The Study On PTC Imaging Characteristics Of Pancreaticobiliary Maljunction And The Correlation Between It And Biliary Carcinoma

Background and objective: Pancreaticobiliary maljunction(PBM) is a congenital embryonic development malformation defined as common bile duct and pancreatic duct union that is located outside the duodenal wall and beyond the regulation of the sphincter of Oddi. Mutual reflux of bile and pancreatic juice into the pancreatic and bile ducts leads to some correlated disease. Japanese scholar Kizumi firstly proposed the concept of PBM in 1916. In 1970s, Komi N carried out the detailed research about the pathological changing of PBM and the relationship among PBM, congenital cholangiectasis and cholangiocarcinoma. He also advocated The Japanese Study Group on PBM and the Committee, and made the complete investigation,including the etiology, pathology, diagnosis, therapy principle and so on,which enormously deepened the clinical cognition to the desease. Recently, the close relation between PBM and correlated pancreaticobiliary deseases has become a research focus, especially the etiology and the pathological association with biliary carcinoma. Many researchers consider that PBM is closely related to occurrence of biliary malignant neoplasms, and have investigated the correlation from the clinic and animal experiment aspects, gene and molecular level. The records concerned with diagnosis of PBM is parum, of the total methods imageology is the main diagnostic examination, consist of endoscopic retrograde cholangiopancreato graphy (ERCP), intraoperative cholangiography, magnetic resonance cholangiopancreatography(MRCP), CT and hepatobiliary scintigraphy. Various kinds of imaging examinations have deferent features. Currently, more and more patients with obstructive jaundice(OJ) are receiving percutaneous transhepatic cholangiodrainage (PTCD) procedure for biliary decompression, sometimes percutaneous transhepatic cholangiography (PTC) can detect the PBM and display the anatomy of confluence. Nevertheless, few detail reports about PTC imaging characteristics of PBM in literature hitherto. Because the puncture and opacification are performed outside confluence of pancreaticobiliary ducts, which has scarcely influence on the function and anatomy of pancreaticobiliary confluence, so PTC is considered to have great diagnostic value for PBM. In addition, percutaneous transhepatic cholangio-biopsy (PTCB) during PTCD provides the pathologic evidence for OJ. To discuss the relationship between PBM and biliary carcinoma from the pathology point of view is an innovation of this study. The previous correlation research mainly concentrated on preclinical medicine.This study aims at retrospectively analyzing the detail data of 31 patients with OJ who were diagnosed as PBM to discuss the PTC technique availability, imaging characteristics of PBM diagnosis. Clarify preliminarily the diagnostic reference criterion for PBM during PTC and the correlation with biliary carcinoma.Materials and methods: Collecting the clinical data of consecutive 282 patients with OJ receiving the PTCD therapy in our hospital from January 1999 to February 2007. Clinical findings and cholangiopancreatographic results were analyzed. But 25 cases received the biliary external drainage as the obstructive sites weren't relieved Meanwhile the standard to be selected for cases and diagnostic conditions was established. Among them 35 cases, both biliary and pancreatic ducts were opacified. 31 cases was radiologically diagnosed as PBM and the detection rate was 12.062%(31/257). Male (n=19) to female(n=12) ratio was 1.583:1, the age ranged from 37y to 88y. the average age was 63.032±12.090 years. All of the cases presented obstructive jaundice, there were 26 patients presented with abdominal pain, abdominal distention or poor appetite, 18 cases presented with yellow urine and white bole sedes, 12 cases accompanied with biliary stone.Of the 226 OJ cases without PBM, 89 detail cases were drawn randomly to be defined as control group to evaluate the dependablity between PBM and biliary carcinoma. There are three methods to determine the etiological factor of OJ. Firstly, the histopathology type and differentiation degree are confirmed by surgery. Secondly, PTCB provides the histopathology evidence. If it is negative, the comprehensive diagnosis is made according to the case history, clinical aspects, specific laboratory examination and the follow-up.All of the patients underwent the standard PTCD procedure successfully. PTC revealed the obstruction site and the dilatation degree of the biliary tract, the guide wire was managed to pass throungh the occlusion, then the PTCB was performed as routine. The positive findings was considered to reflect the ture pathological changes. But the negative results cannot exclude the possibility of false negative. When transcatheter opacification visualized the pancreatic duct, pancreaticobiliary common channel and the duodenum, photographs was necessary to demonstrate the confluence of pancreaticobiliary ducts and the contraction, relaxation condition of Oddi sphincter in the optimal posture in order to measure the correlated data conveniently.The double blind method is applied to analyze the PTC findings. Two radiologists analyze the PTC findings respectively. The obstructive site, the shape of the pancreaticobiliary ducts and the common duct, duodenal papilla's site are the major observation objections. The compasses and ruler are utilized to measure the length and diameter of pancreaticobiliary common duct, pancreatic duct and common bile duct. The confluence angle is also a measure objections. Refer to the diameter of catheter in PTCD and calculate the practical numerical value. The coincident results are recorded. All of the data are analyzed by SPSS13.0 statistical package.Results: As a biliary decompression procedure for OJ, PTCD was performed successfully for all patients. The overall prevalence of PBM in OJ cases was 12.062%. The diameter of common bile duct, pancreatic duct and common duct near the confluence are 3.201±1.617mm, 2.061±0.817mm, 3.027±1.034 mm, respectively. Compared with the normal value, the results did not have statistical difference. The length of common duct and the confluence angle of the pancreaticobiliary ducts are 9.875±4.548 mm, 55.302°±22.513°, respectively. The significant difference exists between them and normal value. With regard to the diameter of common duct and the confluence angle, the difference was not significant between male and female, different year groups. But the length of common duct had significant difference among them. Ectopic duodenal papilla had influence on the length of common duct. The occurrence rate of biliary carcinoma was 61.290% in 31 PBM cases. The biliary carcinoma incidence in cases with PBM was significant higher than one in cases without PBM. The PBM confluence types and angle had no significant influence on the accompanied biliary carcinoma differentiate degree as well as the categories of pancreaticobiliary deseases. Nor had the length of common duct and confluence angle influence on canceration rate.Conclussion:(1) PTC is an effective, reliable, safe and technically available imaging method to diagnose PBM. PTC and PTCD not only make diagnosis for PBM, but undertake palliative therapy on OJ.(2) The referred PTC diagnostic standard of PBM is as follow: The high confluence of pancreaticobiliary ducts is detected by the tangential photograph of descending duodenum, the length of common duct exceeds 6mm. The confluence angle of the pancreaticobiliary ducts is increasing (>45°) and pancreatic amylase level in bile exceeds 1000U/L. The anomalous communicating branch (eg:vestigial Santorini duct) existing between common bile duct and pancreatic duct also leads to the PBM. The diagnosis can be made by one of the items above.(3)PTC imaging characteristics of PBM: The direct sign is a longer pancreaticobiliary common duct(>6mm) presented, generally, it's not dilated. The duodenal papilla is mainly located in the distal part to the middle of descending duodenum. The distaler is the location of duodenal papilla, the longer is the length of common duct. The indirect sign is "sign of suspending in midair " of the common duct, the distance between the confluence and duodenal wall exceeds 6mm, or the confluence angle is larger, the high level of pancreatic amylase in bile certifies the existing pancreatic juice reflux. The forms of pancreaticobiliary confluence are categori zed into three types: When common bile duct appeares to join the main pancreatic duct, it is denoted as B-P type. While the main pancreatic duct appeares to join the common bile duct, it is denoted as P-B type. Complex type is the PBM accompanied with visualizing accessory pancreatic duct. In addition, a stenosis of common bile duct end is usually observed in B-P type.(4)PBM is highly associated with occurrence of biliary malignant neoplasms.