Direct insertion of an ultra‐slim upper endoscope for cholangioscopy in patients undergoing choledochoduodenostomy

Direct peroral cholangioscopy (POC) using an ultra‐slim upper endoscope is one modality of POC for intraductal endoscopic evaluation and treatment of the bile duct. Choledochoduodenostomy (CDS) is one modality of biliary bypass surgery that provides a new route to the bile duct. We carried out direct POC using an ultra‐slim upper endoscope without the use of accessories in 10 patients (four sump syndromes, three bile duct strictures and three intrahepatic duct stones) previously undergoing surgical CDS. Direct POC was successful in all patients. The use of an intraductal balloon catheter was required in one patient for advancement of the endoscope into the bile duct. Distal bile ducts with sump syndromes were cleared using baskets and water irrigation under direct POC. Cholangiocarcinoma was diagnosed in one patient with hilar bile duct stricture after cholangioscopic evaluation and a targeting forceps biopsy under direct POC. Intrahepatic duct stones were successfully extracted after intraductal fragmentation under direct POC. Oozing bleeding occurred during intraductal lithotripsy but stopped spontaneously. Direct POC using an ultra‐slim upper endoscope without the assistance of accessories can easily be carried out in patients undergoing CDS.     

Platelets in Early Antibody-Mediated Rejection of Renal Transplants

Antibody-mediated rejection is a major complication in renal transplantation. The pathologic manifestations of acute antibody-mediated rejection that has progressed to functional impairment of a renal transplant have been defined in clinical biopsy specimens. However, the initial stages of the process are difficult to resolve with the unavoidable variables of clinical studies. We devised a model of renal transplantation to elucidate the initial stages of humoral rejection. Kidneys were orthotopically allografted to immunodeficient mice. After perioperative inflammation subsided, donor-specific alloantibodies were passively transferred to the recipient. Within 1 hour after a single transfer of antibodies, C4d was deposited diffusely on capillaries, and von Willebrand factor released from endothelial cells coated intravascular platelet aggregates. Platelet-transported inflammatory mediators platelet factor 4 and serotonin accumulated in the graft at 100- to 1000-fold higher concentrations compared with other platelet-transported chemokines. Activated platelets that expressed P-selectin attached to vascular endothelium and macrophages. These intragraft inflammatory changes were accompanied by evidence of acute endothelial injury. Repeated transfers of alloantibodies over 1 week sustained high levels of platelet factor 4 and serotonin. Platelet depletion decreased platelet mediators and altered the accumulation of macrophages. These data indicate that platelets augment early inflammation in response to donor-specific antibodies and that platelet-derived mediators may be markers of evolving alloantibody responses.