Re-evaluation of the predictive score for 6-month graft survival in living donor liver transplantation in the modern era

What Are Risk Factors for Graft Loss in Patients Who Underwent Simultaneous Splenectomy During Living-donor Liver Transplantation?

BACKGROUND

The consensus that portal venous pressure modulation, including splenectomy (Spx), prevents portal hypertension-related complications after living-donor liver transplantation (LDLT) has been established. However, little evidence about the risk factors for graft loss after simultaneous Spx during LDLT is available. This study aimed to identify the independent predictors of graft loss after simultaneous Spx during LDLT.

METHODS

Data of 655 recipients who underwent LDLT between 1997 and 2021 were collected and separated into the simultaneous Spx group (n = 461) and no-Spx group (n = 194).

RESULTS

The simultaneous Spx group had significantly lower serum total bilirubin levels, drained ascites volumes, and prothrombin time-international normalized ratios on postoperative day 14 than the no-Spx group ( P  < 0.001 for each). Incidences of small-for-size graft syndrome ( P  < 0.001), acute cellular rejection ( P  = 0.002), and sepsis ( P  = 0.007) were significantly lower in the Spx group. Graft survival of the Spx group was significantly better than that of the no-Spx group ( P  < 0.001; hazard ratio [HR], 1.788; 95% confidence interval, 1.214-2.431). A multivariate analysis revealed that 3 variables, platelet count ≤4.0 × 10 4 /mm 3 ( P  = 0.029; HR, 2.873), donor age ≥60 y old ( P  = 0.013; HR, 6.693), and portal venous pressure at closure ≥20 mm Hg ( P  = 0.010; HR, 3.891), were independent predictors of graft loss within 6 mo after simultaneous Spx during LDLT.

CONCLUSIONS

Spx is a safe inflow modulation procedure with a positive impact on both postoperative complications and prognosis for most patients. However, patients with the 3 aforementioned independent factors could experience graft loss after LDLT.

What is the crux of successful living-donor liver transplantation for recipients aged 70 and beyond?

Aim

There is limited evidence regarding the feasibility of living-donor liver transplantation (LDLT) for patients aged over 70. The aims of this study were to assess postoperative outcomes in elderly recipients and to ascertain the potential feasibility and acceptability of LDLT.

Methods

Data were collected from 762 recipients, including 26 in the elderly group (aged ≥70) and 736 in the younger group (aged <70), and reviewed even by propensity score matching (PSM).

Results

No significant differences were observed in the frequency of postoperative complications between the two groups. Additionally, both groups exhibited a comparable 30-day mortality rate after LDLT (3.9% in both) and similar hospital stays (36 days vs. 40 days). The 1-, 3-, and 5-year graft survival rates in the elderly group were 92.0%, which was comparable to those in the younger group (p = 0.517), as confirmed by PSM. Notably, all donors for elderly patients were the children of the recipients, with an average age of 41.6 years, and grafts from donors aged ≥50 years were not utilized, signifying the use of high-quality grafts. Our inclusion criterion for elderly recipients was strictly defined as an ECOG-PS score of 0-2, which played a pivotal role in achieving favorable postoperative outcomes.

Conclusion

LDLT can be performed safely for elderly patients aged 70 years or older, provided they have a preserved PS and receive high-quality grafts from younger donors, inevitably all children of elderly recipients. This approach yields acceptable long-term outcomes. Consequently, age alone should not serve as an absolute contraindication for LDLT.

Effect of Early Enteral Nutrition on Graft Loss After Living Donor Liver Transplantation: A Propensity Score Matching Analysis

BACKGROUND

This study aimed to elucidate the effect of early enteral nutrition on graft loss within 12 h after living-donor liver transplantation (LDLT) using propensity score-matching analysis and subsequently examine the risk factors for graft loss after LDLT.

METHODS

We retrospectively reviewed the data of 467 LDLT patients who were assigned to the early and non-early groups based on the optimal cutoff value of 12 h for the starting time of early enteral nutrition after LDLT to predict graft loss.

RESULTS

The 1-year graft survival rate of the early group before propensity score-matching was 92.1%, whereas the 1-year graft survival rate of the non-early group was 86.2%. There was no significant difference between the 2 groups (P = .067). The incidences of early allograft dysfunction (EAD), small-for-size graft (SFSG) syndrome, acute cellular rejection (ACR), and sepsis were not statistically different between the 2 groups (P = .12, .91, .46, and .056, respectively). After propensity score-matching, the 1-year graft survival rate of the early group was 94.4%, whereas the 1-year graft survival rate of the non-early group was 85.4% (P = .034). The incidences of EAD, SFSG syndrome, and ACR were not statistically different between the 2 groups (P = .43, .81, and .24, respectively). However, the incidence of sepsis was statistically different between the 2 groups (non-early: 10.7% vs early: 3.6%, P = .038).

CONCLUSION

Early enteral nutrition within 12 h after LDLT may contribute to better graft survival in LDLT patients by preventing sepsis.

Preoperative serum brain-derived neurotrophic factor as a predictive biomarker for sepsis after living-donor liver transplantation

AIM

Although the survival rate after living-donor liver transplantation (LDLT) is improving, sepsis still limits the prognosis. Immune dysfunction and sarcopenia are often observed in LDLT patients, and increase susceptibility to infection. Brain-derived neurotrophic factor (BDNF) is a myokine produced by immune cells and skeletal muscle. We aimed to determine whether serum BDNF could be a feasible biomarker for sepsis of LDLT patients.

METHODS

We measured serum samples from 124 patients who underwent LDLT and 9 healthy volunteers for BDNF. We examined its correlation with incidence rate of sepsis. To clarify the source of BDNF, we examined its expression in lymphocytes, skeletal muscle cells, and hepatocytes.

RESULTS

Patients who experienced sepsis showed worse short-term survival. Preoperative serum BDNF was lower in LDLT patients compared with healthy volunteers, and was also lower in Child-Pugh C compared with Child-Pugh A or B. Serum BDNF was inversely correlated with Model for End-Stage Liver Disease and controlling nutritional status (CONUT) scores, but had a weak positive correlation with skeletal muscle mass index (SMI). Multivariate analysis revealed that serum BDNF was independently associated with sepsis. Preoperative serum BDNF was a better predictor of sepsis in LDLT patients than CONUT score or SMI. Serum BDNF was positively correlated with lymphocyte counts, especially T cells. In vitro, T cells and skeletal muscle cells produced BDNF.

CONCLUSIONS

Preoperative serum BDNF could be a predictive biomarker for sepsis after LDLT, by reflecting the systemic condition including hepatic function, nutritional status, and immune status.

Donor Skeletal Muscle Quality Affects Graft Mortality After Living Donor Liver Transplantation- A Single Center, Retrospective Study

The recipient muscle status is closely associated with postoperative poor survival in recipients of living donor liver transplantation (LDLT). However, it is uncertain whether LDLT donor muscle quality and quantity affect graft quality. Hence, we analyzed the correlation between donor muscle status and graft function. We measured the skeletal muscle mass index (SMI) and intramuscular adipose tissue content (IMAC) of 380 LDLT donors. We examined the correlation between donor SMI or IMAC and graft mortality, the occurrence rates of small-for-size graft (SFSG) syndrome, and 6-month graft survival rates. The donor SMI had no effect on the occurrence of SFSG syndrome and graft survival, while a high IMAC in both male and female donors was significantly correlated with the rate of SFSG syndrome [high vs low: (male donors) 15.8% vs. 2.5%, p = 0.0003; (female donors) 12.8% vs. 3.1%, p = 0.0234] and 6-month graft survival rates [(male donors) 87.7% vs 95.9%, p = 0.02; (female donors) 83.0% vs. 99.0%, p < 0.0001]. Multivariate analysis revealed that a high donor IMAC (HR; 5.42, CI; 2.13-13.8, p = 0.0004) was an independent risk factor for 6-month graft survival, and the donor IMAC is useful for donor selection for high-risk recipients.

Low syntaxin 17 expression in donor liver is associated with poor graft prognosis in recipients of living donor liver transplantation

AIM

Liver transplantation (LT) is the only curative therapy for decompensated liver cirrhosis. For recipients of living donor LT (LDLT), restoration of liver function after transplantation is highly dependent on liver regenerative capacity, which requires large amounts of intracellular energy. Mitochondrial metabolism provides a stable supply of adenosine 5'-triphosphate (ATP) for liver regeneration. Mitophagy is a selective process in which damaged, non-functional mitochondria are degraded and replaced with new functional mitochondria. We investigated the relationship between expression of Syntaxin17 (STX17), a key protein in mitophagy regulation, in donor livers and graft survival.

METHODS

We examined STX17 expression in grafts from 143 LDLT donors who underwent right lobe resection and investigated the relationship between STX17 expression and graft function. We investigated the correlations among STX17 expression, mitochondrial membrane potential and cell proliferation, using a STX17-knockdown hepatocyte cell line.

RESULTS

Recipients transplanted with low STX17-expression grafts had significantly lower graft survival rates than recipients transplanted with high STX17-expression grafts (88.9% vs. 100%, p < 0.01). Multivariate analysis showed that low STX17 expression (HR: 10.7, CI: 1.29-88.0, p < 0.05) and the absence of splenectomy (HR: 6.27, CI: 1.59-24.8, p < 0.01) were independent predictive factors for small-for-size graft syndrome, which is the severe complication in LDLT. In the vitro experiments, the percentage of depolarized damaged mitochondria was increased in the STX17-knockdown hepatocyte cell line, suggesting decreased mitophagy and ATP synthesis. Cell proliferation was significantly decreased in the STX17-knockdown hepatocyte cell line.

CONCLUSION

STX17 contributes to mitophagy and maintenance of mitochondrial function in hepatocytes and may be a predictor of graft dysfunction in LDLT patients.

Up-regulated LRRN2 expression as a marker for graft quality in living donor liver transplantation

The quality and size of liver grafts are critical factors that influence living‐donor liver transplantation (LDLT) function and safety. However, the biomarkers used for predicting graft quality are lacking. In this study, we sought to identify unique graft quality markers, aside from donor age, by using the livers of non‐human primates. Hepatic gene microarray expression data from young and elderly cynomolgus macaques revealed a total of 271 genes with significantly increased expression in the elderly. These candidate genes were then narrowed down to six through bioinformatics analyses. The expression patterns of these candidate genes in human donor liver tissues were subsequently examined. Importantly, we found that grafts exhibiting up‐regulated expression of these six candidate genes were associated with an increased incidence of liver graft failure. Multivariable analysis further revealed that up‐regulated expression of LRRN2 (encoding leucine‐rich repeat protein, neuronal 2) in donor liver tissue served as an independent risk factor for graft failure (odds ratio 4.50, confidence interval 2.08–9.72). Stratification based on graft expression of LRRN2 and donor age was also significantly associated with 6‐month graft survival rates. Conclusion: Up‐regulated LRRN2 expression of liver graft is significantly correlated with graft failure in LDLT. In addition, combination of graft LRRN2 expression and donor age may represent a promising marker for predicting LDLT graft quality.

Which is better to use "body weight" or "standard liver weight", for predicting small-for-size graft syndrome after living donor liver transplantation?

AIM

Little evidence about whether to apply graft-to-recipient body weight ratio (GRWR) or graft weight to standard liver weight (GW/SLW) for graft selection has been published. The aim of the present study was to clarify the importance of the correct use of GRWR and GW/SLW for selecting graft according to the recipients' physique in living donor liver transplantation (LDLT).

METHODS

Data were collected for 694 recipients who underwent LDLT between 1997 and 2020.

RESULTS

One of the marginal grafts meeting GW/SLW ≥ 35% but GRWR < 0.7% has been used in more recipients with men and higher body mass index (BMI), and the other meeting GRWR ≥ 0.7% but GW/SLW < 35% has been used in more recipients with women with lower BMI. In the cohort of BMI > 30 kg/m2, the recipients with GRWR < 0.7% had a significantly higher incidence of small-for-size graft syndrome (SFSS) compared to those with GRWR ≥ 0.7% (P = 0.008, 46.2% vs 5.9%), and using the cutoff of GW/SLW < 35% could not differentiate. In contrast, in the cohort of BMI ≤ 30 kg/m2, the recipients with GW/SLW < 35% also had a significantly higher incidence of SFSS (P = 0.013, 16.9% vs 9.4%). Multivariate analysis showed that GRWR < 0.7% [odds ratio (OR) 14.145, P = 0.048] was the independent risk factor for SFSS in obese recipients, and GW/SLW < 35% [OR 2.685, P = 0.002] was the independent risk factor in non-obese recipients.

CONCLUSION

Proper use of the formulas for calculating GRWR and GW/SLW in choosing graft according to recipient BMI is important, not only to meet metabolic demand for avoiding SFSS but also to ameliorate donor shortages.

The Significant Prognostic Factors in Prolonged Intensive/High Care Unit Stay After Living Donor Liver Transplantation

BACKGROUND

Prolonged stay in an intensive/high care unit (ICU/HCU) after living donor liver transplantation (LDLT) is a significant event with possible mortality.

METHODS

Adult-to-adult LDLTs (n = 283) were included in this study. Univariate and multivariate analyses were performed for the factors attributed to the prolonged ICU/HCU stay after LDLT.

RESULTS

Recipients who stayed in the ICU/HCU 9 days or longer were defined as the prolonged group. The prolonged group was older (P = .0010), had a higher model for end-stage liver disease scores (P < .0001), and had higher proportions of patients with preoperative hospitalization (P < .0001). Delirium (P < .0001), pulmonary complications (P < .0001), sepsis (P < .0001), reintubation or tracheostomy (P < .0001), relaparotomy due to bleeding (P = .0015) or other causes (P < .0001), and graft dysfunction (P < .0001) were associated with prolonged ICU/HCU stay. Only sepsis (P = .015) and graft dysfunction (P = .019) were associated with in-hospital mortality among patients with prolonged ICU/HCU stay or graft loss within 9 days of surgery. Among these patients, grafts from donors aged <42 years and with a graft-to-recipient weight ratio of >0.76% had significantly higher graft survival than grafts from others (P = .0013 and P < .0001, respectively).

CONCLUSION

Prolonged ICU/HCU stay after LDLT was associated with worse short-term outcomes. The use of grafts of sufficient volume from younger donors might improve graft survival.

Simultaneous splenectomy improves outcomes after adult living donor liver transplantation

BACKGROUND & AIMS

Small-for-size graft (SFSG) syndrome is a major cause of graft loss after living donor liver transplantation (LDLT). Splenectomy (Spx) is an option to prevent this catastrophic complication, but its effect remains controversial. Herein, we aimed to elucidate the effect of simultaneous Spx on graft function and long-term outcomes after LDLT.

METHODS

Three hundred and twenty patients were divided into 2 groups: those undergoing (n = 258) and those not undergoing (n = 62) simultaneous Spx. To overcome selection bias, propensity score matching (PSM) was performed (n = 50 in each group).

RESULTS

Before PSM, recipients undergoing simultaneous Spx showed better graft function on post-operative day (POD) 7 and 14, as well as lower sepsis frequency within 6 months after LDLT and better graft survival rates compared to those not undergoing Spx. After PSM, compared to patients not undergoing Spx, those undergoing Spx had a lower frequency of early graft dysfunction on POD 7 (p = 0.04); a lower frequency of SFSG syndrome (p = 0.01), lower serum total bilirubin levels (p = 0.001), and lower international normalized ratio (p = 0.004) on POD 14; lower sepsis frequency within 6 months after LDLT (p = 0.02), and better graft survival rates (p = 0.04). Univariate analysis revealed that not undergoing Spx (hazard ratio 3.06; 95% CI 1.07-11.0; p = 0.037) was the only risk factor for graft loss after LDLT.

CONCLUSIONS

Simultaneous Spx may prevent SFSG syndrome and is a predictive factor for graft survival after LDLT. Simultaneous Spx is recommended when a small graft (≤35% of standard liver weight) is predicted preoperatively, or for patients with portal hypertension or high portal pressure (above 20 mmHg) after reperfusion in LDLT.

LAY SUMMARY

Living donor liver transplantation (LDLT) for patients with acute or chronic liver failure is an alternative to overcome the deceased donor shortage. The potential mismatch between graft and body size is a problem that needs to be solved for LDLT recipients. Herein, we evaluated the impact of simultaneous splenectomy and showed that it was associated with favorable outcomes in patients undergoing LDLT.

The Perioperatively Altered Neutrophil-to-Lymphocyte Ratio Associates with Impaired DNA Damage Response in Liver Transplantation Recipients with Hepatocellular Carcinoma

Increasing evidence has suggested that elevated systemic inflammation with a high neutrophil-lymphocyte ratio (NLR) is associated with poor prognosis after liver transplantation (LT). The ongoing molecular events involved in poor survival remain unclear. This retrospective study evaluated LT recipients whose data was collected at Kaohsiung Chang Gung Memorial Hospital between 2005 and 2014. Clinical records of 347 patients with hepatocellular carcinoma from seven days before LT to 30 days after LT illustrated that longitudinal values of lymphocytes, RBC, and hemoglobin were persistently low in patients with peritransplant high NLR (PTH-NLR, pre-LT ≥ 4 and post-LT ≥ 5), which indicated a significantly worse survival rate in association with increased RDW-CV and pancytopenia when compared to other patients (p = 0.008). We further found that PTH-NLR patients had decreased DNA damage response (DDR) genes and detoxifying enzymes of ADH and ALDH families, and increased mitochondrial stress response genes in their liver tissues. Reduced lineage markers of liver progenitor cells were also observed in PTH-NLR patients signifying the presence of unresolved impairments after LT. Our results demonstrate the association between hematopoietic deficiencies and lack of protection against DDR with PTH-NLR in LDLT recipients with HCC and may imply abnormal hematological and organismal defects in those patients.

Predictor of outcome after living donor liver transplantation for patients with hepatocellular carcinoma beyond the Japan criteria

BACKGROUND

The Japan criteria (JC, maximum tumor size within 5 cm, within five tumor nodules, AFP within 500 ng/mL or within Milan criteria) have been applied to cadaveric liver transplantation (LT) for hepatocellular carcinoma (HCC) and will be used for living donor LT (LDLT) in Japan. The aim of this study was to verify the JC in LDLT and to clarify the risk factor of HCC recurrence and mortality after LDLT beyond the JC.

PATIENTS AND METHODS

Adult patients who underwent LDLT for end-stage liver disease with HCC until October 2019 were reviewed retrospectively (n = 246). Patients were divided into two groups according to whether they were within JC (n = 203) or beyond JC (n = 43). Recurrence-free or overall survival rates after LDLT were compared. Univariate and multivariate analyses were performed to identify risk factors of HCC recurrence and HCC-related mortality after LDLT for patients beyond the JC.

RESULTS

Patients beyond the JC had significantly poorer 5-year recurrence-free (50.3% vs 95.9%, P < .001) or overall (61.7% vs 98.1%, P < .001) survival rates compared with patients within the JC. A multivariate analysis revealed that des-gamma-carboxy prothrombin (DCP) ≥ 300 mAU/mL (hazard ratio 9.36, 95% CI; 2.41-36.4, P = .001) was an independent risk factor for HCC recurrence and HCC-related mortality (hazard ratio 13.8, 95% CI; 1.92-98.6, P = .01) after LDLT in patients beyond the JC.

CONCLUSION

The outcome of LDLT for patients within the JC was favorable. Patients beyond the JC with DCP ≥ 300 mAU/mL might be contraindicated for LDLT.

Body Weight Parameters are Related to Morbidity and Mortality After Liver Transplantation: A Systematic Review and Meta-analysis

BACKGROUND

Weight gain and obesity are well-known clinical issues in liver transplantation (LTx). However, their impacts on patient outcomes remain unclear, as only the impact of pre-LTx body mass index (BMI) on survival has been meta-analyzed. We summarized and synthesized the evidence on pre- and post-LTx body weight parameters' relations with post-LTx outcomes such as survival, metabolic and cardiovascular comorbidities, and healthcare utilization.

METHODS

We followed the Cochrane Handbook for Systematic Reviews of Interventions' recommendations. Quality was assessed via a 19-item instrument. Odds ratios and 95% confidence intervals were calculated for outcomes investigated in ≥5 studies.

RESULTS

Our meta-analysis included 37 studies. Patients with pre-LTx BMI ≥ 30 kg/m and BMI ≥ 35 kg/m had lower overall survival rates than those with pre-LTx normal weight (72.6% and 69.8% versus 84.2%; P = 0.02 and P = 0.03, respectively). Those with pre-LTx BMI ≥ 30 kg/m had worse overall graft survival than normal weight patients (75.8% and 85.4%; P = 0.003). Pre-LTx BMI and pre-LTx overweight were associated with new-onset diabetes (P < 0.001 and P = 0.015, respectively), but post-LTx BMI showed no relationship. No associations were evident with healthcare utilization.

CONCLUSIONS

Patients with BMI values ≥30 kg/m had worse patient and graft survival than those with normal weight. Few of the reviewed studies examined post-LTx body weight parameters or other relevant outcomes such as cardiovascular comorbidities. High heterogeneity as well as diverse definitions and operationalizations of measurement and outcomes severely impeded comparability.

Portal flow modulation in living donor liver transplantation: review with a focus on splenectomy

Small-for-size graft (SFSG) syndrome after living donor liver transplantation (LDLT) is the dysfunction of a small graft, characterized by coagulopathy, cholestasis, ascites, and encephalopathy. It is a serious complication of LDLT and usually triggered by excessive portal flow transmitted to the allograft in the postperfusion setting, resulting in sinusoidal congestion and hemorrhage. Portal overflow injures the liver directly through nutrient excess, endothelial activation, and sinusoidal shear stress, and indirectly through arterial vasoconstriction. These conditions may be attenuated with portal flow modulation. Attempts have been made to control excessive portal flow to the SFSG, including simultaneous splenectomy, splenic artery ligation, hemi-portocaval shunt, and pharmacological manipulation, with positive outcomes. Currently, a donor liver is considered a SFSG when the graft-to-recipient weight ratio is less than 0.8 or the ratio of the graft volume to the standard liver volume is less than 40%. A strategy for transplanting SFSG safely into recipients and avoiding extensive surgery in the living donor could effectively address the donor shortage. We review the literature and assess our current knowledge of and strategies for portal flow modulation in LDLT.

Long-term Outcomes and Risk Factors After Adult Living Donor Liver Transplantation

BACKGROUND

Although risk factors for the long-term mortality of liver transplantation are well described, there is a lack of detailed study regarding these factors for adult living donor liver transplantation (LDLT).

METHODS

We retrospectively analyzed 528 adult LDLT recipients in our hospital. The risk factors were analyzed for overall deaths more than 5 years post-LDLT.

RESULTS

Over the 20-year follow-up, 137 patients died. Patient survival at 1, 3, 5, and 10 years post-LDLT was 87.8%, 81.8%, 79.4%, and 72.8%, respectively. The independent risk factors for more than 5 years post-LDLT overall death were hepatocellular carcinoma recurrence (hazard ratio [HR], 38.9; P < 0.001), lymphoid de novo malignancy (HR, 47.2; P = 0.001), primary sclerosing cholangitis as primary diagnosis (HR, 11.5; P < 0.001), chronic rejection (HR, 6.93; P = 0.006), acute rejection (HR, 2.96; P = 0.017), and bile duct stenosis (HR, 2.30; P = 0.045).

CONCLUSIONS

Not only malignancies and rejection but also bile duct stenosis and primary sclerosing cholangitis had significant impacts on late period post-LDLT mortality.

"Real-time" risk models of postoperative morbidity and mortality for liver transplants

AIM

A comprehensive description of morbidity and mortality risk factors for post liver transplant has not been available to date. In this study, we established real-time risk models of postoperative morbidities and mortality in liver transplant recipients using two Japanese nationwide databases.

METHODS

Data from two Japanese nationwide databases were combined and used for this study. We developed real-time prognostic models for morbidity and mortality from a derivation cohort (n = 1472) and validated the findings with an independent cohort (n = 395). Preoperative variables (C1), preoperative and intraoperative variables (C2), and all variables including postoperative morbidities within 30 days (C3) were analyzed to evaluate the independent risk factors for postoperative morbidity and mortality.

RESULTS

We established real-time risk models for morbidity and mortality. Areas under the curve (AUC) of C1 and C2 risk models for mortality were 0.74 (0.63-0.82) and 0.79 (0.69-0.86), respectively. Multivariate logistic analysis using C3 showed that hemoglobin <10 g/dL, operative time (hours), and five postoperative morbidities (prolonged ventilation >48 hours, coma >24 hours, renal dysfunction, postoperative systemic sepsis, and serum total bilirubin ≥10 mg/dL) represented independent risk factors for mortality (AUC = 0.87, 95% confidence interval [CI]: 0.78-0.93).

CONCLUSIONS

Real-time risk models of postoperative morbidities and mortality at various perioperative time points in liver transplant recipients were established. These novel approaches may improve postoperative outcomes of liver transplant recipients. Furthermore, these real-time risk models may be applicable to other surgical procedures.

Left lobe living donor liver transplantation in adults: What is the safety limit?

Small-for-size syndrome (SFSS) is the most significant cause of graft loss after living donor liver transplantation (LDLT), especially after left lobe (LL) LDLT in adults. The safety limit of applying LL-LDLT in adults without severe SFSS with a high rate of lethality needs to be determined. A total of 207 LL-LDLTs in adults since September 2005 were evaluated to analyze the risk factors for severe SFSS, defined as a serum total bilirubin concentration of ≥20.0 mg/dL after LDLT. Although there were no significant differences in cumulative graft survival after LDLT between medium grafts (graft volume [GV] to standard liver volume [SLV] ratio ≥ 40.0%), small grafts (35.0% ≤ GV/SLV < 40.0%), and extra small grafts (GV/SLV < 35.0%), patients with severe SFSS showed a significantly lower 5-year graft survival rate than those without (42.9% versus 94.3%, respectively; P < 0.001). Multivariate analysis for severe SFSS after LL-LDLT showed that donor age of ≥48 years (P = 0.01), Model for End-Stage Liver Disease (MELD) score of ≥ 19 (P < 0.01), and end portal venous pressure of ≥19 mm Hg (P = 0.04) were the significant and independent factors for severe SFSS after LL-LDLT. Within such high-risk subgroups of patients with a donor age of ≥48 years or MELD score of ≥ 19 before LDLT, operative blood loss volume of ≥8.0 L was a risk factor for severe SFSS. LL-LDLT in adults could be indicated and provide acceptable outcomes for the combinations of donors aged < 48 years and recipients with a MELD score of <19. Smaller grafts might yield acceptable outcomes in appropriately selected donor-recipient combinations. Liver Transplantation 22 1666-1675 2016 AASLD.

Minimum graft size calculated from preoperative recipient status in living donor liver transplantation

Small-for-size graft syndrome is an inevitable complication in living donor liver transplantation (LDLT). We hypothesized that graft weight (GW) measured after graft procurement is one of the variables predicting postoperative graft function. A total of 138 consecutive recipients of adult-to-adult LDLT between March 1999 and October 2014 were included in this study. We investigated the factors associated with small-for-size-associated graft loss (SAGL) to determine the GW required for each patient. Both preoperatively assessed and postoperatively obtained risk factors for SAGL were analyzed in univariate and multivariate logistic regression analysis. Twelve (8.8%) of the transplant recipients had SAGL. In multivariate logistic regression analyses using preoperatively assessed variables, the preoperative Model for End-Stage Liver Disease (MELD) score (P < 0.001) and actual GW/recipient standard liver volume (SLV) ratio (P = 0.008) were independent predictors of SAGL. The recommended graft volume by preoperative computed tomography volumetry was calculated as SLV × (1.616 × MELD + 0.344)/100/0.85 (mL) [MELD ≥ 18.2], or SLV × 0.35 (mL) [MELD < 18.2]. The required allograft volume in LDLT can be determined by the preoperative MELD score of the recipient, and patients with higher MELD scores require larger grafts or deceased donor whole liver transplant to avoid SAGL. Liver Transplantation 22 599-606 2016 AASLD.

Selection of a right posterior sector graft for living donor liver transplantation

Right posterior sector (RPS) grafts have been used to overcome graft size discrepancies, the major concern of living donor liver transplantation. Previous studies have reported the volumetry-based selection of RPS grafts without anatomical exclusion. We reviewed our data and established selection criteria for RPS grafts. The procurement of RPS grafts [conventional (n = 3) and extended (n = 5)] was performed for 8 of 429 recipients at our center. Extended RPS grafts contained the drainage area of the right hepatic vein. The mean graft weight (GW) according to 3-dimensional computed tomography volumetry was 488 g, and the GW/standard liver weight (SLW) ratio was 42.6%. The mean actual GW was 437 g, and the GW/SLW ratio was 38.4%. One donor exhibited standard bifurcation of the right portal vein (PV) and the left PV, and 2 donors exhibited trifurcation of the left PV, the right anterior portal vein (APV), and the posterior PV. The remaining 5 donors exhibited APV branching from the left PV, which is the most suitable anatomy for RPS grafts. Two recipients died of sepsis or small-for-size graft syndrome. One underwent retransplantation because of an intractable bile leak and fibrosing cholestatic hepatitis. Intractable bile duct (BD) stenosis developed in 4 of the 6 survivors. In conclusion, with the significant complications and potential concerns associated with RPS grafts, these grafts should be used very rarely and with extreme caution. Donors with the standard bifurcation of the PV and the posterior BD running through the dorsal side of the posterior PV are not suitable candidates for RPS grafts. Extended RPS graft procurement is recommended for easier parenchymal transection.