Alleviating the burden of small-for-size graft in right liver living donor liver transplantation through accumulation of experience

Indications and results of right-lobe living donor liver transplantation

The shortage of deceased liver donor organs over the years has always posed the need to expand the donor pool. A viable alternative to deceased donors is that of the living donor. Indeed, the living donor in liver transplantation, initially in pediatric transplantation, but for several years now also in adult transplantation, is a more than viable alternative to deceased liver donation. In fact, right liver lobe donation has proven to be a surgical procedure with low impact on the donor's life in terms of morbidity and mortality, with excellent results in recipients of such organs. In recent years, an increasing number of studies have been published that show excellent results in right-lobe living donor liver transplantation, encouraging this practice not only in countries that have historically had a shortage of deceased donor organs, such as Asian countries, but making it a practice of increasing use in Western countries as well. In addition, thanks to improvements in surgical technique and the experience of high-volume centers, this surgery has also begun to be performed using minimally invasive surgical techniques, allowing us to envision ever better outcomes for both donor and recipient in the coming years.

Preventing Small-for-size Syndrome in Living Donor Liver Transplantation: Guidelines From the ILTS-iLDLT-LTSI Consensus Conference

Small-for-size syndrome (SFSS) is a well-recognized complication following liver transplantation (LT), with up to 20% developing this following living donor LT (LDLT). Preventing SFSS involves consideration of factors before the surgical procedure, including donor and recipient selection, and factors during the surgical procedure, including adequate outflow reconstruction, graft portal inflow modulation, and management of portosystemic shunts. International Liver Transplantation Society, International Living Donor Liver Transplantation Group, and Liver Transplant Society of India Consensus Conference was convened in January 2023 to develop recommendations for the prediction and management of SFSS in LDLT. The format of the conference was based on the Grading of Recommendations, Assessment, Development, and Evaluation system. International experts in this field were allocated to 4 working groups (diagnosis, prevention, anesthesia, and critical care considerations, and management of established SFSS). The working groups prepared evidence-based recommendations to answer-specific questions considering the currently available literature. The working group members, independent panel, and conference attendees served as jury to edit and confirm the final recommendations presented at the end of the conference by each working group separately. This report presents the final statements and evidence-based recommendations provided by working group 2 that can be implemented to prevent SFSS in LDLT patients.

Management of Established Small-for-size Syndrome in Post Living Donor Liver Transplantation: Medical, Radiological, and Surgical Interventions: Guidelines From the ILTS-iLDLT-LTSI Consensus Conference

Small-for-size syndrome (SFSS) following living donor liver transplantation is a complication that can lead to devastating outcomes such as prolonged poor graft function and possibly graft loss. Because of the concern about the syndrome, some transplants of mismatched grafts may not be performed. Portal hyperperfusion of a small graft and hyperdynamic splanchnic circulation are recognized as main pathogenic factors for the syndrome. Management of established SFSS is guided by the severity of the presentation with the initial focus on pharmacological therapy to modulate portal flow and provide supportive care to the patient with the goal of facilitating graft regeneration and recovery. When medical management fails or condition progresses with impending dysfunction or even liver failure, interventional radiology (IR) and/or surgical interventions to reduce portal overperfusion should be considered. Although most patients have good outcomes with medical, IR, and/or surgical management that allow graft regeneration, the risk of graft loss increases dramatically in the setting of bilirubin >10 mg/dL and INR>1.6 on postoperative day 7 or isolated bilirubin >20 mg/dL on postoperative day 14. Retransplantation should be considered based on the overall clinical situation and the above postoperative laboratory parameters. The following recommendations focus on medical and IR/surgical management of SFSS as well as considerations and timing of retransplantation when other therapies fail.

Small-For-Size Syndrome and Graft Inflow Modulation Techniques in Liver Transplantation

BACKGROUND

Partial liver transplantation has recently been proposed to alleviate organ shortages. However, transplantation of a small-for-size graft is associated with an increased risk of posttransplant hepatic dysfunction, commonly referred to as small-for-size syndrome (SFSS). This review describes the etiology, pathological features, clinical manifestations, and diagnostic criteria of SFSS. Moreover, we summarize strategies to improve graft function, focusing on graft inflow modulation techniques. Finally, unmet needs and future perspectives are discussed.

SUMMARY

In fact, posttransplant SFSS can be attributed to various factors such as preoperative status of the recipients, surgical techniques, donor age, and graft quality, except for graft size. With targeted improvement measures, satisfactory clinical outcomes can be achieved in recipients at increased risk of SFSS. Given the critical role of relative portal hyperperfusion in the pathogenesis of SFSS, various pharmacological and surgical treatments have been established to reduce or partially divert excessive portal inflow, and recipients will benefit from individualized therapeutic regimens after careful evaluation of benefits against potential risks. However, there remain unmet needs for further research into different aspects of SFSS to better understand the correlation between portal hemodynamics and patient outcomes.

KEY MESSAGES

Contemporary transplant surgeons should consider various donor and recipient factors and develop case-specific prevention and treatment strategies to improve graft and recipient survival rates.

Is 0.6% Reasonable as the Minimum Requirement of the Graft-to-recipient Weight Ratio Regardless of Lobe Selection in Adult Living-donor Liver Transplantation?

BACKGROUND

Several studies reported favorable outcomes of small-for-size grafts with graft-to-recipient weight ratio (GRWR) <0.8% in living-donor liver transplantation (LDLT). However, their indications should be carefully determined because they must have been indicated for low-risk cases over larger grafts with 0.8% ≤ GRWR. Furthermore, evidence for minimum requirements of GRWR remains inconclusive. We investigated the safety of small-for-size grafts against larger grafts by adjusting for confounding risk factors, and minimum requirement of graft volume in adult LDLT.

METHODS

We enrolled 417 cases of primary adult-to-adult LDLT in our center between 2006 and 2019. The outcomes of small grafts (0.6% ≤ GRWR < 0.8%, n = 113) and large grafts (0.8% ≤ GRWR, n = 289) were mainly compared using a multivariate analysis and Kaplan-Meier estimates.

RESULTS

The multivariate analysis showed that small grafts were not a significant risk factor for overall graft survival (GS). In the Kaplan-Meier analysis, small grafts did not significantly affect overall GS regardless of lobe selection (versus large grafts). However, GRWR < 0.6% was associated with poor overall GS. Although there were no significant differences between the 2 groups, unadjusted Kaplan-Meier curves of small grafts were inferior to those of large grafts in subcohorts with ABO incompatibility, and donor age ≥50 years.

CONCLUSIONS

Similar outcomes were observed for small and large graft use regardless of lobe selection. 0.6% in GRWR was reasonable as the minimum requirement of graft volume in LDLT. However, small grafts should be indicated carefully for high-risk cases.

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.

Live Liver Donors: Is Right Still Right?

BACKGROUND

Conventional wisdom dictates that a larger hepatectomy is more prone to complications. Consequently, with the donor safety as paramount, the transplant community has intuitively been proponents of left lobe donation in live donor liver transplantation (LDLT), thereby satisfying the tenet of double equipoise. More recently some data suggest that this may not always be the case, especially in established centres. Our aim was to compare right and left lobe donor outcomes in LDLT from a centre with cumulative experience.

METHODS

Review of a prospectively collected database of right and left lobe liver donors operated between August 2009 and July 2017 was performed. Their preoperative demographics, operative and post-operative outcomes were compared.

RESULTS

Of 904 liver transplantations, 458 were right lobe donors [379 without middle hepatic vein (MHV), 79 with MHV] and 58 left lobe donors. There was a significant difference in GRWR and functional liver remnant between the right and left lobe donors (1.27 ± 0.45 vs. 1.03 ± 0.28 p = 0.004, and 63.2 ± 7.9 vs. 37.7 ± 16.3, respectively, p value). The end portal pressure (7 vs. 8 mmHg p = <0.001), peak bilirubin (1.6 ± 0.8 vs. 2.9 ± 1.5 p = <0.001) and day 5 bilirubin (0.8 ± 0.3 vs. 1.4 ± 0.9 p = <0.001) were significantly higher in right lobe donors. There was no difference in blood loss, duration of surgery or peak lactate between the groups. Complications (20.7% vs. 25.9% p = 0.48), including serious complications (Clavien-Dindo > III) (6.9% vs. 8.1% p = 0.95), duration of ICU and hospital stay, were comparable between the groups. Subgroup analysis between left lobe and right lobe with and without MHV donor was also comparable.

CONCLUSION

Though biochemical differences exist between the groups, no difference in outcomes was noted. Despite larger liver mass loss in right lobe donors, a strict protocol-based approach to donor selection leads to comparable outcomes between left lobe and right lobe donations.

Small-for-size graft, small-for-size syndrome and inflow modulation in living donor liver transplantation

The extended application of living donor liver transplantation (LDLT) has revealed the problem of graft size mismatching called "small-for-size syndrome (SFSS)." The initial trials to resolve this problem involved increasing the procured graft size, from left to right, and even extending to include a right lobe graft. Clinical cases of living right lobe donations have been reported since then, drawing attention to the risks of increasing the liver volume procured from a living donor. However, not only other modes of increasing graft volume (GV) such as auxiliary or dual liver transplantation, but also control of the increased portal pressure caused by a small-for-size graft (SFSG), such as a porto-systemic shunt or splenectomy and optimal outflow reconstruction, have been trialed with some positive results. To establish an effective strategy for transplanting SFSG and preventing SFSS, it is essential to have precise knowledge and tactics to evaluate graft quality and GV, when performing these LDLTs with portal pressure control and good venous outflow. Thus, we reviewed the updated literature on the pathogenesis of and strategies for using SFSG.

Living-donor liver transplantation: Right versus left

A dilemma of graft selection between right or left livers occurs during the planning of living-donor liver transplantation (LDLT) as well as splitting a whole liver graft into full right/full left grafts in deceased-donor liver transplantation. The right liver's relation to the whole liver could be considered as the trunk of a tree; it has a larger volume, the main axis of bile ducts, and the inferior vena cava mainly belongs to the right liver. Therefore, it was considered as the standard graft in LDLTs. Whether to procure the middle hepatic vein (MHV) with a right liver graft or to leave it attached to the left-liver remnant largely depends on the transplant institute. Recently, most transplant institutes tend to leave the MHV with the left liver for the sake of donor safety. Unlike hepatectomy for liver tumors, it is vital to preserve inflow and outflow for both the resected as well as the remaining livers. While procuring any graft type, the most important is to procure a liver graft with reconstructable portal veins, hepatic arteries, hepatic veins, and bile ducts, which should be well preoperatively planned using 3D-computed tomography with considerations given to graft volume and potential congestion areas.

The Risk of Going Small: Lowering GRWR and Overcoming Small-For-Size Syndrome in Adult Living Donor Liver Transplantation

OBJECTIVE

The aim of this study was to determine the outcomes of living donor liver transplantation (LDLT) according to various graft-to-recipient weight ratio (GRWR).

BACKGROUND

The standard GRWR in LDLT is >0.8%. Our center accepted predicted GRWR ≥0.6% in selected patients.

METHODS

Data from patients who underwent LDLT from 2001 to 2017 were included. Patients were stratified according to actual GRWR (Group 1:GRWR ≤0.6%; Group 2: 0.6%<GRWR≤ 0.8%; Group 3:GRWR >0.8%).

RESULTS

There were 545 LDLT (group 1 = 39; group 2 = 159; group 3 = 347) performed. Pretransplant predicted GRWR showed good correlation to actual GRWR (R = 0.834) and these figures differed within a ± 10%margin (P = 0.034) using an equivalence test. There were more left lobe grafts in group 1 (33.3%) than group 2 (10.7%) and 3 (2.9%). Median donor age was <35 years and steatosis >10% was rare.There was no difference in postoperative complication, vascular and biliary complication rate between groups. Over one-fifth (20.5%) of group 1 patients required portal flow modulation (PFM) and was higher than group 2 (3.1%) and group 3 (4%) (P = 0.001). Twenty-six patients developed small-for-size syndrome (SFSS): 5 of 39 (12.8%) in group 1 and 21 of 159 (13.2%) in group 2 and none in group 3 (P < 0.001). There were 2 hospital mortalities; otherwise, the remaining patients [24/26 (92.3%)] survive with a functional liver graft. The 5-year graft survival rates were 85.4% versus 87.8% versus 84.7% for group 1, 2, and 3, respectively (P = 0.718). GRWR did not predict worse survivals in multivariable analysis.

CONCLUSIONS

Graft size in LDLT can be lowered to 0.6% after careful recipient selection, with low incidence of SFSS and excellent outcomes. Accurate graft weight prediction, donor-recipient matching, meticulous surgical techniques, appropriate use of PFM, and vigilant perioperative care is important to the success of such approach.

Conceptual changes in small-for-size graft and small-for-size syndrome in living donor liver transplantation

Early series in living donor liver transplantation (LDLT) in adults demonstrated a lower safe limit of graft volume standard liver volume ratio 25%–45%. A subsequent worldwide large LDLT series proposed a 0.8 graft recipient weight ratio (GRWR) to define small-for-size graft (SFSG) in adult LDLT. Thereafter, researchers identified innate and inevitable factors including changes in liver volume during imaging studies and graft shrinkage due to perfusion solution. Although the definition of small-for-size syndrome (SFSS) advocated in the 2000s was mainly based on prolonged cholestasis and ascites output, the term SFSS was inadequate to describe clinical manifestations possibly caused by multiple factors. Thus, the term “early allograft dysfunction (EAD),” characterized by total bilirubin >10 mg/dL or coagulopathy with international normalized ratio >1.6 on day 7, has become prevalent to describe graft dysfunction including SFSS after LDLT. Although various efforts have been made to overcome EAD in LDLT, graft selection to maintain an expected GRWR >0.8 and full venous drainage, as well as inflow modulation using splenic artery ligation, have become standard in recent LDLT.

Donor ductal anomaly is not a contraindication to right liver lobe donation

BACKGROUND

Data of living-donor liver transplantation (LDLT) suggested that donor ductal anomaly may contribute to postoperative biliary complications in recipients and in donors. This retrospective study aimed to determine if the occurrence of postoperative biliary stricture in donors or recipients in right-lobe LDLT (RLDLT) is related to donor biliary anatomy type.

METHODS

We analyzed our RLDLT recipients' clinical data and those of their graft donors. The recipients were divided into 2 groups: with and without postoperative biliary stricture. The 2 groups were compared. The primary endpoints were donor biliary anatomy type and postoperative biliary complication incidence; the secondary endpoints were 1-, 3- and 5-year graft and patient survival rates.

RESULTS

Totally 127 patients were included in the study; 25 (19.7%) of them developed biliary anastomotic stricture. In these 25 patients, 16 had type A biliary anatomy, 3 had type B, 2 had type C, 3 had type D, and 1 had type E. In the 127 donors, 96 (75.6%) had type A biliary anatomy, 13 (10.2%) had type B, 6 (4.7%) had type C, 10 (7.9%) had type D, and 2 (1.6%) had type E. Biliary stricture was seen in 2 donors, who had type A biliary anatomy. None of the recipients or donors developed bile leakage. No association between the occurrence of postoperative biliary stricture and donor biliary anatomy type was found (P = 0.527).

CONCLUSIONS

The incidence of biliary stricture in donors or recipients after RLDLT was not related to donor biliary anatomy type. As postoperative complications were similar in whatever type of donor bile duct anatomy, donor ductal anomaly should not be considered a contraindication to donation of right liver lobe.

The International Liver Transplantation Society Living Donor Liver Transplant Recipient Guideline

Living donor liver transplantation (LDLT) has been increasingly embraced around the world as an important strategy to address the shortage of deceased donor livers. The aim of this guideline, approved by the International Liver Transplantation Society (ILTS), is to provide a collection of expert opinions, consensus, and best practices surrounding LDLT. Recommendations were developed from an analysis of the National Library of Medicine living donor transplantation indexed literature using the Grading of Recommendations Assessment, Development and Evaluation methodology. Writing was guided by the ILTS Policy on the Development and Use of Practice Guidelines (www.ilts.org). Intended for use by physicians, these recommendations support specific approaches to the diagnostic, therapeutic, and preventive aspects of care of living donor liver transplant recipients.

Compared to cadaveric liver transplantation, live donor LT (LDLT) is challenged by ethical, medical and surgical considerations, many of which are still unresolved. The aim of this guideline is to provide a collection of expert opinions, consensus, and best practices surrounding LDLT.

Outcomes of right-lobe and left-lobe living-donor liver transplantations using small-for-size grafts

AIM

To analyze the outcomes of living-donor liver transplantation (LDLT) using left-lobe (LL) or right-lobe (RL) small-for-size (SFS) grafts.

METHODS

Prospectively collected data of adult patients who underwent LDLT at our hospital in the period from January 2003 to December 2013 were reviewed. The patients were divided into the RL-LDLT group and the LL-LDLT group. The two groups were compared in terms of short- and long-term outcomes, including incidence of postoperative complication, graft function, graft survival, and patient survival. A SFS graft was defined as a graft with a ratio of graft weight (GW) to recipient standard liver volume (RSLV) (GW/RSLV) of < 50%. The Urata formula was used to estimate RSLV.

RESULTS

Totally 218 patients were included for analysis, with 199 patients in the RL-LDLT group and 19 patients in the LL-LDLT group. The two groups were similar in terms of age (median, 53 years in the RL-LDLT group and 52 years in the LL-LDLT group, P = 0.997) but had significantly different ratios of men to women (165:34 in the RL-LDLT group and 8:11 in the LL-LDLT group, P < 0.0001). The two groups were also significantly different in GW (P < 0.0001), GW/RSLV (P < 0.0001), and graft cold ischemic time (P = 0.007). When it comes to postoperative complication, the groups were comparable (P = 0.105). Five patients died in hospital, 4 (2%) in the RL-LDLT group and 1 (5.3%) in the LL-LDLT group (P = 0.918). There were 38 graft losses, 33 (16.6%) in the RL-LDLT group and 5 (26.3%) in the LL-LDLT group (P = 0.452). The 5-year graft survival rate was significantly better in the RL-LDLT group (95.2% vs 89.5%, P = 0.049). The two groups had similar 5-year patient survival rates (RL-LDLT: 86.8%, LL-LDLT: 89.5%, P = 0.476).

CONCLUSION

The use of SFS graft in LDLT requires careful tailor-made surgical planning and meticulous operation. LL-LDLT can be a good alternative to RL-LDLT with similar recipient outcomes but a lower donor risk. Further research into different patient conditions is needed in order to validate the use of LL graft.

Comparable Short- and Long-term Outcomes in Living Donor and Deceased Donor Liver Transplantations for Patients With Model for End-stage Liver Disease Scores ≥35 in a Hepatitis-B Endemic Area

OBJECTIVE

To evaluate if living donor liver transplantation (LDLT) should be offered to patients with Model for End-stage Liver Disease (MELD) scores ≥35.

BACKGROUND

No data was available to support LDLT of such patients.

METHODS

Data of 672 consecutive adult liver transplant recipients from 2005 to 2014 at our center were reviewed. Patients with MELD scores ≥35 were divided into the deceased donor liver transplantation (DDLT) group and the LDLT group and were compared. Univariate analysis was performed to identify risk factors affecting survival.

RESULTS

The LDLT group (n = 54) had younger (33 yrs vs 50 yrs, P < 0.001) and lighter (56 Kg vs 65 Kg, P = 0.004) donors, lighter grafts (627.5 g vs 1252.5 g, P < 0.001), lower graft-weight-to-recipient-standard-liver-volume rates (51.28% vs 99.76%, P < 0.001), shorter cold ischemic time (106.5 min vs 389 min, P < 0.001), and longer operation time (681.5 min vs 534 min, P < 0.001). The groups were comparable in postoperative complication, hospital mortality, and graft survival and patient survival at one year (88.9% vs 92.5%; 88.9% vs 94.7%), three years (87.0% vs 86.9%; 87.0% vs 88.8%), and five years (84.8% vs 81.8%; 84.8% vs 83.3%). Univariate analysis did not show inferior survival in LDLT recipients.

CONCLUSIONS

At centers with experience, the outcomes of LDLT can be comparable with those of DDLT even in patients with MELD scores ≥35. When donor risks and recipient benefits are fully considered and balanced, an MELD score ≥35 should not be a contraindication to LDLT. In Hong Kong, where most waitlisted patients have acute-on-chronic liver failure from hepatitis B, LDLT is a wise alternative to DDLT.

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.

Outcomes of endo-radiological approach to management of bile leakage after right lobe living donor liver transplantation

BACKGROUND AND AIM

Bile leakage is a major complication after right lobe living donor liver transplantation (RLDLT). It can result in significant morbidities and, occasionally, mortalities. Endo-radiology is a non-surgical means that has been used to manage this complication. This study reviews the outcomes of the endo-radiological approach to the management of bile leakage after RLDLT with duct-to-duct anastomosis (DDA) at a high-volume center.

METHOD

A retrospective study was conducted on all adult patients who received RLDLT at our center between January 2001 and December 2013. There were 496 RLDLTs performed during the study period. Only patients who had DDA as the only bile duct reconstruction method were included in the study.

RESULTS

Twelve (3.7%) out of the 328 study subjects developed bile leakage after RLDLT. Six out of these 12 patients were successfully treated with the endo-radiological approach without the need for laparotomy. They had endoscopic retrograde cholangiography with stenting followed by percutaneous drainage of biloma. One of the 12 patients died from recurrence of hepatocellular carcinoma 37 months after transplantation. The remaining 11 patients are all alive.

CONCLUSION

The endo-radiological approach should be the first-line management for bile leakage for selected patients with DDA as the bile duct reconstruction method.

Durability of small-for-size living donor allografts

Our aim was to study the long-term outcomes of living donor liver transplantation using small-for-size (SFS) grafts. From July 2002 to July 2009, 233 patients received a right liver graft with a middle hepatic vein from a living donor in our center. Recipients were stratified according to the graft weight to recipient standard liver volume (GW/SLV) ratio into 4 groups: >50% (n = 89), >40% to 50% (n = 85), >35% to 40% (n = 38), and ≤ 35% (n = 21). They were compared in terms of graft survivals, biliary stricture rates, renal function in terms of estimated glomerular filtration rate (eGFR), platelet counts, and graft function in terms of serum bilirubin and international normalized ratio (INR). The 5-year graft survivals for patients with GW/SLV of >50%, >40% to 50%, >35% to 40% and ≤ 35% were 88.8%, 88.2%, 81.5%, and 81.0%, respectively. Transplantation for hepatocellular carcinoma affected graft survivals (P = 0.02), but graft size did not (P = 0.66). There were no differences in frequency of biliary stricture (21.3% versus 17.1% versus 21.1% versus 28.6%; P = 0.75). At each year after transplant, their platelet counts (P = 0.12-0.65), eGFR (P = 0.49-0.91), bilirubin (P = 0.14-0.51), and INR (P = 0.20-0.98) remained comparable. SFS grafts with GW/SLV ≤ 35% and >35% to 40% had comparable long-term outcomes with larger liver grafts. Graft size did not affect long-term graft survivals.

Transplantation of a 2-year-old deceased-donor liver to a 61-year-old male recipient

The suitable size of a graft is a key element in the success of liver transplantation. A small-for-size liver graft is very likely to sustain a significant degree of injury as a result of ischemia, preservation, reperfusion, and rejection. Usually, small-for-size grafts are a concern in living-donor liver transplantation rather than in deceased-donor liver transplantation. Here, we describe the successful transplantation of a liver from a 2-year-old deceased donor to a 61-year-old male recipient who suffered from liver failure related to hepatitis B. No report of successful deceased-donor liver transplantation with discrepancies between donor and recipient age and size to such an extent has been found in the literature. Despite unusually large discrepancies, with effort in minimizing the ischemic time, revised surgical techniques, and strong regenerative power of the "young" graft, the old patient's liver function gradually returned to normal. This again proves that the definition of a "suitable graft" evolves with time and experience.

Clinical significance of gastrointestinal bleeding after living donor liver transplantation

The clinical presentations of gastrointestinal bleeding (GIB) occurring after living donor liver transplantation (LDLT) have not been fully described. We performed a retrospective analysis of 297 LDLT cases. Nineteen patients (6.4%) experienced GIB after LDLT. The etiology of GIB included bleeding at the jejunojejunostomy following hepaticojejunostomy (n = 13), peptic ulcer disease (n = 2), portal hypertensive gastropathy (n = 2), and other causes (n = 2). Hemostasis was achieved in 13 patients (68.4%) by endoscopic (n = 3), surgical (n = 1), or supportive treatments (n = 15), but not in the other six patients. Graft dysfunction (P < 0.001), hepaticojejunostomy (P = 0.01), portal vein pressure at the end of surgery >20 mmHg (P = 0.002), and operative blood loss >10 L (P = 0.004) were risk factors. One-year graft survival rate was significantly lower in patients with GIB than in patients without GIB (P < 0.001). The inhospital mortality rate was 52.6% for patients with GIB, 75.0% for patients with graft dysfunction, and 14.3% for patients without graft dysfunction (P = 0.028). Despite its infrequency after LDLT, GIB has strong correlation with graft dysfunction and inhospital mortality.

A retrospective study on risk factors associated with failed endoscopic treatment of biliary anastomotic stricture after right-lobe living donor liver transplantation with duct-to-duct anastomosis

OBJECTIVE

This aim of this study is to determine the risk factors in failed endoscopic retrograde cholangiography (ERC).

BACKGROUND

Endoscopic treatment is considered the first-line intervention for biliary anastomotic stricture (BAS) after right-lobe living donor liver transplantation with duct-to-duct anastomosis.

METHODS

A retrospective study was performed on 287 patients who received right-lobe living donor liver transplantation with duct-to-duct anastomosis. The morphology of BAS was defined according to the shape of the distal side of duct-to-duct anastomosis shown on cholangiogram and was categorized into 3 types: pouched, intermediately pouched, and triangular. All cases of ERC were performed by operating surgeons.

RESULTS

Fifty-nine patients (20.6%) had BAS and received ERC and balloon dilatation with or without stenting. The success rate was 73.2%. The median number of sessions needed for successful ERC was 3. In the 15 patients with failed ERC, 4 were successfully treated with percutaneous transhepatic biliary drainage and balloon dilatation and 11 underwent conversion hepaticojejunostomy (6 had external percutaneous transhepatic biliary drainage as a temporizing measure). On multivariate analysis, recipient age [odds ratio (OR): 0.922; 95% confidence interval (CI): 0.85-1.00; P = 0.049], operation time (OR: 1.007; 95% CI: 1.001-1.013; P = 0.025), and morphology of stricture (OR: 6.722; 95% CI: 1.31-34.48; P = 0.022) were independent risk factors associated with failed ERC. The success rates for the 3 types of BAS-pouched, intermediately pouched, and triangular-were 42.9%, 63.6%, and 88.9%, respectively (P = 0.021). Association was found between bile leak and pouched BAS (P = 0.008).

CONCLUSIONS

ERC is highly effective in treating BAS. A success rate of 73%, the highest ever reported, has been achieved. Morphology of stricture is associated with outcome of ERC. Radiological or surgical intervention should be considered for patients with pouched BAS after endoscopic treatment fails for the first time.

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.

Outcome of patients undergoing right lobe living donor liver transplantation with small-for-size grafts

AIM: To investigate the outcome of living donor liver transplantation (LDLT) recipients transplanted with small-for-size grafts (SFSGs).

METHODS: Between November 2001 and December 2010, 196 patients underwent LDLT with right lobe liver grafts at our center. Recipients were divided into 2 treatment groups: group A with an actuarial graft-to-recipient weight ratio (aGRWR) < 0.8% (n = 45) and group B with an aGRWR ≥ 0.8% (n = 151). We evaluated serum liver function markers within 4 wk after transplantation. We also retrospectively evaluated the outcomes of these patients for potential effects related to the recipients, the donors and the transplantation procedures based upon a review of their medical records.

RESULTS: Small-for-size syndrome (SFSS) developed in 7 of 45 patients (15.56%) in group A and 9 of 151 patients (5.96%) in group B (P = 0.080). The levels of alanine aminotransferase and aspartate aminotransferase in group A were higher than those in group B during early period after transplantation, albeit not significantly. The cumulative 1-, 3- and 5-year liver graft survival rates were 82.22%, 71.11% and 71.11% for group A and 81.46%, 76.82%, and 75.50% for group B patients, respectively (P = 0.623). However, univariate analysis of risk factors associated with graft survival in group A demonstrated that the occurrence of SFSS after LDLT was the only significant risk factor affecting graft survival (P < 0.001). Furthermore, multivariate analysis of our data did not identify any additional significant risk factors accounting for poor graft survival.

CONCLUSION: Our study suggests that LDLT recipients with an aGRWR < 0.8% may have liver graft outcomes comparable to those who received larger size grafts. Further studies are required to ascertain the safety of using SFSGs.

Survival outcomes of right-lobe living donor liver transplantation for patients with high Model for End-stage Liver Disease scores

BACKGROUND

Controversy exists over whether living donor liver transplantation (LDLT) should be offered to patients with high Model for End-stage Liver Disease (MELD) scores. This study tried to determine whether a high MELD score would result in inferior outcomes of right-lobe LDLT.

METHODS

Among 411 consecutive patients who received right-lobe LDLT at our center, 143 were included in this study. The patients were divided into two groups according to their MELD scores: a high-score group (MELD score ≥25; n=75) and a low-score group (MELD score <25; n=68). Their demographic data and perioperative conditions were compared. Univariable and multivariable analyses were performed to identify risk factors affecting patient survival.

RESULTS

In the high-score group, more patients required preoperative intensive care unit admission (49.3% vs 2.9%; P<0.001), mechanical ventilation (21.3% vs 0%; P<0.001), or hemodialysis (13.3% vs 0%; P=0.005); the waiting time before LDLT was shorter (4 vs 66 days; P<0.001); more blood was transfused during operation (7 vs 2 units; P<0.001); patients stayed longer in the intensive care unit (6 vs 3 days; P<0.001) and hospital (21 vs 15 days; P=0.015) after transplantation; more patients developed early postoperative complications (69.3% vs 50.0%; P=0.018); and values of postoperative peak blood parameters were higher. However, the two groups had comparable hospital mortality. Graft survival and patient overall survival at one year (94.7% vs 95.6%; 95.9% vs 96.9%), three years (91.9% vs 92.6%; 93.2% vs 95.3%), and five years (90.2% vs 90.2%; 93.2% vs 95.3%) were also similar between the groups.

CONCLUSIONS

Although the high-score group had significantly more early postoperative complications, the two groups had comparable hospital mortality and similar satisfactory rates of graft survival and patient overall survival. Therefore, a high MELD score should not be a contraindication to right-lobe LDLT if donor risk and recipient benefit are taken into full account.

Left hepatectomy versus right hepatectomy for living donor liver transplantation: shifting the risk from the donor to the recipient

Living donor liver transplantation (LDLT), originally used in children with left lateral segment grafts, has been expanded to adults who require larger grafts to support liver function. Most adult LDLT procedures have been performed with right lobe grafts, and this means a significant risk of morbidity for the donors. To minimize the donor risk for adults, there is renewed interest in smaller left lobe grafts. The smaller graft size increases the recipient risk in the form of small-for-size syndrome (SFSS) and essentially transfers the risk from the donor to the recipient. We review the donor and recipient risks of LDLT and pay particular attention to the different types of liver grafts and the use of graft inflow modification to ameliorate the risk of SFSS. Finally, a new metric is proposed for quantifying the recipient benefit in exchange for a specific donor risk.

Outcomes of side-to-side conversion hepaticojejunostomy for biliary anastomotic stricture after right-liver living donor liver transplantation

BACKGROUND

Conversion hepaticojejunostomy is considered the salvage intervention for biliary anastomotic stricture, a common complication of right-liver living donor liver transplantation with duct-to-duct anastomosis, after failed endoscopic treatment. The aim of this study is to compare the outcomes of side-to-side hepaticojejunostomy with those of end-to-side hepaticojejunostomy.

METHODS

Prospectively collected data of 402 adult patients who had undergone right-liver living donor liver transplantation with duct-to-duct anastomosis were reviewed. Diagnosis of biliary anastomotic stricture was made based on clinical, biochemical, histological and radiological results. Endoscopic treatment was the first-line treatment of biliary anastomotic stricture.

RESULTS

Interventional radiological or endoscopic treatment failed to correct the biliary anastomotic stricture in 13 patients, so they underwent conversion hepaticojejunostomy. Ten of them received end-to-side hepaticojejunostomy and three received side-to-side hepaticojejunostomy. In the end-to-side group, two patients sustained hepatic artery injury requiring repeated microvascular anastomosis, two developed re-stenosis requiring further percutaneous transhepatic biliary drainage and balloon dilatation, and two required revision hepaticojejunostomy. In the side-to-side group, one patient developed re-stenosis requiring further endoscopic retrograde cholangiography and balloon dilatation. No re-operation was needed in this group. Otherwise, outcomes in the two groups were similar in terms of liver function and graft survival.

CONCLUSIONS

Despite the similar outcomes, side-to-side hepaticojejunostomy may be a better option for bile duct reconstruction after failed interventional radiological or endoscopic treatment because it can decrease the chance of hepatic artery injury and allows future endoscopic treatment if re-stricture develops. However, more large-scale studies are warranted to validate the results.

Strategies for successful left-lobe living donor liver transplantation in 250 consecutive adult cases in a single center

BACKGROUND

Living donor liver transplantation (LDLT) using left-lobe grafts was not generally recognized as feasible due to the problem of graft size.

STUDY DESIGN

We retrospectively evaluated strategies for successful left-lobe LDLT in 250 consecutive cases stratified into 2 eras: Era 1 (n = 121), in which surgical procedures were continually refined, and Era 2 (n = 129), in which established procedures were used.

RESULTS

Graft volume (GV) did not affect the incidence of graft function or survival. Era 2 patients had decreased portal vein (PV) pressure at closure (16.0 ± 3.5 mmHg vs 19.1 ± 4.6 mmHg, p < 0.01), increased PV flow/GV (301 ± 125 mL/min/100g vs 391 ± 142 mL/min/100g, p < 0.01), and improved graft survival rate (1-year: 90.6% vs 81.8%. p < 0.01) despite the smaller GV/standard volume (SLV) ratio (36.2% ± 5.2% vs 41.2% ± 8.8%, p < 0.01) compared with Era 1. Patients in Era 2 had lower PV pressure and greater PV flow (y = 598-5.7 x, p = 0.02) at any GV/SLV compared with cases in Era 1 (y = 480-4.3 x, p < 0.01), representing greater graft compliance. Univariate analysis for graft survival showed that Era 1, Model for End-Stage Liver Disease (MELD) score ≥ 20, inpatient status, closing portal venous pressure ≥ 20 mmHg, no splenectomy, and operative blood loss ≥ 10 L were the risk factors for graft loss, and multivariate analysis showed that Era 1 was the only significant factor (p < 0.01). During Era 2, development of primary graft dysfunction was associated with inpatient recipient status (p = 0.02) and donor age ≥ 45 years (p < 0.01).

CONCLUSIONS

The outcomes of left-lobe LDLT were improved by accumulated experience and technical developments.

Increasing the recipient benefit/donor risk ratio by lowering the graft size requirement for living donor liver transplantation

In living donor liver transplantation (LDLT), a right liver graft is larger than a left liver graft and hence leads to better recipient survival. However, in comparison with donor left hepatectomy, donor right hepatectomy carries a higher donor risk. We estimated the expansion of the applicability of left liver living donor liver transplantation (LLDLT) by lowering the graft weight (GW)/standard liver volume (SLV) ratio in increments of 5%. Consecutive LDLT cases were included in this study. The results of computed tomography volumetry provided the graft volume measurements, and the GW was derived from the graft volume with the conversion factor of 1.19 mL/g. We tried to estimate how many more times LLDLT would have been feasible if the GW/SLV requirement had been lowered to 40%, 35%, 30%, or 25%. In all, 361 consecutive donor-recipient pairs underwent LDLT. Right liver living donor liver transplantation (RLDLT) accounted for 95% of the LDLT cases. Most recipients were male (74.2%), and most donors were female (60.4%). The median GW/SLV ratio was 46% (47% for RLDLT and 37% for LLDLT, P < 0.001). Two of the 218 female donors donated the left liver, and 12 of the 93 female recipients received a left liver. In 147 of the 173 cases (85%) when the donor was female and the recipient was male, the GW/SLV ratio did not reach 30%. LLDLT could have been performed more often than 5% of the time if a lower GW/SLV requirement had been adopted. With GW/SLV ratios ≥ 40%, ≥ 35%, ≥ 30%, and ≥ 25%, the proportion of LLDLT cases would have risen from 5% to 5.8%, 12.5%, 29.1%, and 62.3%, respectively. LLDLT could have been performed approximately twice as often with every 5% reduction of the GW/SLV requirement. In conclusion, lowering the graft size requirement could improve the applicability of LLDLT and hence reduce donor risk.

Primary graft dysfunction after living donor liver transplantation is characterized by delayed functional hyperbilirubinemia

The purpose of this study is to propose a new concept of primary graft dysfunction (PGD) after living donor liver transplantation (LDLT), characterized by delayed functional hyperbilirubinemia (DFH) and a high early graft mortality rate. A total of 210 adult-to-adult LDLT grafts without anatomical, immunological or hepatitis-related issues were included. All of the grafts with early mortality (n = 13) caused by PGD in LDLT had maximum total bilirubin levels >20 mg/dL after postoperative day 7 (p < 0.001). No other factors, including prothrombin time, ammonia level or ascites output after surgery were associated with early mortality. Thus, DFH of >20 mg/dL for >seven consecutive days occurring after postoperative day 7 (DFH-20) was used to characterize PGD. DFH-20 showed high sensitivity (100%) and specificity (95.4%) for PGD with early mortality. Among the grafts with DFH-20 (n = 22), those with early mortality (n = 13) showed coagulopathy (PT-INR > 2), compared with those without mortality (p = 0.002). Pathological findings in the grafts with DFH-20 included hepatocyte ballooning and cholestasis, which were particularly prominent in the centrilobular zone. PGD after LDLT is associated with DFH-20 caused by graft, recipient and surgical factors, and increases the risk of early graft mortality.

Outcomes of living donor liver transplantation for patients with preoperative type 1 hepatorenal syndrome and acute hepatic decompensation

This study investigated the outcomes of living donor liver transplantation (LDLT) for patients with preoperative type 1 hepatorenal syndrome (HRS) and acute hepatic decompensation. Prospectively collected data for 104 patients who had fulminant hepatic failure, acute decompensation of cirrhosis, or an acute flare of chronic hepatitis B were analyzed. Thirty-three patients (31.7%) had HRS (the HRS group), and 71 patients (68.3%) did not (the non-HRS group). The median follow-up period was 60 months. The HRS group had significantly more preoperative intensive care unit (ICU) admissions (84.8% versus 60.6%, P = 0.01), worse preoperative blood test results (creatinine, 248 versus 88 μmol/L, P < 0.001; total bilirubin, 630 versus 555 μmol/L, P = 0.001), more hemodialysis (48.5% versus 0%, P < 0.001), more blood transfusions (9 versus 4 U, P < 0.001), longer postoperative ICU stays (8 versus 4 days, P < 0.001), worse postoperative blood test results (creatinine at 1 year, 108 versus 96 μmol/L, P = 0.006), and poorer overall survival (P < 0.001). In a multivariate analysis, only HRS was associated with poorer overall survival (hazard ratio = 8.592, 95% confidence interval = 1.782-41.431, P = 0.007). In conclusion, HRS patients had worse postoperative renal function and overall survival than non-HRS patients. However, their 5-year overall survival rate was still nearly 80%, which is satisfactory. Therefore, LDLT can be considered for patients who have acute hepatic decompensation with or without HRS.

Bacterial sepsis after living donor liver transplantation: the impact of early enteral nutrition

BACKGROUND

Bacterial sepsis is a significant problem that must be addressed after living donor liver transplantation (LDLT).

STUDY DESIGN

A retrospective analysis of 346 adult-to-adult LDLT patients was performed.

RESULTS

Forty-six patients (13.3%) experienced bacterial sepsis, with primary and secondary origins in 23.9% and 76.1%, respectively. Gram-negative bacteria accounted for 71.7% of the bacteria isolated. The 2-year cumulative graft survival rate in patients with bacterial sepsis was 45.7%. Patients with bacterial sepsis secondary to pneumonia (n = 12) had poorer 2-year graft survival rates (16.7%) than did those with primary or other types of secondary sepsis (p = 0.004). Multivariate analysis showed that intraoperative massive blood loss >10L (p < 0.001) and no enteral feeding started within 48 hours after transplantation (p = 0.005) were significant risk factors for bacterial sepsis. Among patients who received enteral nutrition, the incidences of bacterial sepsis in patients who received enteral nutrition within 48 hours (n = 135) or later than 48 hours (n = 57) were 5.9% and 21.0%, respectively (p = 0.002). The incidence of early graft loss was 8-fold higher in recipients with massive intraoperative blood loss without early enteral nutrition (p < 0.001).

CONCLUSIONS

Early enteral nutrition was associated with significantly reduced risk of developing bacterial sepsis after LDLT.

Bile duct anastomotic stricture after adult-to-adult right lobe living donor liver transplantation

Duct-to-duct anastomosis (DDA) and hepaticojejunostomy (HJ) are options for biliary reconstruction in patients undergoing adult-to-adult right lobe living donor liver transplantation (ARLDLT), after which biliary anastomotic stricture (BAS) is common as a complication. The risk factors for BAS are not clearly defined. We aimed to determine the rate of post-ARLDLT BAS in our center and its associated factors. In 265 ARLDLT recipients, 55 (20.8%) developed postoperative BAS. The diagnosis was based on clinical, biochemical, histological, and radiological results. The BAS rates were 21.4% (43/201) for recipients undergoing DDA during transplantation, 18.9% (10/53) for recipients undergoing HJ, and 18.2% (2/11) for recipients undergoing both procedures. BAS and non-BAS patients had comparable demographics. The number of graft bile duct openings (P = 0.516) and the size of the graft's smallest bile duct (5 versus 5 mm, P = 0.4) were not significantly different between BAS and non-BAS patients. Univariate analysis showed that the factors associated with postoperative BAS were the recipient warm ischemia time (55 versus 51 minutes, P = 0.026), graft cold ischemia time (120 versus 108 minutes, P = 0.046), stent use (21.8% versus 7.1%, P = 0.001), postoperative acute cellular rejection (29.1% versus 11.0%, P = 0.001), and University of Wisconsin solution use (21.8% versus 7.1%, P = 0.001). Multivariate analysis showed that the cold ischemia time (odds ratio = 1.012, 95% confidence interval = 1.002-1.023, P = 0.014) and acute rejection (odds ratio = 3.180, 95% confidence interval = 1.606-6.853, P = 0.002) were significant factors. The graft survival rates of BAS and non-BAS patients were comparable. One patient required retransplantation for secondary biliary cirrhosis. In conclusion, BAS remains common after ARLDLT regardless of DDA or HJ. The graft cold ischemia time and postoperative acute cellular rejection are significantly associated with postoperative BAS.