Occult pancreatobiliary reflux in patients with a normal pancreaticobiliary junction

Age and incidence of occult pancreaticobiliary reflux in patients with benign gallbladder diseases

BACKGROUND

Occult pancreaticobiliary reflux (OPBR) has a significant correlation with diseases of the gallbladder and biliary system. This study examined the incidence of OPBR by age in patients with benign gallbladder diseases.

METHODS

We assessed 475 patients with benign gallbladder diseases who underwent surgery at Shanghai East Hospital from December 2020 to December 2021. Bile samples collected during surgery were tested for amylase. Patients with bile amylase >110 U/L (n = 64) were classified as the OPBR group; the rest (n = 411) as controls.

RESULTS

Of the participants, 375 had gallbladder stone (GS), 170 had gallbladder polyp (GP), and 49 had gallbladder adenomyomatosis (GA). The OPBR group was generally older, with OPBR incidence increasing with age, peaking post-45. Rates by age were: 4.9% (<35), 5.2% (35-44), 20.7% (45-54), 22.5% (55-64) and 17.6% (≥65), mainly in GS patients. ROC analysis for predicting OPBR by age yielded an area under the curve of 0.656, optimal cut-off at 45 years. Logistic regression indicated age > 45, GP, male gender, and BMI ≥ 24 kg*m-2 as independent OPBR predictors in GS patients. Based on these variables, a predictive nomogram was constructed, and its effectiveness was validated using the ROC curve, calibration curve and decision curve analysis (DCA). Further stratification revealed that among GS patients ≤ 45, concurrent GA was an OPBR risk; for > 45, it was GP and male gender.

CONCLUSIONS

The incidence of OPBR in GS patients is notably influenced by age, with those over 45, especially males without GP, being at heightened risk.

Pancreatic congenital anomalies and their features on CT and MR imaging: a pictorial review

OBJECTIVE

To review the congenital anomalies of the pancreas with their main clinical manifestations and key imaging findings on CT and MRI.

BACKGROUND AND CLINICAL SIGNIFICANCE

Anomalies of pancreatic development are frequent and generally asymptomatic, but can mimic and predispose individuals to pancreatic or peripancreatic pathologies, such as pancreatitis or malignancy. Their correct diagnosis may help avoid unnecessary further investigations and procedures, or establish adequate treatment when they manifest clinically. Differentiating pancreatic congenital anomalies from their main radiological mimics constitutes a challenge for the radiologist and requires familiarity with key imaging findings.

CONCLUSION

The imaging findings of CT and MRI are essential for the correct diagnosis of congenital pancreatic anomalies.

Identification of changes in bile composition in pancreaticobiliary reflux based on liquid chromatography/mass spectrometry metabolomics

INTRODUCTION

Pancreaticobiliary reflux (PBR) can induce gallstone formation; however, its pathogenic mechanism remains unclear. In this study, we explored the mechanism of PBR by the non-targeted metabolomic analysis of bile in patients with PBR.

OBJECTIVE

The aim of this study was to investigate the pathogenic mechanism in PBR by the non-targeted metabolomic analysis of bile collected during surgery.

METHODS

Sixty patients who underwent gallstone surgery at our center from December 2020 to May 2021 were enrolled in the study. According to the level of bile amylase, 30 patients with increased bile amylase ( > 110 U/L) were classified into the PBR group, and the remaining 30 patients were classified into the control group (≤ 110 U/L). The metabolomic analysis of bile was performed.

RESULTS

The orthogonal projections to latent structure-discriminant analysis of liquid chromatography mass spectrometry showed significant differences in bile components between the PBR and control groups, and 40 metabolites were screened by variable importance for the projection value (VIP > 1). The levels of phosphatidylcholine (PC) and PC (20:3(8Z,11Z,14Z)/14:0) decreased significantly, whereas the levels of lysoPC (16:1(9z)/0:0), lysoPC (15:0), lysoPC (16:0), palmitic acid, arachidonic acid, leucine, methionine, L-tyrosine, and phenylalanine increased.

CONCLUSIONS

Significant differences in bile metabolites were observed between the PBR and control groups. Changes in amino acids and lipid metabolites may be related to stone formation and mucosal inflammation.

A case of occult pancreaticobiliary reflux due to endoscopically confirmed relaxation of the Oddi sphincter

An otherwise healthy 45‐year‐old woman had been experiencing intermittent right upper abdominal pain for the past 1 year. Computed tomography showed pneumobilia and pancreatic duct emphysema despite a normal duodenal papilla. Magnetic resonance cholangiopancreatography and endoscopic ultrasound confirmed bile duct dilation but without a pancreaticobiliary maljunction. Duodenoscopy detected a slightly sunken, unfixed, and spontaneously enlarged duodenal papilla. During the cholangiogram, the Oddi sphincter was relaxed and the catheter could be easily inserted into the bile duct. Further, no findings suggestive of pancreaticobiliary maljunction were observed, and the contrast medium leaked spontaneously from the duodenal papilla. As biliary amylase level was high, we surmised the occurrence of occult pancreaticobiliary reflux due to relaxation of the Oddi sphincter. However, as there are no guidelines on the management of this condition, we did not offer any treatment. Nevertheless, the patient continued to experience similar symptoms and was retested 1 year later with similar results. As occult pancreaticobiliary reflux was reconfirmed, we suggested that the patient undergo laparoscopic extrahepatic bile duct resection and cholecystectomy, which is the standard treatment for pancreaticobiliary maljunction. Pathological evaluation revealed fibrous thickening of the bile duct wall and chronic cholecystitis, which are typical findings of pancreaticobiliary reflux. Even though pancreaticobiliary reflux is mainly observed in pancreaticobiliary maljunction, it has also been reported in normal patients. Here, we describe a novel mechanism of pancreaticobiliary reflux, namely, a relaxed or defective Oddi sphincter.

Occult pancreaticobiliary reflux is a pathogenic factor of some benign biliary diseases and gallbladder cancer

BACKGROUND

Pancreaticobiliary maljunction (PBM) is a well-known high-risk factor for biliary malignant tumors because of constant pancreaticobiliary reflux (PBR). However, the impact of occult pancreaticobiliary reflux (OPR), which is characterized by high bile amylase levels in individuals with anatomically normal pancreaticobiliary junction, on biliary diseases remains unclear. The aim of this study was to assess the correlation between OPR and biliary diseases.

METHODS

We enrolled 94 consecutive patients with normal pancreaticobiliary junction and primary biliary diseases confirmed by magnetic resonance cholangiopancreatography. We prospectively collected patients' bile samples and measured bile amylase levels. We investigated the incidence of OPR and the difference in bile amylase levels among these patients and assessed the correlation between high bile amylase levels (HBAL) and benign or malignant biliary diseases, as well as the OPR risk factors.

RESULTS

The incidence of OPR was 36.6% in patients with benign biliary diseases, 26.7% in those with cholangiocarcinoma and 62.5% in those with gallbladder cancer. The median bile amylase level tended to be higher in patients with gallbladder cancer than in those with benign biliary diseases, but there was no significant difference (165.5 IU/L vs. 23.0 IU/L, P = 0.212). The prevalence of an HBAL with bile amylase levels of 1000-7500 IU/L was similar in patients with gallbladder cancer and benign biliary diseases. However, the incidence of HBAL with bile amylase levels greater than 7500 IU/L was significantly higher in patients with gallbladder cancer than in those with benign biliary diseases (37.5% vs. 4.2%, P = 0.012). Multivariate logistic regression analysis revealed that choledocholithiasis was an independent risk factor for OPR.

CONCLUSIONS

OPR can occur in benign and malignant biliary diseases, and it may be a pathogenic factor for some benign biliary diseases and a high-risk factor for gallbladder cancer. There is a correlation between choledocholithiasis and OPR.

Relationship between high bile juice amylase levels and chronic bacterial infections in patients with gallbladder cancer

Purpose

Pancreatic enzyme reflux into the biliary tract is associated with chronic inflammation and increased cellular proliferation in the biliary epithelium, leading to biliary carcinoma. We evaluated the relationship between high bile juice amylase levels and biliary microflora in patients with malignant gallbladder lesions.

Methods

In this retrospective study, 25 gallbladder specimens were obtained from patients with gallbladder cancer to evaluate amylase levels and perform bacterial culture. The samples were divided into high and low amylase groups and culture-positive and negative groups for analysis. Bile juice amylase 3 times higher than the normal serum amylase level (36–128 IU/L) was considered high.

Results

The number of positive cultures was higher in the high amylase group than in the low amylase group, but the difference was insignificant. There were no differences in other clinicopathological factors. Sixteen patients showed positive culture results; Escherichia coli and Klebsiella spp. were the most common gram-negative bacteria, whereas Enterococcus and Streptococcus spp. were the most common gram-positive bacteria. Age and bile juice amylase levels were significantly higher in the culture-positive group than in the culture-negative group. The incidence of bacterial resistance to cephalosporins was 6.25%–35.29%, and this incidence was particularly high for lower-generation cephalosporins.

Conclusion

Bacteria in gallbladder were identified more frequently when the amylase level was high. High amylase levels in the gallbladder can be associated with caused chronic bacterial infections with occult pancreaticobiliary reflux, potentially triggering gallbladder cancer.

Free fatty acids and triglyceride change in the gallbladder bile of gallstone patients with pancreaticobiliary reflux

Background

Pancreaticobiliary reflux (PBR) causes chronic inflammation of the gallbladder mucosa and changes in the bile components, which are known to promote gallstone formation. This study aimed to investigate the bile biochemistry changes in gallstone patients with PBR and provide new clues for research on the involvement of PBR in gallstone formation.

Methods

Patients undergoing surgery for gallstones between December 2020 and May 2021 were eligible for inclusion. The bile biochemistry (including amylase, lipase, triglyceride, cholesterol, free fatty acids [FFAs], alanine aminotransferase [ALT], aspartate aminotransferase [AST], alkaline phosphatase [ALP], and γ-glutamyl transferase [γ-GT]) of the included gallstone patients was analysed to determine correlations with PBR.

Results

In this study, 144 gallstone patients who underwent surgery were enrolled. Overall, 15.97 % of the patients had an increased bile amylase level, which was associated with older age and significantly higher bile levels of ALP, lipase, triglyceride, and FFAs. Positive correlations were observed between amylase and lipase, triglyceride, FFAs levels in the gallbladder bile. However, the bile levels of triglyceride, FFAs, and lipase were positively correlated with each other only in the PBR group and showed no significant correlation in the control (N) group. In addition, elevated bile FFAs levels were found to be an independent risk factor for gallbladder wall thickening.

Conclusions

In conclusion, PBR-induced increase in FFAs and triglyceride in the gallbladder bile is a cause of gallstone formation, and an increase in bile ALP suggests the presence of cholestasis in PBR.

Pancreatic enzyme activity in the bile of healthy cats and its association with biliary morphology

Background

In human medicine, congenital maljunction of the common bile duct (CBD) and main pancreatic duct (MPD), or pancreatobiliary maljunction (PBM), is a known cause of cholecystitis.

Objective

Pancreatic enzyme activity in the bile (a diagnostic marker for PBM) of healthy cats was measured to determine normal values and evaluate its relationship with biliary morphology.

Animals

Fifty‐two healthy cats.

Methods

Cross‐sectional study of the biliary tracts of healthy cats during laparoscopic ovariohysterectomy and measurement of pancreatic enzyme activity in bile. The cats were divided into groups A and B based on the ratio of the diameter of the cystic duct (CD) to the CBD. The normal ratio was 3.4. Pancreatic enzyme activity in bile was compared between the groups.

Results

The CBDs were straight in all cases, whereas the CDs were variably tortuous or dilated. Amylase activity in the bile (median, <100 U/L; range, <100‐591 U/L) was lower than in serum in all cases, and group B, which had a CD/CBD ratio >3.4, had significantly higher amylase activity (median, 109 U/L; range, <100‐591 U/L) in the bile than did group A (median, <100 U/L; range, <100‐238 U/L), which had a CD/CBD ratio <3.4 (P = .0009).

Conclusions and Clinical Importance

The results suggest that a dilated CD is associated with reflux of pancreatic juice. In the future, it will be necessary to examine the clinical usefulness of these findings by measuring pancreatic enzyme activity in the bile of cats with cholangitis.

Automatic gallbladder segmentation using combined 2D and 3D shape features to perform volumetric analysis in native and secretin-enhanced MRCP sequences

OBJECTIVES

We aimed to develop the first fully automated 3D gallbladder segmentation approach to perform volumetric analysis in volume data of magnetic resonance (MR) cholangiopancreatography (MRCP) sequences. Volumetric gallbladder analysis is performed for non-contrast-enhanced and secretin-enhanced MRCP sequences.

MATERIALS AND METHODS

Native and secretin-enhanced MRCP volume data were produced with a 1.5-T MR system. Images of coronal maximum intensity projections (MIP) are used to automatically compute 2D characteristic shape features of the gallbladder in the MIP images. A gallbladder shape space is generated to derive 3D gallbladder shape features, which are then combined with 2D gallbladder shape features in a support vector machine approach to detect gallbladder regions in MRCP volume data. A region-based level set approach is used for fine segmentation. Volumetric analysis is performed for both sequences to calculate gallbladder volume differences between both sequences.

RESULTS

The approach presented achieves segmentation results with mean Dice coefficients of 0.917 in non-contrast-enhanced sequences and 0.904 in secretin-enhanced sequences.

CONCLUSION

This is the first approach developed to detect and segment gallbladders in MR-based volume data automatically in both sequences. It can be used to perform gallbladder volume determination in epidemiological studies and to detect abnormal gallbladder volumes or shapes. The positive volume differences between both sequences may indicate the quantity of the pancreatobiliary reflux.

Common bile duct stones associated with pancreatobiliary reflux and disproportionate bile duct dilatation

Occult pancreatobiliary reflux (PBR) in patients with a normal pancreatobiliary junction has been studied by various methods, but the exact etiology, mechanisms, and implications of this reflux have not yet been clarified. The aim of this study was to investigate the degree of PBR and patterns of biliary ductal dilatation in patients with acute calculous cholangitis by endoscopic retrograde cholangiopancreatography (ERCP).We retrospectively evaluated the degree of PBR and pattern of bile duct dilatation in patients with acute calculous cholangitis due to distal CBD (common bile duct) stones (Group A) as compared with patients with malignant CBD obstruction due to distal CBD cancer (Group B). All related data were prospectively collected. Bile juice was aspirated at the proximal CBD for measurement of biliary amylase and lipase before the injection of contrast dye. The diameters of the CBD and the peripheral intrahepatic duct (IHD) were calculated after contrast dye injection. Patients with pancreatobiliary maljunction and/or gallstone pancreatitis were excluded from the study.ERCP was performed on 33 patients with calculous cholangitis (Group A) and 12 patients with malignant CBD obstruction (Group B). Mean levels of bile amylase and lipase were significantly higher (P < .05) in group A (1387 and 6737 U/l, respectively) versus those in group B (32 and 138 U/l, respectively). Thirty patients in group A (90.9%) showed disproportionate dilatation (i.e., CBD was and IHD was not dilated), whereas only 4 patients in group B (33%) showed disproportionate dilatation.The results of this study suggest that patients with calculous cholangitis exhibit PBR that is associated with disproportionate bile duct dilatation.

Elevated bile amylase level without pancreaticobiliary maljunction is a risk factor for gallbladder carcinoma

BACKGROUND

Elevated bile amylase level in patients with pancreaticobiliary maljunction (PBM) or high confluence of pancreaticobiliary ducts (HCPBD) is well known as a risk factor for gallbladder carcinoma (GBC) development. However, the effects of occult pancreaticobiliary reflux (OPR), a condition characterized by high bile amylase level in the presence of an anatomically normal pancreaticobiliary junction, on GBC development remain unclear. The aim of this study was to assess the relationship between OPR and GBC.

METHODS

Clinicopathological data of 52 patients who were preoperatively diagnosed with gallbladder (GB) tumor (22 malignant, 30 benign) were retrospectively reviewed. All of the patients underwent preoperative endoscopic retrograde cholangiopancreatography to evaluate pancreaticobiliary junction morphology and bile amylase level. The relationship between the histological diagnosis of GB lesions, and pancreaticobiliary junction morphology and bile amylase level were investigated.

RESULTS

Pancreaticobiliary maljunction, HCPBD, and normal pancreaticobiliary junction (NPJ) were identified in 12, nine, and 31 patients, respectively. The rates of GBC in patients with PBM, HCPBD, and NPJ were 58% (7/12), 67% (6/9), and 29% (9/31), respectively. Of the 31 patients with NPJ, 22 had OPR and nine of these had GBC. None of the patients with NPJ and normal bile amylase level had GBC. Additionally, among patients with NPJ, bile amylase level was significantly higher in patients with GBC than in patients with benign tumors.

CONCLUSIONS

Occult pancreaticobiliary reflux, like PBM and HCPBD, is a risk factor for GBC development.

Sphincter of Oddi Dysfunction and the Formation of Adult Choledochal Cyst Following Cholecystectomy: A Retrospective Cohort Study

To determine the causes underlying the formation of adult choledochal cyst.Anomalous pancreaticobiliary junction is the most widely accepted theory regarding the etiology of choledochal cyst. However, choledochal cysts have been found in patients in the absence of this anomaly. Because the number of adult patients with choledochal cyst is increasing, it is important to address this controversy.Bile amylase levels in the cysts of 27 patients (8 males and 19 females) who had undergone cholecystectomy were retrospectively evaluated.The average age of the 27 patients was 45.8 ± 10.1 years and the majority (85.2%) were diagnosed with Todani type I cysts. None of the patients had dilatation of the common bile duct prior to surgery. There were 6 (22.2%) patients with anomalous pancreaticobiliary junction. However, amylase levels did not significantly differ between patients with and without this anomaly (P = 0.251). According to bile amylase levels, pancreatobiliary reflux was present in 21 (77.8%) patients. The mean amylase level significantly differed in patients with pancreatobiliary reflux (23,462 ± 11,510 IU/L) and those without (235 ± 103 IU/L) (P < 0.001). In patients with pancreatobiliary reflux, only 4 patients had anomalous pancreaticobiliary junction. That is, the majority of patients (17/21, 81%) having pancreatobiliary reflux did not have an anomalous junction of the pancreatic and biliary ducts.Since the only explanation for pancreatobiliary reflux in patients with a normal pancreaticobiliary junction is sphincter of Oddi dysfunction, we proposed that the formation of adult choledochal cyst is mainly due to sphincter of Oddi dysfunction.

Clinical significance of bile reflux into the pancreatic duct without pancreaticobiliary maljunction assessed by intraoperative cholangiography

INTRODUCTION

Bile reflux into the pancreatic duct (BRPD) is sometimes demonstrated during intraoperative cholangiography (IOC) even in patients without pancreaticobiliary maljunction. However, the clinical significance of this finding in laparoscopic and open cholecystectomy is unclear.

METHODS

Among 484 patients who underwent cholecystectomy (372 laparoscopic, 112 open), patients whose pancreatic duct was depicted in IOC were selected. The value of pancreatic amylase (p-amylase) of the gallbladder bile, histological changes, and the immunohistochemical expression of proliferating cell nuclear antigen (PCNA) in the gallbladder mucosa were analyzed in patients with BRPD. The data were then compared to those in patients without BRPD whose gallbladder bile p-amylase was measured (control group, n = 20).

RESULTS

The success rate of IOC was 93.6%. The rate of BRPD in laparoscopic and open cholecystectomy was 5.2% and 5.7%, respectively. The value of gallbladder bile p-amylase in patients with BRPD was significantly higher than in the control group (790.5 vs 14.0 IU/L, P = 0.034). The value of the PCNA labeling index in patients with BRPD was significantly higher than that of the control group (15.4% vs 4.1%, P = 0.0026). Among the 24 patients with BRPD, pathological changes in the gallbladder mucosa were detected in five (two hyperplasia, three metaplasia), but there was no correlation between the presence of pathological change and PCNA labeling index or gallbladder bile p-amylase.

CONCLUSIONS

IOC could detect BRPD both in laparoscopic and open cholecystectomy at a similar rate. Patients with BRPD had high levels of gallbladder bile p-amylase and PCNA labeling index, findings similar to those in patients with pancreaticobiliary maljunction.

Pancreaticobiliary reflux as a high-risk factor for biliary malignancy: Clinical features and diagnostic advancements

Pancreaticobiliary junction is composed of complex structure with which biliary duct and pancreatic duct assemble and go out into the ampulla of Vater during duodenum wall surrounding the sphincter of Oddi. Although the sphincter of Oddi functionally prevents the reflux of pancreatic juice, pancreaticobiliary reflux (PBR) occurs when function of the sphincter of Oddi halt. The anatomically abnormal junction is termed pancreaticobiliary maljunction (PBM) and is characterized by pancreatic and bile ducts joining outside of the duodenal wall. PBM is an important anatomical finding because many studies have revealed that biliary malignancies are related due to the carcinogenetic effect of the pancreatic back flow on the biliary mucosa. On the other hand, several studies have been published on the reflux of pancreatic juice into the bile duct without morphological PBM, and the correlation of such cases with biliary diseases, especially biliary malignancies, is drawing considerable attention. Although it has long been possible to diagnose PBM by various imaging modalities, PBR without PBM has remained difficult to assess. Therefore, the pathological features of PBR without PBM have not been yet fully elucidated. Lately, a new method of diagnosing PBR without PBM has appeared, and the features of PBR without PBM should soon be better understood.

Direct visualization of pancreatic juice flow using unenhanced MRI with spin labeling can be aid in diagnosing chronic pancreatitis

OBJECTIVE

The purpose of this study is to prospectively assess whether direct visualization of pancreatic juice flow using an unenhanced MRI technique with spin labeling can aid in the diagnosis of chronic pancreatitis.

SUBJECTS AND METHODS

Ten healthy volunteers and 50 patients who were categorized as having no chronic pancreatitis (n = 11), early chronic pancreatitis (n = 7), or established chronic pancreatitis (n = 32) underwent MRI, including direct pancreatic juice visualization using a flow-out technique with a time-spatial labeling inversion pulse, comprising a nonselective inversion recovery pulse immediately followed by a spatially selective inversion labeling pulse. The mean velocities and volumes of pancreatic juice excretion were also obtained. Variance tests were used to evaluate the clinical groups with respect to the appearance rate and mean velocity; the Kruskal-Wallis test was used for volume.

RESULTS

There were no significant differences between healthy volunteers and patients with no chronic pancreatitis. The appearance rate, mean velocity, and volume of pancreatic juice excretion tended to decrease with the degree of chronic pancreatitis. Although the difference in these values was statistically significant between the healthy group and the established chronic pancreatitis group, the values of the early group and other groups were not statistically significant. There was a significant correlation between the appearance rate of pancreatic juice and the clinical groups (τ = -0.4376, p = 0.0015).

CONCLUSION

The measurement of directly visualized pancreatic juice flow may aid in establishing the diagnosis of chronic pancreatitis.

Pancreatobiliary reflux in individuals with a normal pancreaticobiliary junction: a prospective multicenter study

BACKGROUND

Pancreatobiliary reflux (PBR) can occur in individuals without pancreaticobiliary maljunction. The aim of this study was to elucidate the incidence of PBR in individuals with a normal pancreaticobiliary junction and its impact on the biliary tree.

METHODS

Data were prospectively collected from 15 centers on 420 patients with a morphologically normal pancreaticobiliary junction who had undergone bile sampling and measurement of the biliary amylase level. We investigated the incidence and predictive factors for high biliary amylase levels (HBAL), as well as the relationship of HBAL with biliary malignancy.

RESULTS

Twenty-three patients (5.5%) showed HBAL (≥10,000 IU/L). Univariate analysis showed that risk factors for the elevation of biliary amylase levels were the existence of a relatively long common channel (≥5 mm), acute pancreatitis, and papillitis. Multivariate analysis revealed that only the existence of a relatively long common channel was a significant factor for PBR. Biliary amylase levels in patients with a relatively long common channel were significantly higher than in patients without a long common channel (12,333 vs. 2,070 IU/L, P = 0.001). The incidence of HBAL (P < 0.001), as well as the overall biliary amylase levels (P = 0.007) were significantly higher in patients with gallbladder cancer than in those without gallbladder cancer.

CONCLUSIONS

The PBR was frequently observed in individuals with a relatively long common channel. Patients showing HBAL with normal pancreaticobiliary junction are at high risk for gallbladder cancer.

Magnetic resonance evaluations of biliary malignancy and condition at high-risk for biliary malignancy: Current status

Tumors of the biliary tree are relatively rare; but their incidence is rising worldwide. There are several known risk factors for bile duct cancers, and these are seem to be associated with chronic inflammation of the biliary epithelium. Herein, 2 risk factors have been discussed, primary sclerosing cholangitis and reflux of pancreatic juice into the bile duct, as seen in such as an abnormal union of the pancreatic-biliary junction because magnetic resonance imaging (MRI) is used widely and effectively in the diagnosis of these diseases. When biliary disease is suspected, MRI can often help differentiate between benignity and malignancy, stage tumors, select surgical candidates and guide surgical planning. MRI has many advantages over other modalities. Therefore, MRI is a reliable noninvasive imaging tool for diagnosis and pre-surgical evaluation of bile duct tumors. Nowadays remarkable technical advances in magnetic resonance technology have expanded the clinical applications of MRI in case of biliary diseases. In this article, it is also discussed how recent developments in MRI contributes to the diagnosis of the bile duct cancer and the evaluation of patients with risk factors affecting bile duct cancer.

Long-term follow-up may be needed for pancreaticobiliary reflux in healthy adults

PURPOSE

The reflux of pancreatic enzymes into the biliary tract is associated with chronic inflammation and increases cellular proliferation of the biliary epithelium, leading to biliary carcinoma. The aim of this study is to detect the incidence of occult pancreaticobiliary reflux (OPBR) in patients who underwent elective cholecystectomy.

METHODS

Forty-seven patients with symptomatic gallstones who underwent cholecystectomy were recruited for this study. The gallbladder bile samples were obtained from the specimen of gallbladder and the amylase level was measured. The immunohistochemistry of p53, SMAD4 and Ki-67 were performed for the detection of metaplasia and dysplasia.

RESULTS

Biliary amylase was higher than the serum amylase in 10 patients (group A, 15,402.66 ± 33,592.43 IU/L; group B, 13.06 ± 18.12 IU/L). The mean age was 67.2 years in group A and 51.2 in group B (P < 0.01). The ratio of male to female was 1:2.3 and 1:1.8 in group A and B, respectively (P = 0.297). Eight patients in group A and thirteen patients in group B had inflammation (P = 0.014). The positive results of the Ki-67 test were exhibited in five cases in each group (P = 0.024).

CONCLUSION

Results from the study indicate that the age was older, degree of inflammation and positive rate of Ki-67 were higher when OPBR was suspected. In conclusion, the patients with OPBR would need long-term follow-up, because the OPBR can cause dysplasia and the reflux of pancreatic juice may be considered as a risk factor for extrahepatic bile duct carcinoma.

Imaging findings in 75 pediatric patients with pancreaticobiliary maljunction: a retrospective case study

BACKGROUND

Pancreaticobiliary maljunction (PBM) is often associated with congenital choledochal cyst, protein plugs and pancreatitis. Early diagnosis and timely treatment largely depend on imaging. We assessed a series of PBM in children, comparing imaging procedure with histological and pathological findings with regard to diagnosis.

METHODS

A retrospective analysis was conducted in 75 pediatric patients with PBM. PBM was defined as common channel at >5 mm. Two radiologists assess the shape of the bile duct and gallbladder, pancreatitis, surgical pathology, symptom profiles, operative notes and pathological records were compared with the imaging findings.

RESULTS

Dilatation of the bile duct was detected in 45 subjects out of the 46 subjects who underwent computed tomography (CT) and nine was diagnosis as PBM. Forty out of 41 subjects were revealed bile duct dilatation in ultrasonography (US). Bile duct dilatation was seen in 59 out of 60 subjects receiving magnetic resonance cholangiopancreatography (MRCP) and 39 were diagnosed as PBM. Seventy-four out of 75 subjects successfully underwent intraoperative cholangiography (IOC); a diagnosis of PBM was established in 60 cases based on IOC alone. The diagnosis rate of pediatric PBM varied significantly among the four groups (P < 0.0001). Pair-wise comparison showed a significant difference between the groups of MRCP and CT (P < 0.0001), MRCP and US (P < 0.0001), IOC and CT (P < 0.0001), IOC and US (P < 0.0001), CT and US (P = 0.0027), and there is no significant difference between the groups of IOC and MRCP (P = 0.0502).

CONCLUSION

US, IOC, CT and MRCP are valuable in showing dilatation of the bile duct and complications in pediatric PBM. MRCP is non-invasive, gives clear views of the pancreaticobiliary junction and should be the first choice for the diagnosis of PBM in children.

Japanese clinical practice guidelines for pancreaticobiliary maljunction

There have been no clinical guidelines for the management of pancreaticobiliary maljunction (PBM). The Japanese Study Group on Pancreaticobiliary Maljunction (JSPBM) has proposed to establish clinical practice guidelines on how to deal with PBM, with the support of the Japan Biliary Association (JBA). Because the body of evidence-based literature is relatively small, we decided to create guidelines based on the consensus of experts, using the medical literature for reference. A total of 46 clinical questions (CQs) were considered by the members of the editorial committee responsible for the guidelines. The CQs covered distinct aspects of PBM: (1) Concepts and Pathophysiology (10 CQs); (2) Diagnosis (10 CQs); (3) Pancreatobiliary complications (9 CQs); and (4) Treatments and prognosis (17 CQs). Statements and comments for each CQ were prepared by the guidelines committee members and collaborating partners. The CQs were completed after review by members of the editorial committee, meetings of this committee, public comments on the homepages of the JSPBM and the JBA, public hearings, and assessment and approval by the guidelines evaluation board. PBM includes cases where the bile duct is dilated (PBM with biliary dilatation) and those in which it is not (PBM without biliary dilatation). In these guidelines, PBM with biliary dilatation is defined as being identical to congenital biliary dilatation of Todani type I (except for type Ib) and type IV-A, both of which are accompanied by PBM in almost all cases. These guidelines are created to provide assistance in the clinical practice of PBM management; their contents focus on clinical utility, and they include general information on PBM to make this disease more widely recognized.

Biliary reflux detection in anomalous union of the pancreatico-biliary duct patients

AIM: To demonstrate the imaging findings of biliopancreatic and pancreatico-biliary reflux in patients with anomalous union of the pancreatico-biliary duct (AUPBD) on gadoxetic acid-enhanced functional magnetic resonance cholangiography (fMRC).

METHODS: This study included six consecutive patients (two men and four women; mean age 47.5 years) with AUPBD. All subjects underwent endoscopic retrograde cholangiopancreatography (ERCP); one subject also underwent bile sampling of the common bile duct (CBD) to measure the amylase level because his gadoxetic acid-enhanced fMRC images showed evidence of pancreatico-biliary reflux of pancreatic secretions. Of the five patients with choledochal cysts, four underwent pylorus-preserving pancreaticoduodenectomy.

RESULTS: The five cases of choledochal cysts were classified as Todani classification I. In three of the six patients with AUPBD, injected contrast media reached the distal CBD and pancreatic duct on delay images, suggesting biliopancreatic reflux. In two of these six patients, a band-like filling defect was noted in the CBD on pre-fatty meal images, which decreased in size on delayed post-fatty meal images, suggesting pancreatico-biliary reflux of pancreatic secretions, and the bile sampled from the CBD in one patient had an amylase level of 113 000 IU/L. In one of the six patients with AUPBD, contrast media did not reach the distal CBD due to multiple CBD stones.

CONCLUSION: Gadoxetic acid-enhanced fMRC successfully demonstrated biliopancreatic reflux of bile and pancreatico-biliary reflux of pancreatic secretions in patients with AUPBD with and without choledochal cysts.

Current knowledge on pancreaticobiliary reflux in normal pancreaticobiliary junction

Knowledge on pancreaticobiliary reflux in normal pancreaticobiliary junction and their pathologic implications has experienced tremendous progress during the last few years. This article reviews the current knowledge on this condition and its pathological implications on gallbladder diseases. Many publications with different levels of evidence were found supporting biliary carcinogenesis associated with pancreaticobiliary reflux in normal and abnormal pancreaticobiliary junction. Also, there are many publications supporting the common occurrence of pancreaticobiliary reflux in normal pancreaticobiliary junction, and sphincter of Oddi dysfunction as the most plausible cause of this condition. Although an important body of research has been published regarding pancreaticobiliary reflux in normal pancreaticobiliary junction and their clinical significance, the current evidence does not fully support what has been suggested. The reflux of pancreatic enzymes into the bile tract and gallbladder is a fascinating subject of study which is open to active research. The final demonstration of the pathophysiology and consequences of PBR in NPBL and support by evidence level type I would constitute a major breakthrough in the understanding and eventually in the treatment of gallbladder diseases.

Visualization of pancreatic juice movement using unenhanced MR imaging with spin labeling: preliminary results in normal and pathophysiologic conditions

PURPOSE

To visualize the movement of pancreatic juice noninvasively by using an unenhanced magnetic resonance (MR) imaging technique.

MATERIALS AND METHODS

Institutional review board approval and informed consent were obtained for this study. A flow-out technique of time-spatial labeling inversion pulse (SLIP) technique was applied using both nonselective and selective inversion pulses to label, or tag, pancreatic juice to move out of the region. Ten normal (eight men, two women; age range, 22-61 years; mean age, 35 years) and two pathologic conditions were examined on a commercially available 1.5 Tesla MR imager with quadrature-detected phased-array coils. All images were evaluated by two radiologists to assess depiction of the pancreatic juice movement or pancreatic juice reflux as compared to the pancreatic duct or the common bile duct on MRCP obtained before time-SLIP examination.

RESULTS

The tagged pancreatic juice was satisfactory visualized after applying the pulse labeling. Noninvasive visualization of pancreatic juice movement, including normal pancreatic juice movement and reflux from the main pancreatic duct into the common bile duct, was possible by using the unenhanced time-SLIP technique.

CONCLUSION

Noninvasive visualization of pancreatic juice movement is possible by using the unenhanced MR imaging time-SLIP technique.

Pancreaticobiliary reflux in patients with a normal pancreaticobiliary junction: Pathologic implications

Knowledge on pancreaticobiliary reflux in normal pancreaticobiliary junction and its pathologic implications has experienced tremendous progress during the last few years. This editorial reviews the current knowledge on this condition and its pathological implications on gallbladder diseases. The following aspects were defined appropriate for discussion: (1) Evidence of carcinogenesis associated with pancreaticobiliary reflux; (2) Evidence of pancreaticobiliary reflux in normal pancreaticobiliary junction; and (3) Evidence of sphincter of Oddi (SO) dysfunction as a cause of pancreaticobiliary reflux in normal pancreaticobiliary junction. The articles reviewed were selected and classified according to five levels of evidence: LevelI, meta-analysis double-blind randomized clinical trials, Level II, cohort non-blinded studies and non-randomized clinical trials, Level III, good quality case-control studies and non-randomized cohort studies, Level IV, case series and poor quality case-control studies, and Level V, case report articles and experts’ opinion. Evidence levels II, III, IV and V were found to support biliary carcinogenesis associated with pancreaticobiliary reflux in normal and abnormal pancreaticobiliary junction. The same levels of evidence were found to support the common occurrence of pancreaticobiliary reflux in normal pancreaticobiliary junction, and SO dysfunction as the most plausible cause of this condition. Although an important body of research has been published regarding pancreaticobiliary reflux in normal pancreaticobiliary junction and its clinical significance, the current evidence does not fully support what has been suggested. Studies with evidence level I have not been undertaken. This is a fascinating subject of study, and if finally supported by evidence level I, the importance of this condition will constitute a major breakthrough in biliary pathology.

Pancreatobiliary reflux and the length of a common channel

BACKGROUND/PURPOSE

Gallbladder cancer occurs frequently in patients with pancreaticobiliary maljunction due to pancreatobiliary reflux. Pancreatobiliary reflux is also detected in some patients with a relatively long common channel. This study aimed to clarify the correlation between pancreatobiliary reflux and the length of a common channel.

METHODS

Two hundred and three patients, in whom both the length of a common channel and amylase level in the bile were measured, were enrolled from nine centers.

RESULTS

Bile amylase level was correlated with the length of a common channel (P < 0.01). The minimum length of a common channel that could induce a markedly elevated amylase level in the bile (>1,000 mg/dl) was determined as 5 mm. We redefined high confluence of pancreatobiliary ducts (HCPBD) as cases with a common channel > or = 5 mm, in which the communication between the pancreatic and bile ducts was occluded with the sphincter contraction. Gallbladder cancer was found in 20% of 56 redefined HCPBD patients. Bile amylase level >1,000 mg/dl and biliopancreatic reflux were detected in 79 and 95% of the patients, respectively.

CONCLUSIONS

Patients with a common channel > or = 5 mm (redefined HCPBD) should be monitored for the development of gallbladder cancer, as they frequently showed significant pancreatobiliary reflux.

Progress in research of occult pancreatobiliary reflux

Increasing knowledge regarding pancreaticobiliary maljunction (PBM) has led researchers to find that pancreatobiliary reflux (flow of pancreatic juice into the biliary tract) occurs not only in PBM patients but also in individuals with a normal pancreaticobiliary junction (occult pancreatobiliary reflux, OPR). The functional disorders of the sphincter of Oddi have been proposed as a possible cause for OPR. Some studies have found that OPR is a high risk factor for gallbladder cancer. The incidence of choledochal stones is higher in patients with OPR than in those without OPR. In this article, we review the progress in research of OPR.

Intestinal metaplasia in gallbladder correlates with high amylase levels in bile in patients with a morphologically normal pancreaticobiliary duct

We reported previously that intestinal metaplasia in the gallbladder is strongly associated with expression of caudal-related homeobox transcription factor Cdx2. It has been documented that occult pancreatobiliary reflux, even in the absence of pancreaticobiliary maljunction, is associated with elevated risk of biliary malignancy. We ascertained the correlation between intestinal metaplasia in the gallbladder and occult pancreatobiliary reflux. In 196 patients with a normal pancreaticobiliary ductal arrangement who had undergone laparoscopic cholecystectomy, we performed intraoperative cholangiography and measured amylase levels in bile sampled from the gallbladder. The cutoff value for high cystic amylase was defined as a biliary amylase level higher than the normal upper limit of serum amylase (215 IU/L). We also retrospectively reviewed the cholecystectomized tissue specimens to investigate the presence of intestinal metaplasia and expression of Cdx2. Then, we explored the relationship between intestinal metaplasia in the gallbladder and occult choledocho-pancreatic reflux. Intestinal metaplasia was found in 16.8% (33/196) of the gallbladders. The prevalence of choledocho-pancreatic reflux revealed by intraoperative cholangiography was not significantly different between cases with intestinal metaplasia (5/33, 15.2%) and those without (25/163, 15.3%; P = .81). However, in cases with intestinal metaplasia, the rate of high cystic amylase (13/33, 39.4%) was significantly higher compared with cases without intestinal metaplasia (26/163, 16.0%, P = .005). In conclusion, intestinal metaplasia in the gallbladder is significantly correlated with high amylase levels in bile in patients with a morphologically normal pancreaticobiliary ductal arrangement.

Diagnosis and clinical implications of pancreatobiliary reflux

The sphincter of Oddi is located at the distal end of the pancreatic and bile ducts and regulates the outflow of bile and pancreatic juice. A common channel can be so long that the junction of the pancreatic and bile ducts is located outside of the duodenal wall, as occurs in pancreaticobiliary maljunction (PBM); in such cases, sphincter action does not functionally affect the junction. As the hydropressure within the pancreatic duct is usually greater than in the bile duct, pancreatic juice frequently refluxes into the biliary duct (pancreatobiliary reflux) in PBM, resulting in carcinogenetic conditions in the biliary tract. Pancreatobiliary reflux can be diagnosed from elevated amylase level in the bile, secretin-stimulated dynamic magnetic resonance cholangiopancreatography, and pancreatography via the minor duodenal papilla. Recently, it has become obvious that pancreatobiliary reflux can occur in individuals without PBM. Pancreatobiliary reflux might be related to biliary carcinogenesis even in some individuals without PBM. Since few systemic studies exist with respect to clinical relevance and implications of the pancreatobiliary reflux in individuals with normal pancreaticobiliary junction, further prospective clinical studies including appropriate management should be performed.

Amylase levels in bile in patients with a morphologically normal pancreaticobiliary ductal arrangement

BACKGROUND

We investigated the presence of occult pancreaticobiliary reflux in patients with a morphologically normal pancreaticobiliary ductal arrangement by measuring biliary amylase levels and compared histopathological findings of the gallbladder between groups with high and low biliary amylase levels.

METHODS

In 178 patients with a normal pancreaticobiliary ductal arrangement who had undergone endoscopic retrograde cholangiopancreatography (ERCP), we sampled bile from the bile duct and measured amylase levels. Then we compared clinical features and histological findings of the gallbladder between high (HALG) and low amylase level groups (LALG).

RESULTS

A high biliary amylase level was observed in 25.8% (46/178) of the patients. The prevalence of a high biliary amylase level was high in patients with gallbladder carcinoma (40%) and in those with choledocholithiasis (28.4%). The level of amylase in bile was high in patients with gallbladder carcinoma, adenomyomatosis of the gallbladder, and chronic cholecystitis. A strong correlation between the levels of amylase and lipase in bile and the dominance of amylase of pancreatic origin in bile were confirmed by isozyme analysis. Thickening of the gallbladder mucosa was a significant manifestation in HALG. Histological examination of the gallbladder mucosa showed that incidences of metaplastic change and atypical epithelium and Ki67-LI in were higher in HALG than in LALG.

CONCLUSIONS

Occult pancreaticobiliary reflux is observed in a considerable number of ERCP candidates. Those who show an extremely high biliary amylase level, at least, may be at high risk for biliary malignancies.

Diagnostic role of biliary pancreatic elastase for cholangiocarcinoma in patients with cholestasis

BACKGROUND

A wide array of proteins is secreted into the bile and may be associated with biliary tract diseases. We attempted to discover novel biomarker in bile for cholangiocarcinoma.

METHODS

Bile was collected from patients with bile duct obstruction. Proteins were separated by 2-dimensional electrophoresis and identified by mass spectrometry. Levels of mRNA and protein expression of the candidate biomarker were analyzed by real-time PCR and Western blotting, respectively, whereas enzyme activity was measured by a kinetic method. The diagnostic efficacy was assessed by receiver operating characteristic (ROC) curve analysis.

RESULTS

Pancreatic elastase (PE) 3B was identified as a biomarker for cholangiocarcinoma. The mRNA of PE 3B was up-regulated in cancerous tissues, compared to non-cancerous tissues. The protein expression and enzyme activity of PE in bile were increased in patients with cholangiocarcinoma, compared to gallstone patients. Biliary amylase activity was used to correct the presence of pancreaticobiliary reflux. Significantly higher PE/amylase ratios in bile were found in patients with cholangiocarcinoma (0.214+/-0.045) than those with gallstone (0.023+/-0.005, p<0.001). The area under the ROC curve of the ratio was 0.877 (95% CI: 0.765 to 0.988). Using 0.065 as a cutoff value, the ratio distinguished malignant from benign causes of biliary obstruction with a sensitivity of 82% and a specificity of 89%.

CONCLUSION

PE in bile is a biomarker for cholangiocarcinoma and the combination measurement of PE and amylase enhances diagnostic efficacy.

Occult pancreaticobiliary reflux in gallbladder cancer and benign gallbladder diseases

BACKGROUND AND OBJECTIVES

It was proposed that occult pancreaticobiliary reflux (OPBR) was associated with precancerous mucosal changes in the gallbladder, hence the importance of this disorder. There are no published reports investigating the incidence of OPBR in patients operated on for the entire spectrum of benign gallbladder diseases and gallbladder cancer. Our aim was to determine the incidence of OPBR and measure the levels of active pancreatic enzymes (amylase and lipase) in gallbladder bile of patients undergoing cholecystectomy for benign and malignant gallbladder diseases.

METHODS

One hundred eight patients with normal pancreaticobiliary junction evidenced by operative cholangiography were included in the study.

RESULTS

According to gallbladder bile amylase and lipase levels, 84.2% and 89% patients respectively had OPBR. OPBR was present in all gallbladder cancer patients; in these patients the biliary levels of amylase and lipase were significantly higher than the levels found in patients with benign gallbladder pathology (P < 0.0001).

CONCLUSIONS

OPBR could lead to inflammatory changes of the biliary epithelium and progress towards the development of precancerous mucosal changes and gallbladder cancer. The reason why such high levels of pancreatic enzymes are regurgitated into the biliary tree of patients with gallbladder cancer should be clarified.

Secretin-stimulating MRCP in patients with pancreatobiliary maljunction and occult pancreatobiliary reflux: direct demonstration of pancreatobiliary reflux

We propose the hypothesis that the enlargement of the common bile duct (CBD) or gallbladder (GB) that is occasionally demonstrated on magnetic resonance cholangiopancreatography (MRCP) after secretin stimulation is caused by pancreatobiliary reflux. Recently, occult pancreatobiliary reflux (OPR) has been demonstrated in patients without morphological pancreatobiliary maljunction (MPBM). The aim of this study was to evaluate the efficacy of secretin-stimulating MRCP (SMRCP) in the diagnosis of pancreatobiliary reflux. The study included 14 patients with MPBM and 32 patients with a normal pancreatobiliary junction. OPR was evaluated by bile collection and diagnosed in seven of the 32 patients. All the patients underwent SMRCP; the related findings were considered positive when enlargement of the CBD or GB was observed. Positive findings on SMRCP were observed in all MPBM patients. In the patients with normal pancreatobiliary junction, there was significant difference between the mean amylase levels in the patients with positive and negative SMRCP findings (mean, 4,755.7 and 29.7 IU/l). The sensitivity and specificity of SMRCP for diagnosing OPR was 85.7% and 68.0%, respectively. SMRCP provides a non invasive method for excluding PBR and can identify patients who could benefit from bile duct sampling to diagnose OPR.

Gallbladder carcinoma associated with pancreatobiliary reflux

AIM: To detect the patients with and without pan-creaticobiliary maljunction who had pancreatobiliary reflux with extremely high biliary amylase levels.

METHODS: Ninety-six patients, who had diffuse thickness (> 3 mm) of the gallbladder wall and were suspected of having a pancreaticobiliary maljunction on ultrasonography, were prospectively subjected to endoscopic retrograde cholangiopancreatography, and bile in the common bile duct was sampled. Among them, patients, who had extremely high biliary amylase levels (>10 000 IU/L), underwent cholecystectomy, and the clinicopathological findings of those patients with and without pancreaticobiliary maljunction were examined.

RESULTS: Seventeen patients had biliary amylase levels in the common bile duct above 10 000 IU/L, including 11 with pancreaticobiliary maljunction and 6 without pancreaticobiliary maljunction. The occurrence of gallbladder carcinoma was 45.5% (5/11) in patients with pancreaticobiliary maljunction, and 50% (3/6) in those without pancreaticobiliary maljunction.

CONCLUSION: Pancreatobiliary reflux with extremely high biliary amylase levels and associated gallbladder carcinoma could be identified in patients with and without pancreaticobiliary maljunction, and those patients might be detected by ultrasonography and bile sampling.

The value of biliary amylase and Hepatocarcinoma-Intestine-Pancreas/Pancreatitis-associated Protein I (HIP/PAP-I) in diagnosing biliary malignancies

BACKGROUND/OBJECTIVES

Elevated concentrations of Hepatocarcinoma-Intestine-Pancreas/Pancreatitis-associated Protein I (HIP/PAP-I) in pancreatic juice have been reported in patients with pancreatic adenocarcinoma and have been considered as a promising tumor marker. This study was conducted to investigate whether biliary HIP/PAP-I can be used in the differential diagnosis of the cause of biliary obstruction.

METHODS

Bile was obtained from patients with bile duct obstruction on the day of biliary drainage. The etiology of biliary obstruction included gallstones (n = 131), pancreatic cancer (n = 32), cholangiocarcinoma (n = 47), papilla Vater cancer (n = 13), hepatocellular carcinoma (n = 4) and metastatic cancer (n = 16). In addition to HIP/PAP-I, the samples were analyzed for amylase to check for the presence of pancreaticobiliary reflux.

RESULTS

The biliary concentration of HIP/PAP-I was not statistically different between patients with gallstones (median, 9.70 ng/mL; interquartile range [IQR] 1.80-45.75) and cancers (median, 12.70 ng/mL; IQR, 3.85-36.75), P > 0.05. However, the amylase activity in the bile was markedly elevated in patients with gallstones (median, 228 U/L; IQR, 40-1965), compared to those with cancer (median, 32 U/L; IQR; 30-176), P < 0.001. The area under the ROC curve of amylase was 0.751 (95% CI: 0.69 to 0.81). At a cut-off value of 46 U/L, the biliary amylase distinguished patients with malignant obstruction from those with benign obstruction with a sensitivity of 66% and a specificity of 74%.

CONCLUSIONS

Our data suggest that the biliary HIP/PAP-I measurement is not useful for differentiating causes of biliary obstruction. The divergent extent and duration of biliary obstruction caused by neoplasm and gallstones may contribute to the significant difference in the amylase activity in bile. Thus, amylase in bile represents a candidate marker in the differential diagnosis of the cause of biliary obstruction.

Severe dysplasia of the gallbladder associated with occult pancreatobiliary reflux

Pancreatobiliary reflux usually occurs in patients with pancreaticobiliary maljunction and can be associated with the occurrence of gallbladder carcinoma. We present the case of a patient with pancreatobiliary reflux despite having a normal pancreatobiliary junction (occult pancreatobiliary reflux; OPBR), in whom the resected gallbladder presented severe dysplasia. The patient, a 61-year-old woman, showed thickness of the gallbladder wall, detected by ultrasonography and computed temography (CT). Her biliary amylase level in the common bile duct was 103,000 IU/l, and in the gallbladder it was 153,500 IU/l, although endoscopic retrograde cholangiopancreatography revealed a normal pancreaticobiliary junction. Immunohistochemical staining showed many p53-positive nuclei in the dysplastic lesion, and about 50% of the dysplastic cells exhibited diffuse nuclear staining for Ki-67. In the present patient, early diagnosis of occult pancreatobiliary reflux led to early detection of a precancerous lesion of the gallbladder mucosa.

Precancerous mucosal changes in the gallbladder of patients with occult pancreatobiliary reflux

BACKGROUND

Pancreatobiliary reflux can occur even if the pancreaticobiliary junction is normal (occult pancreatobiliary reflux), and it may be associated with gallbladder carcinoma. The aim of the present study was to examine precancerous mucosal changes in the gallbladder from patients with occult pancreatobiliary reflux.

METHODS

The mucosa of the gallbladder from 13 patients who underwent cholecystectomy was examined histopathologically. These patients had an anatomically normal pancreatobiliary junction and a biliary amylase concentration greater than 10,000 IU/L. The gallbladder of patients without carcinoma was further examined by using immunohistochemical techniques to detect Ki-67, and the results were compared with those from control patients.

RESULTS

Of the 13 patients, 5 (38%) had gallbladder carcinoma and 8 (62%) did not. Of the 8 patients without carcinoma, 4 (50%) had dysplasia accompanied by hyperplasia, and 2 (25%) had hyperplasia alone of the gallbladder mucosa. The Ki-67 labeling index was significantly higher in hyperplastic and dysplastic mucosa than in control gallbladder mucosa (p < 0.0004).

CONCLUSIONS

Occult pancreatobiliary reflux could be associated with precancerous mucosal changes in the gallbladder, such as hyperplasia and dysplasia with increased cellular proliferation, and could be a possible risk factor for gallbladder carcinoma.