New Endoscopic Approach to Diagnosing Pancreatic Diseases Using an Intraductal Ultrasound System

Abstract: We found that pancreatic diseases can be accurately visualized and diagnosed from the main pancreatic duct via the major papilla using an intraductal ultrasound (IDUS) catheter at a frequency of 30 MHz to create a 360 real‐time image. Herein we present the problems and potential future development of the IDUS system in visualizing pancreatic diseases. The clinical application of the IDUS was evaluated in 16 patients with pancreatic diseases (3 with pancreatic cancer, 6 with a mucin‐producing tumor and 7 with chronic pancreatitis). Insertion was successful in all 4 patients (100%) with a wide‐open orifice and in 9 out of 12 patients (75%) with a normal orifice. We encountered four primary difficulties using this modality : 1) As the IDUS catheter is only 135 cm long, it could not be inserted all the way to the pancreatic tail in some patients. Therefore, we had to resort to an unmanageable gastroscope instead of the preferred duodenoscope for scanning. 2) The tip of the catheter is fragile and can be easily damaged during endoscopic examination. 3) Anatomical problems from n reversed Z configuration at the head of the main pancreatic duct prevented insertion all the way to the pancreatic tail in a few patients. 4) The scanning area around the main pancreatic duct was limited to a radius of about 10 mm due to the frequency setting of the IDUS catheter. Further developments of the clinical applications of IDUS in the pancreas may eventually result in more accurate diagnoses, particularly in differential diagnoses between focal chronic pancreatitis and pancreatic carcinoma. The IDUS may also provide valuable details regarding invasion into the pancreatic Parenchyma in patients with mucin‐producing tumors. The IDUS may also be useful in determining the extent of excision necessary in patients with pancreatic diseases.