Pancreatobiliary maljunction in Western adults

I read with interest the recent report by Bechtler et al. [1] about a choledochal cyst type I A with drainage through the ventral duct in a patient with pancreas divisum. It is true that most biliary cysts are secondary to anomalous pancreatobiliary junction, also called pancreatobiliary maljunction (PBMJ). This abnormality (an extramural junction of the pancreatic and biliary ducts in the duodenum, apparently beyond the scope of intramural sphincter function), has been extensively reported in Eastern people [2], but, as we have stated previously [3], PBMJ is not only an Eastern disease and this diagnosis is increasingly being made in other populations [4]. It is important, as Bechtler et al. [1] remark, to give attention to the distal part of the common bile duct as it can show side branches like a pancreatic duct ([Fig. 1], [2]).

Fig. 1 Injection of contrast medium from the papillary orifice in a Western 41-year-old woman who presented with intermittent bouts of mild epigastric pain. After an extensive study, only bile duct dilatation was found in a transcutaneous ultrasound exam. Endoscopic cholangiopancreatography (ERCP) was performed to elucidate this finding, showing a fusiform cyst of the common bile duct. Side branches are present in the distal common bile duct that correspond to the Wirsung duct. Another cyst is present in the left main hepatic duct (biliary cyst type IV A). The distal choledochus joins the ventral pancreatic duct at 1.75 cm from the papillary orifice, making the so-called common channel.

Fig. 2 A guide wire has been passed deep into the bile duct. Injection of contrast at another site in the papillary orifice (perhaps in a small radicle of the ventral pancreas) shows that the common channel joins the dorsal pancreatic duct at the level of the minor papilla by means of an anterior ventral pancreatic branch, also having small radicles at the level of the papilla of Vater.

Magnetic resonance cholangiopancreatography (MRCP) can miss abnormalities near the papilla, especially if radiologists are not used to these conditions (biliary cyst and PBMJ). Therefore, endoscopic retrograde cholangiography (ERC) must be as detailed as possible. In this way, the three types of PBMJ can be diagnosed ([Fig. 3], [4]).

Fig. 3 Types of pancreatobiliary maljunction: type A or C-P (choledochus in pancreas). Type B or P-C (pancreas in choledochus). Type C is a complex junction between both ducts.

Fig. 4 Cannulation of the minor papilla. Injection of contrast into the dorsal pancreatic duct shows a certain kind of ansa or biliopancreatic complex junction (type C in Fig. 3), which also communicates the dorsal duct with the anterior ventral pancreatic branch. The bile duct is also filled with contrast injected at this level.

It is also accepted that to minimize the risk of cancer patients must be referred for surgery. Biliary cysts are associated with cholangiocarcinoma: 10 % – 30 % of adults with biliary cysts present with cancer, and a PBMJ may contribute to the high cancer risk due to reflux of pancreatic enzymes. Because of the risk of malignant degeneration of the cyst, current standard therapy is surgical resection. This is accepted even for minimally symptomatic young patients in Eastern countries, where surgical expertise in these conditions is high. However, we have found some reluctance among both surgeons and patients in our environment to embark upon major surgical procedures such as extrahepatic biliary resections and diversion procedures.

In conclusion, Bechtler et al. [1] are to be congratulated for this diagnosis, and all Western biliary endoscopists should have their attention drawn to it as PBMJ will increasingly be found in Western adults.

Competing interests: None

References

• 1 Bechtler M, Eickhoff A, Willis S, Riemann J F. Choledochal cyst type IA with drainage through the ventral duct in pancreas divisum.  Endoscopy. 2009;  41 E71-E72
• 2 The Japanese Study Group on Pancreaticobiliary Maljunction . Diagnostic criteria of pancreatico-biliary maljunction.  J Hepatobiliary Pancreat Surg. 1994;  1 219-221
• 3 García Cano J, Godoy M A, Morillas Ariño J, Pérez García J I. Pancreatobiliary maljunction. Not only an Eastern disease.  An Med Interna. 2007;  24 384-386
• 4 Adham M, Valette P J, Partensky . Pancreaticobiliary maljunction without choledochal dilatation associated with gallbladder cancer: report of 2 European cases.  Surgery. 2005;  138 961