Improved results for adult split liver transplantation with extended right lobe grafts: could we enhance its application?

Addressing the challenges of split liver transplantation through technical advances. A systematic review

BACKGROUND

Split liver transplantation addresses donor shortages by facilitating the transplant of two recipients using one donor liver. Some still consider these grafts inferior due to prolonged cold ischaemia time and at times difficult vascular reconstruction. Techniques such as in-situ splitting, machine perfusion and interposition grafts may address these challenges and thereby address these concerns. The aim of this review is to assess these technical advances in split liver transplantation, their utility and outcomes.

METHODS

A systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Keywords included 'split liver transplantation', 'arterial reconstruction', and 'machine perfusion'. Data found was synthesised into sections including: methods of splitting, full-left full-right splitting, donor cholangiography, machine perfusion and arterial reconstruction.

RESULTS

A total of 78 articles met inclusion criteria after screening of 151 eligible articles. These were subdivided into the following categories: in-situ (25), ex-vivo (25), full-left full-right splitting (15), donor cholangiography (2), machine perfusion (6), and arterial reconstruction (5). The in-situ splitting technique reduces the cold ischaemia time compared to the ex-vivo technique which may improve graft quality and liver splitting during normothermic machine perfusion is a novel technique with the potential to incorporate the best aspects of both techniques. Interposition grafts are often required during split liver transplantation but have an increased risk of hepatic artery thrombosis.

CONCLUSION

Advancements in technique have allowed many of the unique challenges of split liver transplantation to be overcome. Overall, this supports the use of split liver transplantation in broader and riskier settings and we advocate for liver transplant surgeons to not hesitate in using these grafts liberally and expanding their recipient selection criteria.

Comparison of Liver Graft Regeneration Between ABO-Compatible and ABO-Incompatible Living Donor Liver Transplantation: A Propensity Score Matching Analysis

BACKGROUND ABO-incompatible (ABOi) living donor liver transplantation (LDLT) was accepted as a feasible therapy for end-stage liver disease after the introduction of rituximab. The present study investigated the association between ABO incompatibility and graft regeneration in patients who underwent LDLT. MATERIAL AND METHODS A total of 335 adult patients who underwent elective LDLT were divided into ABO-compatible (ABOc) and ABOi LDLT groups using propensity score (PS) matching of graft regeneration-related factors. Postoperative serial changes in graft volumes were compared between the groups. The factors associated with graft volume on postoperative day (POD) 21 were investigated in patients who underwent ABOi LDLT. RESULTS In total, 300 (89.6%) patients underwent ABOc LDLT and 35 (10.4%) patients underwent ABOi LDLT. After PS matching, the ABOc and ABOi groups each included 32 paired patients. The absolute liver graft volumes on POD 21 were significantly lower in the ABOi group than those in the ABOc group in the PS-matched patients (1098.4 [964.0-1,162.0] vs. 1202.0 [1107.8-1455.2] mL; p=0.007). Major complications, including overall patient mortality during the follow-up period, did not differ between the groups. In patients who underwent ABOi LDLT, the preoperative graft volume/standard liver volume ratio and CD4+ cell level on POD 14 were independent factors related to liver graft volume on POD 21. CONCLUSIONS These results suggest that ABO incompatibility could affect postoperative liver graft regeneration. Therefore, graft regeneration must be investigated using a volumetric assessment in patients who have undergone ABOi LDLT.

Clinical outcomes of right-lobe split-liver versus orthotopic liver transplants from donors more than 70 years old

Context-The imbalance between the organ supply and the number of potential transplant recipients led to consideration of expanded-criteria liver donors. Objective-To compare right-lobe split-liver transplants (RL-SLTs) with orthotopic liver transplants (OLTs) from donors more than 70 years old (OLT-O) and OLTs from donors less than 55 years old (OLT-Y). Methods-Seventy-one patients who received an RL-SLT were matched for age, sex, and Model for End-stage Liver Disease score with 71 patients who underwent OLT-O and 142 patients who underwent OLT-Y. Clinical outcomes were compared between groups. Results-Longer operation time was associated with RL-SLT (P< .001) as well as more blood loss (P= .03) and transfusions (P= .05). Postoperative morbidity was less in the OLT-Y group, with a lower rate of grades III to IV Clavien-Dindo complication (30%), compared with values in OLT-O (52%) and RL-SLT (38%). Kaplan-Meier analysis demonstrated better 1-year and 3-year survival rates in the OLT-Y group (97% and 92%, respectively), compared with 92% and 86.3%, respectively, in the RL-SLT group; and 84.5% and 73%, respectively, in the OLT-O group (P = .03). Kaplan-Meier analysis also demonstrated differences between the groups in terms of 1-year and 3-year graft survival rates, which were 92% and 86%, respectively, in OLT-Y; 77% and 66%, respectively, in the OLT-O, and 84.2% and 76.6%, respectively, in the RL-SLT group (P= .01). Conclusion-Even if OLT-Y guarantees better patient and graft survival, both RL-SLT and OLT-O can be used safely to expand the pool of liver donors, showing acceptable clinical results and complications rates.

Long-term results after adult ex situ split liver transplantation since its introduction in 1987

BACKGROUND

Split liver transplantation is still discussed controversially. Utilization of split liver grafts has been declining since a change of allocation rules for the second graft abolished incentives for German centres to perform ex situ splits. We therefore analysed our long-term experiences with the first ex situ split liver transplant series worldwide.

METHODS

A total of 131 consecutive adult ex situ split liver transplants (01.12.1987-31.12.2010) were analysed retrospectively.

RESULTS

Thirty-day mortality rates and 1- and 3-year patient survival rates were 13, 76.3, and 66.4 %, respectively. One- and three-year graft survival rates were 63.4 and 54.2 %, respectively. The observed 10-year survival rate was 40.6 %. Continuous improvement of survival from era 1 to 3 was observed (each era: 8 years), indicating a learning curve over 24 years of experience. Patient and graft survival were not influenced by different combinations of transplanted segments or types of biliary reconstruction (p > 0.05; Cox regression). Patients transplanted for primary sclerosing cholangitis had better survival (p = 0.021; log-rank), whereas all other indications including acute liver failure (13.6 %), acute and chronic graft failure (9.1 %) had no significant influence on survival (p > 0.05; log-rank). Biliary complications (27.4 %) had no significant influence on patient or graft survival (p > 0.05; log-rank). Hepatic artery thrombosis (13.2 %) had a significant influence on graft survival but not on patient survival (p = 0.002, >0.05, respectively; log-rank).

CONCLUSIONS

Split liver transplantation can be used safely and appears to be an underutilized resource that may benefit from liberal allocation of the second graft.

Split liver transplantation using extended right grafts: the natural history of segment 4 and its impact on early postoperative outcomes

Split liver transplantation (SLT) using extended right grafts is associated with complications related to ischemia of hepatic segment 4 (S4), and these complications are associated with poor outcomes. We retrospectively analyzed 36 SLT recipients so that we could assess the association of radiological, biological, and clinical features with S4 ischemia. The overall survival rates were 84.2%, 84.2%, and 77.7% at 1, 3, and 5 years, respectively. The recipients were mostly male (24/36 or 67%) and had a median age of 52 years (range = 13-63 years), a median body mass index of 22.9 kg/m(2) (range = 17.3-29.8 kg/m(2) ), and a median graft-to-recipient weight ratio of 1.3% (range = 0.9%-1.9%). S4-related complications were diagnosed in 22% of the patients (8/36) with a median delay of 22 days (range = 10-30 days). Secondary arterial complications were seen in 3 of these patients and led to significantly decreased graft survival in comparison with the graft survival of patients without complications (50.0% versus 85.6%, P = 0.017). Patients developing S4-related complications had significantly elevated aspartate aminotransferase (AST) levels (>1000 IU/L) on postoperative day (POD) 1 and elevated gamma-glutamyl transpeptidase (GGT) levels (>300 IU/L) on PODs 7 and 10 (P < 0.05). These AST and GGT elevations conferred a significantly high risk of developing these complications (odds ratio = 42, 95% confidence interval = 4-475, P < 0.05). The ischemic volume of S4 was extremely variable (0%-95%) and did not correlate with S4-related complications. In conclusion, our results suggest that S4-related complications are risk factors for worse graft survival, and the development of these complications can be anticipated by the early identification of a specific biological profile and a routine radiological examination.