Aetiology and risk factors of ischaemic cholangiopathy after liver transplantation

Imaging of Ischemic Cholangiopathy Following Donation after Circulatory Death Liver Transplant

Ischemic cholangiopathy (IC) is the leading cause of inferior long-term outcomes following donation after circulatory death (DCD) liver transplant. Biliary strictures related to IC are nonanastomotic strictures (NASs) by definition and involve the donor hepatic ducts proximal to the anastomosis, compared with postsurgical anastomotic strictures that form due to fibrotic healing. IC-related NASs can be microangiopathic with patent hepatic artery or macroangiopathic with occluded or stenotic hepatic artery. Recently, IC with NASs have been described to have four distinct patterns at imaging: diffuse necrosis, multifocal progressive, confluence dominant, and minor form, which correlate clinically with graft prognosis. Severe IC can lead to ductal wall breakdown with subsequent bile leaks that can cause significant patient morbidity, with imaging playing a vital role in diagnosis and guiding intervention. IC also predisposes the transplanted liver to biliary stasis and subsequent formation of stones, casts, and sludge. Some cases of posttransplant biliary stricturing are not IC but are a sequela of reflux cholangitis seen with choledochojejunal anastomosis. Other biliary findings in the posttransplant liver can be explained by sphincter of Oddi dysfunction that results from denervation. The authors describe and comprehensively categorize the various IC types and their imaging patterns at MRI and MR cholangiopancreatography, review the prognostic significance of these imaging patterns, and discuss imaging features of additional biliary complications associated with IC after DCD liver transplant. ©RSNA, 2024 Supplemental material is available for this article.

Prolonged warm ischemia time in the recipient is associated with post-transplant biliary stricture following living-donor liver transplantation

PURPOSE

Post-transplant biliary stricture (PBS) is a common and important complication following orthotopic liver transplantation (LT). This study clarified the incidence of PBS and identified its risk factors.

METHODS

We retrospectively reviewed the medical records of 67 patients who underwent living-donor LT (LDLT) at our institute between June 2010 and July 2022 and analyzed their clinical characteristics, prognosis, and risk factors for PBS.

RESULTS

Of the 67 patients, 26 (38.8%) developed PBS during the observation period. Multivariate analyses revealed the following independent risk factors for PBS formation: increased red cell transfusion volume per body weight (> 0.2 U/kg; hazard ratio [HR], 3.8; P = 0.002), increased portal vein pressure (PVP) at the end of LT (> 16 mmHg; HR, 2.88; P = 0.032), postoperative biliary leakage (HR, 4.58; P = 0.014), and prolonged warm ischemia time (WIT) (> 48 min; HR, 4.53; P = 0.008). In patients with PBS, the cumulative incidence of becoming stent free was significantly higher in patients with a WIT ≤ 48 min than in those with a WIT > 48 min (P = 0.038).

CONCLUSION

Prolonged WIT is associated with intractable PBS following LDLT.

Comparative Analysis of Digestion Methods for Bile Proteomics: The Key to Unlocking Biliary Biomarker Potential

BACKGROUND

Bile's potential to reflect the health of the biliary system has led to increased attention, with proteomic analysis offering deeper understanding of biliary diseases and potential biomarkers. With the emergence of normothermic machine perfusion (NMP), bile can be easily collected and analyzed. However, the composition of bile can make the application of proteomics challenging. This study systematically evaluated various trypsin digestion methods to optimize proteomics of bile from human NMP livers.

METHODS

Bile was collected from 12 human donor livers that were accepted for transplantation after the NMP viability assessment. We performed tryptic digestion using six different methods: in-gel, in-solution, S-Trap, SMART, EasyPep, and filter-aided sample purification, with or without additional precipitation before digestion. Proteins were analyzed using untargeted proteomics. Methods were assessed for total protein IDs, variation, and protein characteristics to determine the most optimal method.

RESULTS

Methods involving precipitation surpassed crude methods in protein identifications (4500 vs 3815) except for in-gel digestion. Filtered data (40%) resulted in 3192 versus 2469 for precipitated and crude methods, respectively. We found minimal differences in mass, cellular components, or hydrophobicity of proteins between methods. Intermethod variability was notably diverse, with in-gel, in-solution, and EasyPep outperforming others. Age-related biological comparisons revealed upregulation of metabolic-related processes in younger donors and immune response and cell cycle-related processes in older donors.

CONCLUSIONS

Variability between methods emphasizes the importance of cross-validation across multiple analytical approaches to ensure robust analysis. We recommend the in-gel crude method for its simplicity and efficiency, avoiding additional precipitation steps. Sample processing speed, cost, cleanliness, and reproducibility should be considered when a digestion method is selected for bile proteomics.

Modern-Day Practice of DCD Liver Transplantation: Controversies, Innovations, and Future Directions

PURPOSE OF REVIEW

Over the past decade, donation after circulatory death (DCD) liver transplantation has expanded in the United States due to improved surgical experience and perioperative management. Despite these advances, there remains a reluctance towards broader utilization of DCD liver allografts due to lack of standardized donation process, concern for inferior graft survival, and risk of ischemic cholangiopathy associated with temporary lack of oxygenated perfusion during withdrawal of life-supporting treatment during procurement.

RECENT FINDINGS

New perfusion technologies offer potential therapeutic options to mitigate biliary complications and expand utilization of marginal DCD grafts. As these modalities enter routine clinical practice, DCD utilization will continue to increase, and liver allocation policies in turn will evolve to reflect this growing practice. This review describes recent progress in DCD LT, current challenges with utilization of DCD liver allografts, and how novel technologies and policies could impact the future of the field.

Machine perfusion preservation with hemoglobin based oxygen vesicles alleviate ultrastructural damages in porcine liver donated after cardiac death

Midthermic machine perfusion (MMP) of post-circulatory arrest donor liver grafts has the advantage of preserving the functional ultrastructure of hepatocytes in donor grafts. It was reported that oxygenation during MMP reduces portal venous resistance and increases bile production. The MMP with hemoglobin-based oxygen vesicles (HbV) keeps the lower aspartate aminotransferase level (an indicator of liver injury) and maintains the functional ultrastructure of mitochondria in the hepatocytes. To evaluated differences of ultrastructural damages in donor livers between the MMP with and without HbV, porcine liver grafts after 60 min of warm ischemia were perfused at 22°C for 4 h with or without HbV, and a part of liver grafts were analyzed by transmission electron microscopy (TEM) and osmium-maceration scanning electron microscopy (OM-SEM). The remaining grafts were perfused with autologous blood at 38°C for 2 h in an isolated liver reperfusion model (IRM) that mimics the inside of the body after transplantation, and then analyzed by TEM and OM-SEM. Hepatocytes after MMP had small round mitochondria with rod-shaped cristae and reticulovesicular rough endoplasmic reticulum (rER) in both HbV(+) and HbV(-) livers. After IRM of HbV(+) livers, the well-developed lamellar rER was often found in hepatocytes. Liver sinusoidal endothelial cells (LSECs) after MMP contained some large vacuolar structures containing amorphous garbage in the cytoplasm, and their size along with appearance frequency were smaller and lower, respectively, in HbV(+) livers than HbV(-). Oxygenation during the MMP by using HbV suppressed the ultrastructural damages in donor livers, in particular for the LSECs. RESEARCH HIGHLIGHTS: Liver sinusoidal endothelial cells after midthermic machine perfusion had large vacuolar organelles with amorphous garbage. Oxygenation during the perfusion made them less and smaller, ultrastructurally supporting its utility.

Bile proteome reveals biliary regeneration during normothermic preservation of human donor livers

Normothermic machine perfusion (NMP) after static cold storage is increasingly used for preservation and assessment of human donor livers prior to transplantation. Biliary viability assessment during NMP reduces the risk of post-transplant biliary complications. However, understanding of molecular changes in the biliary system during NMP remains incomplete. We performed an in-depth, unbiased proteomics analysis of bile collected during sequential hypothermic machine perfusion, rewarming and NMP of 55 human donor livers. Longitudinal analysis during NMP reveals proteins reflective of cellular damage at early stages, followed by upregulation of secretory and immune response processes. Livers with bile chemistry acceptable for transplantation reveal protein patterns implicated in regenerative processes, including cellular proliferation, compared to livers with inadequate bile chemistry. These findings are reinforced by detection of regenerative gene transcripts in liver tissue before machine perfusion. Our comprehensive bile proteomics and liver transcriptomics data sets provide the potential to further evaluate molecular mechanisms during NMP and refine viability assessment criteria.

Transplant Hepatic Artery Rupture

A case of transplant hepatic artery thrombosis treated with thrombolysis and vascular stenting is presented. Stenting was complicated by hepatic artery rupture necessitating emergent stent graft placement. Hepatic artery occlusion in a liver transplant often leads to biliary complications such as ischemic cholangiopathy, biliary necrosis, cholangitis, biloma formation, intrahepatic abscesses, and liver failure. Prompt recognition and appropriate treatment of hepatic artery thrombosis are necessary to avoid graft failure and possible death.

Doppler ultrasonography blood flow changes of the hepatic artery in liver transplants complicated with cholangitis

PURPOSE

Cholangitis after liver transplantation may lead to bile duct necrosis. Early diagnosis is essential to prevent graft loss. We aimed to investigate cholangitis related hepatic arterial Doppler ultrasonography findings in liver transplants.

METHODS

Patients complicated with biopsy proven cholangitis in grafts were prospectively evaluated. Vascular complications were excluded. Doppler ultrasonography parameters including hepatic arterial diameter, resistive index, volume flow, and portal vein maximum velocity were measured twice: first during cholangitis and after full recovery. Data of two groups were compared using paired samples t test and Mann-Whitney U test.

RESULTS

The mean hepatic arterial volume flow, resistive index, and diameter of 33 patients complicated with cholangitis was observed to decrease after recovery from 0.356 to 0.273 L/min (p = 0.007), from 0.64 to 0.60 (p < 0.001) and from 4.9 to 4.4 mm (p < 0.001), respectively. Portal vein maximum velocity alteration was not statistically significant (p = 0.6).

CONCLUSION

Ultrasound follow-ups after liver transplantation can give us the clue of cholangitis initiation through some altering hepatic arterial Doppler parameters. Even though these are nonspecific findings that can also be observed in vascular complications, baseline Doppler data should be saved for future comparison and considered to prevent biliary associated graft loss.

Application of cholecystic duct plasty in the prevention of biliary complications following orthotopic liver transplantation

Background

The purpose was aimed to evaluate the safety and effectiveness of cholecystic duct plasty (CDP) and biliary reconstruction techniques preventing biliary complications following orthotopic liver transplantation (OLT) first proposed by our center.

Methods

127 enrolled patients who underwent LT in our center from January 2015 to December 2019 were analyzed retrospectively. According to the mode of biliary tract reconstruction, patients were divided into CDP group (Group 1, n = 53) and control group (Group 2, n = 74). The differences of perioperative general data, biliary complications and long-term prognosis between two groups were compared and analyzed.

Results

All patients completed the operation successfully, the incidence of perioperative complications was 22.8%. There was no significant difference in perioperative general data and complications between the two groups. Follow-up ended in June 2020, with a median follow-up period of 31 months. During the follow-up period, biliary complications occurred in 26 patients, with an overall incidence of 20.5%. The overall incidence of biliary complications and anastomotic stenosis in Group 1 was lower than that in Group 2 (P < 0.05). There was no significant difference in overall prognosis between the two groups (P = 0.274), however, the cumulative incidence of biliary complications in Group 1 was lower than that in Group 2 (P = 0.035).

Conclusion

Reconstruction of common bile duct by CDP represents considerable safety and practicability, particularly for patients with small diameter of common bile duct or wide discrepancy of bile duct size between donor and recipient.

Ultrasound-Targeted Microbubble Cavitation During Machine Perfusion Reduces Microvascular Thrombi and Graft Injury in a Rat Liver Model of Donation After Circulatory Death

BACKGROUND

Ischemic cholangiopathy is a process of bile duct injury that might result from peribiliary vascular plexus (PBP) thrombosis and remains a dreaded complication in liver transplantation from donors after circulatory death (DCD). The aim of this study was to propose a mechanical method of clot destruction to clear microvascular thrombi in DCD livers before transplantation.

METHODS

Sonothrombolysis (STL) is a process by which inertial cavitation of circulating microbubbles entering an ultrasound field create a high-energy shockwave at a microbubble-thrombus interface, causing mechanical clot destruction. The effectiveness of STL in DCD liver treatment remains unclear. We carried out STL treatment during normothermic, oxygenated, ex vivo machine perfusion (NMP), introducing microbubbles into the perfusate with the liver enveloped in an ultrasound field.

RESULTS

The STL livers showed reduction in hepatic arterial and PBP thrombus and decreases in hepatic arterial and portal venous flow resistance, reduced parenchymal injury as measured by aspartate transaminase release and oxygen consumption, and improved cholangiocyte function. Light and electron microscopy showed reduction of hepatic arterial and PBP thrombus in STL livers compared with controls and preserved hepatocyte structure, sinusoid endothelial morphology, and biliary epithelial microvilli.

CONCLUSION

In this model, STL improved flow and functional measures in DCD livers undergoing NMP. These data suggest a novel therapeutic approach to treat PBP injury in DCD livers, which may ultimately increase the pool of grafts available to patients awaiting liver transplantation.

Secondary sclerosing cholangitis and IgG4-sclerosing cholangitis - A review of cholangiographic and ultrasound imaging

Sclerosing cholangitis (SC) represents a spectrum of chronic progressive cholestatic diseases of the intrahepatic and/or extrahepatic biliary system characterized by patchy inflammation, fibrosis, and stricturing. Primary and secondary SC must be distinguished given the different treatment modalities, risks of malignancy, and progression to portal hypertension, cirrhosis, and hepatic failure. This review focuses on secondary SC and the pathogenic mechanisms, risk factors, clinical presentation, and novel imaging modalities that help to distinguish between these conditions. We explore the detailed use of cholangiography and ultrasound imaging techniques.

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.

Graft aberrant hepatic arteries in deceased donor liver transplantation: The "one liver, one artery" approach

In liver transplantation (LT), graft aberrant hepatic arteries (aHAs) frequently require complex arterial reconstructions, potentially increasing the risk of post-operative complications. However, intrahepatic hilar arterial shunts are physiologically present and may allow selective aHA ligation. Thus, we performed a retrospective study from a single-center cohort of 618 deceased donor LTs where a selective reconstruction policy of aHAs was prospectively applied. In the presence of any aHA, the vessel with the largest caliber was first reconstructed. In case of adequate bilobar arterial perfusion assessed on intraparenchymal Doppler ultrasound, the remnant vessel was ligated; otherwise, it was reconstructed. Consequently, outcomes of three patient groups were compared: the "no aHAs" group (n = 499), the "reconstructed aHA" group (n = 25), and the "ligated aHA" group (n = 94). Primary endpoint was rate of biliary complications. Only 38.4% of right aHAs and 3.1% of left aHAs were reconstructed. Rates of biliary complications in the no aHA, reconstructed aHA, and ligated aHA groups were 23.4%, 28%, and 20.2% (p = 0.667), respectively. The prevalence rates of primary non-function (p = 0.534), early allograft dysfunction (p = 0.832), and arterial complications (p = 0.271), as well as patient survival (p = 0.266) were comparable among the three groups. Retransplantation rates were 3.8%, 4%, and 5.3% (p = 0.685), respectively. In conclusion, a selective reconstruction policy of aHAs based on Doppler assessment of bilobar intraparenchymal arterial flow did not increase post-operative morbidity and avoided unnecessary and complex arterial reconstructions.

Good post-transplant outcomes using liver donors after circulatory death when applying strict selection criteria: A propensity-score matched-cohort study

INTRODUCTION AND OBJECTIVES

Outcomes of liver transplantation (LT) with donors after circulatory death (DCD) have been considered suboptimal due to higher rates of ischemic cholangiopathy, especially when the super-rapid recovery (SRR) technique is used. This study aimed to compare the incidence of complications between recipients receiving DCD vs those receiving donors after brain death (DBD) in a large-volume liver transplant centre.

METHODS

We performed a retrospective cohort study (LT from January 2015 to December 2018) comparing recipients who underwent a LT with DCD vs. a control group of LT with DBD, matched 1:1 without replacement by propensity score matching that included the following variables: LT indication, recipient sex and age, donor age and MELD score.

RESULTS

51 recipients with DCD-LT (29 SRR, 22 normothermic regional perfusion [NRP]) were matched with 51 DBD-LT recipients. Biliary complications were more frequent in DCD, 10% (n=5), all with SRR technique, vs 2% (n=1) in the DBD group, p=0.2. Two patients (4%) suffered primary graft non-function in the DCD group (1 SRR and 1 NRP) versus zero in the DBD group (p=0.49). Postoperative bleeding and reinterventions were also higher in the DCD group: 7 (13.7%) vs 1 (1.95%) and 8 (15.7%) vs 2 (3.9%) respectively (p=0.06 and 0.09). On the 1^st postoperative day AST/ALT peak was higher in DCD (p≤0001). The incidence of rejection, vascular complications, renal injury, hospital stay, and readmissions were similar in both groups. Cumulative 1-, 2-, 3- and 4-year graft and patient survival were also similar.

CONCLUSIONS

DCD donors are an adequate option to increase the donor pool in LT, achieving similar graft and patient survival rates to those achieved with DBD donors, especially when the NRP technique is used.

Single Center Experience with Incidence, Impact and Predictors of Biliary Complications in Donation After Circulatory Death Liver Transplantation

Introduction: Utilizing allografts from donors after cardiac death (DCD) has improved organ availability, and DCD livers comprise a growing proportion of transplantations. However, it has been suggested that DCD transplantations have worse outcomes. Research Questions: We aimed to characterize outcomes in a large cohort of DCD transplantations, identify trends in outcomes over time, and identify factors associated with the development of biliary complications. Design: We conducted an observational retrospective cohort study of patients receiving DCD liver allografts within a large academic teaching hospital with a high transplantation volume. Consecutive patients who underwent Type III DCD liver transplantation from 2006-2016 were included in our cohort. Re-transplantations and multi-organ transplant recipients were excluded. Results: Ninety-six type III DCD transplantations occurred between 2006-2016. We report a 1one-year patient survival of 90.6% (87) and a 5five-year patient survival of 69.8% (67). Twenty-nine (30.2%) patients experienced any biliary complication in the first year following discharge, with 17 (17.7%) experiencing ischemic cholangiopathy. Five-year patient (P = 0.04) and graft (P = 0.005) survival improved over time. Post-operative biliary complications experienced during index admission and prior to discharge were found to be associated with the development of biliary complications (P = 0.005) and ischemic cholangiopathy (P = 0.01) following discharge. Conclusion: Our data suggested that outcomes using DCD allografts have improved, however biliary complications remain a significant issue in DCD transplantation. Patients who experienced post-operative biliary complications during index admission may require more frequent screening to allow the initiation of earlier treatment for biliary complications.

Ultrastructural changes in porcine liver sinusoidal endothelial cells of machine perfused liver donated after cardiac death

BACKGROUND

The machine perfusion (MP) preservation including hypothermic MP (HMP) and midthermic MP (MMP) has been considered as a promising strategy to preserve the functions of liver donated after cardiac death. The importance of understanding liver sinusoidal endothelial cells (LSEC) damage in regulating liver injury during MP has been emphasized. However, the ultrastructural changes in the LSEC and sinusoids around them after MP are unclear.

AIM

To investigate the ultrastructural changes in the LSEC and sinusoids around them after MP.

METHODS

Porcine liver grafts undergo a warm ischemia time of 60 minutes perfused for 4 h with modified University of Wisconsin gluconate solution. Group A grafts were preserved with HMP at 8 °C constantly for 4 h. Group B grafts were preserved with a rewarming solution at 22 °C by MMP for 4 h. Then the ultrastructural changes in the LSEC and sinusoids in Group A and B were comparatively analyzed by using osmium-maceration scanning electron microscopy with complementary transmission electron microscopy methods.

RESULTS

An analysis of the LSEC after warm ischemia revealed that mitochondria with condensed-shaped cristae, abnormal vesicles, reduction of ribosomes and the endoplasmic reticulum (ER) surround the mitochondria appeared. The MP subsequent after warm ischemia alleviate the abnormal vesicles and reduction of ribosomes in LSEC, which indicated the reduction of the ER damage. However, MMP could restore the tubular mitochondrial cristae, while after HMP the condensed and narrow mitochondrial cristae remained. In addition, the volume of the sinusoidal space in the liver grafts after MMP were restored, which indicated a lower risk of pressure injury than HMP.

CONCLUSION

MMP alleviates the ER damage of LSEC by warm ischemia, additionally restore the metabolism of LSEC via the normalization of mitochondria and prevent the share stress damage of liver grafts.

Sense and Sensibilities of Organ Perfusion as a Kidney and Liver Viability Assessment Platform

Predicting organ viability before transplantation remains one of the most challenging and ambitious objectives in transplant surgery. Waitlist mortality is high while transplantable organs are discarded. Currently, around 20% of deceased donor kidneys and livers are discarded because of “poor organ quality”, Decisions to discard are still mainly a subjective judgement since there are only limited reliable tools predictive of outcome available. Organ perfusion technology has been posed as a platform for pre-transplant organ viability assessment. Markers of graft injury and function as well as perfusion parameters have been investigated as possible viability markers during ex-situ hypothermic and normothermic perfusion. We provide an overview of the available evidence for the use of kidney and liver perfusion as a tool to predict posttransplant outcomes. Although evidence shows post-transplant outcomes can be predicted by both injury markers and perfusion parameters during hypothermic kidney perfusion, the predictive accuracy is too low to warrant clinical decision making based upon these parameters alone. In liver, further evidence on the usefulness of hypothermic perfusion as a predictive tool is needed. Normothermic perfusion, during which the organ remains fully metabolically active, seems a more promising platform for true viability assessment. Although we do not yet fully understand “on-pump” organ behaviour at normothermia, initial data in kidney and liver are promising. Besides the need for well-designed (registry) studies to advance the field, the catch-22 of selection bias in clinical studies needs addressing.

Temporal Trends in Utilization and Outcomes of DCD Livers in the United States

BACKGROUND

Historically, donation after circulatory death (DCD) livers were frequently discarded because of higher mortality and graft loss after liver transplantation (LT). However, the demand for LT continues to outstrip the supply of "acceptable" organs. Additionally, changes in the donor pool, organ allocation, and clinical management of donors and recipients, and improved clinical protocols might have altered post-DCD-LT outcomes.

METHODS

We studied 5975 recovered DCD livers using US Scientific Registry of Transplant Recipients data from 2005 to 2017, with a comparison group of 78 235 adult donation after brain death (DBD) livers recovered during the same time period. We quantified temporal trends in discard using adjusted multilevel logistic regression and temporal trends in post-LT mortality and graft loss for DCD LT recipients using adjusted Cox regression.

RESULTS

DCD livers were more likely to be discarded than DBD livers across the entire study period, and the relative likelihood of discard increased over time (adjusted odds ratio [aOR] of discard DCD versus DBD 3.854.455.14 2005-2007, 5.225.876.59 2015-2017) despite improving outcomes after DCD LT. Mortality risk for DCD LTs decreased in each time period (compared with 2005-2007, aHR 2008-2011 0.720.840.97, aHR 2012-2014 0.480.580.70, aHR 2015-2017 0.340.430.55), as did risk of graft loss (compared with 2005-2007, aHR 2008-2011 0.690.810.94, aHR 2012-2014 0.450.550.67, aHR 2015-2017 0.360.450.56).

CONCLUSIONS

Despite dramatic improvements in outcomes of DCD LT recipients, DCD livers remain substantially more likely to be discarded than DBD livers, and this discrepancy has actually increased over time. DCD livers are underutilized and have the potential to expand the donor pool.

Role of normothermic perfusion with ECMO in donation after controlled cardiac death in Spain

Spain has become one of the most active countries in donation after controlled cardiac death, using normothermic abdominal perfusion with ECMO in more than 50% of all donors - a situation contributed to by the creation of mobile teams to support hospitals lacking this technology. The donation process must be respectful of the wishes and values of the patients and their relatives, especially if there is pre mortem manipulation, and the absence of cerebral perfusion should be guaranteed. The liver is the most benefited organ by reducing biliary complications as well as the loss of grafts. In renal transplantation, the technique could contribute to reduce the incidence of delayed graft function. In addition, the procedure is compatible with surgical rapid recovery in hypothermia when there is also lung donation. The future lies in the consolidation of cardiac donation by extending normothermic perfusion to the thoracic cavity.

Statin Therapy and the Incidence of Thromboembolism and Vascular Events Following Liver Transplantation

Statin therapy may reduce the risk of venous thromboembolism (VTE), which may impact solid organ transplant outcomes. We evaluated the incidence of VTE and other complications after liver transplantation stratified by hyperlipidemia status and statin use using a retrospective cohort study approach. We reviewed all primary orthotopic liver transplantation (OLT) records from January 2014 to December 2019 from our center. Intraoperative deaths were excluded. Recipient, donor clinical and demographic data were collected. We developed risk-adjusted models to assess the effect of statin use on the occurrence of VTE, hepatic artery complications (HACs), graft failure, and death, accounting for clinical covariates and competing risks. A total of 672 OLT recipients were included in the analysis. Of this cohort, 11.9% (n = 80) received statin therapy. A total of 47 patients (7.0%) had VTE events. HACs occurred in 40 patients (6.0%). A total of 42 (6.1%) patients experienced graft loss, whereas 9.1% (n = 61) of the cohort died during the study interval. Eighty OLT recipients (29.8%) were treated with statins. In the statin treated group, 0% of patients had VTE versus 7.9% of those not on statins (P = 0.02). HACs were identified in 1.2% of the statin group and 6.8% of the nonstatin group. Untreated hyperlipidemia was associated with a 2.1-fold higher risk of HACs versus patients with no hyperlipidemia status (P = 0.05). Statin therapy was associated with significantly better risk-adjusted thromboembolic event-free survival (absence of VTE, cerebrovascular accident, myocardial infarction, HACs, and death); hazard ratio, 2.7; P = 0.01. These data indicate that statin therapy is correlated with a lower rate of VTE and HACs after liver transplantation.

A systematic review and meta-analyses of regional perfusion in donation after circulatory death solid organ transplantation

In donation after circulatory death (DCD), (thoraco)abdominal regional perfusion (RP) restores circulation to a region of the body following death declaration. We systematically reviewed outcomes of solid organ transplantation after RP by searching PubMed, Embase, and Cochrane libraries. Eighty-eight articles reporting on outcomes of liver, kidney, pancreas, heart, and lung transplants or donor/organ utilization were identified. Meta-analyses were conducted when possible. Methodological quality was assessed using National Institutes of Health (NIH)-scoring tools. Case reports (13/88), case series (44/88), retrospective cohort studies (35/88), retrospective matched cohort studies (5/88), and case-control studies (2/88) were identified, with overall fair quality. As blood viscosity and rheology change below 20 °C, studies were grouped as hypothermic (HRP, ≤20 °C) or normothermic (NRP, >20 °C) regional perfusion. Data demonstrate that RP is a safe alternative to in situ cold preservation (ISP) in uncontrolled and controlled DCDs. The scarce HRP data are from before 2005. NRP appears to reduce post-transplant complications, especially biliary complications in controlled DCD livers, compared with ISP. Comparisons for kidney and pancreas with ISP are needed but there is no evidence that NRP is detrimental. Additional data on NRP in thoracic organs are needed. Whether RP increases donor or organ utilization needs further research.

Modern imaging of cholangitis

Cholangitis refers to inflammation of the bile ducts with or without accompanying infection. When intermittent or persistent inflammation lasts 6 months or more, the condition is classified as chronic cholangitis. Otherwise, it is considered an acute cholangitis. Cholangitis can also be classified according to the inciting agent, e.g. complete mechanical obstruction, which is the leading cause of acute cholangitis, longstanding partial mechanical blockage, or immune-mediated bile duct damage that results in chronic cholangitis.The work-up for cholangitis is based upon medical history, clinical presentation, and initial laboratory tests. Whereas ultrasound is the first-line imaging modality used to identify bile duct dilatation in patients with colicky abdominal pain, cross-sectional imaging is preferable when symptoms cannot be primarily localised to the hepatobiliary system. CT is very useful in oncologic, trauma, or postoperative patients. Otherwise, magnetic resonance cholangiopancreatography is the method of choice to diagnose acute and chronic biliary disorders, providing an excellent anatomic overview and, if gadoxetic acid is injected, simultaneously delivering morphological and functional information about the hepatobiliary system. If brush cytology, biopsy, assessment of the prepapillary common bile duct, stricture dilatation, or stenting is necessary, then endoscopic ultrasound and/or retrograde cholangiography are performed. Finally, when the pathologic duct is inaccessible from the duodenum or stomach, percutaneous transhepatic cholangiography is an option. The pace of the work-up depends upon the severity of cholestasis on presentation. Whereas sepsis, hypotension, and/or Charcot's triad warrant immediate investigation and management, chronic cholestasis can be electively evaluated.This overview article will cover the common cholangitides, emphasising our clinical experience with the chronic cholestatic liver diseases.

Biliary Strictures: Etiologies and Medical Management

Biliary strictures have several etiologies that can broadly be classified into benign and malignant causes. The clinical presentation is variable with strictures identified incidentally on imaging or during the evaluation of routine laboratory abnormalities. Symptoms and cholangitis lead to imaging that can diagnose biliary strictures. The diagnosis and medical management of biliary strictures will be discussed in this article.

Conditional probability of graft survival in liver transplantation using donation after circulatory death grafts - a retrospective study

The use of livers from donation after circulatory death (DCD) is historically characterized by increased rates of biliary complications and inferior short-term graft survival (GS) compared to donation after brain death (DBD) allografts. This study aimed to evaluate the dynamic prognostic impact of DCD livers to reveal whether they remain an adverse factor even after patients survive a certain period following liver transplant (LT). This study used 74 961 LT patients including 4065 DCD LT in the scientific registry of transplant recipients from 2002-2017. The actual, 1 and 3-year conditional hazard ratio (HR) of 1-year GS in DCD LT were calculated using a conditional version of Cox regression model. The actual 1-, 3-, and 5-year GS of DCD LT recipients were 83.3%, 73.3%, and 66.3%, which were significantly worse than those of DBD (all P < 0.01). Actual, 1-, and 3-year conditional HR of 1-year GS in DCD compared to DBD livers were 1.87, 1.49, and 1.39, respectively. Graft loss analyses showed that those lost to biliary related complications were significantly higher in the DCD group even 3 years after LT. National registry data demonstrate the protracted higher risks inherent to DCD liver grafts in comparison to their DBD counterparts, despite survival through the early period after LT. These findings underscore the importance of judicious DCD graft selection at individual center level to minimize the risk of long-term biliary complications.

Association between intraoperative fluid balance, vasopressors and graft complications in liver transplantation: A cohort study

Introduction

Biliary complications following liver transplantation are common. The effect of intraoperative fluid balance and vasopressors on these complications is unknown.

Materials and methods

We conducted a cohort study between July 2008 and December 2017. Our exposure variables were the total intraoperative fluid balance and the use of vasopressors on ICU admission. Our primary outcome was any biliary complication (anastomotic and non-anastomotic strictures) up to one year after transplantation. Our secondary outcomes were vascular complications, primary graft non-function and survival.

Results

We included 562 consecutive liver transplantations. 192 (34%) transplants had a biliary complication, 167 (30%) had an anastomotic stricture and 56 had a non-anastomotic stricture (10%). We did not observe any effect of intraoperative fluid balance or vasopressor on biliary complications (HR = 0.97; 95% CI, 0.93 to 1.02). A higher intraoperative fluid balance was associated with an increased risk of primary graft non-function (non-linear) and a lower survival (HR = 1.40, 95% CI, 1.14 to 1.71) in multivariable analyses.

Conclusion

Intraoperative fluid balance and vasopressors upon ICU admission were not associated with biliary complications after liver transplantation but may be associated with other adverse events. Intraoperative hemodynamic management must be prospectively studied to further assess their impact on liver recipients’ outcomes.

Cholangiocyte Epithelial to Mesenchymal Transition (EMT) is a potential molecular mechanism driving ischemic cholangiopathy in liver transplantation

Donation after circulatory death (DCD) has expanded the donor pool for liver transplantation. However, ischemic cholangiopathy (IC) after DCD liver transplantation causes inferior outcomes. The molecular mechanisms of IC are currently unknown but may depend on ischemia-induced genetic reprograming of the biliary epithelium to mesenchymal-like cells. The main objective of this study was to determine if cholangiocytes undergo epithelial to mesenchymal transition (EMT) after exposure to DCD conditions and if this causally contributes to the phenotype of IC. Human cholangiocyte cultures were exposed to periods of warm and cold ischemia to mimic DCD liver donation. EMT was tested by assays of cell migration, cell morphology, and differential gene expression. Transplantation of syngeneic rat livers recovered under DCD conditions were evaluated for EMT changes by immunohistochemistry. Human cholangiocytes exposed to DCD conditions displayed migratory behavior and gene expression patterns consistent with EMT. E-cadherin and CK-7 expressions fell while N-cadherin, vimentin, TGFβ, and SNAIL rose, starting 24 hours and peaking 1-3 weeks after exposure. Cholangiocyte morphology changed from cuboidal (epithelial) before to spindle shaped (mesenchymal) a week after ischemia. These changes were blocked by pretreating cells with the Transforming Growth Factor beta (TGFβ) receptor antagonist Galunisertib (1 μM). Finally, rats with liver isografts cold stored for 20 hours in UW solution and exposed to warm ischemia (30 minutes) at recovery had elevated plasma bilirubin 1 week after transplantation and the liver tissue showed immunohistochemical evidence of early cholangiocyte EMT. Our findings show EMT occurs after exposure of human cholangiocytes to DCD conditions, which may be initiated by upstream signaling from autocrine derived TGFβ to cause mesenchymal specific morphological and migratory changes.

Vascular disorders of the gallbladder and bile ducts: Imaging findings

Vascular disorders of the gallbladder and biliary tree are many and varied. In the acute setting, the clinical presentation of vascular conditions such as hemorrhagic cholecystitis and gangrenous cholecystitis are non-specific and rely on imaging for diagnosis and triaging for emergent surgery. These hemorrhagic and ischemic complications of acute cholecystitis are uncommon but potentially fatal. Hemorrhage into the gallbladder and biliary tree, from other causes, may itself result in acute cholecystitis. Knowledge of vascular anatomy of the gallbladder and biliary tree is essential for surgeons to prevent significant operative bleeding complications, particularly in laparoscopic cholecystectomy. The unique venous drainage of the gallbladder and biliary tree, with their connections to the portal venous system, lends itself to less well-recognised vascular phenomena such as gallbladder varices, portal biliopathy, and gallbladder bed perfusion abnormalities.

Biliary Strictures Are Associated With Both Early and Late Hepatic Artery Stenosis

Background.

Hepatic artery stenosis (HAS) following liver transplantation results in hypoperfusion and ischemic damage to the biliary tree. This study aimed to investigate how vascular intervention, liver function test derangement, and time point of HAS onset influence biliary complications.

Methods.

A single-center retrospective study of adult patients that underwent primary liver transplantation. Patients were grouped according to the presence or absence of HAS and then into early (≤90 d) or late (>90 d) subgroups. Biliary complications comprised anastomotic (AS) or non ASs (NASs).

Results.

Computed tomography angiography confirmed HAS was present in 39 of 1232 patients (3.2%). This occurred at ≤90 and >90 days in 20 (1.6%) and 19 (1.5%), respectively. The incidence of biliary strictures (BSs) in the group with HAS was higher than the group without (13/39; 33% versus 85/1193; 7.1%, P = 0.01). BS occurred in 8/20 (40.0%) and 5/19 (26.3%) of the early and late groups, respectively. The need for biliary intervention increased if any liver function test result was ≥3× upper limit of normal (P = 0.019).

Conclusions.

BS occurs at a significantly higher rate in the presence of HAS. Onset of HAS at ≤90 or ≥90 days can both be associated with morbidity. Significant liver function test derangement at HAS diagnosis indicates a higher likelihood of biliary intervention for strictures.

Differential Impact of Extended Criteria Donors After Brain Death or Circulatory Death in Adult Liver Transplantation

Using grafts from extended criteria donors (ECDs) and donation after circulatory death (DCD) donors is a strategy to address organ shortage in liver transplantation (LT). We studied the characteristics and outcomes of ECD and DCD grafts. We retrospectively studied consecutive adults who underwent deceased donor LT between 2006 and 2019. ECD was defined using modified Eurotransplant criteria. Our primary outcomes were graft and patient survival. A total of 798 grafts were used for LT, of which 93.1% were donation after brain death (DBD; 59.9% were also ECD) and 6.9% were DCD grafts (49.1% were also ECD). Among DBD graft recipients, donors having >33% liver steatosis or 3 ECD criteria resulted in poorer graft survival. Otherwise ECD graft recipients had similar graft and patient survival compared with non-ECD graft recipients. DCD graft recipients also had similar patient survival compared with DBD recipients. However, DCD grafts from an ECD appeared to have worse outcomes. DCD graft recipients experienced higher rates of early allograft dysfunction (50.9% versus 24.7%; P < 0.001) and ischemic biliopathy (16.4% versus 1.5%; P < 0.001) compared with DBD graft recipients. Use of DBD grafts from ECDs did not impact outcomes unless there was significant donor steatosis or 3 Eurotransplant criteria were met. DCD graft recipients have similar patient survival compared with DBD graft recipients as long as the donor was not an ECD. We recommend that DBD donors with 3 or more ECD features or >33% steatosis and DCD donors with any ECD features be used with caution in adult LT.

Immunosuppression in Donation After Circulatory Death Liver Transplantation: Can Induction Modify Graft Survival?

Recipients of donation after circulatory death (DCD) LTs historically have an increased risk of graft failure. Antibody induction (AI) with antithymocyte globulin (ATG) or anti-interleukin 2 receptor (anti-IL2R) immunotherapy may decrease the incidence of graft failure by mitigating ischemia/reperfusion injury. A retrospective review of the United Network for Organ Sharing (UNOS) database for LTs between 2002 and 2015 was conducted to determine whether ATG or anti-IL2R AI was associated with graft survival in DCD. A secondary endpoint was postoperative renal function as measured by estimated glomerular filtration rate at 6 and 12 months. Among DCD recipients, ATG (hazard ratio [HR] = 0.71; P = 0.03), but not anti-IL2R (HR = 0.82; P = 0.10), was associated with a decrease in graft failure at 3 years when compared with recipients without AI. ATG (HR = 0.90; P = 0.02) and anti-IL2R (HR = 0.94; P = 0.03) were associated with a decreased risk of graft failure in donation after brain death (DBD) liver recipients at 3 years compared with no AI. When induction regimens were compared between DCD and DBD, only ATG (HR = 1.19; P = 0.19), and not anti-IL2R (HR = 1.49; P < 0.01) or no AI (HR = 1.77; P < 0.01), was associated with similar survival between DCD and DBD. In conclusion, AI therapy with ATG was associated with improved longterm liver allograft survival in DCD compared with no AI. ATG was associated with equivalent graft survival between DCD and DBD, suggesting a beneficial role of immune cell depletion in DCD outcomes.

The Graz Liver Allocation Strategy-Impact of Extended Criteria Grafts on Outcome Considering Immunological Aspects

Background: Transplant centers are forced to use livers of extended criteria donors for transplantation due to a dramatic organ shortage. The outcome effect of extended donor criteria (EDCs) remains unclear. Thus, this study was designed to assess the impact of EDCs on outcome including immunological aspects after liver transplantation (LT).

Patients and Methods: Between November 2016 and March 2018, 49 patients (85.7% male) with a mean age of 57 ± 11 years underwent LT. The impact of EDCs on outcome after LT was assessed retrospectively using both MedOcs and ENIS (Eurotransplant Network Information System).

Results: About 80% of grafts derived from extended criteria donors. Alanine aminotransferase/aspartate aminotransferase (AST/ALT) levels elevated more than three times above normal values in organ donors was the only significant risk factor for primary dysfunction (PDF) and primary non-function (PNF)/Re-LT and early non-anastomotic biliary strictures (NAS). Balance of risk (BAR) score did not differ between EDC and non-EDC recipients. PDF (14.3% of all patients) and PNF (6.1% of all patients) occurred in 23.1% of EDC-graft recipients and in 10.0% of non-EDC-graft recipients (RR 2.31, p = 0.663). The 90-day mortality was 3.6%. There was no difference of early non-anastomotic biliary tract complications and biopsy proven rejections (BPR). There was no correlation of PDF/PNF with BPR and NAS, respectively; however, 66.7% of the patients with BPR also developed early NAS (p < 0.001).

Conclusion: With the Graz liver allocation strategy, excellent survival can be achieved selecting livers with no more than 2 not outcome-relevant EDCs for patients with MELD >20. Further, BPR is associated with biliary complications.

Donation after Circulatory Death: Potential Mechanisms of Injury and Preventative Strategies

Donation after circulatory death (DCD) donors represent a potential means to help address the disparity between the number of patients awaiting liver transplantation (LT) and the availability of donor livers. While initial enthusiasm for DCD LT was high in the early 2000s, early reports of high rates of biliary complications and inferior graft survival resulted in reluctance among many transplant centers to use DCD liver grafts. As with all innovations in transplant practice, there is undoubtedly a learning curve associated with the optimal utilization of liver grafts from DCD donors. More contemporary data has demonstrated that results with DCD LT are improving and the number of DCD LT performed annually has been steadily increasing. In this concise review, potential mechanisms of injury for DCD livers are discussed along with strategies that have been employed in clinical practice to improve DCD LT outcomes.

Role of normothermic perfusión with ECMO in donation after controlled cardiac death in Spain

Spain has become one of the most active countries in donation after controlled cardiac death, using normothermic abdominal perfusion with ECMO in more than 50% of all donors - a situation contributed to by the creation of mobile teams to support hospitals lacking this technology. The donation process must be respectful of the wishes and values of the patients and their relatives, especially if there is pre mortem manipulation, and the absence of cerebral perfusion should be guaranteed. The liver is the most benefited organ by reducing biliary complications as well as the loss of grafts. In renal transplantation, the technique could contribute to reduce the incidence of delayed graft function. In addition, the procedure is compatible with surgical rapid recovery in hypothermia when there is also lung donation. The future lies in the consolidation of cardiac donation by extending normothermic perfusion to the thoracic cavity.

The ultrastructural characteristics of bile canaliculus in porcine liver donated after cardiac death and machine perfusion preservation

The effects of each type of machine perfusion preservation (MP) of liver grafts donated after cardiac death on the bile canaliculi of hepatocytes remain unclear. We analyzed the intracellular three-dimensional ultrastructure of the bile canaliculi and hepatocyte endomembrane systems in porcine liver grafts after warm ischemia followed by successive MP with modified University of Wisconsin gluconate solution. Transmission and osmium-maceration scanning electron microscopy revealed that lumen volume of the bile canaliculi decreased after warm ischemia. In liver grafts preserved by hypothermic MP condition, bile canaliculi tended to recover in terms of lumen volume, while their microvilli regressed. In contrast, midthermic MP condition preserved the functional form of the microvilli of the bile canaliculi. Machine perfusion preservation potentially restored the bile canaliculus lumen and alleviated the cessation of cellular endocrine processes due to warm ischemia. In addition, midthermic MP condition prevented the retraction of the microvilli of bile canaliculi, suggesting further mitigation of the damage of the bile canaliculi.

Addressing organ shortages: progress in donation after circulatory death for liver transplantation

Reducing wait list mortality among patients awaiting liver transplantation remains a substantial challenge because of organ shortage. In efforts to expand the donor pool there has been a trend toward increased use of donation after circulatory death (DCD) liver grafts. However, these marginal grafts are prone to higher complication rates, particularly biliary complications. In addition, many procured DCD livers are then deemed unsuitable for transplant. Despite these limitations, DCD grafts represent an important resource to address the current organ shortage, and as such there are research efforts directed toward improving the use of and outcomes for transplantation of these grafts. We review the current progress in DCD liver transplantation.

Biomarkers of Liver Injury during Transplantation in an Era of Machine Perfusion

Liver ischaemia–reperfusion injury (IRI) is an intrinsic part of the transplantation process and damages the parenchymal cells of the liver including hepatocytes, endothelial cells and cholangiocytes. Many biomarkers of IRI have been described over the past two decades that have attempted to quantify the extent of IRI involving different hepatic cellular compartments, with the aim to allow clinicians to predict the suitability of donor livers for transplantation. The advent of machine perfusion has added an additional layer of complexity to this field and has forced researchers to re-evaluate the utility of IRI biomarkers in different machine preservation techniques. In this review, we summarise the current understanding of liver IRI biomarkers and discuss them in the context of machine perfusion.

New tight junction protein 2 variant causing progressive familial intrahepatic cholestasis type 4 in adults: A case report

BACKGROUND

Progressive familial intrahepatic cholestasis (PFIC) encompasses a group of autosomal recessive disorders with high morbidity and mortality. Variants in the gene encoding tight junction protein-2 (TJP2) have been linked to PFIC type 4 (PFIC4), which predominantly presents in childhood. However, there are only limited data from adults with TJP2-related PFIC4. We report a family with an autosomal recessive disorder with a novel variant in the TJP2 gene in adults with very variable expression of PFIC4.

CASE SUMMARY

The index patient presented at 19 years old with liver cirrhosis and variceal bleeding and was treated with endoscopic banding and beta-blockers. In 2018, he developed primary liver cancer that was treated with radiofrequency ablation followed by liver transplantation in 2019. Genetic testing revealed a novel homozygous TJP2 variant causing PFIC4 (TJP2([NM_004817.3]:c.[3334C>T]; [3334C>T])). The consanguineous family consists of the father and mother (both heterozygous) and their 12 children, of which five carry the variant in a homozygous state; however, these five siblings have highly variable expression of PFIC4. Two homozygous brothers had cirrhosis and portal hypertension at diagnosis at the ages of 19 and 36. Two other homozygous brothers, age 23 and 19, and the homozygous sister, age 21, have elevated liver enzymes but presently no cirrhosis, which may suggest an age-dependent penetrance. In addition, five sisters had severe and mild intrahepatic cholestasis of pregnancy and carry the TJP2 variant in a homozygous and heterozygous state, respectively.

CONCLUSION

This novel TJP2 variant is associated with PFIC4 causing severe liver disease with cirrhosis and primary liver cancer in adolescents/adults.

Intrahepatic biliary strictures after liver transplantation are morphologically similar to primary sclerosing cholangitis but immunologically distinct

OBJECTIVE

Biliary strictures are an important cause of morbidity and mortality in primary hepatic disease and after liver transplantation (LT). We aimed to characterize inflammatory cytokines in biliary fluids in biliary strictures to investigate their immunological origin.

METHODS

We conducted a retrospective study on 72 patients with strictures after LT, eight patients with primary sclerosing cholangitis (PSC) and 15 patients with secondary sclerosing cholangitis (SSC). We measured cytokines interleukin (IL)-2, -4, -6, -10, -17, monocyte chemoattractant protein (MCP)-1, fibroblast growth factor (FGF)-2 and interferon (IFN)-γ as well as biochemical components such as protein and phospholipids in biliary fluid obtained from endoscopic retrograde cholangiography (ERC). Cell viability assays were performed on human cholangiocytes (H69) after being treated with IL-6, IL-4 and IFN-γ.

RESULTS

Bile of patients with diffuse strictures after LT or due to SSC showed low values of all measured cytokines except for IL-6 levels, which were largely elevated in patients with diffuse strictures after LT. Patients high in biliary IL-6 showed an increase in profibrotic markers FGF-2 and MCP-1. In contrast, PSC bile was dominated by a Th1/Th17 profile with elevated IL-2, IL-17 and IFN-γ. In LT patients with biliary strictures, biliary IL-6 negatively predicted retransplantation-free survival after ERC.

CONCLUSION

PSC patients showed a biliary Th1/Th17 cytokine profile, while SSC and diffuse strictures showed low values of cytokines except IL-6. In diffuse intrahepatic strictures after LT, biliary IL-6 is strongly associated with retransplantation-free survival after ERC.

Concise review of machine perfusion in liver transplantation

With the advances and clinical growth in liver transplantation over the last four decades the focus on expanding deceased donor organs has been in need of scientific research. In the past ten years several researchers have looked at the domain of machine perfusion as it applies to deceased donor livers. The following review focuses on the clinical trials and recent advances that will likely have the earliest entrance into the clinical arena.

Controlled donation after circulatory death up to 80 years for liver transplantation: Pushing the limit again

Our main objective was to compare liver transplant (LT) results between donation after circulatory death (DCD) and donation after brainstem death (DBD) in our hospital and to analyze, within the DCD group, the influence of age on the results obtained with DCD donors aged >70 years and up to 80 years. All DCD-LTs performed were analyzed prospectively. The results of the DCD group were compared with those of a control group who received a DBD-LT immediately after each DCD-LT. Later, the results obtained within the DCD group were analyzed according to the age of the donors, considering 2 subgroups with a cut-off point at 70 years. Survival results for LT with DCD and super rapid recovery were not inferior to those obtained in a similar group of patients transplanted with DBD livers. However, the cost of DCD was a higher rate of biliary complications, including ischemic cholangiopathy. Donor age was not a negative factor.

Radiological findings in ischaemic cholangiopathy

Ischaemic cholangiopathy occurs as a consequence of deficient arterial blood flow to the bile duct wall. Bile duct ischaemia can lead to full-thickness necrosis, bile leakage, biloma formation, and sepsis. It is an important cause of graft failure post-orthotopic liver transplantation. In the native liver, the causes of biliary ischaemia are diverse and include vasculitis or a complication of endovascular procedures. The present review describes the pathology and radiological findings of ischaemic cholangiopathy and outlines the role of interventional radiology in its management.

The association of pregnane X receptor activation with outcomes after liver transplantation-A retrospective study

BACKGROUND

Many complications following liver transplantation are linked to ischemia-reperfusion injury. Activation of the pregnane X receptor (PXR) has been shown to alleviate this process in animal models. The aim of this retrospective study was to investigate the effect of early activation of human PXR (hPXR) on postoperative complications and survival following liver transplantation.

METHODS

The study included deceased donor liver transplants at a single center over 6 years. Estimated hPXR activation value on day 7 (EPAV₇ ) was calculated per patient based on potency/total dose of known hPXR-activating drugs administered in the first week post-transplantation. Patients were divided into low and high hPXR activation groups based on EPAV₇ .

RESULTS

Overall, 240 liver transplants were included. Average EPAV₇ was significantly lower in patients who developed anastomotic biliary strictures (17.7 ± 5.5 vs 35.1 ± 5.7 in stricture-free patients; P = .03) and sepsis (16.4 ± 7.1 vs 34.9 ± 5.5; P = .04). Patient survival was significantly improved in the high hPXR group (5-year survival: 88.7% ± 3.8% versus 70.7% ± 5.8% [low hPXR]; P = .023). Regression analysis identified EPAV₇ as a significant independent predictor of patient survival.

CONCLUSION

hPXR activation within the first week of liver transplantation is a prognostic indicator of patient survival, possibly due to the associated lower biliary stricture and infection rates.

Can we reduce ischemic cholangiopathy rates in donation after cardiac death liver transplantation after 10 years of practice? Canadian single-centre experience

Background

Outcomes in liver transplantation with organs obtained via donation after cardiocirculatory death (DCD) have been suboptimal compared to donation after brain death, attributed mainly to the high incidence of ischemic cholangiopathy (IC). We evaluated the effect of a 10-year learning curve on IC rates among DCD liver graft recipients at a single centre.

Methods

We analyzed all DCD liver transplantation procedures from July 2006 to July 2016. Patients were grouped into early (July 2006 to June 2011) and late (July 2011 to July 2016) eras. Those with less than 6 months of follow-up were excluded. Primary outcomes were IC incidence and IC-free survival rate.

Results

Among the 73 DCD liver transplantation procedures performed, 70 recipients fulfilled the selection criteria, 32 in the early era and 38 in the late era. Biliary complications were diagnosed in 19 recipients (27%). Ischemic cholangiopathy was observed in 8 patients (25%) in the early era and 1 patient (3%) in the late era (p = 0.005). The IC-free survival rate was higher in the late era than the early era (98% v. 79%, p = 0.01). The warm ischemia time (27 v. 24 min, p = 0.049) and functional warm ischemia time (21 v. 17 min, p = 0.002) were significantly lower in the late era than the early era.

Conclusion

We found a significant reduction in IC rates and improvement in ICfree survival among DCD liver transplantation recipients after a learning curve period that was marked by more judicious donor selection with shorter procurement times.