Normothermic Machine Perfusion and Normothermic Regional Perfusion of DCD Kidneys Before Transplantation: A Systematic Review.

BACKGROUND: To overcome organ shortages, donation after circulatory death (DCD) kidneys are being increasingly used for transplantation. Prior research suggests that DCD kidneys have inferior outcomes compared with kidneys donated after brain death. Normothermic machine perfusion (NMP) and normothermic regional perfusion (NRP) may enhance the preservation of DCD kidneys and improve transplant outcomes. This study aimed to review the evidence surrounding NMP and NRP in DCD kidney transplantation. METHODS: Two independent reviewers conducted searches for all publications reporting outcomes for NMP and NRP-controlled DCD kidneys, focusing on delayed graft function, primary nonfunction, graft function, graft survival, and graft utilization. Weighted means were calculated for all relevant outcomes and controls. Formal meta-analyses could not be conducted because of significant heterogeneity. RESULTS: Twenty studies were included for review (6 NMP studies and 14 NRP studies). Delayed graft function rates seemed to be lower for NRP kidneys (24.6%) compared with NMP kidneys (54.3%). Both modalities yielded similar outcomes with respect to primary nonfunction (NMP 3.3% and NRP 5.6%), graft function (12-mo creatinine 149.3 µmol/L for NMP and 129.9 µmol/L for NRP), and graft utilization (NMP 83.3% and NRP 89%). Although no direct comparisons exist, our evidence suggests that both modalities have good short- and medium-term graft outcomes and high graft survival rates. CONCLUSIONS: Current literature demonstrates that both NMP and NRP are feasible strategies that may increase donor organ utilization while maintaining acceptable transplant outcomes and likely improved outcomes compared with cold-stored DCD kidneys. Further research is needed to directly compare NRP and NMP outcomes.

Structure-guided discovery of ancestral CRISPR-Cas13 ribonucleases.

The RNA-guided ribonuclease CRISPR-Cas13 enables adaptive immunity in bacteria and programmable RNA manipulation in heterologous systems. Cas13s share limited sequence similarity, hindering discovery of related or ancestral systems. To address this, we developed an automated structural-search pipeline to identify an ancestral clade of Cas13 (Cas13an) and further trace Cas13 origins to defense-associated ribonucleases. Despite being one-third the size of other Cas13s, Cas13an mediates robust programmable RNA depletion and defense against diverse bacteriophages. However, unlike its larger counterparts, Cas13an uses a single active site for both CRISPR RNA processing and RNA-guided cleavage, revealing that the ancestral nuclease domain has two modes of activity. Discovery of Cas13an deepens our understanding of CRISPR-Cas evolution and expands opportunities for precision RNA editing, showcasing the promise of structure-guided genome mining.

The extracellular matrix integrates mitochondrial homeostasis.

Cellular homeostasis is intricately influenced by stimuli from the microenvironment, including signaling molecules, metabolites, and pathogens. Functioning as a signaling hub within the cell, mitochondria integrate information from various intracellular compartments to regulate cellular signaling and metabolism. Multiple studies have shown that mitochondria may respond to various extracellular signaling events. However, it is less clear how changes in the extracellular matrix (ECM) can impact mitochondrial homeostasis to regulate animal physiology. We find that ECM remodeling alters mitochondrial homeostasis in an evolutionarily conserved manner. Mechanistically, ECM remodeling triggers a TGF-ß response to induce mitochondrial fission and the unfolded protein response of the mitochondria (UPRMT). At the organismal level, ECM remodeling promotes defense of animals against pathogens through enhanced mitochondrial stress responses. We postulate that this ECM-mitochondria crosstalk represents an ancient immune pathway, which detects infection- or mechanical-stress-induced ECM damage, thereby initiating adaptive mitochondria-based immune and metabolic responses.

Rapid DNA unwinding accelerates genome editing by engineered CRISPR-Cas9.

Thermostable clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated (Cas9) enzymes could improve genome-editing efficiency and delivery due to extended protein lifetimes. However, initial experimentation demonstrated Geobacillus stearothermophilus Cas9 (GeoCas9) to be virtually inactive when used in cultured human cells. Laboratory-evolved variants of GeoCas9 overcome this natural limitation by acquiring mutations in the wedge (WED) domain that produce >100-fold-higher genome-editing levels. Cryoelectron microscopy (cryo-EM) structures of the wild-type and improved GeoCas9 (iGeoCas9) enzymes reveal extended contacts between the WED domain of iGeoCas9 and DNA substrates. Biochemical analysis shows that iGeoCas9 accelerates DNA unwinding to capture substrates under the magnesium-restricted conditions typical of mammalian but not bacterial cells. These findings enabled rational engineering of other Cas9 orthologs to enhance genome-editing levels, pointing to a general strategy for editing enzyme improvement. Together, these results uncover a new role for the Cas9 WED domain in DNA unwinding and demonstrate how accelerated target unwinding dramatically improves Cas9-induced genome-editing activity.

RNA language models predict mutations that improve RNA function.

Structured RNA lies at the heart of many central biological processes, from gene expression to catalysis. While advances in deep learning enable the prediction of accurate protein structural models, RNA structure prediction is not possible at present due to a lack of abundant high-quality reference data. Furthermore, available sequence data are generally not associated with organismal phenotypes that could inform RNA function. We created GARNET (Gtdb Acquired RNa with Environmental Temperatures), a new database for RNA structural and functional analysis anchored to the Genome Taxonomy Database (GTDB). GARNET links RNA sequences derived from GTDB genomes to experimental and predicted optimal growth temperatures of GTDB reference organisms. This enables construction of deep and diverse RNA sequence alignments to be used for machine learning. Using GARNET, we define the minimal requirements for a sequence- and structure-aware RNA generative model. We also develop a GPT-like language model for RNA in which triplet tokenization provides optimal encoding. Leveraging hyperthermophilic RNAs in GARNET and these RNA generative models, we identified mutations in ribosomal RNA that confer increased thermostability to the Escherichia coli ribosome. The GTDB-derived data and deep learning models presented here provide a foundation for understanding the connections between RNA sequence, structure, and function.

Non-Thermal Solar Wind Electron Velocity Distribution Function.

The quiet-time solar wind electrons feature non-thermal characteristics when viewed from the perspective of their velocity distribution functions. They typically have an appearance of being composed of a denser thermal "core" population plus a tenuous energetic "halo" population. At first, such a feature was empirically fitted with the kappa velocity space distribution function, but ever since the ground-breaking work by Tsallis, the space physics community has embraced the potential implication of the kappa distribution as reflecting the non-extensive nature of the space plasma. From the viewpoint of microscopic plasma theory, the formation of the non-thermal electron velocity distribution function can be interpreted in terms of the plasma being in a state of turbulent quasi-equilibrium. Such a finding brings forth the possible existence of a profound inter-relationship between the non-extensive statistical state and the turbulent quasi-equilibrium state. The present paper further develops the idea of solar wind electrons being in the turbulent equilibrium, but, unlike the previous model, which involves the electrostatic turbulence near the plasma oscillation frequency (i.e., Langmuir turbulence), the present paper considers the impact of transverse electromagnetic turbulence, particularly, the turbulence in the whistler-mode frequency range. It is found that the coupling of spontaneously emitted thermal fluctuations and the background turbulence leads to the formation of a non-thermal electron velocity distribution function of the type observed in the solar wind during quiet times. This demonstrates that the whistler-range turbulence represents an alternative mechanism for producing the kappa-like non-thermal distribution, especially close to the Sun and in the near-Earth space environment.

Kidney Transplantation Outcomes From Uncontrolled Donation After Circulatory Death: A Systematic Review and Meta-analysis.

BACKGROUND: Uncontrolled donation after circulatory death (uDCD) is a potential additional source of donor kidneys. This study reviewed uDCD kidney transplant outcomes to determine if these are comparable to controlled donation after circulatory death (cDCD). METHODS: MEDLINE, Cochrane, and Embase databases were searched. Data on demographic information and transplant outcomes were extracted from included studies. Meta-analyses were performed, and risk ratios (RR) were estimated to compare transplant outcomes from uDCD to cDCD. RESULTS: Nine cohort studies were included, from 2178 uDCD kidney transplants. There was a moderate degree of bias, as 4 studies did not account for potential confounding factors. The median incidence of primary nonfunction in uDCD was 12.3% versus 5.7% for cDCD (RR, 1.85; 95% confidence intervals, 1.06-3.23; P = 0.03, I 2 = 75). The median rate of delayed graft function was 65.1% for uDCD and 52.0% for cDCD. The median 1-y graft survival for uDCD was 82.7% compared with 87.5% for cDCD (RR, 1.43; 95% confidence intervals, 1.02-2.01; P = 0.04; I 2 = 71%). The median 5-y graft survival for uDCD and cDCD was 70% each. Notably, the use of normothermic regional perfusion improved primary nonfunction rates in uDCD grafts. CONCLUSIONS: Although uDCD outcomes may be inferior in the short-term, the long-term outcomes are comparable to cDCD.

CasPEDIA Database: a functional classification system for class 2 CRISPR-Cas enzymes.

CRISPR-Cas enzymes enable RNA-guided bacterial immunity and are widely used for biotechnological applications including genome editing. In particular, the Class 2 CRISPR-associated enzymes (Cas9, Cas12 and Cas13 families), have been deployed for numerous research, clinical and agricultural applications. However, the immense genetic and biochemical diversity of these proteins in the public domain poses a barrier for researchers seeking to leverage their activities. We present CasPEDIA (http://caspedia.org), the Cas Protein Effector Database of Information and Assessment, a curated encyclopedia that integrates enzymatic classification for hundreds of different Cas enzymes across 27 phylogenetic groups spanning the Cas9, Cas12 and Cas13 families, as well as evolutionarily related IscB and TnpB proteins. All enzymes in CasPEDIA were annotated with a standard workflow based on their primary nuclease activity, target requirements and guide-RNA design constraints. Our functional classification scheme, CasID, is described alongside current phylogenetic classification, allowing users to search related orthologs by enzymatic function and sequence similarity. CasPEDIA is a comprehensive data portal that summarizes and contextualizes enzymatic properties of widely used Cas enzymes, equipping users with valuable resources to foster biotechnological development. CasPEDIA complements phylogenetic Cas nomenclature and enables researchers to leverage the multi-faceted nucleic-acid targeting rules of diverse Class 2 Cas enzymes.

Eukaryotic RNA-guided endonucleases evolved from a unique clade of bacterial enzymes.

RNA-guided endonucleases form the crux of diverse biological processes and technologies, including adaptive immunity, transposition, and genome editing. Some of these enzymes are components of insertion sequences (IS) in the IS200/IS605 and IS607 transposon families. Both IS families encode a TnpA transposase and a TnpB nuclease, an RNA-guided enzyme ancestral to CRISPR-Cas12s. In eukaryotes, TnpB homologs occur as two distinct types, Fanzor1s and Fanzor2s. We analyzed the evolutionary relationships between prokaryotic TnpBs and eukaryotic Fanzors, which revealed that both Fanzor1s and Fanzor2s stem from a single lineage of IS607 TnpBs with unusual active site arrangement. The widespread nature of Fanzors implies that the properties of this particular lineage of IS607 TnpBs were particularly suited to adaptation in eukaryotes. Biochemical analysis of an IS607 TnpB and Fanzor1s revealed common strategies employed by TnpBs and Fanzors to co-evolve with their cognate transposases. Collectively, our results provide a new model of sequential evolution from IS607 TnpBs to Fanzor2s, and Fanzor2s to Fanzor1s that details how genes of prokaryotic origin evolve to give rise to new protein families in eukaryotes.

Eukaryotic RNA-guided endonucleases evolved from a unique clade of bacterial enzymes.

RNA-guided endonucleases form the crux of diverse biological processes and technologies, including adaptive immunity, transposition, and genome editing. Some of these enzymes are components of insertion sequences (IS) in the IS200/IS605 and IS607 transposon families. Both IS families encode a TnpA transposase and TnpB nuclease, an RNA-guided enzyme ancestral to CRISPR-Cas12. In eukaryotes and their viruses, TnpB homologs occur as two distinct types, Fanzor1 and Fanzor2. We analyzed the evolutionary relationships between prokaryotic TnpBs and eukaryotic Fanzors, revealing that a clade of IS607 TnpBs with unusual active site arrangement found primarily in Cyanobacteriota likely gave rise to both types of Fanzors. The wide-spread nature of Fanzors imply that the properties of this particular group of IS607 TnpBs were particularly suited to adaptation and evolution in eukaryotes and their viruses. Experimental characterization of a prokaryotic IS607 TnpB and virally encoded Fanzor1s uncovered features that may have fostered coevolution between TnpBs/Fanzors and their cognate transposases. Our results provide insight into the evolutionary origins of a ubiquitous family of RNA-guided proteins that shows remarkable conservation across domains of life.

Outcomes of endovascular, open surgical and autotransplantation techniques for renal artery aneurysm repair: a systematic review and meta-analysis.

BACKGROUND: Renal artery aneurysms (RAA) can be repaired with endovascular exclusion (EVR), open repair (OR), or ex-vivo repair with renal autotransplantation (ERAT). This systematic review compares repair indications, aneurysm characteristics, and complications following these interventions. METHODS: A systematic review of databases including MEDLINE, PUBMED, and EMBASE by two independent reviewers for studies from January 2000-November 2022. All studies evaluating repair indications, RAA morphology, morbidity and mortality following EVR, OR, and ERAT were included. RESULTS: A total of 38 studies were included with 1540 EVR, 2377 OR and 109 ERAT subjects. Increasing aneurysm size, or diameters >20 mm, were the most common repair indications across EVR and OR (n = 537; 48%), and ERAT (n = 23; 52%). All ERAT repairs were at or distal to renal artery bifurcations (n = 46). Meta-analyses demonstrated significantly shorter length of stay (LOS) with EVR compared to OR (mean difference -4.06, 95% confidence interval (CI) -5.69 to -2.43, P < 0.001). No significant differences were found in mean aneurysm diameter (P = 0.23), total complications (P = 0.17), and mortality (P = 0.85). Major complications (Clavien-Dindo ≥III) across studies most commonly included acute renal failure (EVR 4.9% vs. OR 7.0%). Nephrectomy was the most common major complication in ERAT (5.5%). CONCLUSIONS: Outcomes following EVR and OR of RAAs are comparable. EVR offers a shorter LOS, with no difference in morbidity or mortality. ERAT is currently only utilized for distal RAAs, however carries higher risk of infarction and nephrectomy necessitating specialized expertise or algorithms to assist appropriate selection of repair methods.

Outcomes of liver transplantation in non-alcoholic steatohepatitis (NASH) versus non-NASH associated hepatocellular carcinoma.

BACKGROUND: Non-alcoholic steatohepatitis (NASH)-associated hepatocellular carcinoma (HCC) is a rising indication for liver transplantation. This unique population, with multiple comorbidities, has potential for worse post-transplant outcomes. We compared post-transplant survival of NASH and non-NASH HCC patients using a large cohort. METHODS: Adults transplanted for HCC between 2008 and 2018, from United Network for Organ Sharing (UNOS) and University Health Network (UHN) databases were divided into two populations: NASH and non-NASH. Recipient characteristics and post-transplant survival were compared. Subgroup analyses were performed within and beyond Milan criteria. RESULTS: 2071 of 20,672 (10.0%) patients underwent transplantation for NASH HCC, with annual proportional increase of 1.2%UHN (p = 0.02) and 1.3%UNOS (p < 0.001). The 1-,3-,5-year post-transplant survival were 90.8%, 83.9%, 76.3% NASH HCC versus 91.9%, 82.1%, 74.9% non-NASH HCC (p = 0.94). No survival differences were observed in populations within or beyond Milan. Competing-risk analysis demonstrated no differences in risk for cardiovascular-related death (HR1.24, 95%CI 0.87-1.55, p = 0.16), or HCC recurrence-related death (HR1.21, 95%CI 0.89-1.65, p = 0.23). NASH HCC patients had lower risk of liver-related deaths (HR0.57, 95%CI 0.34-0.98, p = 0.04). DISCUSSION: NASH HCC is a rising indication for liver transplantation. Despite demographic differences, no post-transplantation survival differences were observed between NASH and non-NASH HCC. This justifies equivalent organ allocation, irrespective of NASH status.

Insulating jackets thermally protect kidneys in an ex vivo model of second warm ischemia.

BACKGROUND: Kidney transplantation is the current optimal treatment for suitable patients with end-stage renal disease. The second warm ischemic time (SWIT) is known to negatively impact delayed graft function, and long-term graft survival, and methods are required to ameliorate the impacts of SWIT on transplantation outcomes. MATERIALS AND METHODS: This study primarily focused on determining the effect of a novel thermally insulating jacket on the thermal profile of the human kidney and quantifying the reduction in thermal energy experienced using this device (KPJ™). An ex vivo simulated transplantation model was developed to determine the thermal profiles of non-utilized human kidneys with and without KPJ™ (n = 5). Control kidney temperature profiles were validated against the temperature profiles of n = 10 kidneys during clinical kidney transplantation. RESULTS: Using the ex-vivo water bath model, the thermally insulated human kidney reached the 15°C metabolic threshold temperature at 44.5 ± 1.9 min (vs control: 17.3 ± 1.8 min (p = 0.00172)) and remained within the 18°C threshold until 53.3 ± 1.3 min (vs control: 20.9 ± 2.0 min (p = 0.002)). The specific heat capacity of KPJ™ protected kidney was four-fold compared to the control kidney. The clinical temperature audit, closely correlated with the water bath model, hence validating this ex-vivo human kidney transplant model. CONCLUSION: Intraoperative thermal protection is a simple and viable method of reducing the thermal injury that occurs during the SWIT and increasing the specific heat capacity of the system. Such technology could easily be translated into clinical kidney transplant practice.

Optimal common limb length in Roux-en-Y gastric bypass surgery: is it important for an ideal outcome? - a systematic review.

BACKGROUND: In Roux-en-Y gastric bypass (RYGB) surgery the common limb length (CLL) is thought to significantly impact on nutritional and metabolic outcomes. However, there has been little focus on establishing routine standardized CLL measurements and its subsequent effect on weight loss and nutritional status. This review aimed to determine the effect of variations of CLL in RYGB surgery on post-operative outcomes, particularly nutritional status, while considering the need for routine CLL measurements in addition to measuring biliopancreatic limb and alimentary limb lengths. METHODS: A systematic review was performed in accordance with the PRISMA guidelines. All English language articles addressing CLL and impact on weight loss, nutritional and metabolic outcomes were retrieved and reviewed. RESULTS: Thirteen relevant studies were identified with CLLs varying from 76 to >600 cm. No significant difference in total body weight loss or excess weight loss was observed. Significant metabolic improvements occurred with shorter CLLs. Nutritional deficiencies were more severe when the CLL was <400 cm. CONCLUSION: The data from this systematic review suggests that reasonable weight loss and positive impacts on metabolic outcomes can be achieved with CLLs of >400 cm.

Trends in liver transplantation for autoimmune liver diseases: a Canadian study.

BACKGROUND: To our knowledge, no analysis of data from liver transplantation registries exists in Canada. We aimed to describe temporal trends in the number of liver transplantation procedures, patient characteristics and posttransplantation outcomes for autoimmune liver diseases (AILDs) in Canada. METHODS: We used administrative data from the Canadian Organ Replacement Register, which contains liver transplantation information from 6 centres in Canada. This study included transplantation information from 5 of the centres, as liver transplantation procedures in children were not included. We included adult (age ≥ 18 yr) patients with a diagnosis of primary biliary cholangitis (PBC), primary sclerosing cholangitis (PSC), autoimmune hepatitis (AIH) or overlap syndrome (PBC-AIH or PSC-AIH) who received a liver transplant from 2000 to 2018. RESULTS: Of 5722 primary liver transplantation procedures performed over the study period, 1070 (18.7%) were for an AILD: 489 (45.7%) for PSC, 341 (31.9%) for PBC, 220 (20.6%) for AIH and 20 (1.9%) for overlap syndrome. There was a significant increase in the absolute number of procedures for PSC, with a yearly increase of 0.6 (95% confidence interval 0.1 to 1.2), whereas the absolute number of procedures for PBC and AIH remained stable. The proportion of transplantation procedures decreased for PBC and AIH but remained stable for PSC. Recipient age at transplantation increased over time for males with PBC (median 53 yr in 2000-2005 to 57 yr in 2012-2018, p = 0.03); whereas the median age among patients with AIH decreased, from 53 years in 2000-2005 to 44 years in 2006-2011 (p = 0.03). The Model for Endstage Liver Disease score at the time of transplantation increased over time for all AILDs, particularly AIH (median 16 in 2000-2005 v. 24 in 2012-2018, p < 0.001). There was a trend toward improved survival in the PBC group, with a 5-year survival rate of 81% in 2000-2005 and 90% in 2012-2018 (p = 0.06). CONCLUSION: Between 2000 and 2018, the absolute number of liver transplantation procedures in Canada increased for PSC but remained stable for PBC and AIH; proportionally, PBC and AIH decreased as indications for transplantation. Posttransplantation survival improved only for the PBC group. An improved understanding of trends and outcomes on a national scale among patients with AILD undergoing liver transplantation can identify disparities and areas for potential health care improvement.

Utilizing the same incision for staged renal transplant in patients with polycystic kidney disease requiring hand-assisted laparoscopic nephrectomy.

BACKGROUNDS: Many autosomal dominant polycystic kidney disease (ADPKD) patients undergo nephrectomy and subsequent renal transplantation. We report our outcomes after hand-assisted laparoscopic nephrectomy (HALN) where a Rutherford-Morrison incision is used as a hand-port site and kidney extraction site, as well the future incision site for staged transplantation. METHODS: A retrospective review was performed on all adult nephrectomies for ADPKD by the Transplant Surgery department at Westmead Hospital between June 2011 and June 2021. Outcomes were compared between HALN, laparoscopic nephrectomy (LN) and open nephrectomy (ON) including operation time, hospital length of stay (LOS), post-operative complications, subsequent transplantation and post-transplantation wound complications. RESULTS: Twenty-two HALN, 8 LN and 5 ON were performed during the study period. Median kidney weights for HALN, LN and ON were significantly different (1575, 403, 3420 g respectively, P = 0.001). There was a significant difference in LOS between the HALN and ON (5.8 versus 9.8 days, P = 0.04), but not between HALN and LN (5.8 versus 5.1, P = 0.06). There was no significant difference for operation time (P = 0.34) and major complication rates (P = 0.58). There were 8 HALN, 5 LN and 2 ON who have had subsequent renal transplantation with one wound complication, an incisional hernia in the HALN group. CONCLUSION: Our HALN is associated with a shorter LOS and similar complication rate to ON and can be efficiently performed for significantly larger kidneys than LN without a significant difference in operation time or LOS. The same Rutherford-Morrison incision site can be used for transplantation.

Right Lobe Versus Left Lobe Living Donor Liver Transplantation: A Systematic Review and Meta-analysis of Donor and Recipient Outcomes.

BACKGROUND: Living donor liver transplantation (LDLT) is an established treatment for advanced liver disease. Whether right lobe (RL) or left lobe (LL) LDLT provides the best outcomes for donors and recipients remains contentious. METHODS: MedLine, Embase, PubMed, and Cochrane Central were searched to identify studies comparing RL- and LL-LDLT and reporting donor and/or recipient outcomes. Effect sizes were pooled using random-effect meta-analysis. Meta-regressions were used to explore heterogeneity. RESULTS: Sixty-seven studies were included. RL donors were more likely to experience major complications (relative risk [RR] = 1.63; 95% confidence interval [CI] = 1.30-2.05; I2 = 19%) than LL donors; however, no difference was observed in the risk of any biliary complication (RR = 1.41; 95% CI = 0.91-2.20; I2 = 59%), bile leaks (RR = 1.56; 95% CI = 0.97-2.51; I2 = 52%), biliary strictures (RR = 0.99; 95% CI = 0.43-1.88; I2 = 27%), or postoperative death (RR = 0.51; 95% CI = 0.25-1.05; I2 = 0%). Among recipients, the incidence of major complications (RR = 0.85; 95% CI = 0.68-1.06; I2 = 21%), biliary complications (RR = 1.10; 95% CI = 0.91-1.33; I2 = 8%), and vascular complications (RR = 0.79; 95% CI = 0.44-1.43; I2 = 0%) was similar. Although the rate of small for size syndrome (RR = 0.47; 95% CI = 0.30-0.74; I2 = 0%) and postoperative deaths (RR = 0.62; 95% CI = 0.44-0.87; I2 = 0%) was lower among RL-LDLT recipients, no differences were observed in long-term graft (hazard ratio = 0.87; 95% CI = 0.55-1.38; I2 = 74%) and overall survival (hazard ratio = 0.86; 95% CI = 0.60-1.22; I2 = 44%). CONCLUSIONS: LL donors experience fewer complications than RL donors, and LL-LDLT recipients had similar outcomes to RL-LDLT recipients. These findings suggest that LL-LDLT offers the best outcomes for living donors and similar outcomes for recipients when measures are taken to prevent small for size syndrome.

Outcomes of Adult Liver Retransplantation: A Canadian National Database Analysis.

Background: Liver retransplantation remains as the only treatment for graft failure. This investigation aims to assess the incidence, post-transplant outcomes, and risk factors in liver retransplantation recipients in Canada. Materials and Methods: The Canadian Organ Replacement Register was used to obtain and analyse data on all adult liver retransplant recipients, matched donors, transplant-specific variables, and post-transplant outcomes from January 2000 to December 2018. Results: 377 (6.5%) patients underwent liver retransplantation. Autoimmune liver disease and hepatitis C virus (HCV) were the most common underlying diagnoses. Graft failure was 7.9% and 12.5%, and overall survival was 77.1% and 65.6% at 1 year and 5 years, respectively. In contrast to recipients receiving their first graft transplant, the retransplantation group had a significantly higher incidence of graft failure (p < 0.001) and lower overall survival (p < 0.001). The graft failure and patient survival rates were comparable between second transplant and repeat retransplant recipients. Furthermore, there were no differences in graft failure and patient survival when stratified according to time to retransplantation. Recipient and donor age (HR = 1.12, p=0.011; HR = 1.09, p=0.008), recipient HCV status (HR = 1.81, p=0.014), and donor cytomegalovirus status (HR = 4.10, p=0.006) were predictors of patient mortality. Conclusion: This analysis of liver retransplantation demonstrates that this is a safe treatment for early and late graft failure. Furthermore, even in patients requiring more than two grafts, similar outcomes to initial retransplantation can be achieved with careful selection.

The effect of perioperative packed red blood cells transfusion on patient outcomes after liver transplant for hepatocellular carcinoma.

BACKGROUND: The impact of packed Red Blood Cell (pRBC) transfusion on oncological outcomes after liver transplantation (LT) for Hepatocellular Carcinoma (HCC) remains controversial. We evaluated the impact of pRBC transfusion on HCC recurrence and overall survival (OS) after LT for HCC. METHODS: Patients with HCC transplanted between 2000 and 2018 were included and stratified by receipt of pRBC transfusion. Outcomes were HCC recurrence and OS. Propensity score matching was performed to account for confounders. RESULTS: Of the 795 patients, 234 (29.4%) did not receive pRBC transfusion. After matching the 1-, 3-, and 5-year cumulative incidence of recurrence was 6.6%, 12.5% and 14.8% for no-pRBC transfusion, and 8.6%, 18.8% and 21.3% (p = 0.61) for pRBC transfusion. The OS at 1-, 3-, 5-year was 93.0%, 84.6% and 75.8% vs 92.0%, 79.7% and 73.5% (p = 0.83) for no-pRBC transfusion and pRBC transfusion, respectively. There were no differences in recurrence (HR 1.13, 95%CI 0.71-1.78, p = 0.61) or OS (HR 1.04, 95%CI 0.71-1.54, p = 0.83). CONCLUSION: Perioperative administration of pRBC in liver transplant recipients for HCC resulted in a nonsignificant increase of HCC recurrence and death after accounting for confounder. Surgeons should continue to exercise cation and optimize patients iron stores medically preoperatively.