A proposed difficulty grading system for laparoscopic bile duct exploration: benefits to clinical practice, training and research

Background: A gap remains between the mounting evidence for single session management of bile duct stones and the adoption of this approach. Laparoscopic bile duct exploration (LBDE) is limited by the scarcity of training opportunities and adequate equipment and by the perception that the technique requires a high skill-set. The aim of this study was to create a new classification of difficulty based on operative characteristics and to stratify postoperative outcomes of easy vs. difficult LBDE irrespective of the surgeon’s experience. Methods: A cohort of 1335 LBDEs was classified according to the location, number and size of ductal stones, the retrieval technique, utilisation of choledochoscopy and specific biliary pathologies encountered. A combination of features indicated easy (Grades I and II A & B) or difficult (Grades III A and B, IV and V) transcystic or transcholedochal explorations. Results: 78.3% of patients with acute cholecystitis or pancreatitis, 37% with jaundice and 46% with cholangitis had easy explorations. Difficult explorations were more likely to present as emergencies, with obstructive jaundice, previous sphincterotomy and dilated bile ducts on ultrasound scans. 77.7% of easy explorations were transcystic and 62.3% of difficult explorations transductal. Choledochoscopy was utilised in 23.4% of easy vs. 98% of difficult explorations. The use of biliary drains, open conversions, median operative time, biliary-related complications, hospital stay, readmissions, and retained stones increased with the difficulty grade. Grades I and II patients had 2 or more hospital episodes in 26.5% vs. 41.2% for grades III to V. There were 2 deaths in difficulty Grade V and one in Grade IIB. Conclusion: Difficulty grading of LBDE is useful in predicting outcomes and facilitating comparison between studies. It ensures fair structuring and assessment of training and progress of the learning curve. LBDEs were easy in 72% with 77% completed transcystically. This may encourage more units to adopt this approach

Failures of nerve regeneration caused by aging or chronic denervation are rescued by restoring Schwann cell c-Jun.

After nerve injury, myelin and Remak Schwann cells reprogram to repair cells specialized for regeneration. Normally providing strong regenerative support, these cells fail in aging animals, and during chronic denervation that results from slow axon growth. This impairs axonal regeneration and causes significant clinical problems. In mice, we find that repair cells express reduced c-Jun protein as regenerative support provided by these cells declines during aging and chronic denervation. In both cases, genetically restoring Schwann cell c-Jun levels restores regeneration to control levels. We identify potential gene candidates mediating this effect and implicate Shh in the control of Schwann cell c-Jun levels. This establishes that a common mechanism, reduced c-Jun in Schwann cells, regulates success and failure of nerve repair both during aging and chronic denervation. This provides a molecular framework for addressing important clinical problems, suggesting molecular pathways that can be targeted to promote repair in the PNS

Senolytic treatment preserves biliary regenerative capacity lost through cellular senescence during cold storage

Liver transplantation is the only curative option for patients with end-stage liver disease. Despite improvements in surgical techniques, nonanastomotic strictures (characterized by the progressive loss of biliary tract architecture) continue to occur after liver transplantation, negatively affecting liver function and frequently leading to graft loss and retransplantation. To study the biological effects of organ preservation before liver transplantation, we generated murine models that recapitulate liver procurement and static cold storage. In these models, we explored the response of cholangiocytes and hepatocytes to cold storage, focusing on responses that affect liver regeneration, including DNA damage, apoptosis, and cellular senescence. We show that biliary senescence was induced during organ retrieval and exacerbated during static cold storage, resulting in impaired biliary regeneration. We identified decoy receptor 2 (DCR2)–dependent responses in cholangiocytes and hepatocytes, which differentially affected the outcome of those populations during cold storage. Moreover, CRISPR-mediated DCR2 knockdown in vitro increased cholangiocyte proliferation and decreased cellular senescence but had the opposite effect in hepatocytes. Using the p21KO model to inhibit senescence onset, we showed that biliary tract architecture was better preserved during cold storage. Similar results were achieved by administering senolytic ABT737 to mice before procurement. Last, we perfused senolytics into discarded human donor livers and showed that biliary architecture and regenerative capacities were better preserved. Our results indicate that cholangiocytes are susceptible to senescence and identify the use of senolytics and the combination of senotherapies and machine-perfusion preservation to prevent this phenotype and reduce the incidence of biliary injury after transplantation.This work was supported by the UK Medical Research MRC (MR/K017047/1) (to S.J.F.), the Computational and Chemical Biology of Stem Cell Niche (MR/L012766/1) (to S.J.F.), the UK Regenerative Medicine Platform (MR/K026666/1) (to S.J.F.), and the Wellcome Trust Institutional Translational Partnership Award (WT iTPA) (to S.F.-G.). J.M.B. was supported by the Spanish Carlos III Health Institute (ISCIII) (PI15/01132, PI18/01075, and Miguel Servet Program CON14/00129 and CPII19/00008) cofinanced by “Fondo Europeo de Desarrollo Regional” (FEDER); “Instituto de Salud Carlos III” (CIBERehd), Spain; “Euskadi RIS3” (2019222054 and 2020333010); and the Department of Industry of the Basque Country (Elkartek: KK-2020/00008). This research was funded in whole or in part by The Wellcome Trust (grant number 209710/Z/17/Z), a cOAlition S organization

Biliary senescence affects the transcriptomic landscape of murine hepatocytes

Trabajo presentado en EASL (European Association for the Study of the Liver) monothematic conference on Biliary Fibrosis: Pathophysiology and translational opportunities, celebrada en Florencia (Italia) del 12 al 13 de mayo de 2023.Peer reviewe

Human biliary epithelial cells from discarded donor livers rescue bile duct structure and function in a mouse model of biliary disease

Biliary diseases can cause inflammation, fibrosis, bile duct destruction, and eventually liver failure. There are no curative treatments for biliary disease except for liver transplantation. New therapies are urgently required. We have therefore purified human biliary epithelial cells (hBECs) from human livers that were not used for liver transplantation. hBECs were tested as a cell therapy in a mouse model of biliary disease in which the conditional deletion of Mdm2 in cholangiocytes causes senescence, biliary strictures, and fibrosis. hBECs are expandable and phenotypically stable and help restore biliary structure and function, highlighting their regenerative capacity and a potential alternative to liver transplantation for biliary disease