Intraoperative common duct pressure and flow measurements

Apical bulkheads accumulate as adaptive response to impaired bile flow in liver disease

Hepatocytes form bile canaliculi that dynamically respond to the signalling activity of bile acids and bile flow. Little is known about their responses to intraluminal pressure. During embryonic development, hepatocytes assemble apical bulkheads that increase the canalicular resistance to intraluminal pressure. Here, we investigate whether they also protect bile canaliculi against elevated pressure upon impaired bile flow in adult liver. Apical bulkheads accumulate upon bile flow obstruction in mouse models and patients with primary sclerosing cholangitis (PSC). Their loss under these conditions leads to abnormally dilated canaliculi, resembling liver cell rosettes described in other hepatic diseases. 3D reconstruction reveals that these structures are sections of cysts and tubes formed by hepatocytes. Mathematical modelling establishes that they positively correlate with canalicular pressure and occur in early PSC stages. Using primary hepatocytes and 3D organoids, we demonstrate that excessive canalicular pressure causes the loss of apical bulkheads and formation of rosettes. Our results suggest that apical bulkheads are a protective mechanism of hepatocytes against impaired bile flow, highlighting the role of canalicular pressure in liver diseases.

Common bile duct pressure in patients with and without cholelithiasis: A case-control study

BACKGROUND

The reflux of pancreatic enzymes into the bile duct and the gallbladder is an abnormal phenomenon that plays a role in lithogenesis and carcinogenesis. Because the pressure of the common bile duct depends on the pressures of the sphincter of Oddi, its dysfunction would be reflected in an increase in the pressure of the common bile duct in patients with cholelithiasis. The objective of this study was to measure the pressures of the common bile duct in patients with and without cholelithiasis and to relate them to the presence of pancreatobiliary reflux.

METHODS

A prospective case-control study was designed. The study universe was constituted by all patients undergoing total gastrectomy for gastric cancer stages I and II over 30 months. The primary outcome measure was to establish differences between common bile duct pressures in patients with and without cholelithiasis.

RESULTS

Common bile duct pressures in patients with gallstones showed a significant elevation (16.9 mmHg) compared to patients without gallstones (3.3 mm Hg) (p < 0.0001). These pressures correlated with the levels of amylase and lipase in gallbladder bile; higher levels were found in patients with gallstones compared to patients without gallstones (P < 0.0001).

CONCLUSIONS

Common bile duct pressure in patients with cholelithiasis was significantly higher compared to patients without cholelithiasis leading to pancreatobiliary reflux.

Regulatory effect of electroacupuncture at auriculo-body acupoints on the functions of the biliary system and actions of the vagus nerve

AIM: To study the mechanism of electroacupuncture at auriculo-body acupoints in treating disorders of the biliary system and the actions of the vagus nerve in regulating biliary functions.

METHODS: A rabbit model of common bile duct stones was created. The influence of the vagus nerve on the functions of the biliary system was evaluated using bile current capacity, biliary duct pressure, and Oddi sphincter myoelectricity. The changes in these parameters were observed after electroacupuncture at a frequency of 20 Hz for 30 minutes at "Yi-Dan" area, Auriculo-acupoint and "Danshu".

RESULTS: A pathological increase in bile current capacity, biliary duct pressure, and Oddi sphincter myoelectricity was observed in rabbits with common bile duct stones. Oddi sphincter myoelectricity was transformed from orderly electric discharge into disorder and paroxysmal discharge. Electroacupuncture at ear-body acupoints further increased bile current capacity. The myotensity of the Oddi sphincter was decreased and myoelectricity was restored into rhythmicity. The regulatory effect of electroacupuncture at ear-body acupoints on biliary duct functions was not obvious in rabbits whose vagus nerve was removed. Increased bile current capacity and reduced biliary duct pressure were observed 30 minutes after stopping electroacupuncture.

CONCLUSION: The integrity of the vagus nerve is necessary for maintaining the normal functions of the biliary system in rabbits. Electroacupuncture at ear-body acupoints regulates biliary duct function mainly through modulating the vagus nerve.

Pathogenesis of gallstones

The many developments in nonoperative methods for the treatment of gallstone disease underscore the importance of understanding the pathogenesis of these stones. Elucidation of the factors responsible for nucleation of crystals and the mechanism by which it occurs would appear to be the challenge if we are to define the cascade of events that results in gallstone formation.

Certain aspects of normal and abnormal motility of sphincter of Oddi

Applications of electromyographic and endoscopic manometric techniques in experimental and clinical studies have enhanced our knowledge of the normal physiology and motility disturbances of the sphincter of Oddi. The sphincter of Oddi has an active role in coordinating the time and rate of secretion of biliopancreatic juice into the duodenum. In the opossum, the sphincter of Oddi exhibits spontaneous contractions that migrate distally along the sphincter and expels its contents into the duodenum. Although the motor activity of the sphincter of Oddi is independent from that of the duodenum, there is a correlation between the frequency of bursts of spike potentials in the sphincter of Oddi and the migrating motor complex phases in the duodenum. Abnormal motility of the sphincter of Oddi has been reported during endoscopic manometric evaluation of patients with choledocholithiasis and sphincter of Oddi dyskinesia. Patients with common bile duct stones have an increase in the frequency of retrograde propagation of phasic waves. Elevation of basal pressure as well as an increase in the frequency and amplitude of sphincter of Oddi phasic waves and the common bile duct-duodenum gradient pressure may occur in patients with sphincter of Oddi dyskinesia. Endoscopic manometric studies of the sphincter of Oddi may become an important method to diagnose sphincter of Oddi dyskinesia.

Endoscopic pancreatic and biliary manometry in pancreatic, biliary, and papillary disease, and after endoscopic sphincterotomy and surgical sphincteroplasty

Endoscopic manometry was used to measure pancreatic duct, common bile duct, pancreatic duct sphincter and bile duct sphincter pressures in 43 healthy volunteers and 162 patients with a variety of papillary, pancreatic and biliary disorders. Common bile duct pressure was significantly raised after cholecystectomy, with common bile duct stones and papillary stenosis but pancreatic duct pressure only in papillary stenosis. After endoscopic sphincterotomy mean common bile duct pressure fell from 11.2 to 1.1 mmHg and pancreatic duct pressure from 18.0 to 11.2 mmHg. Distinct pancreatic duct sphincter and bile duct sphincter zones were identified as phasic pressures of 3-12 waves/minute on pull-through from pancreatic duct and common bile duct to duodenum. Pancreatic duct sphincter pressures were higher with common bile duct stones and stenosis whereas bile duct sphincter pressures were higher in pancreatitis and stenosis. Bile duct sphincter activity was present in 60% of patients after surgical sphincteroplasty but 21% of patients after endoscopic sphincterotomy. Endoscopic manometry facilitated the diagnosis of papillary stenosis, has allowed study of papillary pathophysiology and has shown a functional inter-relationship between the two sphincteric zones.