Yukihiro Satoh

Transpapillary intraductal US prior to biliary drainage in the assessment of longitudinal spread of extrahepatic bile duct carcinoma

BACKGROUND The utility of intraductal US via the transpapillary route prior to biliary drainage in the assessment of longitudinal extension of extrahepatic bile duct carcinoma was investigated. METHODS In 19 patients with extrahepatic bile duct carcinoma who underwent surgical resection, an ultrasonic probe (diameter, 2.0 mm; frequency, 20 MHz) was inserted into the bile duct via the transpapillary route prior to biliary drainage. Longitudinal cancer extension along the bile duct was prospectively determined and compared with the histologic findings in the resected specimens. RESULTS Results on the hepatic side were as follows: Intraductal US demonstrated more extensive longitudinal cancer spread than cholangiography in 9 of 19 patients with one instance of overdiagnosis. The accuracy of intraductal US in assessing the extent of spread (84%) was superior to that of cholangiography (47%) (p < 0.05). Results on the duodenal side were as follows: In patients with suprapancreatic bile duct cancer (n = 14), intraductal US demonstrated more extensive longitudinal cancer spread than cholangiography in 8 of 14 patients. The accuracy of intraductal US in assessing the extent of the spread (86%) was superior to that of cholangiography (43%) (p < 0.05). CONCLUSIONS Transpapillary intraductal US prior to biliary drainage is useful in demonstrating longitudinal extension of bile duct cancer. However, the surgical margins were inaccurate in some patients.

Distinct Roles of Smad2-, Smad3-, and ERK-dependent Pathways in Transforming Growth Factor-β1 Regulation of Pancreatic Stellate Cellular Functions

Pancreatic stellate cells (PSCs) play a major role in promoting pancreatic fibrosis. Transforming growth factor-β1 (TGF-β1) regulates PSC activation and proliferation in an autocrine manner. The intracellular signaling pathways of the regulation were examined in this study. Immunoprecipitation and immunocytochemistry revealed that Smad2, Smad3, and Smad4 were functionally expressed in PSCs. Adenovirus-mediated expression of Smad2, Smad3, or dominant-negative Smad2/3 did not alter TGF-β1 mRNA expression level or the amount of autocrine TGF-β1 peptide. However, expression of dominant-negative Smad2/3 inhibited PSC activation and enhanced their proliferation. Co-expression of Smad2 with dominant-negative Smad2/3 restored PSC activation inhibited by dominant-negative Smad2/3 expression without changing their proliferation. By contrast, co-expression of Smad3 with dominant-negative Smad2/3 attenuated PSC proliferation enhanced by dominant-negative Smad2/3 expression without altering their activation. Exogenous TGF-β1 increased TGFβ1 mRNA expression in PSCs. However, PD98059, a specific inhibitor of mitogen-activated protein kinase kinase (MEK1), inhibited ERK activation by TGF-β1, and consequently attenuated TGF-β1 enhancement of its own mRNA expression in PSCs. We propose that TGF-β1 differentially regulates PSC activation, proliferation, and TGF-β1 mRNA expression through Smad2-, Smad3-, and ERK-dependent pathways, respectively.

Bile duct wall thickness measured by intraductal US in patients who have not undergone previous biliary drainage

BACKGROUND We investigated the bile duct wall thickness measured on intraductal US in patients who had not undergone biliary drainage, with special attention to the influence of cancer at the distal bile duct, bile duct stones, obstructive jaundice, longitudinal cancer extension, and primary sclerosing cholangitis on wall thickness. METHODS The study included 183 patients. Patients who had undergone previous biliary drainage were excluded. Intraductal US was performed by the transpapillary route with use of a thin-caliber ultrasonic probe (2.0 mm diameter, 20 MHz frequency). The bile duct wall thickness (width of the inside hypoechoic layer) was retrospectively measured on US images. RESULTS Bile duct wall thicknesses of the common hepatic duct for the control group (n = 95), cancer at the distal bile duct group (n = 9), bile duct stone group (n = 56), and obstructive jaundice group (n = 17) were 0.6 +/- 0.3 mm (mean +/- SD), 0.8 +/- 0.5 mm, 0.8 +/- 0.6 mm, and 0.8 +/- 0. 5 mm, respectively. No significant differences (p > 0.05) were found between them. However, wall thickness for the cancer extension to the common hepatic duct group (n = 4, 2.0 +/- 0.4 mm) and sclerosing cholangitis group (n = 2, 2.5 +/- 0.4 mm) were significantly greater than in the other groups (p < 0.005). CONCLUSIONS In patients who have not undergone previous biliary drainage, the bile duct wall thickness was not thicker in patients with obstructive jaundice. However, the duct wall was significantly thicker in patients with either longitudinal cancer extension or primary sclerosing cholangitis compared with that of other groups.

Preoperative assessment of extrahepatic bile duct carcinoma using three-dimensional intraductal US

BACKGROUND We investigated the utility of a new imaging modality, three-dimensional intraductal ultrasonography (US), for staging bile duct cancer. METHODS In eight patients with extrahepatic bile duct carcinoma, two- and three-dimensional intraductal US was used to assess tumor invasion of the right hepatic artery, portal vein, and pancreatic parenchyma before resection. The findings were correlated with histologic information from the resected specimen. RESULTS Three-dimensional intraductal US enabled accurate assessment of tumor invasion of the right hepatic artery in 88% of cases, the portal vein in 100%, and pancreatic parenchyma in 100%. Two-dimensional intraductal US enabled accurate assessment of invasion of these structures in 88%, 88%, and 88% of cases. CONCLUSIONS Three-dimensional intraductal US is useful in assessing tumor stage in bile duct carcinoma.

Biliary guidewire facilitates bile duct biopsy and endoscopic drainage

Background: The introduction of a guidewire through bile duct strictures may facilitate transpapillary bile duct biopsy and subsequent biliary drainage.

Epinephrine irrigation for the prevention of pancreatic damage after endoscopic balloon sphincteroplasty

Background and Aim: Endoscopic balloon sphincteroplasty (EBS) is an alternative to sphincterotomy for the treatment of bile duct stones. The purpose of this study was to determine if epinephrine irrigation of the papilla can prevent the pancreatic damage associated with EBS.

p53 expression in the gastric mucosa before and after eradication of Helicobacter pylori.

Accumulation of p53 has been recognized in the gastric mucosa infected with Helicobacter pylori. We investigated the prevalence of p53‐positive cells in the gastric mucosa before and one month after eradication of H. pylori and the relationship between p53 positivity and inflammation and cell proliferation.

Intraductal US in assessing the effects of radiation therapy and prediction of patency of metallic stents in extrahepatic bile duct carcinoma

BACKGROUND We assessed the local effects of radiation therapy using intraductal ultrasonography (US) to predict the subsequent patency of metallic stents in bile duct carcinoma. METHODS Data from 16 patients with extrahepatic-suprapancreatic bile duct carcinoma were prospectively analyzed. Thin-caliber US probes (2.0 mm diameter/20 MHz frequency and 2.8 mm diameter/10 MHz frequency) were inserted into the bile duct via a percutaneous transhepatic approach pre- and postradiation therapy to evaluate the effects of treatment. When intraductal US showed a reduction in bile duct wall thickness of 30% or greater or showed a lessening of vessel (portal vein or right hepatic artery) invasion, radiation therapy was judged to be effective. Noncovered metallic stents were then inserted, and their patency was evaluated over time. RESULTS When radiation therapy was effective (n = 7), the metallic stent was patent for 522 +/- 571 days. When radiation was ineffective (n = 9), the metallic stent was patent for only 188 +/- 159 days. When radiation therapy was ineffective, stent obstruction occurred in 6 of 9 (66.7%) patients during this period, significantly more frequently than when radiation therapy was effective (14.3%, p < 0.05). CONCLUSIONS Assessment of local radiation effects by intraductal US is useful for predicting patency of metallic stents in bile duct cancer.

Preoperative assessment of congenital bile duct dilatation using intraductal US.

BACKGROUND Although congenital bile duct dilatation is frequently associated with biliary tract cancer, conventional cholangiography often does not demonstrate small ductal tumors. This is the first prospective study of the value of intraductal ultrasonography (US) in the examination of the extrahepatic bile ducts in patients with congenital bile duct dilatation. METHODS Intraductal US via a transpapillary route was used in consecutive patients with congenital bile duct dilatation. A 2.0 mm diameter, 20 MHz frequency catheter probe was used. The images were correlated with the results of histologic examination of the resection specimens. RESULTS Intraductal US was performed successfully via the transpapillary route in 8 of 10 patients. In the other 2 patients, the percutaneous transhepatic route was used. In the 6 patients with cylindrical dilatation, intraductal US demonstrated the entire extrahepatic bile duct. In 1 patient, it showed a bile duct cancer not demonstrated by cholangiography. In 2 of the 4 patients with cystic dilatation, intraductal US did not demonstrate the entire extrahepatic bile duct because of the low penetration depth of the probe. Percutaneous transhepatic cholangioscopy was required in these patients. CONCLUSIONS Intraductal US is useful for demonstrating cancers in the extrahepatic bile ducts in patients with congenital cylindrical ductal dilatation.

Comparison of intraductal ultrasonography with percutaneous transhepatic cholangioscopy for the identification of residual bile duct stones during lithotripsy

Background: An imaging modality that can be used to identity small stones after a biliary lithotripsy is required. Intraductal ultrasonography was evaluated by using percutaneous transhepatic cholangioscopy as the gold standard.