Dilatation of the Proximal Cystic Duct: Is It a Variant to "Type VI" Choledochal Cyst?

Type VI Choledochal Cyst and the Anomalous Pancreaticobiliary Junction: A Systematic Review

Background

The type VI choledochal cyst of the cystic duct (CC-CD) is not only a taxonomical conundrum but also a matter of research in terms of its etiopathogenesis and optimal therapeutic options. The role of anomalous pancreaticobiliary junction (PBJ) and pancreatic juice regurgitation in the etiopathogenesis of CC-CD and its association with biliary malignancies has not been elucidated yet.

Objective

To evaluate the role of anomalous PBJ in the etiopathogenesis of CC-CD and generate a scientific opinion through a systematic review of the literature.

Materials and Methods

A literature review (PUBMED, PUBMED Central, PMC, Google Scholar, Google search engine) following the PRISMA guidelines revealed 32 articles of interest. Search terms included choledochal cyst, choledochal, cyst, type VI, type 6, cystic duct dilatation, dilated cystic duct and cystic anomaly. Two independent reviewers extracted the data; the third reviewer had been involved in case of discrepancy.

Results

The study-cohort comprised of 45 patients. Roughly, 30% and 60% of the patients were diagnosed in the first and first-two decades of life, respectively. Sex ratio was skewed in favor of females (M:F = 1:1.4). Although males presented earlier than females, females were twice as likely to be diagnosed in the first decade of life. Anomalous PBJ was found in only one-third of these patients and was more common in females. Patients with anomalous PBJ presented early with three-fourth presenting in the first two decades of life. Anomalous PBJ was twice as prevalent in patients with concomitant involvement of other parts of the biliary tract (Group II) as compared to those with isolated CC-CD (Group I). Besides, patients in Group II presented early when compared to Group I, within the group females presented earlier. No significant association of biliary malignancies with anomalous PBJ was seen; the incidence of biliary malignancies was higher in those with a normal PBJ.

Conclusions

Observations from the study-cohort fail to establish a strong association of anomalous pancreaticobiliary junction in the etiopathogenesis of CC-CD or the development of biliary malignancies in these patients. It is likely that there are additional or alternative mechanisms that are important in the context of CC-CD.

Choledochal cyst of the proximal cystic duct: a taxonomical and therapeutic conundrum

Isolated choledochal cysts involving the cystic duct are rare. We present a case of a choledochal cyst involving only the proximal cystic duct, and discuss the taxonomic and therapeutic challenges. There is a need for a clearly defined classification system for these cysts as they may be categorised as either type II or type VI cysts. The optimal treatment remains debatable, with some authors recommending a bilioenteric reconstruction owing to the wide cystic duct-bile duct junction. However, we suggest that a cholecystectomy should be performed with examination of the specimen and frozen section in case of any abnormality rather than upfront bile duct excision. In addition, given the rarity of this condition and the paucity of long-term data, we recommend meticulous follow-up for development of any malignancy.

Pediatric types I and VI choledochal cysts complicated with acute pancreatitis and spontaneous perforation: A case report and literature review

RATIONALE

Choledochal cysts are a congenital disorder of the common bile duct that can cause progressive biliary obstruction and biliary cirrhosis. They were classified by Todani into five types. Of these, type VI choledochal cysts are rarely reported in the literature.

PATIENT CONCERNS

A 22-month-old girl presented with intermittent epigastralgia for approximately 10 days and fever for three days. Fasting and total parenteral nutrition were administered after admission. However, sudden onset of severe epigastric pain occurred. An abdominal sonogram showed turbid ascites and peritonitis was impressed.

DIAGNOSES

An emergent exploratory laparotomy was performed, and perforation of the posterior wall of types I and VI choledochal cysts was observed.

INTERVENTIONS

Intraoperative cholangiography revealed concomitant types I and VI choledochal cysts with stricture of the distal common bile duct. Definite surgery for resection of the choledochal cysts and gallbladder was performed with Roux-en-Y choledochojejunostomy.

OUTCOMES

The patient had no evidence of ascending cholangitis at three years after the operation.

LESSONS

Type VI choledochal cysts are rarely reported in the literature. To our knowledge, this is the first reported pediatric case of concomitant types I and VI choledochal cysts complicated with acute pancreatitis and spontaneous perforation.