic development of the extrahepatic biliary tract is discussed in this article as is the highly variable anatomy of the biliary tract and its associated vasculature. The salient conditions related to the embryology and anatomy of the extrahepatic biliary tract, including biliary atresia, choledochal cysts, gallbladder agenesis, sphincter of Oddi dysfunction, and ducts of Luschka, are addressed.

Diagnosis and treatment of choledochoceles.

Choledochoceles are cystic dilatations of the intraduodenal portion of the common bile duct. Although often classified as Type III biliary cysts, choledochoceles have distinctive demographic and anatomic features and a lower risk of malignancy than other types of choledochal cysts. Type A choledochoceles are cystic dilatations of a segment of the intra-ampullary bile duct and are located proximal to the ampullary orifice. Type B choledochoceles are diverticula of the intra-ampullary common channel and are located distal to the ampullary orifice; they can be distinguished from duodenal duplication cysts both anatomically and histologically. Both types of choledochocele may present with pancreatitis, biliary obstruction, or nonspecific gastrointestinal symptoms. Cross-sectional imaging, endoscopic ultrasound, and endoscopic retrograde cholangiopancreatography are useful for diagnosis. Choledochoceles may be drained or resected endoscopically. Surveillance for dysplasia should be considered for lesions that are not resected.

Congenital cystic lesions of the biliary tree.

OBJECTIVE: The purpose of this essay is to illustrate the imaging findings of congenital cystic lesions of the biliary tract. CONCLUSION: Congenital cystic lesions of the biliary tract include ductal plate malformations and choledochal cysts and can be recognized with characteristic imaging findings and basic knowledge of the embryologic development of the biliary tree.

Understanding choledochal malformation.

Choledochal malformations (also known as choledochal cysts) may be characterised as an abnormal dilatation of the biliary tract, in the absence of any acute obstruction. Most appear to be of congenital origin probably related to distal bile duct stenosis, and almost 15% can now be detected antenatally. Excision and biliary reconstruction using a Roux loop as an open operation is still the standard to compare to. This article discusses recent advances in the understanding of their aetiology and classification together with the place of newer modalites of surgical treatment such as laparoscopic excision and biliary reconstruction. Although these are definitely feasible and safe, care should be taken before dispensing with standard open techniques which have minimal complications and proven long-term benefit.

Postnatal management for prenatally diagnosed choledochal cysts.

PURPOSE: The aim of this study was to determine an appropriate postnatal management plan for prenatally diagnosed congenital biliary dilatation (CBD). METHODS: Between 1962 and 2002, 5 (5.9 %) of 85 patients had CBD diagnosed prenatally and were examined clinically. Of these 5 patients, 2 (group A) underwent delayed primary definitive surgery after percutaneous transhepatic cholangiodrainage (PTCD), 1 (group B) underwent early definitive surgery in the neonatal period, and 2 (group C) underwent delayed primary definitive surgery without PTCD in early infancy (within 6 months after birth). The clinical data, operative findings, intra- and postoperative complications, and follow-up were evaluated in these 3 groups. RESULTS: There were no postoperative complications, such as catheter-related complications, in group A. However, there was adhesion around the choledochal cyst, and the operation was therefore difficult in group A. The diameter of the anastomosis in the hepaticojejunostomy was small, and the cyst wall was thin in group B. Consequently, anastomotic leakage of the hepaticojejunostomy occurred in group B. Neither operative nor postoperative complications such as anastomotic leakage or stenosis occurred in group C. Slight fibrosis of Glisson's sheath was seen in 2 patients of groups A and C. No liver cirrhosis was seen in any group. CONCLUSIONS: The authors propose that asymptomatic patients should undergo elective definitive surgery by 6 months of age. For symptomatic patients, especially when a differential diagnosis of type I cystic biliary atresia is doubtful, early definitive surgery is needed before 2 months of age. PTCD appears to be indicated only under certain circumstances, and delayed primary definitive surgery should be performed as early as possible thereafter.

Biliary cystic disease.

Cystic diseases of the biliary tract encompass a complex group of congenital disorders. Some of the disorders, such as Caroli disease and the hepatobiliary cysts of autosomal-dominant polycystic kidney disease, share common embryologic origins, whereas others, such as choledochal cysts, biliary diverticula, and choledochoceles, have unclear origins. This article reviews the embryologic, clinical, pathologic, and imaging features of biliary cystic disease.

Diagnóstico ultrasonográfico antenatal de quiste del colédoco y su manejo perinatal / Prenatal ultrasonographic diagnosis of choledochal cyst and perinatal management

Se presentan dos casos de dilatación quística de la vía biliar fetal diagnosticados antenatalmente mediante ultrasonografía, además de su correlación posnatal y manejo quirúrgico, en el Servicio de Obstetricia Ginecología del Hospital San Juan de Dios. Es de notar que estas malformaciones son de muy escasas incidencia. Además, el diagnóstico prenatal muchas veces es difícil y se engloba bajo el diagnóstico de quiste abdominal fetal

Embryogenesis of pancreaticobiliary maljunction inferred from development of duodenal atresia.

The embryogenesis of pancreaticobiliary maljunction is inferred from the embryogenesis of duodenal atresia. The epithelial cells of the duodenum begin to proliferate and completely plug the lumen, but a process of vacuolation recanalizes the duodenum. Recanalization of the common duct frequently appears with two lumina and openings into the duodenum with two orifices. These two major canals create a narrow segment of the duodenum and this narrow zone is the area in the duodenum that is most prone to faulty recanalization and atresia formation. A bifid biliary system inserts at blind upper and lower pouches of the duodenum, and the common bile duct inserts in a Y fashion. The common bile duct inserts at the stenotic segment, and the end result is a T-shaped formation in patients with duodenal stenosis. During the development of the bile duct, abnormal fusion may occur between the bile duct and branches of the right ventral pancreatic duct. The site in the bile duct where a branch of the pancreatic duct joins is likely to develop atresia due to disturbance of the recanalization process, as seen in duodenal atresia. Severe impairment of vacuolation causes divided atretic bile duct at the site where the pancreatic duct inserts in a Y-fashion into the upper and lower bile duct. Moderate impairment of vacuolation causes a stenosis at the site where the pancreatic duct inserts in a T-shape, with a moderate dilatation of the bile duct.

Is it possible to differentiate between choledochal cyst and congenital biliary atresia (type I cyst) by antenatal ultrasonography?

Both choledochal cyst and congenital biliary atresia (type I cyst) may share the same ultrasonographic pattern. We report 2 cases which were shown to have cystic structures on the upper abdomen by antenatal ultrasonography. The size of the choledochal cyst found at 24 weeks' gestation increased steadily as gestational age advanced. But the size of the cyst in congenital biliary atresia found at 29 weeks' gestation remained unchanged throughout the remaining pregnancy. Cyst enlargement, therefore, may suggest the possibility of a choledochal cyst.

[Prenatal diagnosis of biliary atresia associated with choledochal cyst]. / Diagnóstico prenatal de atresia biliar asociada a quiste de colédoco.

We report a case of biliary atresia promptly detected by its association with a choledochal cyst, prenatally diagnosed at 20 weeks' gestation. The baby was operated at 14 days of life. A choledochal cyst was found and fibrosis of the extrahepatic bile ducts was also noted. So, excision of the choledochal cyst and a Roux-en-Y porto-jejunostomy was done. Nine months later, despite an appropriate biliary drainage, echographic and histological changes compatible with liver cirrhosis have been detected. Including this one, six cases have been reported.

Prenatally diagnosed choledochal cysts: observation or early surgery?

The incidence of subhepatic cysts later confirmed as choledochal cyst has changed with the use of prenatal ultrasonography. A new group has emerged: the neonatal patient with an antenatal diagnosis. Optimal timing for cyst excision depends on variables such as gestational age, weight, associated conditions, biochemical liver alterations, development of complications, and the sonographic surveillance of size. The author's experience (1992) with an antenatally diagnosed choledochal cyst prompted this literature review. The present case showed an abnormal choledochopancreatic ductal junction, high amylase content, and a linear pattern of growth over time (2 mm/wk). Management consisted of cyst excision and bilio-enteric reconstruction. Fourteen cases (including the present one) have been reported in the world literature. All were females. Seventy-two percent of the ultrasound examinations were performed for dating purposes. Subhepatic cysts were identified at a mean gestational age of 26.9 weeks (range, 15 to 37 weeks). Excision and bilio-enteric reconstruction were performed at a mean age of 45 days (range, 9 hours to 6 months). Clinically, 50% of the babies were anicteric, 43% were jaundiced, and 7% had a palpable mass. Evidence of cyst growth was present in 56% of cases, and 60% had liver fibrosis that reverted to normal. The indications for surgery were jaundice (43%), cyst growth (21%), delayed HIDA excretion (7%), and elective (29%). Recommendations for managing the asymptomatic, anicteric neonate are discussed, entailing a rational approach based on growth potential, biochemical liver alterations, and the development of obstructive jaundice.

Obliteration of the distal bile duct in the development of congenital choledochal cyst.

The authors report the first case of antenatally diagnosed choledochal cyst having evidence of early fetal bile drainage and complete obliteration of the distal bile duct. This disputes the traditional hypothesis of reflux of pancreatic enzymes and supports the recent theory of primary obstruction as the etiologic cause of choledochal cyst. Coexisting congenital hypothyroidism and pulmonary stenosis had not been reported previously.

Choledochal cyst: findings on cholangiopancreatography with emphasis on ectasia of the common channel.

Choledochal cyst is a congenital malformation of the biliary tree that is unusual but by no means rare. During a 13-year period, we encountered eight patients with choledochal cysts who were evaluated with cholangiopancreatography. All of our cases showed an anomalous union of the pancreatic duct and common bile duct, resulting in a long common channel. Review of cholangiopancreatograms also showed ectasia of the common channel in six of the eight patients. Mean length of the common channel, corrected for magnification, was 26 mm (normal, less than 15 mm). The mean corrected diameter of the common channel was 7 mm (normal, 3-5 mm). We conclude that ectasia of the common channel is an important additional radiographic observation in the diagnosis of choledochal cyst. This observation has not been emphasized before.