***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: The European trial investigating normothermic ex vivo liver perfusion ( NEVLP ) as a preservation technique for liver transplantation ( LT ) uses gelofusine , a non-US Food and Drug Administration-approved , bovine-derived , gelatin-based perfusion solution . We report a safety and feasibility clinical NEVLP trial with human albumin-based Steen solution . Transplant outcomes of 10 human liver grafts that were perfused on the Metra device at 37 ° C with Steen solution , plus 3 units of erythrocytes were compared with a matched historical control group of 30 grafts using cold storage ( CS ) as the preservation technique . Ten liver grafts were perfused for 480 minutes ( 340 - 580 minutes ) . All livers cleared lactate ( final lactate 1.46 mmol/L ; 0.56 - 1.74 mmol/L ) and produced bile ( 61 mL ; 14 - 146 mL ) during perfusion . No technical problems occurred during perfusion , and all NEVLP-preserved grafts functioned well after LT . NEVLP versus CS had lower aspartate aminotransferase and alanine aminotransferase values on postoperative days 1 - 3 without reaching significance . No difference in postoperative graft function between NEVLP and CS grafts was detected as measured by day 7 international normalized ratio ( 1.1 [ 1 - 1.56 ] versus 1.1 [ 1 - 1.3 ] ; P = 0.5 ) and bilirubin ( 1.5 ; 1 - 7.7 mg/dL versus 2.78 ; 0.4 - 15 mg/dL ; P = 0.5 ) . No difference was found in the duration of intensive care unit stay ( median , 1 versus 2 days ; range , 0 - 8 versus 0 - 23 days ; P = 0.5 ) and posttransplant hospital stay ( median , 11 versus 13 days ; range , 8 - 17 versus 7 - 89 days ; P = 0.23 ) . Major complications ( Dindo-Clavien ≥ 3b ) occurred in 1 patient in the NEVLP group ( 10 % ) compared with 7 ( 23 % ) patients in the CS group ( P = 0.5 ) . No graft loss or patient death was observed in either group . Liver preservation with normothermic ex vivo perfusion with the Metra device using Steen solution is safe and results in comparable outcomes to CS after LT . Using US Food and Drug Administration-approved Steen solution will avoid a potential regulatory barrier in North America . Liver Transplantation 22 1501 - 1508 2016 AASLD Experimental studies have suggested that end‐ischaemic dual hypothermic oxygenated machine perfusion ( DHOPE ) may restore hepatocellular energy status and reduce reperfusion injury in donation after circulatory death ( DCD ) liver grafts . The aim of this prospect i ve case – control study was to assess the safety and feasibility of DHOPE  in DCD liver transplantation Dual hypothermic oxygenated machine perfusion ( DHOPE ) of the liver has been advocated as a method to reduce ischemia/reperfusion injury ( IRI ) . This study aim ed to determine whether DHOPE reduces IRI of the bile ducts in donation after circulatory death ( DCD ) liver transplantation . In a recently performed phase 1 trial , 10 DCD livers were preserved with DHOPE after static cold storage ( SCS ; http://www.trialregister.nl NTR4493 ) . Bile duct biopsies were obtained at the end of SCS ( before DHOPE ; baseline ) and after graft reperfusion in the recipient . Histological severity of biliary injury was grade d according to an established semiquantitative grading system . Twenty liver transplantations using DCD livers not preserved with DHOPE  served as controls . Baseline characteristics and the degree of bile duct injury at baseline ( end of SCS ) were similar between both groups . In controls , the degree of stroma necrosis ( P = 0.002 ) and injury of the deep peribiliary gl and s ( PBG ; P = 0.02 ) increased after reperfusion compared with baseline . In contrast , in DHOPE‐preserved livers , the degree of bile duct injury did not increase after reperfusion . Moreover , there was less injury of deep PBG ( P = 0.04 ) after reperfusion in the DHOPE group compared with controls . In conclusion , this study suggests that DHOPE  reduces IRI of bile ducts after DCD liver transplantation . Liver Transplantation 24 655–664 2018 AASLD Liver transplantation is a highly successful treatment , but is severely limited by the shortage in donor organs . However , many potential donor organs can not be used ; this is because sub-optimal livers do not tolerate conventional cold storage and there is no reliable way to assess organ viability preoperatively . Normothermic machine perfusion maintains the liver in a physiological state , avoids cooling and allows recovery and functional testing . Here we show that , in a r and omized trial with 220 liver transplantations , compared to conventional static cold storage , normothermic preservation is associated with a 50 % lower level of graft injury , measured by hepatocellular enzyme release , despite a 50 % lower rate of organ discard and a 54 % longer mean preservation time . There was no significant difference in bile duct complications , graft survival or survival of the patient . If translated to clinical practice , these results would have a major impact on liver transplant outcomes and waiting list mortality .  Normothermic machine perfusion of the liver improved early graft function , demonstrated by reduced peak serum aspartate transaminase levels and early allograft dysfunction rates , and improved organ utilization and preservation times , although no differences were seen in graft or patient survival Non‐anastomotic biliary stricture ( NAS ) formation is a major complication of liver transplantation . We prospect ively determined the time to development of responsiveness to treatment , and clinical outcomes following NAS formation . In addition , an extensive analysis of the association of recipient , donor , and clinical variables with NAS formation was performed . A total of 749 consecutive patients was studied in a prospect i ve , protocol ‐based fashion . Seventy‐two patients ( 9.6 % ) developed NAS at a mean of 23.6 ± 34.2 weeks post‐transplantation . Non‐anastomotic biliary stricture formation resolved in only 6 % of affected patients . Although patient survival was not affected , retransplantation and graft loss rates were significantly greater in recipients who developed NAS . In contrast to previous reports , a pretransplant diagnosis of HCV was associated with a low frequency of NAS formation . The incidence of NAS was independently associated with pretransplant diagnoses of PSC and autoimmune hepatitis . Hepatic artery thrombosis , and prolonged warm and cold ischemia times were also independent risk factors for NAS formation . We conclude that NAS developed in ∼10 % of primary liver transplant recipients . A pretransplant diagnosis of autoimmune hepatitis has been identified as a novel independent risk factor for NAS formation . Development of NAS significantly attenuates graft but not patient survival The use of livers from donation after circulatory death ( DCD )  is increasing , but concerns exist regarding outcomes following use of grafts from “ marginal ” donors . To compare outcomes in transplants using DCD and donation after brain death ( DBD ) , propensity score matching was performed for 973 patients with chronic liver disease and /or malignancy who underwent primary whole‐liver transplant between 2004 and 2014 at University Hospitals Birmingham NHS Foundation Trust . Primary end points were overall graft and patient survival . Secondary end points included postoperative , biliary and vascular complications . Over 10 years , 234 transplants were carried out using DCD grafts .  Of the 187 matched DCDs , 82.9 % were classified as marginal per British Transplantation Society guidelines . Kaplan – Meier analysis of graft and patient survival found no significant differences for either outcome between the paired DCD and DBD patients ( p = 0.162 and p = 0.519 , respectively ) . Aspartate aminotransferase was significantly higher in DCD recipients until 48 h after transplant ( p < 0.001 ) . The incidences of acute kidney injury and ischemic cholangiopathy were greater in DCD recipients ( 32.6 % vs. 15 % [ p < 0.001 ] and 9.1 % vs. 1.1 % [ p < 0.001 ] , respectively ) . With appropriate recipient selection , the use of DCDs , including those deemed marginal , can be safe and can produce outcomes comparable to those seen using DBD grafts in similar recipients Objective : To assess the incidence and impact of biliary complications in recipients transplanted from donors after cardiac death ( DCD ) at one single large institution . Background : Shortage of available cadaveric organs is a significant limiting factor in  liver transplantation ( LT ) . The use of DCD offers the potential to increase the organ pool . However , early results with DCD liver grafts were associated with a greater incidence of ischemic cholangiopathy ( IC ) , leading to several programs to ab and oning this source of organs . Methods : A retrospective analysis of a prospect i ve data base from April 2001 to 2010 focused on 167 consecutive DCD-LT . Each DCD transplant  was matched with  2 brain death donors ( DBD ) grafts ( n = 333 ) according to the period of transplantation . Primary outcome measures were biliary complications including the severity of complications , graft survival and patient survival . Minimum follow-up was 3 months . Results : Anastomotic stricture was the most common biliary complication ( DCD = 30 , 19 % vs. DBD = 41 , 13 % ) . Most were treated endocoscopically ( grade IIIa = 72 % ) , whereas hepatico-jejunostomy ( grade IIIb ) was performed in 22 % . Primary IC occurred in 4 ( 2.5 % ) recipients from the DCD group and was absent in the DBD group ( P = 0.005 ) . However , none of these patients required retransplantation . Patient and graft survival at 1 , 3 , and 5 years were similar between DCD and DBD groups ( P = 0.106 , P = 0.138 , P = 0.113 , respectively ) . Conclusions : The encouraging results with DCD-LT are probably due to the selection of DCD grafts and clear definition of warm ischemia The number of donor organs suitable for liver transplantation is restricted by cold preservation and ischemia – reperfusion injury . We present the first patients transplanted using a normothermic machine perfusion ( NMP ) device that transports and stores an organ in a fully functioning state at 37 ° C . In this Phase 1 trial , organs were retrieved using st and ard techniques , attached to the perfusion device at the donor hospital , and transported to the implanting center in a functioning state . NMP livers were matched 1:2 to cold‐stored livers . Twenty patients underwent liver transplantation after NMP . Median NMP time was 9.3 ( 3.5–18.5 ) h versus median cold ischaemia time of 8.9 ( 4.2–11.4 ) h. Thirty‐day graft survival was similar ( 100 % NMP vs. 97.5 % control , p = 1.00 ) . Median peak aspartate aminotransferase in the first 7 days was significantly lower in the NMP group ( 417 IU [ 84–4681 ] ) versus ( 902 IU [ 218–8786 ] , p = 0.03 ) . This first report of liver transplantation using NMP‐preserved livers demonstrates the safety and feasibility of using this technology from retrieval to transplantation , including transportation . NMP may be valuable in increasing the number of donor livers and improving the function of transplantable organs Hypothermic machine perfusion ( HMP ) is widely used to preserve kidneys for transplantation with improved results over cold storage ( CS ) . To date , successful transplantation of livers preserved with HMP has been reported only in animal models . In this , the first prospect i ve liver HMP study , 20 adults received HMP‐preserved livers  and were compared to a matched group transplanted with CS livers . HMP was performed for 3–7 h using centrifugal perfusion with Vasosol ® solution at 4–6 ° C . There were no cases of primary nonfunction in either group . Early allograft dysfunction rates were 5 % in the HMP group versus 25 % in controls ( p = 0.08 ) . At 12 months , there were two deaths in each group , all unrelated to preservation or graft function . There were no vascular complications  in HMP livers . Two biliary complications were observed in HMP livers compared with four in the CS  group . Serum injury markers were significantly lower in the HMP  group . Mean hospital stay was shorter in the HMP group ( 10.9 ± 4.7 days vs. 15.3 ± 4.9 days in the CS group , p = 0.006 ) . HMP of donor livers provided safe and reliable preservation in this pilot case‐controlled series . Further multicenter HMP trials are now warranted Introduction The use of  marginal or extended criteria donor livers is increasing . These organs carry a greater risk of initial dysfunction and early failure , as well as inferior long-term outcomes . As such , many are rejected due to a perceived risk of use and use varies widely between centres . Ex situ normothermic machine 
    Output:
    
MP techniques which have per se the potential to alleviate ischaemia-reperfusion injury : Such as hypothermic MP and NRP , have also reported lower rates of ITBL .
Other biliary complications , such as biliary leak and anastomotic biliary strictures , are reported with similar incidences with all MP techniques .
There is currently less clinical evidence available to support normothermic MP as a mitigator of biliary complications following liver transplantation .
On the other h and , restoration of organ to full metabolism during normothermic MP allows assessment of hepatobiliary function before transplantation , although universally accepted criteria have yet to be vali date d. CONCLUSION MP of the liver has the potential to have a positive impact on  post-transplant biliary complications  , specifically ITBL , and exp and extended criteria donor livers utilisation