Challenges and Outcome of Left-lobe Liver Transplants in Adult Living Donor Liver Transplants

Early Graft Failure After Living-Donor Liver Transplant

BACKGROUND

Living-donor liver transplantation (LDLT) has been increasing in the USA. While data exist on longer-term patient and graft outcomes, a contemporary analysis of short-term outcomes is needed.

AIM

Evaluate short-term (30-day) graft failure rates and identify predictors associated with these outcomes.

METHODS

Adult (≥ 18) LDLT recipients from 01/2004 to 12/2021 were analyzed from the United States Scientific Registry of Transplant Recipients. Graft status at 30 days was assessed with graft failure defined as retransplantation or death. Comparison of continuous and categorical variables was performed and a multivariable logistic regression was used to identify risk factors of early graft failure.

RESULTS

During the study period, 4544 LDLTs were performed with a graft failure rate of 3.4% (155) at 30 days. Grafts from male donors (aOR: 0.63, CI 0.44-0.89), right lobe grafts (aOR: 0.40, CI 0.27-0.61), recipients aged > 60 years (aOR: 0.52, CI 0.32-0.86), and higher recipient albumin (aOR: 0.73, CI 0.57-0.93) were associated with superior early graft outcomes, whereas Asian recipient race (vs. White; aOR: 3.75, CI 1.98-7.10) and a history of recipient PVT (aOR: 2.7, CI 1.52-4.78) were associated with inferior outcomes. LDLTs performed during the most recent 2016-2021 period (compared to 2004-2009 and 2010-2015) resulted in significantly superior outcomes (aOR: 0.45, p < 0.001).

CONCLUSION

Our study demonstrates that while short-term adult LDLT graft failure is uncommon, there are opportunities for optimizing outcomes by prioritizing right lobe donation, improving candidate nutritional status, and careful pre-transplant risk assessment of candidates with known PVT. Notably, a period effect exists whereby increased LDLT experience in the most recent era correlated with improved outcomes.

Protection of liver sinusoids by intravenous administration of human Muse cells in a rat extra-small partial liver transplantation model

Small-for-size syndrome (SFSS) has a poor prognosis due to excessive shear stress and sinusoidal microcirculatory disturbances in the acute phase after living-donor liver transplantation (LDLT). Multilineage-differentiating stress enduring (Muse) cells are reparative stem cells found in various tissues and currently under clinical trials. These cells selectively home to damaged sites via the sphingosine-1-phosphate (S1P)-S1P receptor 2 system and repair damaged tissue by pleiotropic effects, including tissue protection and damaged/apoptotic cell replacement by differentiating into tissue-constituent cells. The effects of intravenously administered human bone marrow-Muse cells and -mesenchymal stem cells (MSCs) (4 × 105 ) on liver sinusoidal endothelial cells (LSECs) were examined in a rat SFSS model without immunosuppression. Compared with MSCs, Muse cells intensively homed to the grafted liver, distributed to the sinusoids and vessels, and delivered improved blood chemistry and Ki-67(+) proliferative hepatocytes and -LSECs within 3 days. Tissue clearing and three-dimensional imaging by multiphoton laser confocal microscopy revealed maintenance of the sinusoid continuity, organization, and surface area, as well as decreased sinusoid interruption in the Muse group. Small-interfering RNA-induced knockdown of hepatocyte growth factor and vascular endothelial growth factor-A impaired the protective effect of Muse cells on LSECs. Intravenous injection of Muse cells might be a feasible approach for LDLT with less recipient burden.

Current status of left lobe adult to adult living donor liver transplantation

PURPOSE OF REVIEW

This review describes the history and current state of left lobe living donor liver transplantation (LDLT). The transplant community continues to face an organ shortage on a global scale, and the expansion of LDLT is attractive because it allows us to provide life-saving liver transplants to individuals without drawing from, or depending on, the limited deceased donor pool. Donor safety is paramount in LDLT, and for this reason, left lobe LDLT is particularly attractive because the donor is left with a larger remnant.

RECENT FINDINGS

This article reviews the donor and recipient evaluations for left lobe LDLT, discusses small for size syndrome and the importance of portal inflow modification, and reviews recipient outcomes in right lobe versus left lobe LDLT.

SUMMARY

Left lobe LDLT was the first adult-to-adult LDLT ever to be performed in Japan in 1993. Since that time, the use of both right and left lobe LDLT has expanded immensely. Recent work in left lobe LDLT has emphasized the need for inflow modification to reduce portal hyperperfusion and early graft dysfunction following transplant. Accumulating evidence suggests, however, that even though early graft dysfunction following LDLT may prolong hospitalization, it does not predict graft or patient survival.

Successful auxiliary two-staged partial resection liver transplantation (ASPIRE-LTx) for end-stage liver disease to avoid small-for-size situations

Background

Risks for living-liver donors are lower in case of a left liver donation, however, due to lower graft volume, the risk for small-for-size situations in the recipients increases. This study aims to prevent small-for-size situations in recipients using an auxiliary two-staged partial resection liver transplantation (LTX) of living-donated left liver lobes.

Case presentation

Two patients received a two-stage auxiliary LTX using living-donated left liver lobes after left lateral liver resection. The native extended right liver was removed in a second operation after sufficient hypertrophy of the left liver graft had occurred. Neither donor developed postoperative complications. In both recipients, the graft volume increased by an average of 105% (329 ml to 641 ml), from a graft-to-body-weight ratio of 0.54 to 1.08 within 11 days after LTX, so that the remnant native right liver could be removed. No recipient developed small-for-size syndrome; graft function and overall condition is good in both recipients after a follow-up time of 25 months.

Conclusions

Auxiliary two-staged partial resection LTX using living-donor left lobes is technically feasible and can prevent small-for-size situation. This new technique can expand the potential living-donor pool and contributes to increase donor safety.

Post-operative imaging anatomy in liver transplantation

The article describes and illustrates the surgical techniques and the post-operative imaging anatomy in liver transplantation. Special attention is paid to the variant vascular and biliary anatomy that are important for surgical planning. Considering the ever-growing number of liver transplants performed and the key role that imaging plays in the pre-operative planning and post-operative assessment, it is important for the radiologist to be familiar with the surgical techniques and the normal post-operative appearance in these patients.

Is Portal Venous Pressure Modulation Still Indicated for All Recipients in Living Donor Liver Transplantation?

There is a consensus that portal venous pressure (PVP) modulation prevents portal hypertension (PHT) and consequent complications after adult-to-adult living donor liver transplantation (ALDLT). However, PVP-modulation strategies need to be updated based on the most recent findings. We examined our 10-year experience of PVP modulation and reevaluated whether it was necessary for all recipients or for selected recipients in ALDLT. In this retrospective study, 319 patients who underwent ALDLT from 2007 to 2016 were divided into 3 groups according to the necessity and results of PVP modulation: not indicated (n = 189), indicated and succeeded (n = 92), and indicated but failed (n = 38). Graft survival and associations with various clinical factors were investigated. PVP modulation was performed mainly by splenectomy to lower final PVP to ≤15 mm Hg. Successful PVP modulation improved prognosis to be equivalent to that of patients who did not need modulation, whereas failed modulation was associated with increased incidence of small-for-size syndrome (SFSS; P = 0.003) and early graft loss (EGL; P = 0.006). Among patients with failed modulation, donor age ≥ 45 years (hazard ratio [HR], 3.67; P = 0.02) and ABO incompatibility (HR, 3.90; P = 0.01) were independent risk factors for graft loss. Survival analysis showed that PVP > 15 mm Hg was related to poor prognosis in grafts from either ABO-incompatible or older donor age ≥ 45 years (P < 0.001), but it did not negatively affect grafts from ABO-compatible/identical and young donor age < 45 years (P = 0.27). In conclusion, intentional PVP modulation is not necessarily required in all recipients. Although grafts from both ABO-compatible/identical and young donors can tolerate PHT, lowering PVP to ≤15 mm Hg is a key to preventing SFSS and consequent EGL with grafts from either ABO-incompatible or older donors.

Feasibility of using marginal liver grafts in living donor liver transplantation

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

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).

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).

Adult living donor liver imaging

Adult living donor liver transplantation (LDLT) is increasingly used for the treatment of end-stage liver disease. The three most commonly harvested grafts for LDLT are left lateral segment, left lobe, and right lobe grafts. The left lateral segment graft, which includes Couinaud's segments II and III, is usually used for pediatric recipients or small size recipients. Most of the adult recipients need either a left or a right lobe graft. Whether a left or right lobe graft should be harvested from the donors depends on estimated graft and donor remnant liver volume, as well as biliary and vascular anatomy. Detailed preoperative assessment of the potential donor liver volumetrics, biliary and vascular anatomy, and liver parenchyma is vital to minimize risks to the donors and maximize benefits to the recipients. Computed tomography (CT) and magnetic resonance imaging (MRI) are currently the imaging modalities of choice in the preoperative evaluation of potential donors. This review provides an overview of key surgical considerations in LDLT that the radiologists must be aware of, and imaging findings on CT and MRI that the radiologists must convey to the surgeons when evaluating potential donors for LDLT.

Graft-to-recipient weight ratio threshold adjusted to the model for end-stage liver disease score for living donor liver transplantation

The graft-to-recipient weight ratio (GRWR) is an important selection criterion for living donor liver transplantation (LDLT). The generally accepted threshold is known to be 0.8%. We believe that this threshold can be reduced under certain conditions. The aim of this study was to evaluate the results of these patients with GRWR < 0.8%. Between 2004 and 2015, 649 patients underwent right lobe LDLT for end-stage liver disease in adult patients. All recipients who had GRWR < 0.8% were identified. The data of these patients were retrospectively analyzed and compared to patients with GRWR ≥ 0.8%. There were 43 patients with GRWR < 0.8%. Out of these patients, 7 (16%) had GRWR of 0.6%. The median Model for End-Stage Liver Disease (MELD) score was 15, and the median donor age was 30 years. Anterior segment drainage was ensured. Portal inflow modulation was performed by splenic artery ligation according to the portal flow. Postoperative complications were seen in 6 (14%) patients. Of all 43 patients, 3 (7%) died perioperatively within 1 month, and 1 (2%) patient underwent retransplantation due to graft failure. The mean hospital stay was 18 days. The 1-year survival rate was 93%. None of the patients had a laboratory MELD score above 20. The comparison of the results with the patients who had GRWR ≥ 0.8% has shown no significant difference, except MELD score, body mass index (BMI), and rate of anterior segment drainage. The GRWR can be decreased even to 0.6% if the MELD score is below 20, donor age is below 45 years, and there are no signs for any hepatosteatosis of the donor graft. In these patients, it is essential that the anterior segment drainage is secured and the portal inflow modulation is performed according to the portal flow. Liver Transplantation 22 1643-1648 2016 AASLD.

How far can we lower graft-to-recipient weight ratio for living donor liver transplantation under modulation of portal venous pressure?

BACKGROUND

Smaller size grafts for living donor liver transplantation (LDLT) can enhance donor safety and expand donor availability. We previously reported that modulation of portal venous pressure (PVP) was key for successful LDLT with small grafts, and that it actively lowered graft-to-recipient weight ratio (GRWR) for adult-to-adult LDLT. This retrospective study investigated the outcome of LDLT using small grafts with PVP modulation.

METHOD

This study analyzed 221 adult LDLT patients between March 2008 and December 2013 and divided them into 3 groups based on GRWR: large (L), GRWR ≥ 0.8% (n = 154), medium (M), ≥ 0.7% GRWR < 0.8% (n = 38); and small (S) GRWR < 0.7% (n = 29). Donor and recipient factors, PVP, pressure gradient between PVP and central venous pressure (CVP), occurrence of small for size syndrome (SFSS), ascites, and posttransplant laboratory data were compared across the 3 groups. Patient and graft survival were compared using Kaplan-Meier methods.

RESULTS

There was no difference in patient or graft survival between the 3 groups. Amount of posttransplant ascites and posttransplant International Normalized Ratio were similar, but the S and M groups had more prolonged cholestasis. SFSS was identified in 17%, 13%, and 13% in the S, M, and L groups, respectively (P = NS). Patients with a final PVP of ≤15 mmHg had better survival than patients with a final PVP of >15 mmHg (P < .001). Multivariate analysis showed that donor age >40 years old, final PVP of >15 mmHg, and pressure gradient of PVP-CVP >5 mmHg were risk factors for inferior patient survival.

CONCLUSION

We achieved satisfactory outcomes in LDLT with GRWR as low as 0.6% using PVP modulation. Thus, we currently set a lower limit of GRWR at 0.6% while protecting donor safety and expanding donor availability.