Association of donor hepatectomy time with liver transplantation outcomes: A multicenter retrospective study

BACKGROUND Prolonged donor hepatectomy time may be implicated in early and late complications of liver transplantation.AIM To evaluate the impact of donor hepatectomy time on outcomes of liver transplant recipients,mainly early allograft dysfunction.METHODS This multicenter retrospective study included brain-dead donors and adult liver graft recipients.Donor-recipient matching was obtained through a crossover list.Clinical and laboratory data were recorded for both donors and recipients.Donor hepatectomy,cold ischemia,and warm ischemia times were recorded.Primary outcome was early allograft dysfunction.Secondary outcomes included need for retransplantation,length of intensive care unit and hospital stay,and patient and graft survival at 12 months.RESULTS From January 2019 to December 2021,a total of 243 patients underwent a liver transplant from a brain-dead donor.Of these,57(25%)developed early allograft dysfunction.The median donor hepatectomy time was 29(23–40)min.Patients with early allograft dysfunction had a median hepatectomy time of 25(22–38)min,whereas those without it had a median time of 30(24–40)min(P=0.126).CONCLUSION Donor hepatectomy time was not associated with early allograft dysfunction,graft survival,or patient survival following liver transplantation.

Portal vein arterialization in 25 liver transplant recipients:A Latin American single-center experience

BACKGROUND Portal vein arterialization(PVA)has been used in liver transplantation(LT)to maximize oxygen delivery when arterial circulation is compromised or has been used as an alternative reperfusion technique for complex portal vein thrombosis(PVT).The effect of PVA on portal perfusion and primary graft dysfunction(PGD)has not been assessed.All patients receiving PVA and LT at the Fundacion Santa Fe de Bogota between 2011 and 2022 were analyzed.To account for the time-sensitive effects of graft perfusion,patients were classified into two groups:prereperfusion(pre-PVA),if the arterioportal anastomosis was performed before graft revascularization,and postreperfusion(post-PVA),if PVA was performed afterward.The pre-PVA rationale contemplated poor portal hemodynamics,severe vascular steal,or PVT.Post-PVA was considered if graft hypoperfusion became evident.Conservative interventions were attempted before PVA.

How to protect liver graft with nitric oxide

Organ preservation and ischemia reperfusion injury as- sociated with liver transplantation play an important role in the induction of graft injury. One of the earliest events associated with the reperfusion injury is en- dothelial cell dysfunction. It is generally accepted that endothelial nitric oxide synthase (e-NOS) is cell-pro- tective by mediating vasodilatation, whereas inducible nitric oxide synthase mediates liver graft injury after transplantation. We conducted a critical review of the literature evaluating the potential applications of regu- lating and promoting e-NOS activity in liver preservation and transplantation, showing the most current evidenceto support the concept that enhanced bioavailability of NO derived from e-NOS is detrimental to ameliorate graft liver preservation, as well as preventing subse- quent graft reperfusion injury. This review deals mainly with the beneficial effects of promoting "endogenous" pathways for NO generation, via e-NOS inducer drugs in cold preservation solution, surgical strategies such as ischemic preconditioning, and alternative "exogenous" pathways that focus on the enrichment of cold storage liquid with NO donors. Finally, we also provide a basic bench-to-bed side summary of the liver physiology and cell signalling mechanisms that account for explaining the e-NOS protective effects in liver preservation and transplantation. ? 2011 Baishideng. All rights reserved.

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.

Primary graft dysfunction after liver transplantation

BACKGROUND: Primary graft dysfunction (PGD) causes complications in liver transplantation, which result in poor prognosis. Recipients who develop PGD usually experience a longer intensive care unit and hospital stay and have higher mortality and graft loss rates compared with those without graft dysfunction. However, because of the lack of universally accepted definition, early diagnosis of graft dysfunction is difficult. Additionally, numerous factors affect the allograft function after transplantation, making the prediction of PGD more difficult. The present review was to analyze the literature available on PGD and to propose a definition.DATA SOURCE: A search of PubMed (up to the end of 2012) for English-language articles relevant to PGD was performed to clarify the characteristics, risk factors, and possible treatments or interventions for PGD.RESULTS: There is no pathological diagnostic standard; many documented definitions of PGD are different. Many factors such as donor status, procurement and transplant process and recipient illness may affect the function of graft, and ischemia reperfusion injury is considered the direct cause. Potentia managements which are helpful to improve graft function were investigated. Some of them are promising.CONCLUSIONS: Our analyses suggested that the definition of PGD should include one or more of the following variables: (1)bilirubin ≥10 mg/dL on postoperative day 7; (2) internationa normalized ratio ≥1.6 on postoperative day 7; and (3) alanine aminotransferase or aspartate aminotransferase 】2000 IU/L within 7 postoperative days. Reducing risk factors may decrease the incidence of PGD. A majority of the recipients could recover from PGD; however, when the graft progresses intoprimary non-function, the patients need to be treated with retransplantation.

Protocol liver biopsy is the only examination that can detect mid-term graft fibrosis after pediatric liver transplantation

AIM:To assessed the clinical significance of protocol liver biopsy(PLB)in pediatric liver transplantation(LT).METHODS:Between July 2008 and August 2012,89and 55 PLBs were performed in pediatric patients at two and five years after LT,respectively.We assessed the histopathological findings using the Metavir scoring system,including activity(A)and fibrosis(F),and we identified factors associated with scores of≥A1 and≥F1.Our results clarified the timing and effectiveness of PLB.RESULTS:The incidences of scores of≥A1 and≥F1 were 24.7%and 24.7%,respectively,at two years after LT and 42.3%and 34.5%,respectively,at five years.Independent risk factors in a multivariate analysis of a score of≥A1 at two years included≥2 h ofcold ischemic time,no acute cellular rejection and an alanine amino transaminase(ALT)level of≥20 IU/L(P=0.028,P=0.033 and P=0.012,respectively);however,no risk factors were identified for a score of≥F1.Furthermore,no independent risk factors associated with scores of≥A1 and≥F1 at five years were identified using multivariate analysis.A ROC curve analysis of ALT at two years for a score of≥A1 demonstrated the recommended cutoff value for diagnosing≥A1 histology to be 20 IU/L.The incidence of scores of≥A2 or≥F2 at two years after LT was 3.4%(three cases),and all patients had an absolute score of≥A2.In contrast to that observed for PLBs at five years after LT,the incidence of scores of≥A2 or≥F2 was 20.0%(11 cases),and all patients had an absolute score of≥F2.In all cases,the dose of immunosuppressants was increased after the PLB,and all ten patients who underwent a follow-up liver biopsy improved to scores of≤A1 or F1.CONCLUSION:PLB at two years after LT is an unnecessary examination,because the serum ALT level reflects portal inflammation.In addition,immunosuppressive therapy should be modulated to maintain the ALT concentration at a level less than 20 IU/L.PLB at five years is an excellent examination for the detection of early reversible graft fibrosis because no serum markers reflect this finding.

Emerging concepts in liver graft preservation

The urgent need to expand the donor pool in order to attend to the growing demand for liver transplantation has obliged physicians to consider the use of suboptimal liver grafts and also to redefine the preservation strategies. This review examines the different methods of liver graft preservation, focusing on the latest advances in both static cold storage and machine perfusion(MP). The new strategies for static cold storage are mainly designed to increase the fatty liver graft preservation via the supplementation of commercial organ preservation solutions with additives. In this paper we stress the importance of carrying out effective graft washout after static cold preservation, and present a detailed discussion of the future perspectives for dynamic graft preservation using MP at different temperatures(hypothermia at 4 ℃, normothermia a t 3 7 ℃ and subnormothermia at 20 ℃- 2 5 ℃). Finally, we highlight some emerging applications of regenerative medicine in liver graft preservation. In conclusion, this review discusses the "state of the art" and future perspectives in static and dynamic liver graft preservation in order to improve graft viability.

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.

Liver graft preservation methods during cold ischemia phase and normothermic machine perfusion

The growing demand for donor organs requires measures to expand donor pool.Those include extended criteria donors, such as elderly people, steatotic livers,donation after cardiac death, etc. Static cold storage to reduce metabolic requirements developed by Collins in late 1960 s is the mainstay and the golden standard for donated organ protection. Hypothermic machine perfusion provides dynamic organ preservation at 4°C with protracted infusion of metabolic substrates to the graft during the ex vivo period. It has been used instead of static cold storage or after it as short perfusion in transplant center. Normothermic machine perfusion(NMP) delivers oxygen, and nutrition at physiological temperature mimicking regular environment in order to support cellular function. This would minimize effects of ischemia/reperfusion injury.Potentially, NMP may help to estimate graft functionality before implantation into a recipient. Clinical studies demonstrated at least its non-inferiority or better outcomes vs static cold storage. Regular grafts donated after brain death could be safely preserved with convenient static cold storage. Except for prolonged ischemia time where hypothermic machine perfusion started in transplant center could be estimated to provide possible positive reconditioning effect. Use of hypothermic machine perfusion in regular donation instead of static cold storage or in extended criteria donors requires further investigation. Multicenter randomized clinical trial supposed to be completed in December 2021. Extended criteria donors need additional measures for graft storage and assessment until its implantation. NMP is actively evaluating promising method for this purpose.Future studies are necessary for precise estimation and confirmation to issue clinical practice recommendations.

Modulation of graft vascular inflow guided by flowmetry and manometry in liver transplantation

BACKGROUND:Survival of the partial graft after living donor liver transplantation owes much to its tremendous regenerative ability.With excellent venous outflow capacity,a graft within a wide range of graft-to-standard-liver-volume ratios can cope with portal hypertension that is common in liver transplant recipients.However,when the ratio range is exceeded,modulation of graft vascular inflow becomes necessary for graft survival.The interplay between graft-to-standard-liver-volume ratio and portal pressure,in the presence of portosystemic shunt or otherwise,requires individualized modulation of graft portal and arterial inflows.Boosting of portal inflow by shunt ligation can be guided by transonic flowmetry,whereas muting of portal inflow by splenic artery ligation can be monitored by portal electronic manometry.METHOD:We describe four cases to illustrate the above.RESULTS:One patient had hepatic artery thrombosis resulting from splenic artery steal syndrome which was the sequela of small-for-size syndrome.Emergency splenic artery ligation and re-anastomosis of the hepatic artery successfully muted the portal inflow and boosted the hepatic arterial inflow.Another patient with portal vein thrombosis underwent thrombendvenectomy.Portal inflow was boosted with ligation of portosystemic shunt,which is often present in these patients with portal hypertension.The coexistence of splenic aneurysm and splenorenal shunt required ligation of both in the third patient.The fourth patient,with portal pressure and flow monitoring,avoided ligation of a coronary vein which became a main portal inflow after portal thrombendvenectomy.CONCLUSION:Management of graft inflow modulation guided selectively by transonic flowmetry or portal manometry was described.

Effect of donor age on graft function and longterm survival of recipients undergoing living donor liver transplantation

BACKGROUND： Donor shortage is the biggest obstacle in organ transplantation. Living donor liver transplantation（LDLT） has been considered as a valuable approach to shortening waiting time. The objectives of this study were to investigate the feasibility of utilizing donors older than 50 years in LDLT and to evaluate the graft function and recipient survival.METHODS： All LDLT cases（n=159） were divided into the older（donor age ≥50 years, n=10） and younger（donor age 〈50 years,n=149） donor groups. Donor graft and recipient condition pre-,intra- and post-operation were compared between the two groups.In particular, graft functions and recipient survivals were analyzed.RESULTS： The median donor age was 58.5（52.5-60.0） years in the older donor group and 25.0（23.0-32.0） in the younger donor group. There was no significant difference in cold ischemic time, anhepatic phase and operation time between the older and younger donor groups（P〉0.05）. However, the volume of red blood cell transfused in operation was greater in the older donor group than in the younger donor group（1900 vs 1200 m L, P=0.023）. The 1-, 3- and 5-year graft survival rates were 90%, 80% and 80% for the older donor group, and 92%, 87% and 87% for the younger donor group, respectively（P=0.459）.The 1-, 3- and 5-year survival rates were 100%, 90% and 90% for recipients with older grafts, and 93%, 87% and 87% for those with younger grafts, respectively（P=0.811）.CONCLUSION： It is safe for a LDLT recipient to receive liver from donors older than 50 years, and there is no significant adverse effect on graft function and long-term patients’ survival.

Impact of small-for-size liver grafts on medium-term and long-term graft survival in living donor liver transplantation: A meta-analysis

BACKGROUND Small-for-size grafts (SFSGs) in living donor liver transplantation (LDLT) could optimize donor postoperative outcomes and also expand the potential donor pool. Evidence on whether SFSGs would affect medium-term and long-term recipient graft survival is lacking. AIM To evaluate the impact of small-for-size liver grafts on medium-term and longterm graft survival in adult to adult LDLT. METHODS A systematic review and meta-analysis were performed by searching eligible studies published before January 24, 2019 on PubMed, EMBASE, and Web of Science databases. The primary outcomes were 3-year and 5-year graft survival. Incidence of small-for-size syndrome and short term mortality were also extracted. RESULTS This meta-analysis is reported according to the guidelines of the PRISMA 2009 Statement. Seven retrospective observational studies with a total of 1821 LDLT recipients were included in the meta-analysis. SFSG is associated with significantly poorer medium-term graft survival. The pooled odds ratio for 3-year graft survival was 1.58 [95% confidence interval 1.10-2.29, P = 0.014]. On the other hand, pooled results of the studies showed that SFSG had no significant discriminatory effect on 5-year graft survival with an odds ratio of 1.31 (95% confidence interval 0.87-1.97, P = 0.199). Furthermore, incidence of small-for-size syndrome detected in recipients of SFSG ranged from 0-11.4% in the included studies. CONCLUSION SFSG is associated with inferior medium-term but not long-term graft survival. Comparable long-term graft survival based on liver graft size shows that smaller grafts could be accepted for LDLT with appropriate flow modulatory measures. Close follow-up for graft function is warranted within 3 years after liver transplantation.

Early lactate clearance as a reliable predictor of initial poor graft function after orthotopic liver transplantation

BACKGROUND:Initial poor graft function (IPGF) following orthotopic liver transplantation is a major determinant of postoperative survival and morbidity.Lactate clearance is a good marker of liver function.In this study,we investigated the clinical utility of early lactate clearance as an early and accurate predictor for IPGF following liver transplantation.METHODS:This was a prospective observational study of 222 patients referred to the surgical intensive care unit (SICU) after orthotopic liver transplantation.The IPGF group consisted of patients with alanine aminotransferase (ALT) and/or aspartate aminotransferase (AST) >1500 IU/L within 72 hours after orthotopic liver transplantation.Early lactate clearance was defined as lactate at SICU presentation (hour 0) minus lactate at hour 6,divided by lactate at SICU presentation.The model for end-stage liver disease (MELD) score,Child-Pugh score and laboratory data including AST,ALT,total bilirubin (TB) and prothrombin time (PT) were recorded at SICU presentation and compared between the non-IPGF and IPGF groups Receiver operating characteristic (ROC) curves were plotted to measure the performance of early lactate clearance,MELD score,Child-Pugh score,TB and PT.RESULTS:IPGF occurred in 45 of the 222 patients (20.3%).The early lactate clearance in the non-IPGF group was markedly higher than that in the IPGF group (43.2±13.8% vs 13.4±13.7% P<0.001).The optimum cut-off value for early lactate clearance predicting IPGF was 24.8% (sensitivity 95.5%,specificity 88.9%).The area under the curve of the ROC was 0.961,which was significantly superior to MELD score,Child-Pugh score TB and PT.Patients with early lactate clearance ≤24.8% had a higher IPGF rate (OR=169) and a higher risk of in-hospital mortality (OR=3.625).CONCLUSIONS:Early lactate clearance can serve as a prompt and accurate bedside predictor of IPGF.Patients with early lactate clearance less than 24.8% are associated with a higher incidence of IPGF.

Living donor liver transplantation using dual grafts:Ultrasonographic evaluation

AIM: To evaluate the dual-graft living donor liver transplantation (LDLT) with ultrasonography, with special emphasis on the postoperative complications. METHODS: From January 2002 to August 2007, 110 adult-to-adult LDLTs were performed in West China Hos- pital of Sichuan University. Among them, dual-graft implantations were performed in six patients. Sonographic findings of the patients were retrospectively reviewed. RESULTS: All the six recipients survived the dual-graft adult-to-adult LDLT surgery. All had pleural effusion. Four patients had episodes of postoperative abdominal complications, including fluid collection between the grafts in three patients, intrahepatic biliary dilatation in two, hepatofugal portal flow of the left lobe in two, and atrophy of the left lobe in one. CONCLUSION: Although dual-graft LDLT takes more efforts and is technically complicated, it is safely feasible. Postoperative sonographic monitoring of the recipient is important.

Feasibility of using marginal liver grafts in living donor liver transplantation

Liver transplantation(LT) is one of the most effective treatments for end-stage liver disease caused by related risk factors when liver resection is contraindicated. Additionally,despite the decrease in the prevalence of hepatitis B virus(HBV) over the past two decades,the absolute number of HBs Ag-positive people has increased,leading to an increase in HBV-related liver cirrhosis and hepatocellular carcinoma. Consequently,a large demand exists for LT. While the wait time for patients on the donor list is,to some degree,shorter due to the development of living donor liver transplantation(LDLT),there is still a shortage of liver grafts. Furthermore,recipients often suffer from emergent conditions,such as liver dysfunction or even hepatic encephalopathy,which can lead to a limited choice in grafts. To expand the pool of available liver grafts,one option is the use of organs that were previously considered "unusable" by many,which are often labeled "marginal" organs. Many previous studies have reported on the possibilities of using marginal grafts in orthotopic LT; however,there is still a lack of discussion on this topic,especially regarding the feasibility of using marginal grafts in LDLT. Therefore,the present review aimed to summarize the feasibility of using marginal liver grafts for LDLT and discuss the possibility of expanding the application of these grafts.

Hypothermic oxygenated perfusion for a steatotic liver graft

To the Editor:Donor steatosis represents a well-known risk factor for primary non-function,early allograft dysfunction,and biliary complications after liver transplantation(LT)[1,2].Recently,machine perfusion(MP)technology has been implemented in the clinical practice,with the primary intent to assess the graft quality and to optimize the organ selection process[3].A limited number of articles has been published specifically investigated the role of MP in steatotic livers[4–10],with few of them looking at the role of hypothermic MP.

Hypothermic machine perfusion with metformin-University of Wisconsin solution for ex vivo preservation of standard and marginal liver grafts in a rat model

AIM To compare the effect of University of Wisconsin(UW) solution with or without metformin, an AMP-activated protein kinase(AMPK) activator, for preserving standard and marginal liver grafts of young and aged rats ex vivo by hypothermic machine perfusion(HMP).METHODS Eighteen young(4 mo old) and 18 aged(17 mo old)healthy male SD rats were selected and randomly divided into three groups: control group, UW solution perfusion group(UWP), and UW solution with metformin perfusion group(MUWP). Aspartate aminotransferase(AST), alanine aminotransferase(ALT), lactate dehydrogenase(LDH), interleukin-18(IL-18), and tumor necrosis factor-alpha(TNF-α) in the perfused liquid were tested. The expression levels of AMPK and endothelial nitric oxide synthase(e NOS) in liver sinusoidal endothelial cells were also examined.Additionally, microscopic evaluation of the harvested perfused liver tissue samples was done. RESULTS AST, ALT, LDH, IL-18 and TNF-α levels in the young and aged liver-perfused liquid were, respectively,significantly lower in the MUWP group than in the UWP group(P < 0.05), but no significant differences were found between the young and aged MUWP groups.Metformin increased the expression of AMPK and e NOS protein levels, and promoted the extracellular release of nitric oxide through activation of the AMPK-e NOS mediated pathway. Histological examination revealed that in the MUWP group, the extent of liver cells and tissue damage was significantly reduced compared with the UWP group.CONCLUSION The addition of metformin to the UW preservative solution for ex vivo HMP can reduce rat liver injury during cold ischemia, with significant protective effects on livers, especially of aged rats.

Low platelet count: Predictor of death and graft loss after liver transplantation

BACKGROUND The impact of platelets on liver transplantation(LT) is well recognized, but not completely understood. Platelets exert dichotomous effects on the graft and on the patient. On the one hand, they are essential for primary hemostasis and tissue repair and regeneration. On the other hand, they support ischemia/reperfusion injury and inflammatory processes. Recent evidence has shown a new role for platelet count(PC) in predicting outcomes after LT.AIM To evaluate if low PC is a predictor of short-and long-term outcomes after LT.METHODS Four hundred and eighty consecutive LT patients were retrospectively assessed.PC from the preoperative to the seventh postoperative day(POD) were considered. C-statistic analysis defined the ideal cutoff point for PC. Cox regression was performed to check whether low PC was a predictor of death,retransplantation or primary changes in graft function within one year after LT.RESULTS The highest median PC was 86 × 109/L [interquartile range(IQR) = 65–100 ×109/L] on seventh POD, and the lowest was 51 × 109/L(IQR = 38–71 × 109/L) on third POD. The C-statistic defined a PC < 70 × 109/L on fifth POD as the ideal cutoff point for predicting death and retransplantation. In the multivariate analysis, platelets < 70 × 109/L on 5 POD was an independent risk factor for death at 12 mo after LT [hazard ratio(HR) = 2.01; 95% confidence interval(CI) 1.06-3.79;P = 0.031]. In the Cox regression, patients with PC < 70 × 109/L on 5 POD had worse graft survival rates up to one year after LT(HR = 2.76; 95%CI 1.52-4.99; P =0.001).CONCLUSION PC < 70 × 109/L on 5 POD is an independent predictor of death in the first year after LT. These results are in agreement with other studies that indicate that low PC after LT is associated with negative outcomes.

Donor liver natural killer cells alleviate liver allograft acute rejection in rats

BACKGROUND:Liver enriched natural killer (NK) cells are of high immune activity.However,the function of donor liver NK cells in allogeneic liver transplantation (LTx) remains unclear.METHODS:Ten Gy of whole body gamma-irradiation (WBI) from a 60 Co source at 0.6 Gy/min was used for depleting donorderived leukocytes,and transfusion of purified liver NK cells isolated from the same type rat as donor (donor type liver NK cells,dtl NKs) through portal vein was performed immediately after grafting the irradiated liver.Post-transplant survival observation on recipients and histopathological detection of liver grafts were adoptive to evaluate the biological impact of donor liver NK cells on recipients’ survival in rat LTx.RESULTS:Transfusion of dtl NKs did not shorten the survival time among the recipients of spontaneous tolerance model (BN to LEW rat) after rat LTx,but prolonged the liver graft survival among the recipients depleted of donor-derived leukocytes in the acute rejection model (LEW to BN rat).Compared to the recipients in the groups which received the graft depleted of donor-derived leukocytes,better survival and less damage in the allografts were also found among the recipients in the two different strain combinations of liver allograft due to transfusion of dtl NKs.CONCLUSIONS:Donor liver NK cells alone do not exacerbate liver allograft acute rejection.Conversely,they can alleviate it,and improve the recipients’ survival.

Measures for increasing the safety of donors in living donor liver transplantation using right lobe grafts

BACKGROUND: The safety of donors in living donor liver transplantation (LDLT) should be the primary consideration. The aim of this study was to report our experience in increasing the safety of donors in LDLTs using right lobe grafts. METHODS: We retrospectively studied 37 living donors of right lobe grafts from January 2002 to March 2006. The measures for increasing the safety of donors in LDLT included carefully selected donors, preoperative evaluation by ultrasonography, angiography and computed tomography; and necessary intraoperative cholangiography and ultrasonography. Right lobe grafts were obtained using an ultrasonic dissector without inflow vascular occlusion on the right side of the middle hepatic vein. The standard liver volume and the ratio of left lobe volume to standard liver volume were calculated. RESULTS: There was no donor mortality in our group. Postoperative complications only included bile leakage (I donor), biliary stricture (1) and portal vein thrombosis (1). All donors recovered well and resumed their previous occupations. In recipients, complications included acute rejection (2 patients), hepatic artery thrombosis (1), bile leakage (1), intestinal bleeding (1), left subphrenic abscess (1) and pulmonary infection (1). The mortality rate of recipients was 5.4% (2/37); one recipient with pulmonary infection died from multiple organ failure and another from occurrence of primary disease. CONCLUSIONS: The first consideration in adult-to-adult LDLT is the safety of donors. The donation of a right lobe graft is safe for adults if the remnant hepatic vasculature and bile duct are ensured, and the volume-of the remnant liver exceeds 35% of the total liver volume.