The impact of donor age on living donor liver transplantation

Living-donor liver transplantation using donors older than 50 years of age: Recipient criteria and donor risk: A multicenter study of Japanese Society of Hepato-Biliary-Pancreatic Surgery

BACKGROUND

Few published reports have addressed the feasibility of living-donor liver transplantation (LDLT) using elderly donors. We aimed to examine LDLT outcomes in elderly donors and identify clinical factors impacting safely conducted LDLT.

METHODS

This study was conducted in collaboration with the Japanese Society of Hepatobiliary-Pancreatic Surgery. Data were collected from 140 patients who underwent LDLT using donors aged ≥50 years between 2013 and 2017 at nine collaborating hospitals.

RESULTS

The 1-, 3-, and 5-year graft survival rates in recipients after LDLT employing elderly donors were 84.3%, 78.5%, and 76.3%, respectively, with 6-month mortality of 12.1%. Specific recipient-donor age combinations did not emerge as adverse prognostic factors. A total of 32 recipients (22.9%) had major complications requiring reoperation after LDLT, and 15 donors (10.7%) had major complications of Clavien-Dindo grade ≥II. Multivariate analysis revealed that graft-to-recipient weight ratio (GRWR) <0.84% and neutrophil-to-lymphocyte ratio (NLR) >6.6 were independent predictors of 6-month graft loss after LDLT.

CONCLUSION

LDLT using elderly donors aged ≥50 years has acceptable graft survival and morbidity rates, and donor age >50 years should not be an absolute contraindication for LDLT. In LDLT involving elderly donors, it is crucial to consider that GRWR <0.84% and NLR >6.6 are adverse prognostic factors. Addressing these factors is necessary to enhance the prognosis, aligning with the increasing public demand for this surgical procedure.

Donor Evaluation Protocol for Live and Deceased Donors

Donor evaluation is a critical step before proceeding with liver transplantation (LT) in both deceased donor LT (DDLT) and living donor LT (LDLT). A good, healthy graft is necessary for the success of the transplantation. Other issues in selecting a donor include the transmission of infections and malignancies from the donor. Because of the scarcity of cadaver organs, an increasing number of extended-criteria donors, or 'marginal donors', are being utilized. LDLT also has potential risks to the donor, and donor safety needs to be kept in mind before proceeding with LT. The current review highlights the factors to be considered during donor evaluation for living and deceased donors before LT.

Increasing practice and acceptable outcomes of high-MELD living donor liver transplantation in the USA

Recent deceased-donor allocation changes in the United States may have increased high-Model for End-Stage Liver Disease (MELD) living donor liver transplantation (LDLT); however, outcomes in these patients remain poorly defined. We aimed to examine the impact of the MELD score on LDLT outcomes. Using UNOS data (January 1, 2010-December 31, 2021), LDLT recipients were identified and stratified into low-MELD (<15), intermediate-MELD (15-24), and high-MELD (≥25) groups. We compared outcomes between MELD-stratified LDLT groups and between MELD-stratified LDLT and donation after brain death liver transplantation recipients. We used Kaplan-Meier analysis to compare graft survival rates and multivariable Cox proportional hazards modeling to identify factors associated with graft outcomes. Of 3558 LDLTs, 1605 (45.1%) were low-MELD, 1616 (45.4%) intermediate-MELD, and 337 (9.5%) high-MELD. Over the study period, the annual number of LDLTs increased from 282 to 569, and the proportion of high-MELD LDLTs increased from 3.9% to 7.7%. Graft survival was significantly higher in low-MELD versus high-MELD LDLT recipients (adjusted HR = 1.36, 95% CI: 1.03-1.79); however, 5-year survival exceeded 70.0% in both groups. We observed no significant difference in graft survival between high-MELD LDLT and high-MELD donation after brain death liver transplantation recipients (adjusted HR: 1.25, 95% CI:0.99-1.58), with a 5-year survival of 71.5% and 77.3%, respectively. Low LDLT center volume (<3 LDLTs/year) and recipient life support requirement were both associated with inferior graft outcomes among high-MELD LDLT recipients. While higher MELD scores confer graft failure risk in LDLT, high-MELD LDLT outcomes are acceptable with similar outcomes to MELD-stratified donation after brain death liver transplantation recipients. Future practice guidance should consider the expansion of LDLT recommendations to high-MELD recipients in centers with expertise to help reduce donor shortage.

Pure laparoscopic donor right hepatectomy in patients over 50 years old: Why age should not be a barrier

INTRODUCTION

Given the global aging population, the average age of liver donors is increasing. This study aimed to evaluate the surgical outcomes of grafts from pure laparoscopic donor right hepatectomy (PLDRH) in liver donors aged > 50 years.

METHODS

The medical records of liver donors were retrospectively reviewed. The donors underwent conventional donor right hepatectomy (CDRH) from January 2011 to May 2019 or PLDRH from March 2016 to May 2019. We divided the donors into three groups: PLDRH donors aged ≥50 (n = 26; Group 1) and aged < 50 (n = 257; Group 2), and CDRH donors aged ≥50 years (n = 66; Group 3).

RESULTS

Operation time (p < .01) and hospital stay (p < .01) were significantly lower in Group 1 than in Group 3. Other postoperative outcomes of donors including graft anatomical variation, graft weight, graft-to-recipient weight ratio, and hepatic steatosis were similar among the three groups. Although no postoperative complications occurred in Groups 1 and 3, they were detected in 17 cases (6.6%) in Group 2. No postoperative complications were detected among the recipients.

CONCLUSIONS

PLDRH was feasible and safe in donors aged over 50 years, with outcomes similar to those for donors aged <50 years. PLDRH should not be avoided solely based on the donor's age ≥50 years.

Outcomes of sexagenarian living liver donors in Korea: A multicenter study

The safety of elderly living liver donors and recipient outcomes are always of concern. In the present study, the effects of age in 2 donor groups, a 60+years old group and a 50-59 years old group (referred to as the 60s and 50s donor groups, respectively), on living donor liver transplantation were compared regarding donor safety and recipient outcomes. We retrospectively identified 209 patients 50 years and above of age at 9 centers from 2005 to 2017 in Korea. The 60s donor group represented 10% (n=21) of donor patients. One case in each group was a left liver graft, respectively, and the others were right liver grafts. Postoperative complications were more common in the 60s donor group, but the proportion of Clavien-Dindo grade III in the 60s donor group did not differ from that in the 50s donor group. In-hospital mortality did not occur among donors, and donor mortality was not reported during the observation period. Postoperative total bilirubin and hospitalization in recipients of the 60s donor group were higher and longer than in recipients of the 50s donor group, respectively. Although the cumulative overall survival of the recipients in the 60s donor group was significantly lower than that of the 50s donor group, a difference was not observed in graft survival. Multivariate analysis showed that increased living liver donors age, the coexistence of HCC, and increased intraoperative blood loss during the recipient operation were important predisposing factors for patient death. Present study suggests that highly selected elderly living donors (≥60 y) can safely donate with similar recipient graft survival rates though the recipient overall patient survival is inferior compared to the 50s donor group.

Impact of the preoperative skeletal muscle index on early remnant liver regeneration in living donors after liver transplantation

Background

We investigated the correlation between the preoperative skeletal muscle index (SMI) and remnant liver regeneration after right hemihepatectomy for living-donor liver transplantation and aimed to identify preoperative predictors of greater early remnant liver regeneration in living donors.

Methods

This retrospective study included 525 right hemiliver donors (mean age, 28.9±8.3 years; 345 male patients) between 2017 and 2018, who underwent computed tomography before surgery and on postoperative day (POD) 7. Preoperative anthropometry, laboratory parameters, skeletal muscle area at the third lumbar vertebral level, and liver volume before and after surgery were evaluated. Correlations were analyzed using Pearson correlation coefficients, and stepwise multiple regression analysis was performed to identify independent predictors of greater remnant liver regeneration.

Results

Remnant liver regeneration volume on POD 7 was positively correlated with body mass index (BMI; r=0.280, P<0.001) and SMI (r=0.322, P<0.001), and negatively correlated with age (r=-0.154, P<0.001) and the ratio of future remnant liver volume (FRLV) to total liver volume (TLV; r=-0.261, P<0.001). Stepwise multiple regression analysis showed that high BMI (β=0.146; P=0.001) and SMI (β=0.228, P<0.001), young age (β=-0.091, P=0.025), and a low FRLV/TLV ratio (β=-0.225, P<0.001) were predictors of greater remnant liver regeneration.

Conclusions

High SMI and BMI, young age, and a low FRLV/TLV ratio may predict greater early remnant liver regeneration in living donors after LDLT.

Trends and Health Care Outcomes Among Living Liver Donors: Are We Ready to Expand the Donor Pool With Living Liver Donations?

We studied the trends and various outcomes, including the readmission rates, health care utilization, and complications among living liver donors (LLDs) in the United States. We queried the National Database for data from 2010 to 2017 for all LLDs. The primary outcomes were 30-day and 90-day readmission rates. The secondary outcomes included health care use (length of stay [LOS], cost of care), index admission, and calendar-year mortality. Logistic regression models were fit for various outcomes. A total of 1316 LLDs underwent hepatectomy during the study period. The median donor age was 35.0 years (interquartile range, 27.4-43.6), and donors were predominantly women (54.2%). The trend of LLD surgeries remained stable at large medical centers (85.3%). The 30-day and 90-day readmission rates were low at 5% and 5.9%, respectively. Older age (50 years and older; 8%; confidence interval [CI], 0.6%-15.9%; P = 0.03) and hepatectomy at small to medium-sized hospitals were associated with increased index LOS (13.4%; 95% CI, 3.1%-24.7%; P = 0.01). Moreover, older age of donor (-11.3%; 95% CI, -20.3% to -1.4%; P = 0.03), Elixhauser score ≥3 (17%; 95% CI, 1.2%-35.3%; P = 0.03), and Medicaid insurance (24.5%; 95% CI, 1.2%-53.1%; P = 0.04) were also associated with increased cost. The overall rate of any complications during index admission was 42.8%. Male sex (odds ratio [OR], 1.63; 95% CI, 1.19-2.23) was an independent predictor of post-LLD complications. There was no index admission or calendar-year mortality reported during the study period. This is the largest national report of LLDs to date, showing that the trend of LLD surgeries is stable in the United States. With established safety, fewer complications, and less health care utilization, LLDs can be a potential source of continuation of liver transplantation in the context of changing liver allocation policies in the United States.

Impact of Donor Age on the Outcome of Living-donor Liver Transplantation: Special Consideration to the Feasibility of Using Elderly Donors

BACKGROUND

The use of elderly donors (≥60 y) in living-donor liver transplantation (LDLT) remains controversial. In this study, we aimed to determine the safety of surgery for elderly donors and the impact of donor age on LDLT outcomes.

METHODS

We, retrospectively, reviewed 470 cases of LDLT at Kumamoto University Hospital from December 1998 to March 2017.

RESULTS

Donors were divided into 5 groups according to age: 20-29 (n = 109), 30-39 (n = 157), 40-49 (n = 87), 50-59 (n = 81), and ≥60 (n = 36). At our institution, elderly donor candidates required additional preoperative work-up. There were no significant differences in the incidence of postoperative complications and duration of postoperative hospital stay among the 5 donor groups. Regardless of graft type, elderly donors were comparable to younger donor groups (<30 y) in postoperative recovery of liver function. Risk-adjusted overall survival rates of recipients among donor groups were not significantly different. Additionally, donor age was not significantly associated with 6-month graft survival of adult and pediatric recipients.

CONCLUSIONS

Elderly candidates ≥60 years of age can safely be selected as LDLT donors after meticulous preoperative work-up.

The combination of a male donor's high muscle mass and quality is an independent protective factor for graft loss after living donor liver transplantation

We evaluated the hypothesis that grafts from donors with high muscle mass and quality may have a better outcome after living-donor-liver-transplantation (LDLT) than those from usual donors. A total of 376 primary adult-to-adult LDLT cases were enrolled in this study. Donor skeletal muscle mass index (SMI) and intramuscular adipose tissue content (IMAC) were used as markers of muscle mass and quality. In male donor cases (n = 198), those with higher SMI and lower IMAC than age-adjusted values were defined as the "high muscularity donors" (n = 38) and the others were defined as the "control" (n = 160). The high muscularity donor showed better 1-year (97% vs 82%, P = .020) and overall graft survival rate (88% vs 67%, P = .024) than the control group after LDLT. Contrastingly, the influence of the muscularity was not observed in female donor cases. Multivariable analysis including donor age confirmed that a high muscularity donor was an independent protective factor for overall graft survival after LDLT (hazard ratio, 0.337; 95% CI: 0.101-0.838; P = .017). Our study first confirmed that high muscle mass and quality of a male donor is a protective factor of allograft loss after LDLT, independently from donor age.

Is there any correlation between liver graft regeneration and recipient's pretransplant skeletal muscle mass?-a study in extended left lobe graft living-donor liver transplantation

BACKGROUND

The end-stage liver disease causes a metabolic dysfunction whose most prominent clinical feature is the loss of skeletal muscle mass (SMM). In living-donor liver transplantation (LDLT), liver graft regeneration (GR) represents a crucial process to normalize the portal hypertension and to meet the metabolic demand of the recipient. Limited data are available on the correlation between pre-LDLT low SMM and GR.

METHODS

Retrospective study on a cohort of 106 LDLT patients receiving an extended left liver lobe graft. The skeletal muscle index (SMI) at L3 level was used for muscle mass measurement, and the recommended cut-off values of the Japanese Society of Hepatology guidelines were used as criteria for defining low muscularity. GR was evaluated as rate of volume increase at 1 month post-LT [graft regeneration rate (GRR)].

RESULTS

The median GRR at 1 month post-LT was 91% (IQR, 65-128%) and a significant correlation with graft volume-to-recipient standard liver volume ratio (GV/SLV) (rho -0.467, P<0.001), graft-to-recipient weight ratio (GRWR) (rho -0.414, P<0.001), donor age (rho -0.306, P=0.001), 1 month post-LT cholinesterase serum levels (rho 0.397, P=0.002) and pre-LT low muscularity [absent vs. present GRR 97.5% (73.1-130%) vs. 83.5% (45.2-110.9%), P=0.041] was noted. Moreover in male recipients, but not in women, it was shown a direct correlation with pre-LT SMI (rho 0.352, P=0.020) and inverse correlation with 1 month post-LT SMI variation (rho -0.301, P=0.049). A low GRR was identified as an independent prognostic factor for recipient overall survival (HR 6.045, P<0.001).

CONCLUSIONS

Additionally to the hemodynamic factors of portal circulation and the quality of the graft, the metabolic status of the recipients has a significant role in the GR process. A pre-LT low SMM is associated with impaired GRR and this negative impact is more evident in male recipients.

Therapeutic targets for liver regeneration after acute severe injury: a preclinical overview

Introduction: Liver transplantation is the only viable treatment with a proven survival benefit for acute liver failure (ALF). Donor organ shortage is, however, a major hurdle; hence, alternative approaches that enable liver regeneration and target acute severe hepatocellular damage are necessary.Areas covered: This article sheds light on therapeutic targets for liver regeneration and considers their therapeutic potential. ALF following extensive hepatocyte damage and small-for-size syndrome (SFSS) are illuminated for the reader while the molecular mechanisms of liver regeneration are assessed in accordance with relevant therapeutic strategies. Furthermore, liver background parameters and predictive biomarkers that might associate with liver regeneration are reviewed.Expert opinion: There are established and novel experimental strategies for liver regeneration to prevent ALF resulting from SFSS. Granulocyte-colony stimulating factor (G-CSF) is a promising agent targeting liver regeneration after acute severe injury. Autophagy and hepatocyte senescence represent attractive new targets for liver regeneration in acute severe hepatic injury. Liver support strategies, including tissue engineering, constitute novel regenerative means; the success of this is dependent on stem cell research advances. However, there is no firm clinical evidence that these supportive strategies may alleviate hepatocellular damage until liver transplantation becomes available or successful self-liver regeneration occurs.

Impact of Donor Age on Recipient Survival in Adult-to-Adult Living-donor Liver Transplantation

OBJECTIVE

To investigate the influence of donor age on recipient outcome after living-donor partial liver transplantation (LDLT).

BACKGROUND

Donor age is a well-known prognostic factor in deceased donor liver transplantation; however, its role in LDLT remains unclear.

METHODS

We retrospectively analyzed 315 consecutive cases of primary adult-to-adult LDLT in our center between April 2006 and March 2014. Recipients were divided into 5 groups according to the donor age: D-20s (n = 60); D-30s (n = 72); D-40s (n = 57); D-50s (n = 94); and D-60s (n = 32). The recipient survival and the association with various clinical factors were investigated.

RESULTS

Recipient survival proportions were significantly higher in D-20s compared with all the other groups (P = 0.008, < 0.001, < 0.001, and = 0.006, vs D-30s, -40s, -50s, and -60s, respectively), whereas there was no association between recipient survival and their own age. There are 3 typical relationships between donors and recipients in adult-to-adult LDLT: from child-to-parent, between spouses/siblings, and from parent-to-child. The overall survival in child-to-parent was significantly higher than in spouses/siblings (P = 0.002) and in parent-to-child (P = 0.005), despite significantly higher recipient age in child-to-parent [59 (42-69) years, P < 0.001]. Contrastingly, parent-to-child exhibited the lowest survival, despite the youngest recipient age [26 (20-43) years, P < 0.001]. In addition, younger donor age exhibited significantly better recipient survival both in hepatitis C virus-related and in non-hepatitis C virus diseases. Univariate and multivariate analyses both demonstrated that donor age and graft-type (right-sided livers) are independent prognostic factors for recipient survival.

CONCLUSIONS

Donor age is an independent, strong prognostic factor in adult-to-adult LDLT.

Recipient Outcomes with Younger Donors Undergoing Living Donor Liver Transplantation

Introduction

The impact of donor age on liver transplantation is well known. Data on an appropriate donor age cut-off for living donor liver transplantation (LDLT) with a background of hepatitis C (HCV) is generally limited. The objective of this study was to determine whether limiting donor age to less than 35 years improved outcomes in patients with HCV-related end-stage liver disease (ESLD).

Methods

This was a retrospective review of 169 patients who underwent LDLT for HCV-related ESLD. The patients were divided into two groups based on whether they received grafts from donors ≤ 35 (Group 1) or > 35 (Group 2) years of age. Kaplan Meier curves were used to determine survival. Uni and multivariate analysis were performed to determine independent predictors of mortality.

Results

Mean donor age was 25.1 ± 5.2 and 40.1 ± 3.4 years (P < 0.0001). Early allograft dysfunction (EAD) was seen in 11.7% patients in Group 1 versus 29.6% in Group 2 (P = 0.02). A significant difference in mortality was present between the two groups, i.e., 33.3% versus 15.8% (P = 0.04). The estimated four-year overall survival (OS) was 78% and 64% (P = 0.03). Upon doing univariate analysis, the donor age (P = 0.04) and EAD (P = 0.006) were found to be significant variables for mortality. On multivariate analysis, EAD was the only independent predictor of mortality (Hazard ratio: 2.6; confidence interval: 1.1 - 5.8; P = 0.01).

Conclusion

Opting for younger donors (≤ 35 years) for HCV-related ESLD patients lowers the risk of EAD and improves overall survival.

Results of Adult Living Donor Liver Transplantation with Sixth-Decade Donors: A Propensity Score Matching Study in a High-Volume Institution

BACKGROUND We assessed the prognostic impact of donor age on the outcome of adult living donor liver transplantation (LDLT). MATERIAL AND METHODS The study population comprised adult donor and recipients of right lobe grafts for LDLT performed from January 2005 to December 2016. There were 35 living donors aged ≥50 years (old-age donor group). As a control group, donors in their 20s (young-age donor group) were selected after one-to-one propensity score matching based on sex, model for end-stage liver disease (MELD) score, and primary diagnosis. RESULTS Donor age was 52.5±1.5 years versus 25.4±3.1 years in the old- and young-age donor groups, respectively. Remnant volumes of the 2 groups were 38.9±3.0% versus 38.1±2.9%, respectively (p=0.98). One-month regeneration rate of the remnant liver was 101.1±10.6% versus 104.5±11.8%, respectively (p=0.08), and there was no significant difference in the incidences of donor complications. Mean MELD score was 15 versus 14, respectively (p=0.82). Graft-to-recipient weight ratio was 1.02±0.43 versus 0.91±0.63, respectively (p=0.28). In the recipients, biliary complication occurred in 11.4% versus 8.6%, respectively (p=0.12), and there was no difference in 5-year survival rates of both groups (p=0.15). The 1-week and 1-month regeneration rates of the remnant left liver were 71.6±9.9% and 100.1±10.6% in the old-age group, respectively, whereas those were 80.2±12.1% and 104.5±11.8% in the young-age group, respectively (p=0.08). CONCLUSIONS Right lobe grafts from donors aged ≥50 years showed the usual recovery of graft function but rather delayed liver regeneration. Thus, old-aged donors should be selected prudently after consideration of hepatic resection rate, graft size, and hepatic steatosis.

Right lobe living donors ages 55 years old and older in liver transplantation

The evidence is insufficient for safe use of elderly donors in adult-to-adult living donor liver transplantation (LDLT). The aim of this study was to evaluate the outcomes of right lobe LDLT by donor age (≥55 versus < 55 years). All living donors who underwent right hepatectomy at the authors' institution between March 2008 and December 2015 were divided into 2 groups: group A with an age ≥ 55 years and group B with an age of <55 years. The selection criteria for elderly donor were preservation of middle hepatic vein, remnant liver volume ≥30%, and no or mild fatty liver. The matching criteria of recipients for the elderly donor grafts were Model for End-Stage Liver Disease score of <25, graft-to-recipient weight ratio of >0.8%, and body mass index of <25 kg/m² . Perioperative data, complications by the Clavien classification, and the outcomes with at least 12 months follow-up were compared. A total of 42 donors were enrolled in group A and 498 in group B. No significant differences in operative parameters were observed between the 2 groups. The peak postoperative aspartate aminotransferase, alanine aminotransferase, and total bilirubin levels made no difference between the 2 groups. The peak international normalized ratio level was significantly lower in group A than in group B (P = 0.001). All donors recovered completely with no significant differences in overall complications between the 2 groups. All recipients of grafts from donors in group A showed good initial function with no significant differences in 1-year graft and patient survival or biliary complications between 2 groups. These results provide clinical evidence for feasibility of right hepatectomy in living donors aged ≥ 55 years without compromising donor safety or recipient outcomes. Liver Transplantation 23 1305-1311 2017 AASLD.

Small for size syndrome difficult dilemma: Lessons from 10 years single centre experience in living donor liver transplantation

AIM

To analyze the incidence, risk factors, prevention, treatment and outcome of small for size syndrome (SFSS) after living donor liver transplantation (LDLT).

METHODS

Through-out more than 10 years: During the period from April 2003 to the end of 2013, 174 adult-to-adults LDLT (A-ALDLT) had been performed at National Liver Institute, Menoufiya University, Shibin Elkoom, Egypt. We collected the data of those patients to do this cohort study that is a single-institution retrospective analysis of a prospectively collected database analyzing the incidence, risk factors, prevention, treatment and outcome of SFSS in a period started from the end of 2013 to the end of 2015. The median period of follow-up reached 40.50 m, range (0-144 m).

RESULTS

SFSS was diagnosed in 20 (11.5%) of our recipients. While extra-small graft [small for size graft (SFSG)], portal hypertension, steatosis and left lobe graft were significant predictors of SFSS in univariate analysis (P = 0.00, 0.04, 0.03, and 0.00 respectively); graft size was the only independent predictor of SFSS on multivariate analysis (P = 0.03). On the other hand, there was lower incidence of SFSS in patients with SFSG who underwent splenectomy [4/10 (40%) SFSS vs 3/7 (42.9%) no SFSS] but without statistical significance, However, there was none significant lower incidence of the syndrome in patients with right lobe (RL) graft when drainage of the right anterior and/or posterior liver sectors by middle hepatic vein, V5, V8, and/or right inferior vein was done [4/10 (28.6%) SFSS vs 52/152 (34.2%) no SFSS]. The 6-mo, 1-, 3-, 5-, 7- and 10-year survival in patients with SFSS were 30%, 30%, 25%, 25%, 25% and 25% respectively, while, the 6-mo, 1-, 3-, 5-, 7- and 10-year survival in patients without SFSS were 70.1%, 65.6%, 61.7%, 61%, 59.7%, and 59.7% respectively, with statistical significant difference (P = 0.00).

CONCLUSION

SFSG is the independent and main factor for occurrence of SFSS after A-ALDLT leading to poor outcome. However, the management of this catastrophe depends upon its prevention (i.e., selecting graft with proper size, splenectomy to decrease portal venous inflow, and improving hepatic vein outflow by reconstructing large draining veins of the graft).

A Donor Age-Based and Graft Volume-Based Analysis for Living Donor Liver Transplantation in Elderly Recipients

Background

Given the expected increase in the number of elderly recipients, details regarding how clinical factors influence the outcome in living donor liver transplantation (LDLT) for the elderly remain unclear. We examined the survival outcomes according to the results of donor age-based and graft volume–based analyses and assessed the impact of prognostic factors on the survival after LDLT for elderly recipients.

Methods

The 198 adult recipients were classified into 2 groups: an elderly group (n = 70, E group; ≥ 60 years of age) and a younger group (n = 128, Y group; <60 years of age). We analyzed the prognostic factors for the survival in the E group and the survival rate for both groups at several follow-up points and conducted subgroup analyses in the E group by combining the donor age (≥50 vs <50 years) and graft weight (GW)/standard liver volume (SLV) (≥40% vs <40%).

Results

Donor age (hazard ratio [HR], 2.17; P = 0.062) and GW/SLV (HR, 1.80; P = 0.23) tended to have a high HR in the E group. The overall patient survival rates at 1, 3, and 5 years were 78.3%, 73.0%, and 61.0% in the E group, and 82.0%, 75.1%, and 69.2% in the Y group, respectively (P = 0.459). However, the outcomes tended to be worse in recipients of grafts from donors ≥50 years of age than in those with grafts from younger donors with GW/SLV < 40% (P = 0.048).

Conclusions

A worse outcome might be associated with aging of the donor, which leads to impairment of the graft function and liver regeneration. Both the graft volume and donor age should be considered when choosing grafts for LDLT in elderly patients.

Mechanism of impairment on liver regeneration in elderly patients: Role of hepatic stellate cell function

Japan, along with most other countries in the world, is facing an increasingly aging population with a prolonged life expectancy. Concurrently, the need for medical intervention, including hepatectomy, has also increased for the elderly. Although surgical outcomes for older patients are reported to be comparable with those for younger patients, additional care in the selection of older patients for hepatectomy is considered necessary. Although the effect of aging on human liver regeneration is not fully understood, the regeneration of liver tissue after hepatectomy in elderly patients is shown to be generally worse than in younger patients and, to date, the mechanisms involved in the impairment of liver regeneration have not been fully clarified. Hepatic stellate cells (HSCs) are liver-specific mesenchymal cells that play critical roles in liver physiology and fibrogenesis. Recent studies in liver regeneration have increasingly focused on HSCs rather than on hepatocytes, Kupffer cells, endothelial cells, or infiltrating immune cells and suggest that HSCs might play a critical role in liver regeneration. In this review, we summarize the mechanisms involved in the impairment of liver regeneration in elderly patients, especially focusing on HSCs. We also discuss how HSCs contribute to the impairment of liver regeneration.

Liver function declines with increased age

INTRODUCTION

Age itself is not considered a contraindication for high impact surgery. However, the aging process of the liver remains largely unknown. This study evaluates age-dependent changes in liver function using a quantitative liver function test.

METHODS

Between January 2005 and December 2014, 508 patients underwent (99m)Tc-mebrofenin hepatobiliary scintigraphy (HBS) for the assessment of liver function. These included 203 patients with healthy livers (group A) and 57 patients with HCC and Child-Pugh A (group B). (99m)Tc-mebrofenin-uptake-rate of the whole liver corrected for body surface area (cMUR) was calculated for all patients. Linear regression analysis was performed to assess the relationship between age and cMUR.

RESULTS

The mean cMUR was 8.50 ± 2.05%/min/m(2) and 6.94 ± 2.03%/min/m(2) in group A and B, respectively. A negative linear correlation was found between patient's age and cMUR in group A, r = 0.244, p = 0.000. In group B, there was no correlation between age and cMUR, however, a trend in decline of liver function with age was noted.

CONCLUSION

This study shows that liver function deteriorates with age. Since the regenerative capacity of the liver correlates with liver function, this finding should be taken into account when assessing surgical risk in patients considered for major liver resection.

How important is donor age in liver transplantation?

The age of liver donors has been increasing in the past several years because of a donor shortage. In the United States, 33% of donors are age 50 years or older, as are more than 50% in some European countries. The impact of donor age on liver transplantation (LT) has been analyzed in several studies with contradictory conclusions. Nevertheless, recent analyses of the largest databases demonstrate that having an older donor is a risk factor for graft failure. Donor age is included as a risk factor in the more relevant graft survival scores, such as the Donor Risk Index, donor age and Model for End-stage Liver Disease, Survival Outcomes Following Liver Transplantation, and the Balance of Risk. The use of old donors is related to an increased rate of biliary complications and hepatitis C virus-related graft failure. Although liver function does not seem to be significantly affected by age, the incidence of several liver diseases increases with age, and the capacity of the liver to manage or overcome liver diseases or external injuries decreases. In this paper, the importance of age in LT outcomes, the role of donor age as a risk factor, and the influence of aging on liver regeneration are reviewed.

Kidney and liver transplantation in the elderly

BACKGROUND

Transplant surgery is facing a shortage of deceased donor organs. In response, the criteria for organ donation have been extended, and an increasing number of organs from older donors are being used. For recipients, the benefits of transplantation are great, and the growing ageing population has led to increasing numbers of elderly patients being accepted for transplantation.

METHODS

The literature was reviewed to investigate the impact of age of donors and recipients in abdominal organ transplantation, and to highlight aspects of the fine balance in donor and recipient selection and screening, as well as allocation policies fair to young and old alike.

RESULTS

Overall, kidney and liver transplantation from older deceased donors have good outcomes, but are not as good as those from younger donors. Careful donor selection based on risk indices, and potentially biomarkers, special allocation schemes to match elderly donors with elderly recipients, and vigorous recipient selection, allows good outcomes with increasing age of both donors and recipients. The results of live kidney donation have been excellent for donor and recipient, and there is a trend towards inclusion of older donors. Future strategies, including personalized immunosuppression for older recipients as well as machine preservation and reconditioning of donor organs, are promising ways to improve the outcome of transplantation between older donors and older recipients.

CONCLUSION

Kidney and liver transplantation in the elderly is a clinical reality. Outcomes are good, but can be optimized by using strategies that modify donor risk factors and recipient co-morbidities, and personalized approaches to organ allocation and immunosuppression.

Results of liver transplantation from old donors

INTRODUCTION

Faced with a shortage of organs for liver transplantation, the use of grafts from older donors is justified. However, there remains little consensus on how this use impacts the graft and patient outcomes after transplantation from these older donors. The aim of the present analysis was to assess the graft and patient outcomes after liver transplantation from deceased donors >60 years of age.

METHODS

From January 2007 to January 2011, 505 subjects were identified as liver graft donors after brain death, of which 7.35% were ≥60. To determine the effect of donor age on graft and patient outcomes, we analyzed donor age, recipient age, the Model for End-State Liver Disease (MELD) score of recipients at the time of transplantation, early posttransplant complications, and mortality.

RESULTS

The posttransplant follow-up was 29 ± 25.5 months, and 3-year patient mortality from donors, grouped according to age, was 7.92% with donors <30; 15.78% with donors 30-50, 10.68% with donors 50-60, and 12.50% with donors >60. After analysis of patient and graft survival based on donor graft age, 3-year patient survival according donor age was 89.29% with donors <30, 83.85% with donors 30-50, 89.89% with donors 50-60, and 87.50% with donors >60. Analysis showed overall patient and graft survival rates from older donors were not worse than those from younger donors (P > .1). Among the cases, 3-year patient survival according to MELD score was 91.19% with a MELD of I, 85.37% with a MELD of II, and 67.67% with a MELD of III; differences in graft and patient survival when comparing low MELD I and high MELD III were significantly different (P < .01).

CONCLUSIONS

A more advanced age of a donor should not be a contraindication for liver transplantation. The present analysis shows that liver grafts from donors >60 can be used safely in older recipients who presented with relatively low MELD scores. Analyses also indicate that high MELD obtained before transplantation may be an important prognostic factor for graft and patient survival.

Importance of donor-recipient age gradient to the prediction of graft outcome after living donor liver transplantation

PURPOSE

Advanced donor age is a well-known risk factor for poor graft function after living donor liver transplantation (LDLT). In addition, advanced recipient age has a significant impact because of the high prevalence of comorbidities. We investigated the relationship between donor-recipient age gradient (DRAG) and the posttransplant outcomes in LDLT.

METHODS

We included 821 consecutive adult recipients who underwent LDLT from June 1997 to May 2011. According to the value of DRAG, they were divided into 2 groups: Negative years (the donor was younger than the recipient) and positive years (the donor was older than the recipient). These groups were further divided into subgroups (≤-21, -20 to -1, 0 to 20, and ≥21 years). We collected retrospectively patient characteristics, laboratory results, medical and surgical complications, and graft loss.

RESULTS

The positive DRAG group had higher level of posttransplant alkaline phosphatase, but a lower incidence of biliary complications. The negative DRAG group, particularly DRAG ≤ -21 years was associated with the superior 1-, 3-, 5-, and 10-year graft survivals. Recipients with DRAG ≥ 21 showed persistently inferior graft survival during the observation period. In cases of young donors, transplants utilizing lower DRAG seen between young donors and older recipients showed more favorable graft survival than that of young-to-young transplants.

CONCLUSION

This study demonstrated that DRAG and a fixed donor age limit could be significant factors to predict graft survival after LDLT. Patients should carefully consider the worse graft survival if the donor is older than the recipient by ≥20.

Outcomes of living donor liver transplantation using elderly donors

Purpose

Living donor liver transplantation (LDLT) using elderly donors is increasing in frequency in response to organ shortage. However, elderly donor graft has been reported to negatively affect graft patency and patient survival.

Methods

We retrospectively reviewed the medical records of 604 patients who underwent LDLT at Seoul St. Mary's Hospital, The Catholic University of Korea between May 1999 and September 2012. Elderly donors were defined as those ≥55 years of age. Here, we evaluate the survival differences and causes of death of recipients of elderly donor grafts.

Results

The overall mortality rate of the recipients was significantly higher in the elderly donor group (group A) than in the younger donor group (group B: 46.2% vs. 18.1%, P = 0.004). The survival length of group A was significantly shorter than that of group B (31.2 ± 31.3 and 51.4 ± 40.8 months, P = 0.014). The significantly common causes of death in group A were biliary (41.7%) and arterial complication (16.7%), and it was higher than those in group B (P = 0.000 and P = 0.043, respectively).

Conclusion

LDLT using elderly donors could induce more serious complications and higher mortality rates than those at using younger donors. As such, careful donor selection is needed, especially with regard to assessing the condition of potential elderly donor livers. Furthermore, a large-volume and multicenter study of complications and outcomes of LDLT using elderly donor liver is required.

Early Graft Dysfunction in Living Donor Liver Transplantation and the Small for Size Syndrome

LDLT has arisen as a viable means to reduce waitlist mortality. However, its widespread embrace by the liver transplant community has been met with frustration centered on donor morbidity and small-for-size-syndrome. Focusing on the later entity, we describe the initial recognition of this early graft dysfunction, the theorized pathophysiology and solutions to remedy its emergence.

Recipient-donor age matching in liver transplantation: a single-center experience

OBJECTIVE

The aim of this study was to investigate whether donor age was a predictor of outcomes in liver transplantation, representing an independent risk factor as well as its impact related to recipient age-matching.

METHODS

We analyzed prospectively collected data from 221 adult liver transplantations performed from January 2006 to September 2009.

RESULTS

Compared with recipients who received grafts from donors <60 years old, transplantation from older donors was associated with significantly higher rates of graft rejection (9.5% vs 3.5%; P = .05) and worse graft survival (P = .021). When comparing recipient and graft survivals according to age matching, we observed significantly worse values for age-mismatched (P values .029 and .037, respectively) versus age-matched patients. After adjusting for covariates in a multivariate model, age mismatch was an independent risk factor for patient death (hazard ratio [HR] 2.13, 95% confidence interval [CI] 1.1-4.17; P = .027) and graft loss (HR 3.86, 95% CI 1.02-15.47; P = .046).

CONCLUSIONS

The results of this study suggest to that optimized donor allocation takes into account both donor and recipient ages maximize survival of liver-transplanted patients.

Prediction factors of postoperative hyperbilirubinemia in living right lobe donor: a single-center analysis of 210 cases

BACKGROUND

Hyperbilirubinemia in living liver donor is very common, but the causes are still unclear.

AIMS

We sought to clarify the risk factors and predictors of nonobstructive hyperbilirubinemia among living donors.

METHODS

We divided 210 consecutive right liver lobe donors into two groups according to the peak total bilirubin postoperatively. We collected data on preoperative, intraoperative, and postoperative biochemical measurements retrospectively, performing multivariate logistic regression analysis adjusting for potential confounders of the risk of hyperbilirubinemia.

RESULTS

There were significant differences between the two groups in donor age, body mass index, operative time, blood loss, macrovescicular steatosis, allogeneic blood transfusion rate, intensive care unit stay, hospital stay and Clavien score after donation (P < .05). Age, graft/donor weight, operative time, and blood loss were significantly associated with the risk of hyperbilirubinemia upon logistic regression analysis.

CONCLUSION

Hyperbilirubinemia, one type of hepatic dysfunction after a living donor procedure, was associated with multiple independent risk factors.

The outcomes of patients with severe hyperbilirubinemia following living donor liver transplantation

BACKGROUND

Prolonged hyperbilirubinemia (HB) following living donor liver transplantation (LDLT) can be a risk factor for early graft loss and mortality. However, some recipients who present with postoperative hyperbilirubinemia do recover and maintain a good liver function.

AIM

The purpose of this study was to investigate the risk factors for hyperbilirubinemia following LDLT and to identify predictors of the outcomes in patients with post-transplant hyperbilirubinemia.

METHODS

A total of 107 consecutive adults who underwent LDLT in Nagasaki University Hospital were investigated retrospectively. The patients were divided into two groups according to postoperative peak serum bilirubin level (HB group: ≥ 30 mg/dl; non-HB group: <30 mg/dl). These two groups of patients and the prognosis of patients in the HB group were analyzed using several parameters.

RESULTS

Seventeen patients (15.9 %) presented with hyperbilirubinemia, and their overall survival was significantly worse than patients in the non-HB group (n = 90). Donor age was significantly higher in the HB group (P < 0.05). Of the 17 patients in the HB group, nine survived. The postoperative serum prothrombin level at the time when the serum bilirubin level was >30 mg/dl was significantly higher in surviving patients (P < 0.01).

CONCLUSIONS

The use of a partial liver graft from an aged donor is a significant risk factor for severe hyperbilirubinemia and a poorer outcome. However, those patients who maintain their liver synthetic function while suffering from hyperbilirubinemia may recover from hyperbilirubinemia and eventually achieve good liver function, thus resulting in a favorable survival.

Small-for-size syndrome in living donor liver transplantation

When the graft volume is too small to satisfy the recipient's metabolic demand, the recipient may thus experience small-for-size syndrome (SFSS). Because the occurrence of SFSS is determined by not only the liver graft volume but also a combination of multiple negative factors, the definitions of small-for-size graft (SFSG) and SFSS are different in each institute and at each time. In the clinical setting, surgical inflow modulation and maximizing the graft outflow are keys to overcoming SFSS. Accordingly, relatively smaller-sized grafts can be used with surgical modification and pharmacological manipulation targeting portal circulation and liver graft quality. Therefore, the focus of the SFSG issue is now shifting from how to obtain a larger graft from the living donor to how to manage the use of a smaller graft to save the recipient, considering donor safety to be a priority.

Serotonin: from top to bottom

Serotonin is a monoamine neurotransmitter, which is phylogenetically conserved in a wide range of species from nematodes to humans. In mammals, age-related changes in serotonin systems are known risk factors of age-related diseases, such as diabetes, faecal incontinence and cardiovascular diseases. A decline in serotonin function with aging would be consistent with observations of age-related changes in behaviours, such as sleep, sexual behaviour and mood all of which are linked to serotonergic function. Despite this little is known about serotonin in relation to aging. This review aims to give a comprehensive analysis of the distribution, function and interactions of serotonin in the brain; gastrointestinal tract; skeletal; vascular and immune systems. It also aims to demonstrate how the function of serotonin is linked to aging and disease pathology in these systems. The regulation of serotonin via microRNAs is also discussed, as are possible applications of serotonergic drugs in aging research and age-related diseases. Furthermore, this review demonstrates that serotonin is potentially involved in whole organism aging through its links with multiple organs, the immune system and microRNA regulation. Methods to investigate these links are discussed.

Liver regeneration after liver transplantation

BACKGROUND/PURPOSE

The liver has a remarkable capacity to regenerate after injury or resection. The aim of this review is to outline the mechanisms and factors affecting liver regeneration after liver transplantation.

METHODS

Relevant studies were reviewed using Medline, PubMed and Springer databases.

RESULTS

A variety of cytokines (such as interleukin-6 and tumor necrosis factor-α), growth factors (like hepatocyte growth factor and transforming growth factor-α) and cells are involved in liver regeneration. Several factors affect liver regeneration after transplantation such as ischemic injury, graft size, immunosuppression, steatosis, donor age and viral hepatitis.

CONCLUSION

Liver regeneration has been studied for many years. However, further research is essential to reveal the complex processes affecting liver regeneration, which may provide novel strategies in the management of liver transplantation recipients and donors.

Donor age affects liver regeneration during early period in the graft liver and late period in the remnant liver after living donor liver transplantation

BACKGROUND

The aim of the present study was to evaluate the influence of donor age on liver regeneration and surgical outcomes in recipients and donors.

PATIENTS AND METHODS

Among 101 cases of adult-to-adult living donor liver transplantation (LDLT) between March 2002 and March 2011, according to donor age: younger (Y) <50 years of age or older (O) ≥ 50 years of age, the donors and recipients using right (R) or left (L) graft were divided into groups Y/R (n = 51) and O/R (n = 17), and groups Y/L (n = 26) and O/L (n = 7), respectively. Remnant liver volume (RemLV) and graft liver volume (GLV) were estimated by computed tomography (CT) volumetry. A disintegrin and metalloprotease with thrombospondin type I domain 13 (ADAMTS13) activities and von Willebrand factor (vWF) antigen levels were measured as factors reflecting thrombotic microangiopathy.

RESULTS

Among the donors, RemLV/total liver volume (TLV) was lower in group O/R than in group Y/R, although there were no significant differences by t-test with the Bonferroni correction (rough p value = 0.02 at 6 months and rough p value > 0.05 at 1, 3, and 12 months). Donor age (≥ 50 years) was independently correlated with impaired remnant liver regeneration at 6 months in right lobe LDLT (p = 0.04). Among the recipients, GLV/standard liver volume (SLV) was lower during the first month, although there were no significant differences between the two groups by t-test with the Bonferroni correction (rough p value = 0.03 at 1 week and rough p value >0.05 at 2 weeks and 1 and 3 months). Donor age (≥ 50 years) was independently correlated with impaired graft liver regeneration at 1 week in both right and left lobe LDLT (p < 0.05). ADAMTS13 activities were lower in group O/R than in group Y/R, although there were no significant differences by t-test with the Bonferroni correction (rough p value = 0.049 on postoperative days (POD) 1 and 28 and rough p value >0.05 on POD 7 and 14). vWF/ADAMTW13 ratios were higher on POD 14, although there were no significant differences between the two groups by t-test with the Bonferroni correction (rough p value = 0.044 on POD 14 and rough p value >0.05 on POD 1, 7, 14, and 28).

CONCLUSIONS

The surgical outcomes using older donor livers for LDLT were comparable to those using younger donor livers. When using older donor livers, however, we should pay attention to the liver volume for recipients as well as donors, because older donor livers might have impaired regenerative ability.

Extended donors in liver transplantation

Several criteria are used to differentiate between standard and extended allograft donors. These criteria include deceased after cardiac death, advanced donor age, steatosis, previous malignancy in the donor, hepatitis C virus-positive allografts, human T-cell lymphotropic virus-positive allografts, active infections in the donor, high-risk donors, split liver transplantations, and living donor liver transplantations. Review of the literature can lead each practitioner to incorporate extended criteria donors into their transplant program, thereby individualizing the use of these allografts, increasing the donor pool, and decreasing overall waitlist mortality.

Liver transplantation in the 21st century: expanding the donor options

Over the past decade, use of ECD organs for OLT has allowed many transplant programs to afford patients access to an otherwise scarce resource and to maintain center volume. Although overall posttransplant outcomes are inferior to results with optimal, whole-liver grafts, aggressive utilization of ECD and DCD organs significantly lowers median wait-times for OLT, MELD score at OLT, and death while awaiting transplantation. It is incumbent on the transplant community to provide continued scrutiny of the many factors involved in ECD organ utilization, evaluate the degree of risk and benefit such allografts may impart on particular recipients, and thereby provide suitable “matching” to maximize favorable outcomes. Transplant caregivers need to provide patients with evidence-based care decisions, be good stewards of a scarce resource, and maintain threshold survival results for their programs. This requires balancing the urgency with which a transplant is needed and the utility of such a transplant. There is a clear necessity to pursue additional donor research to improve use of these marginal grafts and assess interventions that enhance the safety of ECD livers.

The influence of donor age on liver regeneration and hepatic progenitor cell populations

BACKGROUND

Recent reports suggest that donor age might have a major impact on recipient outcome in adult living donor liver transplantation (LDLT), but the reasons underlying this effect remain unclear. The aims of this study were to compare liver regeneration between young and aged living donors and to evaluate the number of Thy-1+ cells, which have been reported to be human hepatic progenitor cells.

METHODS

LDLT donors were divided into 2 groups (Group O, donor age ≥ 50 years, n = 6 and Group Y, donor age ≤ 30 years, n = 9). The remnant liver regeneration rates were calculated on the basis of computed tomography volumetry on postoperative days 7 and 30. Liver tissue samples were obtained from donors undergoing routine liver biopsy or patients undergoing partial hepatectomy for metastatic liver tumors. Thy-1+ cells were isolated and counted using immunomagnetic activated cell sorting (MACS) technique.

RESULTS

Donor liver regeneration rates were significantly higher in young donors compared to old donors (P = .042) on postoperative day 7. Regeneration rates were significantly higher after right lobe resection compared to rates after left lobe resection. The MACS findings showed that the number of Thy-1+ cells in the human liver consistently tended to decline with age.

CONCLUSION

Our study revealed that liver regeneration is impaired with age after donor hepatectomy, especially after right lobe resection. The declining hepatic progenitor cell population might be one of the reasons for impaired liver regeneration in aged donors.

Elevated interferon gamma signaling contributes to impaired regeneration in the aged liver

Our previous study on immune-related changes in the aged liver described immune cell infiltration and elevation of inflammation with age. Levels of interferon (IFN)-γ, a known cell cycle inhibitor, were elevated in the aging liver. Here, we determine the role played by IFN-γ in the delayed regenerative response observed in the aged livers. We observed elevated IFN signaling in both aged hepatocytes and regenerating livers post-partial hepatectomy. In vivo deletion of the major IFN-γ producers-the macrophages and the natural killer cells, leads to a reduction in the IFN-γ levels accompanied with the restoration of the DNA synthesis kinetics in the aged livers. Eighteen-month-old IFN-γ-/- mice livers, upon resection, exhibited an earlier entry into the cell cycle compared with age-matched controls. Thus, our study strongly suggests that an age-related elevation in inflammatory conditions in the liver often dubbed as "inflammaging" has a detrimental effect on the regenerative response.

Utilization of elderly donors in living donor liver transplantation: when more is less?

An accepted definition of donor exclusion criteria has not been established for living donor liver transplantation (LDLT). The use of elderly donors to expand the living donor pool raises ethical concerns about donor safety. The aims of this study were (1) the comparison of the postoperative outcomes of living liver donors by age (≥ 50 versus < 50 years) and (2) the evaluation of the impact of the extent of right hepatectomy on donor outcomes. The study group included 150 donors who underwent donor right hepatectomy between October 2004 and April 2009. Extended criteria surgery (ECS) was defined as right hepatectomy with middle hepatic vein (MHV) harvesting or right hepatectomy resulting in an estimated remnant liver volume (RLV) less than 35%. The primary endpoints were donor outcomes in terms of donor complications graded according to the Clavien classification. Group 1 consisted of donors who were 50 years old or older (n = 28), and group 2 consisted of donors who were less than 50 years old (n = 122). At least 1 ECS criterion was present in 74% of donors: 57% had 1 criterion, and 17% had 2 criteria. None of the donors had grade 4 complications or died. The overall and major complication rates were similar in the 2 donor age groups [28.6% and 14.3% in group 1 and 32% and 8.2% in group 2 for the overall complication rates (P = 0.8) and the major complication rates (P = 0.2), respectively]. However, there was a significant correlation between the rate of major complications and the type of surgery in donors who were 50 years old or older. In LDLT, extending the limits of surgery comes at the price of more complications in elderly donors. Right hepatectomy with MHV harvesting and any procedure causing an RLV less than 35% should be avoided in living liver donors who are 50 years old or older.

Preoperative estimation of the liver graft weight in adult right lobe living donor liver transplantation using maximal portal vein diameters

An accurate preoperative estimate of the graft weight is vital to avoid small-for-size syndrome in the recipient and ensure donor safety after adult living donor liver transplantation (LDLT). Here we describe a simple method for estimating the graft volume (GV) that uses the maximal right portal vein diameter (RPVD) and the maximal left portal vein diameter (LPVD). Between June 2004 and December 2009, 175 consecutive donors undergoing right hepatectomy for LDLT were retrospectively reviewed. The GV was determined with 3 estimation methods: (1) the radiological graft volume (RGV) estimated by computed tomography (CT) volumetry; (2) the computed tomography-calculated graft volume (CGV-CT), which was obtained by the multiplication of the standard liver volume (SLV) by the RGV percentage with respect to the total liver volume derived from CT; and (3) the portal vein diameter ratio-calculated graft volume (CGV-PVDR), which was obtained by the multiplication of the SLV by the portal vein diameter ratio [PVDR; ie, PVDR = RPVD(2) /(RPVD(2) + LPVD(2) )]. These values were compared to the actual graft weight (AGW), which was measured intraoperatively. The mean AGW was 633.63 ± 107.51 g, whereas the mean RGV, CGV-CT, and CGV-PVDR values were 747.83 ± 138.59, 698.21 ± 94.81, and 685.20 ± 90.88 cm(3) , respectively. All 3 estimation methods tended to overestimate the AGW (P < 0.001). The actual graft-to-recipient body weight ratio (GRWR) was 1.00% ± 0.19%, and the GRWRs calculated on the basis of the RGV, CGV-CT, and CGV-PVDR values were 1.19% ± 0.25%, 1.11% ± 0.22%, and 1.09% ± 0.21%, respectively. Overall, the CGV-PVDR values better correlated with the AGW and GRWR values according to Lin's concordance correlation coefficient and the Landis and Kock benchmark. In conclusion, the PVDR method is a simple estimation method that accurately predicts GVs and GRWRs in adult LDLT.

Serotonin reverts age-related capillarization and failure of regeneration in the liver through a VEGF-dependent pathway

The function of the liver is well-preserved during the aging process, although some evidence suggests that liver regeneration might be impaired with advanced age. We observed a decreased ability of the liver to restore normal volume after partial hepatectomy in elderly mice, and we identified a pathway that rescued regeneration and was triggered by serotonin. 2,5-dimethoxy-4-iodoamphetamine (DOI), a serotonin receptor agonist, reversed the age-related pseudocapillarization of old liver and improved hepatosinusoidal blood flow. After hepatectomy, the open fenestrae were associated with a restored attachment of platelets to endothelium and the initiation of a normal regenerative response, including the up-regulation of essential growth mediators and serotonin receptors. In turn, hepatocyte proliferation recovered along with regain of liver volume and animal survival. DOI operates through the release of VEGF, and its effects could be blocked with anti-VEGF antibodies both in vitro and in vivo. These results suggest that pseudocapillarization in the aged acts as a barrier to liver regeneration. DOI breaks this restraint through an endothelium-dependent mechanism driven by VEGF. This pathway highlights a target for reversing the age-associated decline in the capacity of the liver to regenerate.

The biopsied donor liver: incorporating macrosteatosis into high-risk donor assessment

To expand the donor liver pool, ways are sought to better define the limits of marginally transplantable organs. The Donor Risk Index (DRI) lists 7 donor characteristics, together with cold ischemia time and location of the donor, as risk factors for graft failure. We hypothesized that donor hepatic steatosis is an additional independent risk factor. We analyzed the Scientific Registry of Transplant Recipients for all adult liver transplants performed from October 1, 2003, through February 6, 2008, with grafts from deceased donors to identify donor characteristics and procurement logistics parameters predictive of decreased graft survival. A proportional hazard model of donor variables, including percent steatosis from higher-risk donors, was created with graft survival as the primary outcome. Of 21,777 transplants, 5051 donors had percent macrovesicular steatosis recorded on donor liver biopsy. Compared to the 16,726 donors with no recorded liver biopsy, the donors with biopsied livers had a higher DRI, were older and more obese, and a higher percentage died from anoxia or stroke than from head trauma. The donors whose livers were biopsied became our study group. Factors most strongly associated with graft failure at 1 year after transplantation with livers from this high-risk donor group were donor age, donor liver macrovesicular steatosis, cold ischemia time, and donation after cardiac death status. In conclusion, in a high-risk donor group, macrovesicular steatosis is an independent risk factor for graft survival, along with other factors of the DRI including donor age, donor race, donation after cardiac death status, and cold ischemia time.

Optimal utilization of extended hepatic grafts

Orthotopic liver transplantation has emerged as the standard treatment for end-stage liver disease. In the United States, the number of listed patients has tripled in the last two decades. Organ availability during the same period has plateaued at approximately 6000 grafts annually, resulting in a fivefold increase in wait-list mortality. The problem is not specific to the United States; European and Asian registries report similar shortages. Donor pool expansion strategies such as the use of living donors, cadaveric split livers, and "extended criteria donors"; (ECD) are being pursued. Used judiciously, ECD grafts provide an opportunity for addressing the shortage. Although there is no universally accepted definition of ECD, the term generally refers to donor factors predisposing recipients to poor initial graft function and/or increased long-term risk. These factors include advanced donor age, hypernatremia, prolonged warm ischemic time, pressor requirement, and donation after cardiac death. The transplant community is scrutinizing all factors to evaluate the degree of risk they impart on the recipient and the extent to which grafts can be "matched"; to maintain acceptable outcomes. We review the importance of selected factors and the impact of a "matching"; strategy to minimize recipient risk while optimizing graft use.

Graft size and donor age are independent factors for graft loss in adult-to-adult living-donor liver transplantation using the left liver

BACKGROUND/PURPOSE

Graft survival is affected by various factors, such as preoperative state and the ages of the recipient and donor, as well as graft size. The objective of this study was to analyze the risk factors for graft survival.

METHODS

From September 1997 to July 2005, 24 patients who had undergone living-donor liver transplantation (LDLT) were retrospectively analyzed. Sixteen patients survived and the eight graft-loss cases were classified into two groups according to the cause of graft loss: graft dysfunction without major post-transplantation complications (graft dysfunction group; n = 3), and graft dysfunction with such complications (secondary graft dysfunction group; n = 5). Various factors were compared between these groups and the survival group.

RESULTS

Mean donor age was 31.9 years in the survival group and 49.2 years in the secondary graft dysfunction group (P = 0.024). Graft weight/recipient standard liver volume ratios (G/SLVs) were 36.7% in the survival group, and 26.2% in the graft dysfunction group (P = 0.037). The postoperative mean PT% for 1 week was 48.6% in the survival group and 38.1% in the secondary graft dysfunction group (P = 0.05).

CONCLUSIONS

Our surgical results demonstrated that G/SLV and donor age were independent factors that affected graft survival rates.

Liver failure after major hepatic resection

INTRODUCTION

The consequence of excessive liver resection is the inexorable development of progressive liver failure characterised by the typical stigmata associated with this condition, including worsening coagulopathy, hyperbilirubinaemia and encephalopathy. The focus of this review will be to investigate factors contributing to hepatocyte loss and impaired regeneration.

METHODS

A literature search was undertaken of Pubmed and related search engines, examining for articles relating to hepatic failure following major hepatectomy.

RESULTS

In spite of improvements in adjuvant chemotherapy and increasing surgical confidence and expertise, the parameters determining how much liver can be resected have remained largely unchanged. A number of preoperative, intraoperative and post-operative factors all contribute to the likelihood of liver failure after surgery.

CONCLUSIONS

Given the magnitude of the surgery, mortality and morbidity rates are extremely good. Careful patient selection and preservation of an obligate volume of remnant liver is essential. Modifiable causes of hepatic failure include avoidance of sepsis, drainage of cholestasis with restoration of enteric bile salts and judicious use of portal triad inflow occlusion intra-operatively. Avoidance of post-operative sepsis is most likely to be achieved by patient selection, meticulous intra-operative technique and post-operative care. Modulation of portal vein pressures post-operatively may further help reduce the risk of liver failure.

Liver regeneration in donors and adult recipients after living donor liver transplantation

In living donor liver transplantation, the safety of the donor operation is the highest priority. The introduction of the right lobe graft was late because of concerns about donor safety. We investigated donor liver regeneration by the types of resected segments as well as recipients to assess that appropriate regeneration was occurring. Eighty-seven donors were classified into 3 groups: left lateral section donors, left lobe donors, and right lobe donors. Forty-seven adult recipients were classified as either left or right lobe grafted recipients. Volumetry was retrospectively performed at 1 week, 1, 2, 3, and 6 months, and 1 year after the operation. In the right lobe donor group, the remnant liver volume was 45.4%, and it rapidly increased to 68.9% at 1 month and 89.8% at 6 months. At 6 months, the regeneration ratios were almost the same in all donor groups. The recipient liver volume increased rapidly until 2 months, exceeding the standard liver volume, and then gradually decreased to 90% of the standard liver volume. Livers of the right lobe donor group regenerated fastest in the donor groups, and the recipient liver regenerated faster than the donor liver. Analyzing liver regeneration many times with a large number of donors enabled us to understand the normal liver regeneration pattern. Although the donor livers did not reach their initial volume, the donors showed normal liver function at 1 year. The donors have returned to their normal daily activities. Donor hepatectomy, even right hepatectomy, can be safely performed with accurate preoperative volumetry and careful decision-making concerning graft-type selection.