Isolation and propagation of primary human cholangiocyte organoids for the generation of bioengineered biliary tissue.

Pediatric liver transplantation is often required as a consequence of biliary disorders because of the lack of alternative treatments for repairing or replacing damaged bile ducts. To address the lack of availability of pediatric livers suitable for transplantation, we developed a protocol for generating bioengineered biliary tissue suitable for biliary reconstruction. Our platform allows the derivation of cholangiocyte organoids (COs) expressing key biliary markers and retaining functions of primary extra- or intrahepatic duct cholangiocytes within 2 weeks of isolation. COs are subsequently seeded on polyglycolic acid (PGA) scaffolds or densified collagen constructs for 4 weeks to generate bioengineered tissue retaining biliary characteristics. Expertise in organoid culture and tissue engineering is desirable for optimal results. COs correspond to mature functional cholangiocytes, differentiating our method from alternative organoid systems currently available that propagate adult stem cells. Consequently, COs provide a unique platform for studies in biliary physiology and pathophysiology, and the resulting bioengineered tissue has broad applications for regenerative medicine and cholangiopathies.

A retrospective study assessing fully covered metal stents as first-line management for malignant biliary strictures.

OBJECTIVES: Fully covered self-expanding metal stents (FCSEMS) constitute the first type of metal stent that can easily be removed endoscopically and/or intraoperatively, which may be advantageous in the management of distal malignant biliary strictures (DMBS). To assess the efficacy of FCSEMS as first-line treatment for DMBS, we compared patency, survival and complication rates between FCSEMS, uncovered self-expanding metal stents (USEMS) and plastic stents (PS). METHODS: This was a multicentre retrospective study of 315 consecutive patients with DMBS, who underwent endoscopic retrograde cholangiopancreatography and stenting (FCSEMS, USEMS or PS) at two hospitals between 1 January 2007 and 31 December 2013. Stent patency and patient survival were compared using the Kaplan-Meier method; complication rates were compared using Fisher's exact test; and Cox regression analysis was used to screen for confounding factors. RESULTS: FCSEMS were associated with prolonged stent patency (median=145 days) compared with USEMS (median=110 days, P<0.003) and PS (median=34 days, P<0.001). Biliary sepsis rates were lower for FCSEMS compared with PS (4.7 vs. 17.8%, P=0.02), whereas pancreatitis rates were higher for FCSEMS compared with USEMS (7.8 vs. 1.0%, P=0.04), but not PS (2.6%, P=NS). CONCLUSION: The use of FCSEMS as first-line management for DMBS is associated with longer patency and reduced complication rates compared with the use of PS. However, the higher rate of pancreatitis compared with USEMS requires further evaluation in a large randomized controlled trial.