Hironao Miyoshi

Clinical features of eosinophilic esophagitis: Ten Japanese cases

Aim:  We studied eosinophilic esophagitis (EE) to clarify the clinical and endoscopic features of a Japanese case series.

Differential Diagnosis and Treatment of Biliary Strictures

Biliary tract strictures present both diagnostic and therapeutic challenges to clinicians. Advances in imaging and endoscopic techniques have improved our ability to differentiate between benign and malignant lesions. Intraductal ultrasonography (IDUS), using an endoscopic approach, has the potential to aid in separating benign and malignant biliary lesions. In a series of 93 patients, a majority of whom had cancer, we found that IDUS had a sensitivity and specificity of 89.7% and 84%, respectively, for diagnosing biliary strictures. However, benign strictures associated with untreated autoimmune pancreatitis and/or the intrapancreatic portion of the distal common bile duct could not be easily distinguished from malignant strictures. Direct visualization of biliary mucosa using a percutaneous transhepatic endoscopic approach also helps separate benign from malignant biliary strictures. Further, the ability to obtain multiple directed biopsies using a percutaneous approach also increases diagnostic accuracy. A final advantage of the percutaneous approach is that once a suitable sized tract has been established, biliary strictures and stents can be placed. IDUS and percutaneous biliary endoscopy are promising new modalities for the diagnosis and treatment of biliary strictures.

SHORT-TERM METAL STENTING FOR TREATMENT OF MAIN PANCREATIC DUCT STRICTURES ASSOCIATED WITH CHRONIC PANCREATITIS

Background:  Stricture of the main pancreatic duct associated with chronic pancreatitis is a cause of pain due to ductal high pressure and the formation of pancreatic stones, but there is no established non‐surgical therapeutic procedure. We attemped a new method for treating this condition, called short‐term metal stenting.

Endoscopic approach via the minor duodenal papilla.

Background/Aims: We describe procedures for endoscopic approach via the minor papilla in symptomatic patients with pancreas divisum, pancreatic stones, and stricture of the Santorini’s duct, and neoplasms of the minor papilla: endoscopic minor papilla sphincterotomy, endoscopic pancreatic stone removal, endoscopic stent placement in Santorini’s duct, and resection of minor papilla neoplasms. Methods: The most important procedural detail was insertion of a guide wire into Santorini’s duct via the minor papilla, requiring gentle manipulation of both the cannula and guide wire to avoid subsequent complications such as pancreatitis. Results: Minor papilla sphincterotomy was most effective in the treatment of patients with pancreas divisum and associated with acute recurrent pancreatitis; these patients are the best candidates for endoscopic dorsal duct decompression including minor papilla sphincterotomy and stenting. Endoscopic treatment via the minor duodenal papilla was the only useful method for patients whose lesions could not be approached via the major papilla. It is a safe procedure to relieve pain. Long-term results of dorsal ductal stenting were satisfactory in 76 and 90% of patients (19/25 and 9/10, respectively). Conclusion: The high level of endoscopic skills necessary and the small number of patients who need these procedures should limit this approach to select institutions with appropriate endoscopic expertise.

New developments in diagnosis and non-surgical treatment of chronic pancreatitis.

Chronic pancreatitis is progressive and irreversible, leading to digestive and absorptive disorders by destruction of the exocrine pancreas and to diabetes mellitus by destruction of the endocrine pancreas. When complications such as pancreatolithiasis and pseudocyst occur, elevated pancreatic ductal pressure exacerbates pain and induces other complications, worsening the patients general condition. Combined treatment with extracorporeal shock‐wave lithotripsy and endoscopic lithotripsy is a useful, minimally invasive, first‐line treatment approach that can preserve pancreatic exocrine function. Pancreatic duct stenosis elevates intraductal pressure and favor both pancreatolithiasis and pseudocyst formation, making effective treatment vitally important. Endoscopic treatment of benign pancreatic duct stenosis stenting frequently decreases pain in chronic pancreatitis. Importantly, stenosis of the main pancreatic duct increases risk of stone recurrence after treatment of pancreatolithiasis. Recently, good results were reported in treating pancreatic duct stricture with a fully covered self‐expandable metallic stent, which shows promise for preventing stone recurrence after lithotripsy in patients with pancreatic stricture. Chronic pancreatitis has many complications including pancreatic carcinoma, pancreatic atrophy, and loss of exocrine and endocrine function, as well as frequent recurrence of stones after treatment of pancreatolithiasis. As early treatment of chronic pancreatitis is essential, the new concept of early chronic pancreatitis, including characteristics findings in endoscopic ultrasonograms, is presented.

Long-term outcomes in patients with gallstones detected by mass screening.

Gallstones are detected in about 5% of healthy Japanese. We followed up individuals showing gallstones upon screening, investigating features of those requiring surgery.

Development of Pancreatic Ductal Adenocarcinoma Associated with Intraductal Papillary Mucinous Neoplasia

We retrospectively investigated the incidence of pancreatic ductal adenocarcinoma among patients with intraductal papillary mucinous neoplasms of the pancreas. Based on imaging in 195 such patients, we chose surgery as initial treatment for 54, and periodic evaluation over 6 to 192 months (mean, 52) for 141. In 6 of the 141 patients observed for intraductal papillary mucinous neoplasm (4.2%), pancreatic ductal adenocarcinoma developed. Further, careful monitoring for cancer occurrence in the remnant pancreas proved essential in the surgical resection group; 2 of 26 patients (7.7%) subsequently developed pancreatic ductal adenocarcinoma in the remnant pancreas, at 41 months and 137 months after surgery. Serial observation of patients with intraductal papillary mucinous neoplasms by contrast-enhanced computed tomography or magnetic resonance cholangiopancreatography therefore is critical, whether or not surgical treatment initially was performed.

SPECIFIC DIAGNOSIS OF BILIARY STRICTURES BY QUANTITATIVE ASSESSMENT USING A CHOLANGIOSCOPICALLY DERIVED HEMOGLOBIN INDEX

Background:  We used percutaneous transhepatic cholangioscopy for detailed assessment of biliary tumors. Among the most important endoscopic findings is greater mucosal vascularity in malignant than in benign biliary strictures. Development of digital image processing now permits measurement of mucosal hemoglobin volume as a hemoglobin index. We studied the clinical usefulness of this hemoglobin index for differentiating malignant from benign biliary strictures.

A Case of Pancreatolithiasis Treated by a Combination of Endoscopic Extraction and Extracorporeal Shock Wave Lithotripsy

We report on the case of a 50‐year‐old woman with idiopathic chronic calcifying pancreatitis and diabetes. An endoscopic retrograde pancreatography showed a stone with a diameter of 23 mm and multiple small stones in the head of the pancreas. An endoscopic pancreatic sphincterotomy was performed. However, the stone could not be removed endoscopically. So we performed an extracorporeal shock wave lithotripsy (ESWL) using a Tripter X1. The stone was located in the shock wave focus by fluoroscopy. Under intravenous sedation, the patient received 5 ESWL sessions (a total of 11700 shock waves with an energy of 18kv). ESWL permitted stone disintegration and successful endoscopic extraction of the fragments. Complete clearance in the main pancreatic duct was achieved. No severe complications were observed. After treatment, an improvement in the PFD test was seen. ESWL is an effective method for treatment of endoscopically unextractable pancreatic ductal stones.

Development of Three-Dimensional Intraductal Ultrasonography in Diagnosis for Bile Duct Carcinoma

We have performed three-dimensional intraductal ultrasonography (3D-IDUS) since 1995. 3D-IDUS is useful for evaluation of bile duct carcinoma because it has a comprehensive image display. We can produce longitudinal reconstruction images with using the functions of the 3D-IDUS systems, dual-plane reconstruction images, including radial and longitudinal reconstruction images and oblique reconstruction images. The advantage of 3D-IDUS is that the time required for the examination is reduced compared with that required for conventional IDUS. We studied the results of 3D-IDUS and pathological findings for tumor extension in 25 patients with bile duct carcinoma. Overall accuracy for depth of tumor invasion was 88%, for tumor invasion to the portal vein 92%, and for tumor invasion to the pancreas was 84%. 3D-IDUS clearly demonstrates invasion of the pancreas or portal vein. However, intraductal spreading of the tumor is difficult to diagnose precisely. Diagnostic accuracy for intraductal spreading was only 70.0%, sensitivity 60%, and specificity 80%. 3D-IDUS could not detect subsequently demonstrated histological infiltration of the fibrous layer of perimuscular loose connective tissue. Another problem of 3D-IDUS is the limitation in diagnosis of lymph node metastasis. We have to continue to study the development 3D-IDUS systems to resolve these problems.