Relationship between papilla-related variables and post endoscopic retrograde cholangiopancreatography pancreatitis: A multicenter, prospective study.

BACKGROUND AND AIM: Papilla with hooknose or long protruding shape may increase the difficulty of cannulation during endoscopic retrograde cholangiopancreatography (ERCP). However, the relationship between papilla anatomy and complications of ERCP has not been fully understood. We aimed to investigate the effect of major duodenal papilla morphology on post-ERCP pancreatitis (PEP) and the procedure of cannulation. METHODS: Patients with native papilla who underwent ERCP were recruited to this multicenter study. Papilla-related variables were collected, including the length of long axis (L), short axis (S) and opening width (OW), transverse fold, periampullary diverticulum (PAD), papilla location, orientation, swelling, and presence of duodenal stenosis. Demographic data and the procedure of cannulation were also prospectively evaluated. The primary outcome was PEP incidence. Multivariate analysis was used to identify high risk factors for PEP. RESULTS: Six hundred and fifty-eight patients were enrolled. Overall PEP incidence was 4.7% (31/658). The papilla of patients complicated with PEP had higher long to short axis (L/S) ratio (odds ratio [OR] 3.84, 95% confidence interval [CI]: 1.37-10.74, P = 0.010), higher long axis to opening width (L/OW) ratio (OR 1.35, 95%CI: 1.06-1.71, P = 0.014), more transverse folds (OR 2.53, 95%CI: 1.02-6.26, P = 0.044), and less periampullary diverticulum (OR 0.21, 95%CI: 0.06-0.70, P = 0.011). Multivariate analysis revealed that the indication of common bile duct stones, normal bilirubin, inadvertent pancreatic duct cannulation > 1, L/S ratio ≥ 1.5, and absence of PAD were independent risk factors for PEP. CONCLUSION: Besides patient-related and procedure-related factors, papilla-related variables, such as L/S ratio and PAD, can be considered as a third type of factors associated with PEP (Clinicaltrials.gov number: NCT03550768).

MDCT and MRI of the ampulla of Vater. Part I: technique optimization, normal anatomy, and epithelial neoplasms.

The purpose of this two-part article is to review the cross-sectional anatomy of the ampulla and periampullary region, to propose novel and optimized MDCT and MRI techniques that allow accurate evaluation of the ampulla of Vater, and to summarize the cross-sectional imaging features of benign and malignant ampullary conditions. In this first part, we will review the normal anatomy of the ampullary region, provide suggestions on how to optimize evaluation of the ampullary region by MDCT and MRI, and review the imaging features of select epithelial neoplasms of the ampulla. Familiarity with the normal ampullary anatomy and the pathologic conditions involving the ampulla, as well as the use of optimized MDCT and MRI techniques, may improve the diagnostic accuracy of radiologists facing ampullary abnormalities.

Development of a novel and simple ex vivo biologic ERCP training model.

BACKGROUND: Training and teaching of ERCP in biologic models has gained importance over the past decade. However, many existing models are expensive, are not widely available, or rely on live animals. OBJECTIVE: We describe a novel and simple ex vivo, biologic model for hands-on teaching. DESIGN: Ex vivo porcine study. SETTING: Experimental endoscopy unit. METHODS: Experimental study using a custom-made ex vivo biologic ERCP simulation model. This model contains 2 new key concepts: (1) formation of a duodenal sweep by using the porcine stomach and (2) use of multiple neo-papillae for endoscopic sphincterotomy and biliary stent placement. The papilla was re-created with chicken heart, and the bile ducts were built from chicken trachea. Endoscopic sphincterotomy was performed by using a pull-type sphincterotome. Stenting was performed with Amsterdam-type plastic stents and guidewires. MAIN OUTCOME MEASUREMENTS: The following definitions were used to evaluate the model: successful implantation of the neo-papilla, stability of the neo-papilla to the neo-duodenum, successful removal of the neo-papilla, and damage to the model. The following endoscopic endpoints were evaluated: successful cannulation, cannulation time, difficulties in positioning the papilla, quality of the biliary sphincterotomy, and prosthesis placement. Procedure-related adverse events such as perforation were also assessed. RESULTS: Ten neo-papillae were consecutively used in 1 duodenalized stomach. The implantation and removal of the neo-papillae were easily and successfully accomplished in all 10 cases without any damage to the duodenalized stomach. The stability of the neo-papilla on the duodenal sweep was excellent in all cases. Cannulation, biliary sphincterotomy, and stent placement could be successfully performed in 100% of cases. There was no damage and were no technical problems with the model. There were no adverse events during endoscopy (ie, perforations, stent misplacement). LIMITATIONS: Pilot study. CONCLUSION: Although further studies are necessary, this simple, novel ex vivo model appears useful for training in sphincterotomy and bile duct cannulation. Because the neo-papillae are interchangeable, repetitive sphincterotomies and other interventions can be performed using a single porcine model.

Feasibility of endoscopic retrograde cholangiopancreatography in healthy cats.

Cats are predisposed to diseases of the biliary tract and the exocrine pancreas and these can be challenging to diagnose. In humans and dogs > 10 kg, endoscopic retrograde cholangiopancreatography (ERCP) has been successfully used to diagnose some of these disorders. The purpose of our study was to determine whether ERCP would also be feasible in cats using a pediatric duodenoscope. Four purpose-bred, clinically healthy, castrated domestic shorthair cats participated in two studies. Study 1 compared standard white light endoscopy with chromoendoscopy for localizing the major duodenal papilla. In Study 2 ERCP was performed. Repeated clinical examinations and measurements of serum feline pancreatic lipase immunoreactivity (fPLI) were performed before and up to 18 hours after interventions on all cats. Chromoendoscopy was subjectively judged to be superior for localizing the major papilla. Insertion of the ERCP catheter was best accomplished when cats were in dorsal recumbency. Complete ERCP was successful in two cats. In the other cats, either retrograde cholangiography or pancreatography was possible. Serum fPLI concentrations increased temporarily in two cats during Study 2 when measured immediately, 2, 4, and 18 h after ERCP. Peak fPLI concentrations were detected either immediately after ERCP or 2 h later. No clinical signs of complications were observed within 18 h after the procedures. Findings indicated that ERCP is technically demanding but feasible in healthy cats. Future studies need to determine whether the temporary increases in serum fPLI concentrations are clinically important and to investigate the utility of ERCP in feline patients.

Results of the Tokyo trial of prevention of post-ERCP pancreatitis with risperidone-2: a multicenter, randomized, placebo-controlled, double-blind clinical trial.

BACKGROUND: Our previous study suggested that a combination of ulinastatin and risperidone reduced post-ERCP pancreatitis (PEP) compared with ulinastatin alone. OBJECTIVE: The aim of this study was to evaluate the efficacy of risperidone alone for prevention of PEP. DESIGN: A multicenter, randomized, placebo-controlled, double-blind clinical trial. SETTING: Two academic hospitals and 5 referral hospitals in Tokyo and Saitama, Japan. PATIENTS: Patients undergoing therapeutic or interventional-diagnostic ERCP. INTERVENTION: The patients were randomized to receive 2 mg of oral risperidone or oral placebo at 0.5 to 2 hours before ERCP. MAIN OUTCOME MEASUREMENTS: The primary endpoint was the incidence of PEP. Secondary endpoints were the incidence of hyperenzymemia and enzyme levels (amylase, pancreatic amylase, lipase). Risk factors for PEP were evaluated. RESULTS: We initially enrolled 500 patients in the study (250 in the risperidone group and 250 in the placebo group), but 17 (11 in the risperidone and 6 in the placebo group) were excluded after randomization. PEP developed in 24 patients (10.0%) in the risperidone group and 21 patients (8.6%) in the placebo group (P = .587). Serum amylase levels at 3 hours after ERCP were lower in the risperidone group (P = .007 in a single test of hypothesis, significance removed by Bonferroni correction for multiple testing). In multivariate analysis, a small papilla of Vater, total procedure time ≥40 minutes, and stenosis of the intrahepatic duct were significantly associated with PEP. LIMITATIONS: Multiplicity of study centers and a relatively wide time range of drug administration time. CONCLUSION: Risperidone did not show a benefit in prevention of PEP in this trial. ( CLINICAL TRIAL REGISTRATION NUMBER: NCT000004592.).

The mucosal folds at the pancreaticobiliary junction.

PURPOSE: The structure and function of the mucosal folds in the terminal bile and pancreatic ducts and hepatopancreatic ampulla are poorly characterised. The distribution, muscularity, and innervation of these folds were investigated. METHODS: The pancreaticobiliary junction was excised from ten cadavers (five male, 66-90 years) and examined histologically by serially sectioning (4-µm thickness) along the length of the terminal bile and pancreatic ducts from the tip of the major duodenal papilla. Three surgical specimens (two male, 63-72 years) were also evaluated. Sections were stained with haematoxylin and eosin, anti-actin (smooth muscle), anti-S100 (innervation), and anti-cholecystokinin (CCK)-A receptor antibodies. ImageJ software was used to compare relative radial fold projection and semi-quantitatively assess the smooth muscle and nerve content. In one additional cadaver specimen, folds were examined by scanning electron microscopy. RESULTS: Mucosal folds in the terminal bile duct were arranged circumferentially in a lattice-like arrangement and were distributed over an average distance of 7.3 mm along the terminal bile duct compared to 4.2 mm along the pancreatic duct (P = 0.001), projected further into the lumen, and were more densely innervated than those in the terminal pancreatic duct. Folds in both ducts contained smooth muscle which was more prominent in folds nearest to the major duodenal papilla. Mucosal folds in cadaver and surgical specimens showed no evidence of CCK-A receptor immunoreactivity. CONCLUSIONS: This study demonstrates that the mucosal folds of the terminal bile and pancreatic ducts contain muscle and nerve fibres, suggesting an active rather than purely passive function.

Major duodenal papilla and its normal anatomy.

The major duodenal papilla (papilla of Vater) is the point where the dilated junction of the bile and pancreatic ducts (ampulla of Vater) enter the duodenum. The ampulla is surrounded by the sphincter of Oddi, which not only controls the flow of bile and pancreatic juice into the duodenum, but also prevents the reflux of duodenal contents, bile and pancreatic juice into the bile and pancreatic ducts.

Evaluation of periampullary pathology with CT volumetric oblique coronal reformations.

OBJECTIVE: The purpose of this article is to show the value of volumetric oblique coronal reformation of CT data sets for assessing the normal anatomy and abnormalities of the ampulla of Vater. CONCLUSION: Volumetric oblique coronal reformations are a useful noninvasive method to provide diagnostic information about periampullary abnormalities as well as show secondary features important for local staging and management. The technique is also valuable in providing a time-efficient method to review pertinent findings with clinicians.

Ampulla of Vater: comprehensive anatomy, MR imaging of pathologic conditions, and correlation with endoscopy.

Endoscopic retrograde cholangiopancreaticography with or without an endoscopic biopsy is the method for making a definitive diagnosis of disease in or around the ampulla of Vater. However, the endoscopic findings of neoplastic and non-neoplastic conditions involving the perimapullary area may be similar and an endoscopic assessment is not entirely reliable for diagnosis. Recent MR and MRCP can allow the detection of lesions in a small complex structure such as the ampulla of Vater, and distinguish between an ampullary from periampullary lesion. This article reviews the normal anatomy of the ampulla of Vater, describes the role of MR in the detection and characterization of the lesion in or around the ampulla of Vater, and attempts to correlate them with ERCP.

Clinical significance of the duodenal papilla in patients with separate orifices for the bile and pancreatic ducts.

BACKGROUND: There have been few reports of separate orifices (SPO) for the bile and pancreatic ducts. The aim of this study was to elucidate the clinical significance of SPO. METHODS: Clinical data of patients with SPO (n = 21) were compared with those of 324 patients without SPO. The duodenal papillae in the patients with SPO were classified endoscopically into three types. Furthermore, we compared three subgroups (n = 221) among 345 patients (group A, 10 patients with bile duct stones with SPO; group B, 66 patients with bile duct stones without SPO; and group C, 145 patients without bile duct dysfunction) to evaluate the bile stasis of SPO. Various factors were retrospectively analyzed to identify any relationship in patients with SPO. RESULTS: Univariate analysis revealed that the diameter of the common bile duct, cholangiographic angulation, and the presence of common bile duct stones (CBDS) were significantly associated with the presence of SPO. Multivariate analysis of the different risk factors for SPO in all patients revealed that the presence of CBDS (relative risk, 3.000; 95% confidence interval, 1.083-8.313; P = 0.0346) and cholangiographic angulation (relative risk, 1.041; 95% confidence interval, 1.010-1.072; P = 0.0085) were independent risk factors. Moreover, univariate analysis among the three subgroups revealed that age, the presence of periampullary diverticula, the diameter of the common bile duct, and the length of the short narrow distal segment were significantly associated with the presence of SPO. CONCLUSIONS: CBDS and cholangiographic angulation are independent risk factors for SPO. This result suggests that SPO may be associated with an elevated risk of CBDS owing to bile stasis.

Microanatomical profiles on the lymphatic system in the human ampulla of Vater (immunohistochemistry and scanning electron microscopy).

BACKGROUND: Little information is available regarding microanatomy of lymphatic system in the ampulla of Vater, though it is of critical importance for an understanding of tumor progression via the lymphatics and determination of surgical strategy. The present study, therefore, aimed to demonstrate the distribution and microanatomical profiles on the lymphatic system in the ampulla. METHODS: The fine distribution and structure of the lymphatic vessels were investigated in the ampulla and the stomach by immunohistochemistry for lymphatic- (D2-40) and blood vascular- (CD31) specific markers and scanning electron microscopy. The densities of lymphatic and blood vessels were also compared. RESULTS: The duodenal papilla densely developed the lymphatics with distinct aspects of lymphatic capillaries, together with blood vessels. The density of lymphatic capillaries in the extramuscular layer in the ampulla was higher than those of both the other ampullary layers and the gastric extramuscular (subserosal) layer. CONCLUSIONS: The ampulla of Vater showed widespread lymphatic capillaries throughout the entire wall. The specific vascular system is suited to produce lymph everywhere and drain without via such a large vessel as lymphatic collector. This suggests that tumor cells invade the lymphatics and metastasize more easily in the ampulla than in the other gastrointestinal regions.

Benign anatomical mistakes: "ampulla of Vater" and "papilla of Vater".

The anatomy of the ampullary termination of the bile and pancreatic ducts is complex; appropriate terminology for this area is confusing and inaccurate. We examine the terms "ampulla of Vater" and "papilla of Vater" for anatomical and historical correctness. The term "ampulla" refers to a dilated part of a duct or other channel. Thus, this word is topographically correct to describe the dilatation at the confluence of the bile and main pancreatic ducts; historically, however, there is considerable reason to believe that its first description was by Santorini rather than Vater. The eponymous term "papilla of Vater" is also incorrect historically. The use of eponyms is firmly entrenched in the medical literature, but some are so problematic that they should be discarded. The eponymous terms for both the ampulla and the papilla should be replaced with the terms "hepatopancreatic ampulla" (or "biliaropancreatic ampulla") and "major [or "greater"] duodenal papilla," respectively.

A study on the human pancreaticobiliary duct system and ampulla region with their clinical considerations.

INTRODUCTION: The purpose of this study is to present the variations of the pancreatic duct system and hepatopancreatic ampulla so that an awareness of these variations may help in surgical planning and prevention of ductal injury. METHODS: Forty human pancreatic specimens were used to study the duct pattern of the pancreas and the formation and mode of termination of the pancreatic ducts. Also, the patency of the main pancreatic ducts, length of the hepatopancreatic ampulla, and length of the main pancreatic duct were measured. RESULTS: The main pancreatic duct was patent in 37 out of 40 specimens, 2 specimens showed the embryonic type of the duct system, and one had the duct obliterated at its duodenal end. The mode of termination of the main pancreatic and common pancreatic ducts was divided into four types. Seventy-five percent specimens belonged to type I, followed by type II in 22.5 % and type III in 2.5 % of specimens. The length of the main pancreatic duct ranged from 11 to 21.2 cm, the average being 17.3 cm, and the length of the hepatopancreatic ampulla varied from 1 to 10 mm (1 to 2 mm-5 %, 3 to 8 mm-55 %, and more than 8 mm in 15 % of specimens), and it was absent in 25 %. CONCLUSION: Awareness of these anomalies may help in surgical planning and prevention of undue ductal injury.

MRI Findings of Intrinsic and Extrinsic Duodenal Abnormalities and Variations.

This pictorial review aims to illustrate the magnetic resonance imaging (MRI) findings and presentation patterns of anatomical variations and various benign and malignant pathologies of the duodenum, including sphincter contraction, major papilla variation, prominent papilla, diverticulum, annular pancreas, duplication cysts, choledochocele, duodenal wall thickening secondary to acute pancreatitis, postbulbar stenosis, celiac disease, fistula, choledochoduodenostomy, external compression, polyps, Peutz-Jeghers syndrome, ampullary carcinoma and adenocarcinoma. MRI is a useful imaging tool for demonstrating duodenal pathology and its anatomic relationships with adjacent organs, which is critical for establishing correct diagnosis and planning appropriate treatment, especially for surgery.

The gross anatomy and histology of the gallbladder, extrahepatic bile ducts, Vaterian system, and minor papilla.

The gross anatomy, histology, and immunohistochemistry of the normal gallbladder, extrahepatic bile ducts, Vaterian system, and minor papilla are reviewed. The variability in the gross and microscopic morphology of the extrahepatic biliary system is emphasized.

Pancreatic development and anatomical variation.

The pancreas is formed by the fusion of the ventral and dorsal anlage, and a wide spectrum of anomalies or anatomical variations may appear related to this complicated process of fusion: e.g., agenesis, aplasia of a pancreatic anlage, hypoplasia, annular pancreas, pancreas divisum or nonfusion of the ventral and dorsal duct system, pancreaticobiliary maljunction, etc. Every endoscopist who engages in pancreatography or related diagnostic and therapeutic procedures should always be aware of all sorts of anatomical variations he or she might encounter.