Linear echoendoscope-guided ERCP for the diagnosis of occult common bile duct stones.

BACKGROUND: Less than 67% of patients with intermediate risk for common bile duct (CBD) stones require therapeutic intervention. It is important to have an accurate, safe, and reliable method for the definitive diagnosis of CBD stones before initiating therapeutic endoscopic retrograde cholangiopancreatography (ERCP). Few publications detail the diagnostic efficacy of linear echoendoscopy (EUS) for CBD stones. METHODS: 30 patients with biliary colic, pancreatitis, unexplained derangement of liver function tests, and/or dilated CBD without an identifiable cause were enrolled in the study. When a CBD stone was disclosed by linear EUS, ERCP with stone extraction was performed. Patients who failed ERCP were referred for surgical intervention. If no stone was found by EUS, ERCP would not be performed and patients were followed-up for possible biliary symptoms for up to three months. RESULTS: The major reason for enrollment was acute pancreatitis. The mean predicted risk for CBD stones was 47% (28-61). Of the 12 patients who were positive for CBD stones by EUS, nine had successful ERCP, one failed ERCP (later treated successfully by surgical intervention) and two were false-positive cases. No procedure-related adverse events were noted. For those 18 patients without evidence of CBD stones by EUS, no false-negative case was noted during the three-month follow-up period. Linear EUS had sensitivity, specificity, positive and negative predicted values for the detection of CBD stones of 1, 0.9, 0.8 and 1, respectively. CONCLUSION: Linear EUS is safe and efficacious for the diagnosis of occult CBD stones in patients with intermediate risk for the disease.

EUS-guided photodynamic therapy of the pancreas: a pilot study.

BACKGROUND: Photodynamic therapy of pancreatic cancer by using percutaneously placed light catheters has been reported. The feasibility and safety of EUS-guided photodynamic therapy of the pancreas was studied in a porcine model. METHODS: After injection of porfimer sodium, a 19-gauge needle was inserted into the pancreas, the liver, the spleen, and the kidney under EUS guidance. A small diameter quartz optical fiber was passed through the EUS needle and used to illuminate the tissue with laser light. The tissue response to photodynamic therapy was examined. RESULTS: Localized tissue necrosis was achieved in all organs, without significant complication. There was no significant difference in inflammation induced by photodynamic therapy within the various organs. CONCLUSIONS: EUS-guided photodynamic therapy is a safe and simple technique that can induce small areas of focal tissue ablation within the liver, the pancreas, the kidney, and the spleen, and potentially could be used to treat a variety of benign and malignant conditions.