Expectations from imaging for pre-transplant evaluation of living donor liver transplantation

Living donor liver transplant(LDLT)is a major surgi-cal undertaking.Detailed pre-operative assessment of the vascular and biliary anatomy is crucial for safe and successful harvesting of the graft and transplantation.Computed tomography(CT)and magnetic resonance imaging(MRI)are currently the imaging modalities of choice in pre-operative evaluation.These cross-sec-tional imaging techniques can reveal the vascular and biliary anatomy,assess the hepatic parenchyma and perform volumetric analysis.Knowledge of the broad indications and contraindications to qualify as a recipi-ent for LDLT is essential for the radiologist reporting scans in a pre-transplant patient.Similarly,awareness of the various anatomical variations and pathological states in the donor is essential for the radiologist to generate a meaningful report of his/her observations.CT and MRI have largely replaced invasive techniques such as catheter angiography,percutaneous cholan-giography and endoscopic retrograde cholangiopan-creatography.In order to generate a meaningful report based on these pre-operative imaging scans,it is also mandatory for the radiologist to be aware of the sur-geon’s perspective.We intend to provide a brief over-view of the common surgical concepts of LDLT and give a detailed description of the minimum that a radiologist is expected to seek and report in CT and MR scans per-formed for LDLT related evaluation.

Safety evaluation of donors for living-donor liver transplantation in Chinese mainland:A single-center report

AIM： To discuss the safety of donors during living donor liver transplantation （LDLT） and the authors＇ experience with 50 cases. METHODS： Between January 1995 and March 2006, 50 patients with end-stage liver disease received LDLT in our department. Donors （at the age of 27-58 years） were healthy and antibody （ABO）-compatible. The protocol of evaluation and selection of donors, choice of surgical methods and strategy applied in the safety evaluation of donors were analyzed. RESULTS： A total of 115 candidate donors were evaluated for LDLT at our center. Of these, 50 underwent successful hepatectomy for living donation. The elimination rate for donors was 43.5%. Positive hepatitis serology and ABO incompatibility were the main factors for excluding candidates. All donors recovered uneventfully. The follow-up time ranged from 3 to 135 too. The incidence of major and minor medical complications was 12.0% and 28.0%, respectively. CONCLUSION： LDLT provides an excellent approach to the problem of donor shortage in China. With a thorough and complete preoperative workup and meticulous intra-and postoperative management, LDLT can be performed with minimal donor morbidity.

Graft-to-recipient weight ratio lower to 0.7% is safe without portal pressure modulation in right-lobe living donor liver transplantation with favorable conditions

BACKGROUND: The low graft-to-recipient weight ratio(GRWR) in adult-to-adult living donor liver transplantation(LDLT) is one of the major risk factors affecting graft survival. The goal of this study was to evaluate whether the lower limit of the GRWR can be safely reduced without portal pressure modulation in right-lobe LDLT. METHODS: From 2005 to 2011, 317 consecutive patients from a single institute underwent LDLT with right-lobe grafts without portal pressure modulation. Of these, 23 had a GRWR of less than 0.7%(group A), 27 had a GRWR of ≥0.7%, 【0.8%(group B), and 267 had a GRWR of more than and equal to 0.8%(group C). Medical records, including recipient, donor, operation factors, laboratory findings and complications were reviewed retrospectively. RESULTS: The baseline demographics showed low model for end-stage liver disease score(mean 16.3±8.9) and high percentage of hepatocellular carcinoma(231 patients, 72.9%). Three groups by GRWR demonstrated similar characteristics except recipient body mass index and donor gender. For smallforsize syndrome, there were 3(13.0%) in group A, 1(3.7%) in group B, and 2 patients(0.7%) in group C(P【0.001). Hepatic artery thrombosis was more frequently observed in group A than in groups B and C(8.7% vs 3.7% vs 1.9%, P=0.047). However, among the three groups, graft survival rates at 1 year(100% vs 96.3% vs 93.6%) and 3 years(91.7% vs 73.2% vs 88.1%) were not different(P=0.539). In laboratory measurements,there was no group difference in total bilirubin and albumin. However, prothrombin time was longer in group A within postoperative 1 week and platelet count was lower in groups A and B within postoperative 1 month. CONCLUSION: A GRWR lower to 0.7% is safe and does not need to modulate portal pressure in adult-to-adult LDLT using the right-lobe in favorable conditions including low model for end-stage liver disease score.

Matching donor to recipient in liver transplantation: Relevance in clinical practice

Achieving optimum outcomes after liver transplantation requires an understanding of the interaction between donor,graft and recipient factors.Within the cohort of patients waiting for a transplant,better matching of the donor organ to the recipient will improve transplant outcomes and benefit the overall waiting list by minimizing graft failure and need for re-transplantation.A PubMed search was conducted to identify published literature investigating the effects of donor factors such as age,gender,ethnicity,viral serology;graft factors such as size and quality,recipient factors such as age,size,gender and transplant factors such as major or minor blood group incompatibility and immunological factors.We also report technical and therapeutic modifications that can be used to manage donor-recipient mismatch identified from literature and the authors’clinical experience.Multiple donor and recipient factors impact graft survival after liver transplantation.Appropriate matching based on donor-organ-recipient variables,modification of surgical technique and innovative peri-transplant strategies can increase the donor pool by utilizing grafts from marginal donors that are traditionally turned down.

Donor-to-recipient gender match in liver transplantation: A systematic review and meta-analysis

AIM To perform a systematic review and meta-analysis on donor-to-recipient gender mismatch as a risk factor for post-transplant graft loss. METHODS A systematic literature search was performed using PubM ed, Cochrane Library database and EMBASE. The primary outcome was graft loss after liver transplantation. Odds ratios and 95% confidence intervals were calculated to compare the pooled data between groups with different donor-to-recipient gender matches. Three analyses were done considering(1) gender mismatches(F-M and M-F) vs matches(M-M and F-F);(2) Femaleto-Male mismatch vs other matches; and(3) Male-toFemale mismatch vs other matches.RESULTS A total of 7 articles were analysed. Gender mismatch(M-F and F-M) was associated with a significant increase of graft loss respect to match(M-M and F-F)(OR: 1.30; 95%CI: 1.13-1.50; P < 0.001). When F-M mismatch was specifically investigated, it confirmed its detrimental role in terms of graft survival(OR: 1.83; 95%CI: 1.20-2.80; P = 0.005). M-F mismatch failed to present a significant role(OR: 1.09; 95%CI: 0.73-1.62; P = 0.68).CONCLUSION Gender mismatch is a risk factor for poor graft survival after liver transplantation. Female-to-male mismatch represents the worst combination. More studies are needed with the intent to better clarify the reasons for these results.

Evaluating twenty-years of follow-up after orthotopic liver transplantation, best practice for donor-recipient matching: What can we learn from the past era?

AIM To characterize major determinants of 20-year survival after liver transplantation(LT).METHODS This longitudinal single-institution study includes 313 consecutive patients who received a LT between 1988 and 1992. Pretransplant clinical characteristics and laboratory values were assessed and compared between 20-year survivors and non-survivors. Particular attention was paid to the Model for End-Stage Liver Disease(labM ELD)-score and the Eurotransplant Donor Risk Index(ET-DRI) to unravel their impact on 20-year survival after LT.RESULTS Twenty-year survivors were significantly younger(44 vs 50 years, P = 0.001), more likely to be female(49% vs 36%, P = 0.03) and less likely to be obese at the time of LT(19% vs 32%, P = 0.011). Mean labM ELD-score(P = 0.156), rate of high-urgency LT(P = 0.210), coldischemia time(P = 0.994), rate of retransplantation(P = 0.12) and average donor age(28 vs 33 years, P = 0.099) were not statistically different. The mean estimated glomerular filtration rate was higher among survivors(P = 0.007). ET-DRI > 1.4(P = 0.020) and donor age ≥ 30 years(P < 0.022) had significant influence on 20-year survival. The overall survival was not significantly impacted by labM ELD-score categories(P = 0.263).CONCLUSION LT offers excellent long-term results in case of optimal donor and recipient conditions. However, mainly due to the current organ shortage, these ideal circumstances are rarely given; thus algorithms for donor-recipient matching need to be refined, in order to enable a maximum benefit for the recipients of high quality as well as marginal organs.

Weight loss interventions in living donor liver transplantation as a tool in expanding the donor pool: A systematic review and metaanalysis

BACKGROUND With increasing rates of liver transplantation and a stagnant donor pool,the annual wait list removals have remained high.Living donor liver transplantation(LDLT)is an established modality in expanding the donor pool and is the primary method of liver donation in large parts of the world.Marginal living donors,including those with hepatic steatosis,have been used to expand the donor pool.However,due to negative effects of steatosis on graft and recipient outcomes,current practice excludes overweight or obese donors with more than 10%macro vesicular steatosis.This has limited a potentially important source to help expand the donor pool.Weight loss is known to improve or resolve steatosis and rapid weight loss with short-term interventions have been used to convert marginal donors to low-risk donors in a small series of studies.There is,however,a lack of a consensus driven standardized approach to such interventions.AIM To assess the available data on using weight loss interventions in potential living liver donors with steatotic livers and investigated the feasibility,efficacy,and safety of using such donors on the donor,graft and recipient outcomes.The principal objective was to assess if using such treated donor livers,could help expand the donor pool.METHODS We performed a comprehensive literature review and meta-analysis on studies examining the role of short-term weight loss interventions in potential living liver donors with hepatic steatosis with the aim of increasing liver donation rates and improving donor,graft,and recipient outcomes.RESULTS A total of 6 studies with 102 potential donors were included.Most subjects were males(71).All studies showed a significant reduction in body mass index postintervention with a mean difference of-2.08(-3.06,1.10,I2=78%).A significant reduction or resolution of hepatic steatosis was seen in 93 of the 102(91.2%).Comparison of pre-and post-intervention liver biopsies showed a significant reduction in steatosis with a mean difference of-21.22(-27.02,-15.43,I2=56%).The liver donation rates post-intervention was 88.5(74.5,95.3,I2=42%).All donors who did not undergo LDLT had either recipient reasons or had fibrosis/steatohepatitis on post intervention biopsies.Post-operative biliary complications in the intervention group were not significantly different compared to controls with an odds ratio of 0.96[(0.14,6.69),I2=0].The overall post-operative donor,graft,and recipient outcomes in treated donors were not significantly different compared to donors with no steatosis.CONCLUSION Use of appropriate short term weight loss interventions in living liver donors is an effective tool in turning marginal donors to low-risk donors and therefore in expanding the donor pool.It is feasible and safe,with comparable donor,graft,and recipient outcomes,to non-obese donors.Larger future prospective studies are needed.

Hepatobiliary scintigraphy for detecting biliary strictures after living donor liver transplantation

AIM:To investigate the diagnostic accuracy of hepatobiliary scintigraphy(HBS) in detecting biliary strictures in living donor liver transplantation(LDLT) patients.METHODS:We retrospectively reviewed 104 adult LDLT recipients of the right hepatic lobe with duct-toduct anastomosis,who underwent HBS and cholangiography.The HBS results were categorized as normal,parenchymal dysfunction,biliary obstruction,or bile leakage without re-interpretation.The presence of biliary strictures was determined by percutaneous cholangiography or endoscopic retrograde cholangiopancreatography(ERCP).RESULTS:In 89 patients with biliary strictures,HBS showed biliary obstruction in 50 and no obstruction in 39,for a sensitivity of 56.2%.Of 15 patients with no biliary strictures,HBS showed no obstruction in 11,for a specificity of 73.3%.The positive predictive value(PPV) was 92.6%(50/54) and the negative predictive value(NPV) was 22%(11/50).We also analyzed the diagnostic accuracy of the change in bile duct size.The sensitivity,NPV,specificity,and PPV were 65.2%,27.9%,80% and 95%,respectively.CONCLUSION:The absence of biliary obstruction on HBS is not reliable.Thus,when post-LDLT biliary strictures are suspected,early ERCP may be considered.

Management of the Middle Hepatic Vein in Right Lobe Living Donor Liver Transplantation: A Meta-analysis

Summary： Living donor liver transplantation （LDLT） is a curative treatment for end stage liver disease. It is advantageous due to the shortage of deceased donors. However, in LDLT, whether the middle he- patic vein （MHV） should be preserved in donors remains controversial. We conducted searches in Pub- reed, Embase, Cochrane Library, Web of Science, Ovid, and Google Scholar using the key words ＂living donor liver transplantation＂ and ＂middle hepatic vein＂. Due to ethical issues, there were no randomized control trails focusing on MHV in LDLT. The majority of reports were retrospective studies. We exam- ined the reference lists to identify related investigations. Google Scholar was then used to obtain full texts. Nine observational studies were analyzed. There were no significant differences in liver function （WMD, -5.51; P=0.12） and complications （RR, 0.98; P=0.89） in donors with or without MHV. How- ever, the liver function in recipients was greatly improved after LDLT with MHV （WMD, -78.32; P=0.01）. No definite conclusion was obtained in terms of the liver regeneration indices between LDLT with or without MHV. It was conclude that grafts with MHV in LDLT favor recipient outcomes and do not harm the living donor if a careful preoperative evaluation is oerformed.

Influence of sex on outcomes of liver transplantation for hepatocellular carcinoma:a multicenter cohort study in China

Objective:Sex-specific differences are observed in various liver diseases,but the influence of sex on the outcomes of hepatocellular carcinoma(HCC)after liver transplantation(LT)remains to be determined.This study is the first Chinese nationwide investigation of the role of sex in post-LT outcomes in patients with HCC.Methods:Data for recipients with HCC registered in the China Liver Transplant Registry between January 2015 and December 2020 were analyzed.The associations between donor,recipient,or donor-recipient transplant patterns by sex and the post-LT outcomes were studied with propensity score matching(PSM).The survival associated with different sex-based donor-recipient transplant patterns was further studied.Results:Among 3,769 patients enrolled in this study,the 1-,3-,and 5-year overall survival(OS)rates of patients with HCC after LT were 96.1%,86.4%,and 78.5%,respectively,in female recipients,and 95.8%,79.0%,and 70.7%,respectively,in male recipients after PSM(P=0.009).However,the OS was comparable between recipients with female donors and male donors.Multivariate analysis indicated that male recipient sex was a risk factor for post-LT survival(HR=1.381,P=0.046).Among the donor-recipient transplant patterns,the male-male donor-recipient transplant pattern was associated with the poorest post-LT survival(P<0.05).Conclusions:Our findings highlighted that the post-LT outcomes of female recipients were significantly superior to those of male recipients,and the male-male donor-recipient transplant pattern was associated with the poorest post-LT survival.Livers from male donors may provide the most benefit to female recipients.Our results indicate that sex should be considered as a critical factor in organ allocation.

Splenectomy in living donor liver transplantation and risk factors of portal vein thrombosis

Background:Graft inflow modulation(GIM)during adult-to-adult living donor liver transplantation(LDLT)is a common strategy to avoid small-for-size syndrome,and some transplant surgeons attempt small size graft strategy with frequent GIM procedures,which are mostly performed by splenectomy,in LDLT.However,splenectomy can cause serious complications such as portal vein thrombosis and overwhelming postsplenectomy infection.Methods:Forty-eight adult-to-adult LDLT recipients were enrolled in this study and retrospectively reviewed.We applied the graft selection criteria,which routinely fulfill graft-to-recipient weight ratio≥0.8%,and consider GIM as a backup strategy for high portal venous pressure(PVP).Results:In our current strategy of LDLT,splenectomy was performed mostly due to hepatitis C and splenic arterial aneurysms,but splenectomy for GIM was intended to only one patient(2.1%).The final PVP values≤20 mmHg were achieved in all recipients,and no significant difference was observed in patient survival or postoperative clinical course based on whether splenectomy was performed or not.However,6 of 18 patients with splenectomy(33.3%)developed postsplenectomy portal vein thrombosis(PVT),while none of the 30 patients without splenectomy developed PVT after LDLT.Splenectomy was identified as a risk factor of PVT in this study(P<0.001).Our study revealed that a lower final PVP could be risk factor of postsplenectomy PVT.Conclusions:Using sufficient size grafts was one of the direct solutions to control PVP,and allowed GIM to be reserved as a backup procedure.Splenectomy should be avoided as much as possible during LDLT because splenectomy was found to be a definite risk factor of PVT.In splenectomy cases with a lower final PVP,a close follow-up is required for early detection and treatment of PVT.

Impact of intra-operative cholangiography and parenchymal resection to donor liver function in living donor liver transplantation

BACKGROUND: Living donor liver transplantation(LDLT)has been widely accepted over the past decade, and hepatic dysfunction often occurs in the donor in the early stage after liver donation. The present study aimed to evaluate the effect of intraoperative cholangiography(IOC) and parenchymal resection on liver function of donors in LDLT, and to assess the role of IOC in influencing the biliary complications and improving the overall outcome.METHODS: Data from 40 patients who had donated their right lobes for LDLT were analyzed. Total bilirubin(TB), alanine aminotransferase(ALT), aspartate aminotransferase(AST),alkaline phosphatase(ALP) and γ-glutamyl transpeptidase(GGT)at different time points were compared, and the follow-up data and the biliary complications were also analyzed.RESULTS: The ALT and AST values were significantly increased after IOC(P<0.001) and parenchymal resection(P<0.001).However, the median values of TB, ALP and GGT were not significantly influenced by IOC(P>0.05) or parenchymal resection(P>0.05). The biochemical changes caused by IOC or parenchymal resection were not correlated with the degree of post-operative liver injury or the recovery of liver function. The liver functions of the donors after operation were stable, and none of the donors suffered from biliary stenosis or leakage during the follow-up.CONCLUSIONS: IOC and parenchymal resection may induce a transient increase in liver enzymes of donors in LDLT, but do not affect the recovery of liver function after operation. Moreover,the routine IOC is helpful to clarify the division line of the hepatic duct, thus reducing the biliary complication rate.

Outcomes of adult patients adopting small-for-size grafts in living donor liver transplantation: A systematic review and meta-analysis

Background: Small-for-size graft(SFSG) has emerged as one of the very contentions in adult-to-adult living donor liver transplantation(LDLT) as a certain graft size is related to recipients’ prognosis. Graftto-recipient weight ratio(GRWR)≥0.8% was considered as a threshold to conduct LDLT. However, this also has been challenged over decades as a result of technique refinements. For a better understanding of SFSG in practice, we conducted this meta-analysis to compare the perioperative outcomes and long-term outcomes between patients adopting the grafts with a lower volume(GRWR < 0.8%, SFSG group) and sufficient volume(GRWR ≥ 0.8%, non-SFSG group) in adult-to-adult LDLT. Data sources: The studies comparing recipients adopting graft with a GRWR < 0.8% and ≥ 0.8% were searched by three authors independently in Pub Med, Web of Science, Embase, the Cochrane Library, MEDLINE and Google Scholar databases until September 2018 and data were analyzed by RevMan 5.3.5. Results: Sixteen studies with a total of 3272 subjects were included in this meta-analysis. In terms of small-for-size syndrome(SFSS), no significant difference was found in subjects enrolled after year 2010(before 2010, OR = 3.00, 95% CI: 1.69–5.35, P = 0.0002;after 2010, OR = 1.23, 95% CI: 0.79–1.90, P = 0.36;P for interaction: 0.02). There was no significant difference in operative duration, blood loss, cold ischemia time, biliary complications, acute rejection, postoperative bleeding, hospitalization time, perioperative mortality, and 1-, 3-and 5-year overall survival rates between two groups. Conclusions: This meta-analysis suggested that adopting SFSG in adult LDLT has comparable outcomes to those with non-SFSG counterparts since 2010.

Adult-to-adult living donor liver transplantation for acute liver failure in China

AIM:To investigate the long-term outcome of recipients and donors of adult-to-adult living-donor liver transplantation(AALDLT) for acute liver failure(ALF).METHODS:Between January 2005 and March 2010,170 living donor liver transplantations were performed at West China Hospital of Sichuan University.All living liver donor was voluntary and provided informed consent.Twenty ALF patients underwent AALDLT for rapid deterioration of liver function.ALF was defined based on the criteria of the American Association for the Study of Liver Diseases,including evidence of coagulation abnormality [international normalized ratio(INR) ≥ 1.5] and degree of mental alteration without pre-ex-isting cirrhosis and with an illness of < 26 wk duration.We reviewed the clinical indications,operative procedure and prognosis of AALDTL performed on patients with ALF and corresponding living donors.The potential factors of recipient with ALF and corresponding donor outcome were respectively investigated using multivariate analysis.Survival rates after operation were analyzed using the Kaplan-Meier method.Receiver operator characteristic(ROC) curve analysis was undertaken to identify the threshold of potential risk factors.RESULTS:The causes of ALF were hepatitis B(n = 18),drug-induced(n = 1) and indeterminate(n = 1).The score of the model for end-stage liver disease was 37.1 ± 8.6,and the waiting duration of recipients was 5 ± 4 d.The graft types included right lobe(n = 17) and dual graft(n = 3).The mean graft weight was 623.3 ± 111.3 g,which corresponded to graft-torecipient weight ratio of 0.95% ± 0.14%.The segment Ⅴor Ⅷ hepatic vein was reconstructed in 11 right-lobe grafts.The 1-year and 3-year recipient's survival and graft survival rates were 65%(13 of 20).Postoperative results of total bilirubin,INR and creatinine showed obvious improvements in the survived patients.However,the creatinine level of the deaths was increased postoperatively and became more aggravated compared with the level of the survived recipients.Multivariate analysis showed that waiting duration was independently correlated with increased mortality(P = 0.014).Furthermore,ROC curve revealed the cut-off value of waiting time was 5 d(P = 0.011,area under the curve = 0.791) for determining the mortality.The short-term creatinine level with different recipient's waiting duration was described.The recipients with waiting duration ≥ 5 d showed the worse renal function and higher mortality than those with waiting duration < 5 d(66.7% vs 9.1%,P = 0.017).In addition,all donors had no residual morbidity.Furthermore,univariate analysis did not show that short assessment time induced the high morbidity(P = 0.573).CONCLUSION:Timely AALDLT for patients with ALF greatly improves the recipient survival.However,further systemic review is needed to investigate the optimal treatment strategy for ALF.

Risk factors, surgical complications and graft survival in liver transplant recipients with early allograft dysfunction

Background: Early allograft dysfunction (EAD) is a severe complication after liver transplantation. The associated risk factors and complications have re-gained recent interest. This study investigated risk factors, survival and complications associated with EAD in a large liver transplant center in Latin America. Methods: Retrospective, unicenter, cohort, based on data from adult patients undergoing first deceaseddonor liver transplant from January 2009 to December 2013. EAD was defined by one or more of the following:(i) bilirubin ≥10 mg/dL on postoperative day 7;(ii) international normalized ratio ≥1.6 on postoperative day 7, and (iii) alanine aminotransferase or aspartate aminotransferase > 2000 IU/L within the first seven days after transplant. Results: A total of 602 patients were included;of these 34.2% developed EAD. Donor risk factors were male ( P = 0.007), age between 50 and 59 years ( P = 0.034), overweight ( P = 0.028) or grade I obesity ( P = 0.012), sodium > 157 mmol/L ( P = 0.002) and grade IV ischemia/reperfusion injury ( P = 0.002). Cold ischemia time ≥10 h ( P = 0.008) and warm ischemia time ≥40 min ( P = 0.013) were the surgical factors. Male ( P < 0.001) was the only recipient protective factor. Compared with the non-EAD group, patients with EAD were submitted to more reoperations (24.3% vs. 13.4%, P = 0.001) and had higher graft loss rates (37.9% vs. 21.2%, P < 0.001), with similar patient survival rates ( P = 0.238). Conclusions: EAD risk factors are related to donor, surgical procedure and recipient. Donor risk factors for EAD were male, age between 50 and 59 years, donor overweight or grade Ⅰ obesity, sodium > 157 mmol/L and grade Ⅳ ischemia/reperfusion injury. Cold ischemia time ≥10 h and warm ischemia time ≥40 min were the surgical risk factors. Male was the only recipient protective factor. Patients with EAD had higher reoperations and graft loss rates.

Split liver transplantation in adults

Split liver transplantation(SLT),while widely accepted in pediatrics,remains underutilized in adults. Advancements in surgical techniques and donor-recipient matching,however,have allowed expansion of SLT from utilization of the right trisegment graft to now include use of the hemiliver graft as well. Despite less favorable outcomes in the early experience,better outcomes have been reported by experienced centers and have further validated the feasibility of SLT. Importantly,more than two decades of experience have identified key requirements for successful SLT in adults. When these requirements are met,SLT can achieve outcomes equivalent to those achieved with other types of liver transplantation for adults. However,substantial challenges,such as surgical techniques,logistics,and ethics,persist as ongoing barriers to further expansion of this highly complex procedure. This review outlines the current state of SLT in adults,focusing on donor and recipient selection based on physiology,surgical techniques,surgical outcomes,and ethical issues.

Impact of the COVID-19 pandemic on liver donation and transplantation:A review of the literature

The coronavirus disease 2019(COVID-19)pandemic has upended healthcare systems worldwide and led to an inevitable decrease in liver transplantation(LT)activity.During the first pandemic wave,administrators and clinicians were obliged to make the difficult decision of whether to suspend or continue a lifesaving procedure based on the scarce available evidence regarding the risk of transmission and mortality in immunosuppressed patients.Those centers where the activity continued or was heavily restricted were obliged to screen donors and recipients,design COVID-safe clinical pathways,and promote telehealth to prevent nosocomial transmission.Despite the ever-growing literature on COVID-19,the amount of high-quality literature on LT remains limited.This review will provide an updated view of the impact of the pandemic on LT programs worldwide.Donor and recipient screening,strategies for waitlist prioritization,and posttransplant risk of infection and mortality are discussed.Moreover,a particular focus is given to the possibility of donor-to-recipient transmission and immunosuppression management in COVID-positive recipients.

Female gender in the setting of liver transplantation

The evolution of liver diseases to end-stage liver disease or to acute hepatic failure, the evaluation process for liver transplantation, the organ allocation decisionmaking, as well as the post-transplant outcomes are different between female and male genders. Women's access to liver transplantation is hampered by the use of model for end-stage liver disease(MELD) score, in which creatinine values exert a systematic bias against women due to their lower values even in the presence of variable degrees of renal dysfunction. Furthermore, even when correcting MELD score for gender-appropriate creatinine determination, a quantifiable uneven access to transplant prevails, demonstrating that other factors are also involved. While some of the differences can be explained from the epidemiological point of view, hormonal status plays an important role. Moreover, the pre-menopausal and post-menopausal stages imply profound differences in a woman's physiology, including not only the passage from the fertile age to the non-fertile stage, but also the loss of estrogens and their potentially protective role in delaying liver fibrosis progression, amongst others. With menopause, the tendency to gain weight may contribute to the development of or worsening of pre-existing metabolic syndrome. As an increasing number of patients are transplanted for non-alcoholic steatohepatitis, and as the average age at transplant increases, clinicians must be prepared for the management of this particular condition, especially in post-menopausal women, who are at particular risk of developing metabolic complications after menopause.

Hepatic vessel segmentation on contrast enhanced CT image sequence for liver transplantation planning

The structure and morphology of the hepatic vessels and their relationship between tumors and liver segments are major interests to surgeons for liver surgical planning. In case of living donor liver transplantation (LDLT), the most important step in determining donor suitability is an accurate assessment of the liver volume available for transplantation. In addition, the mutual principles of the procedures include dissection in the appropriate anatomic plane without portal occlusion, minimization of blood loss, and avoidance of injury to the remaining liver. It is essential first step to identify and evaluate the major hepatic vascular structure for liver surgical planning. In this paper, the threshold was determined to segment the liver region automatically based on the distribution ratio of intensity value;and the hepatic vessels were extracted with mathematical morphology transformation, which called hit operation, that is slightly modified version of hit-and-miss operation on contrast enhanced CT image sequence. We identified the vein using the preserved voxel connectivity between two consecutive transverse image sequences, followed by resection into right lobe including right hepatic vein, middle hepatic vein branches andleft lobe including left hepatic vein. An automated hepatic vessel segmentation scheme is recommended for liver surgical planning such as tumor resection and transplantation. These vessel extraction method combined with liver region segmentation technique could be applicable to extract tree-like organ structures such as carotid, renal, coronary artery, and airway path from various medical imaging modalities.

Chinese expert consensus on evaluation of donor and donor liver for split liver transplantation

With the advent of the era of organ donation after citizen's death,split liver transplantation(SLT)can effectively increase the supply of donor livers and shorten the transplantation wait time for patients,especially pediatric recipients.In recent years,SLT has been performed to varying degrees in many transplant centers in China,and varying levels of efficacy have been achieved.The quality of donors and donor livers for SLT is an important factor affecting the outcome of the surgery.At this stage,it is necessary to reach a consensus on the evaluation of SLT donor and liver donor that is suitable for the conditions in China by combining the well-established experience of the international community with advanced transplantation technology.This approach will aid in enhancing the efficacy of SLT.Based on the experience of experts,a consensus on the evaluation of donors and donor livers for SLT has been formulated in this study,which focuses on evaluation of donors and donor livers,evaluating the functional and anatomical aspects of the donor liver and donorerecipient matching.