Split-liver transplantation: a review

Application Effectiveness of Segment IV Portal Vein Reconstruction for Early Postoperative Liver Function Recovery in Split Liver Transplantation

The objective of this study was to investigate the significance of portal vein reconstruction in segment IV of the liver on early postoperative liver function recovery in split liver transplantation. The clinical data of patients of right trilobe split liver transplantation in our center were analyzed and divided into two groups, including a group without portal vein reconstruction and a group with portal vein reconstruction. Clinical data of alanine aminotransferase (ALT), aspartate transaminase (AST), albumin (ALB), creatinine (Cr), total bilirubin (TB), alkaline phosphatase (ALP), gamma-glutamyl Transferase (GGT), lactic acid (Lac), and international normalized ratio (INR) levels were analyzed. The technique of segment IV portal vein reconstruction is beneficial to the early postoperative recovery of liver function. Statistically, there was no significant effect of portal vein reconstruction in the IV segment of the liver on the recovery of liver function within 1 week after split liver transplantation. There was no significant difference in survival rate between the control group and reconstruction group over the 6 months follow-up period after surgery.

Anatomical Variations of Left Hepatic Vein and Outflow Reconstruction Techniques in Paediatric Living Donor Liver Transplantation

Anatomical variations of left hepatic vein (LHV) are observed in nearly a third of left lateral segment (LLS) donors in living donor liver transplantation (LDLT). There is paucity of studies and no structured algorithm for customised outflow reconstruction in LLS grafts with variant anatomy. Analysis of a prospectively collected database of 296 LLS paediatric LDLT was done to identify different venous drainage patterns of segments 2 (V2) and 3 (V3). LHV anatomy was classified into three types: type 1(n=270, 91.2%): V2 and V3 joined to form a common trunk which drains into middle hepatic vein (MHV)/inferior vena cava (IVC), subtype 1a length of trunk ≥ 9mm and subtype 1b length of trunk < 9mm; type 2(n=6, 2%): V2 and V3 drain independently into IVC; type 3(n=20, 6.8%): V2 and V3 drain into IVC and MHV respectively. Analysis of post-operative outcomes between LLS grafts with single and reconstructed multiple outflows showed no difference in the occurrence of hepatic vein thrombosis/stenosis, major morbidity (p 0.91) and 5 year survival (log rank p 0.562). This classification is a simple yet effective tool for pre-operative donor assessment and we propose a schema for customised reconstruction of LLS grafts, with excellent and consistently reproducible outcomes.

The first successful report of liver transplantation from category III donation after circulatory death in South Korea: a case report

Deceased donor liver transplantation (DDLT) using donations after brain death (DBDs) has been widely performed in Korea. However, to date, there is no report regarding donation after circulatory death (DCD) category III. A 56-year-old male patient diagnosed with hepatitis B virus-associated liver cirrhosis underwent DDLT using DCD category III. The recipient's recovery was uneventful, and he was discharged on postoperative day 37. Currently, the patient is alive, with no complications 20 months after transplantation. This case suggests that DCD with LT is both feasible and safe. Further studies are required to validate this finding.

Full-left-full-right split liver transplantation for adult recipients: a systematic review and meta-analysis

Full-left-full-right split liver transplantation (FSLT) for adult recipients, may increase the availability of liver grafts, reduce waitlist time, and benefit recipients with below-average body weight. However, FSLT may lead to impaired graft and patient survival. This study aims to assess outcomes after FSLT. Five databases were searched to identify studies concerning FSLT. Incidences of complications, graft- and patient survival were assessed. Discrete data were pooled with random-effect models. Graft and patient survival after FSLT were compared with whole liver transplantation (WLT) according to the inverse variance method. Vascular complications were reported in 25/273 patients after FSLT (Pooled proportion: 6.9%, 95%CI: 3.1-10.7%, I² : 36%). Biliary complications were reported in 84/308 patients after FSLT (Pooled proportion: 25.6%, 95%CI: 19-32%, I² : 44%). Pooled proportions of graft and patient survival after 3 years follow-up were 72.8% (95%CI: 67.2-78.5, n = 231) and 77.3% (95%CI: 66.7-85.8, n = 331), respectively. Compared with WLT, FSLT was associated with increased graft loss (pooled HR: 2.12, 95%CI: 1.24-3.61, P = 0.006, n = 189) and patient mortality (pooled HR: 1.81, 95%CI: 1.17-2.81, P = 0.008, n = 289). FSLT was associated with high incidences of vascular and biliary complications. Nevertheless, long-term patient and graft survival appear acceptable and justify transplant benefit in selected patients.

Clinical sequence of an adult recipient undergone split liver transplantation using a right liver graft with erroneous deprivation of the middle hepatic vein trunk: a case report

The anatomy of middle hepatic vein (MHV) varies widely, and some individuals have aberrant MHV anatomy, thus there is risk of iatrogenic damage to graft MHV during liver splitting. We present the clinical sequences of an adult recipient who received a split right liver graft with erroneous deprivation of the MHV trunk. This is the case was a 58-year-old male patient with hepatitis B virus-associated liver cirrhosis who suffered from hepatic encephalopathy. The split right liver graft had a graft-to-recipient weight ratio of 2.1%. Soon after graft reperfusion, large-sized hepatic venous congestion (HVC) appeared at the graft liver surface, indicating lack of MHV drainage. The amount of HVC was approximately 20% of the right liver graft mass at day 1, which had gradually reduced on follow-up computed tomography (CT) scans. Although liver function recovered progressively, the patient remained bed-ridden because of pre-existing hypoxic brain damage. The patient passed away 4 years after transplantation because of pneumonia and multi-organ failure. The present case implies that there is some possibility of unrecognized damage to the graft MHV during liver splitting, suggesting the necessity of preoperative donor abdomen CT scan and preparation of intraoperative ultrasonography for easy evaluation of graft liver MHV anatomy.

Fates of retained hepatic segment IV and its prognostic impact in adult split liver transplantation using an extended right liver graft

PURPOSE

When splitting a liver for adult and pediatric graft recipients, the retained left medial section (S4) will undergo ischemic necrosis and the right trisection graft becomes an extended right liver (ERL) graft. We investigated the fates of the retained S4 and its prognostic impact in adult split liver transplantation (SLT) using an ERL graft.

METHODS

This was a retrospective analysis of 25 adult SLT recipients who received split ERL grafts.

RESULTS

The mean model for end-stage liver disease (MELD) score was 27.3 ± 10.9 and graft-recipient weight ratio (GRWR) was 1.98 ± 0.44. The mean donor age was 26.5 ± 7.7 years. The split ERL graft weight was 1,181.5 ± 252.8 g, which resulted in a mean GRWR of 1.98 ± 0.44. Computed tomography of the retained S4 parenchyma revealed small ischemic necrosis in 16 patients (64.0%) and large ischemic necrosis in the remaining 9 patients (36.0%). No S4-associated biliary complications were developed. The mean GRWR was 1.87 ± 0.43 in the 9 patients with large ischemic necrosis and 2.10 ± 0.44 in the 15 cases with small ischemic necrosis (P = 0.283). The retained S4 parenchyma showed gradual atrophy on follow-up imaging studies. The amount of S4 ischemic necrosis was not associated with graft (P = 0.592) or patient (P = 0.243) survival. A MELD score of >30 and pretransplant ventilator support were associated with inferior outcomes.

CONCLUSION

The amount of S4 ischemic necrosis is not a prognostic factor in adult SLT recipients, probably due to a sufficiently large GRWR.

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.

Induction of liver hypertrophy for extended liver surgery and partial liver transplantation: State of the art of parenchyma augmentation-assisted liver surgery

Background

Liver surgery and transplantation currently represent the only curative treatment options for primary and secondary hepatic malignancies. Despite the ability of the liver to regenerate after tissue loss, 25–30% future liver remnant is considered the minimum requirement to prevent serious risk for post-hepatectomy liver failure.

Purpose

The aim of this review is to depict the various interventions for liver parenchyma augmentation–assisting surgery enabling extended liver resections. The article summarizes one- and two-stage procedures with a focus on hypertrophy- and corresponding resection rates.

Conclusions

To induce liver parenchymal augmentation prior to hepatectomy, most techniques rely on portal vein occlusion, but more recently inclusion of parenchymal splitting, hepatic vein occlusion, and partial liver transplantation has extended the technical armamentarium. Safely accomplishing major and ultimately total hepatectomy by these techniques requires integration into a meaningful oncological concept. The advent of highly effective chemotherapeutic regimen in the neo-adjuvant, interstage, and adjuvant setting has underlined an aggressive surgical approach in the given setting to convert formerly “palliative” disease into a curative and sometimes in a “chronic” disease.

A Novel Surgical Technique to Assure Donor and Recipient Safety: Pyloric to Segment 4 Arterial Reconstruction

Background.

Strategies to extend the pool of organs include and promote the use of segmental liver grafts. While performing a living donor left lateral segment (LLS) liver transplant and in split procedures, the hepatic artery´s division becomes critical when a dominant segment 4 artery (S4A) emerges from the left hepatic artery (LHA). We aim to describe a novel technique that consists of performing microsurgical reconstruction from the pyloric artery (PA) to S4A.

Case Reports.

A 45-y-old living donor was evaluated to use his LLS as a graft for a pediatric recipient. During the procedure, a dominant S4A born from the LHA was dissected. To obtain an appropriate LHA length and diameter for the recipient, it was necessary to transect it. An extended right lobe split graft was used in a 61-y-old patient. The S4A born from LHA had to be sectioned during the split procedure. In both cases, segment 4 remained incompletely perfused. The PA was dissected with enough length to be rotated, to perform a microsurgical anastomosis to the S4A, recovering parenchyma’s color and Doppler signal while vascular permeability was demonstrated using CT scan. There was no biliary or cut surface complication.

Conclusions.

PA to S4A reconstruction is a simple and novel technique that can be used for LLS and extended right lobe split graft and might contribute to increase donor selection and reduce living donor and recipient S4A-related complications.

Prognosis of Split Liver Transplantation Compared with Whole Liver Transplantation in Adult Patients: Single-center Results under the Korean MELD Score-based Allocation Policy

BACKGROUND

Split liver transplantation (SLT) has been occasionally performed in Korea. This study compared the incidence and prognosis of SLT with whole liver transplantation (WLT) in adult patients.

METHODS

Between June 2016 and November 2019, 242 adult patients underwent a total of 256 deceased donor liver transplantation operations. SLT was performed in 7 patients (2.9%).

RESULTS

The mean age of SLT donors was 29.7 ± 7.4 years, and the mean age of recipients was 55.7 ± 10.6 years, with the latter having a mean model for end-stage liver disease score of 34.6 ± 3.1. Mean split right liver graft weight was 1,228.6 ± 149.7 g and mean graft-recipient weight ratio was 1.97 ± 0.39. Of the seven SLT recipients, Korean Network for Organ Sharing (KONOS) status was one in status 1, one in status 2 and five in status 3. The graft (P = 0.72) and patient (P = 0.84) survival rates were comparable in the SLT and WLT groups. Following propensity score matching, graft (P = 0.61) and patient (P = 0.91) survival rates remained comparable in the two groups. Univariate analysis showed that pretransplant ventilator support and renal replacement therapy were significantly associated with patient survival, whereas KONOS status category and primary liver diseases were not. Multivariate analysis showed that pretransplant ventilator support was an independent risk factor for patient survival.

CONCLUSION

Survival outcomes were similar in adult SLT and WLT recipients, probably due to selection of high-quality grafts and low-risk recipients. Prudent selection of donors and adult recipients for SLT may expand the liver graft pool for pediatric patients without affecting outcomes in adults undergoing SLT.

RAPID procedure for colorectal cancer liver metastasis

Liver transplantation for colorectal cancer has regained renewed interest with reported good overall survival in selected patients. The scarcity of grafts is a major obstacle to wider implementation and exploration of this field of transplant oncology. The use of small segmental auxiliary grafts from deceased or living donors might be one way to expand the donor pool with minimal negative impact on the waiting list for deceased donor transplantation and minimal risk for the donor in case of living donor liver transplantation. This review provides an insight into the physiological background for this technique and summarizes technical and surgical considerations and the experiences with this novel concept. Although the international experience still is very limited, the short term outcome could suggest that this is technically feasible. There is not sufficient data to assess long term oncological outcome. The RAPID concept (i.e. resection and partial liver segment 2-3 transplantation with delayed total hepatectomy) is still an experimental surgical procedure and should be reserved for prospective clinical trials. Herein, we describe the main technical issues of RAPID procedure from deceased and from living donor as well and report preliminary results of the first cases performed worldwide.

Application of pediatric donors in split liver transplantation: Is there an age limit?

The experience of using pediatric donors in split liver transplant is exceedingly rare. We aim to investigate the outcomes of recipients receiving split pediatric grafts. Sixteen pediatric recipients receiving split liver grafts from 8 pediatric donors < 7 years were enrolled. The donor and recipient characteristics, perioperative course, postoperative complications, and graft and recipient survival rates were evaluated. The mean follow-up time was 8.0 ± 2.3 months. The graft and recipient survival rates were 100%. The liver function remained in the normal range at the end of the follow-up time in all recipients. No life-threatening complications were seen in these recipients, and the only surgery-related complication was portal vein stenosis in 1 recipient. Cytomegalovirus infection was the most common complication (62.5%). The transaminase level was significant higher in extended right lobe recipients in the early postoperative days, but the difference vanished at the end of first week; postoperative complications and graft and recipient survival rates did not differ between left and right graft recipients. Notably, the youngest split donor graft (2.7 years old) was associated with ideal recipient outcomes. Split liver transplant using well-selected pediatric donors is a promising strategy to expand pediatric donor source in well-matched recipients.

Normal and transitory ultrasonography findings in the immediate postoperative period after liver transplantation

OBJECTIVE

Liver transplantation is one of the treatments for patients with advanced stage chronic liver disease and for selected patients with hepatic tumors. Ultrasonography is the first-choice imaging technique to evaluate liver transplants. This article reviews the surgical technique, anatomy, and normal findings on ultrasonography in the immediate postoperative period in patients who have undergone liver transplantation, which will be used as a reference in follow-up studies.

CONCLUSION

Early vascular (arterial and portal) complications can represent a threat for the graft or the patient. During the period after liver transplantation, the patient is recovering from surgery and the transplanted organ is adapting to its new environment. In this period, ultrasonography can show alterations in the parenchyma or Doppler findings that would be considered abnormal in other situations; these findings are usually transitory. Knowing how to interpret them is key to detecting or ruling out complications.

Is there an ethical obligation to split every donor liver? Scarce resources, medical factors, and ethical reasoning

SLT has the potential to counter the worldwide shortage of donor organs. Although the preferred recipients of SLT are usually pediatric patients, a more stringent ethical argument than the fundamental prioritization of children is to demonstrate that SLT of deceased donor organs could increase access to this potentially lifesaving resource for all patients, including children. Several empirical studies show that SLT also makes it possible to achieve similar outcomes to WLT in adults if several factors are observed. In general, it can be regarded as ethically permissible to insist on splitting a donor liver if, in an individual case, SLT is expected to have a similar outcome to that of WLT. The question is therefore no longer whether, but under what conditions SLT is able to achieve similar results to WLT. One of the main challenges of the current debate is the restricted comparability of the available data. We therefore have an ethical obligation to improve the available empirical data by implementing prospective clinical studies, SLT programs, and national registries. The introduction of 2 modes of allocation-one for patients willing to accept both SLT and WLT, and a second for patients only willing to accept WLT-would help to resolve the issue of patient autonomy in the case of mandatory splitting policy.

Right lobe split liver graft versus whole liver transplantation: A systematic review by updated traditional and cumulative meta-analysis

INTRODUCTION

Advancements in surgical techniques and experience of donor-recipient pairing has led to a wider use of right split liver grafts in adults. An update meta-analysis was conducted to compare right split liver graft (RSLG) and whole liver transplantation (WLT) using traditional and cumulative approaches.

METHODS

Databases were searched for relevant articles over the previous 20 years (MEDLINE, Embase, Cochrane Library, and Google Scholar). Meta-analyses were performed using both fixed and random effects models. Patient and graft survival were obtained using the inverse variance hazard ratio method.

RESULTS

Donors were significantly younger in the RSLG group than in the WLT group (MD = -12.06 [-16.29 to -7.83]; P < .001). In addition, the model for end-stage liver disease (MELD) score was significantly lower in the RSLG group than in the WLT group (MD = -2.45 [-4.61 to -.28]; P = .03). However, cold ischaemia time was significantly longer by 1 h in the RSLG group than in the WLT group (MD = 57 [20.63-92.73]; P = .002). Overall biliary, vascular, and outflow tract complications and hepatic artery thrombosis were significantly lower in the WLT group than in the RSLG group (odds ratio [OR] = 1.75 [1.35-2.27], P < .001; OR = 1.91 [1.37-2.65], P = .006; Peto OR = 1.83 [1.19-2.82], P = .006; and Peto OR = 2.07 [1.39-3.10], P = .004, respectively). However, no difference in patient and graft survival was noted between the two cohorts.

CONCLUSIONS

Although the RSLG group had a higher postoperative complication rate than the WLT group, equal patient and graft survival benefits were observed.

Growth of liver allografts over time in pediatric transplant recipients

The liver's capacity to grow in response to metabolic need is well known. However, long-term growth of liver allografts in pediatric recipients has not been characterized. A retrospective review of pediatric recipients at a single institution identified patients who had cross-sectional imaging at 1, 5, and 10 years post-transplant. Using volumetric calculations, liver allograft size was calculated and percent SLV were compared across the different time points; 18 patients ranging from 0.3 to 17.7 years old were identified that had imaging at 2 or more time points. Measured liver volumes increased by 59% after 5 years and 170% after 10 years. The measured liver volumes compared to calculated %SLV for these patients were 123 ± 37%, 97 ± 19%, and 118 ± 27% at 1, 5, and 10 years after transplant, respectively. Our data suggest that liver allografts in pediatric recipients increase along with overall growth, and reach SLVs for height and weight by 5 years post-transplantation. Additionally, as pediatric recipients grow, the livers appear to maintain appropriate SLV.

An Empirically Informed Analysis of the Ethical Issues Surrounding Split Liver Transplantation in the United Kingdom

Surgical advances have allowed for the development of split liver transplantation, providing two recipients with the opportunity to potentially benefit from one donated liver by splitting the liver into two usable parts. Although current data suggest that the splitting of livers provides overall benefit to the liver-recipient population, relatively low numbers of livers are actually split in the United Kingdom. This article addresses the question of whether ethical concerns are posing an unnecessary barrier to further increasing the number of life-saving transplantations. Recognizing that an important aspect of exploring these concerns is gaining insight into how transplant staff and patients regard splitting livers, the article presents the findings of a qualitative study examining the views of senior transplant staff and liver transplant patients in the UK and uses these to inform a commentary on the ethical issues relating to split liver transplantation.

Use of fibrinogen and thrombin sponge in pediatric split liver transplantation

Purpose:

To analyze the use of this sponge in pediatric patients undergoing split-liver transplantation.

Methods:

Retrospective study, including 35 pediatric patients undergoing split-liver transplantation, divided into two groups according to the use of the sponge: 18 patients in Group A (no sponge) and 17 in Group B (with sponge).

Results:

The characteristics of recipients and donors were similar. We observed greater number of reoperation due to bleeding in the wound area in Group A (10 patients - 55.5%) than in Group B (3 patients - 17.6%); p = 0.035. The median volume of red blood cells transfused in Group A was significantly higher (73.4 ± 102.38 mL/kg) than that in Group B (35.1 ± 41.67 mL/kg); p = 0.048. Regarding bile leak there was no statistical difference.

Conclusion:

The use of the human fibrinogen and thrombin sponge, required lower volume of red blood cell transfusion and presented lower reoperation rates due to bleeding in the wound area.

In Situ Split Liver Transplantation for 2 Adult Recipients: A Single-Center Experience

Background Material and Methods Results Conclusions.

Liver transplantation for hepatocellular carcinoma: outcomes and novel surgical approaches

Liver transplantation for hepatocellular carcinoma (HCC) is the best treatment option for patients with early-stage tumours and accounts for ∼20-40% of all liver transplantations performed at most centres worldwide. The Milan criteria are the most common criteria to select patients with HCC for transplantation but they can be seen as too restrictive. Several proposals have been made for a moderate expansion of the criteria, which result in good outcomes but with an increase in the risk of tumour recurrence. In this Review, we provide a comprehensive overview of the outcomes after liver transplantation for HCC, focusing on tumour recurrence in terms of surveillance, prevention and treatment. Additionally, novel surgical techniques have been developed to increase the available pool of organs for liver transplantation (such as living donor liver transplantation, donation after circulatory death and split livers), but the effect of these techniques on patients with HCC is still under debate. Thus, we will describe these techniques and expose the benefits and disadvantages of each surgical approach. Finally, we will comment on the limitations of the current priority policies for liver transplantation and the need to further refine them to better serve the population.

PEDIATRIC LIVER TRANSPLANTATION WITH EX-SITU LIVER TRANSECTION AND THE APPLICATION OF THE HUMAN FIBRINOGEN AND THROMBIN SPONGE IN THE WOUND AREA

Background

Surgical strategy to increase the number of liver transplants in the pediatric population is the ex-situ liver transection (reduction or split). However, it is associated with complications such as hemorrhage and leaks. The human fibrinogen and thrombin sponge is useful for improving hemostasis in liver surgery.

Aim

Compare pediatric liver transplants with ex-situ liver transection (reduction or split) with or without the human fibrinogen and thrombin sponge.

Methods

Was performed a prospective analysis of 21 patients submitted to liver transplantation with ex-situ liver transection with the application of the human fibrinogen and thrombin sponge in the wound area (group A) and retrospective analysis of 59 patients without the sponge (group B).

Results

The characteristics of recipients and donors were similar. There were fewer reoperations due to bleeding in the wound area in group A (14.2%) compared to group B (41.7%, p=0.029). There was no difference in relation to the biliary leak (group A: 17.6%, group B: 5.1%, p=0.14).

Conclusion

There was a lower number of reoperations due to bleeding of the wound area of ​​the hepatic graft when the human fibrinogen and thrombin sponge were used.

Improving graft survival by understanding the mechanism of segment 4 complications after split liver transplantation

BACKGROUND

This study was designed to assess the actual mechanism of segment 4 (S4)-related complications after split liver transplantation (SLT) and their impact on graft and overall survival with reference to those of left lateral sectionectomy for pediatric living donor liver transplantation (LLSLD).

METHODS

Clinical data from 53 SLT recipients and 62 LLSLD patients were assessed to determine the mechanism of S4-related complications. The postoperative parameters of SLT and their impact on graft and overall survival were also evaluated.

RESULTS

Although two biliary leakages were noted (3.2%), no necrosis of S4 developed after LLSLD. S4-related complications were seen in 15 (28.3%) patients after SLT. Radiological volumetry of S4 and the ischemic area after SLT showed no significant difference between those with and without S4-related complications. There were no significant differences between the patients with and without S4-related complications regarding both overall and graft survival rates. Significant better overall and graft survival rates were observed in patients treated during the later period.

CONCLUSIONS

S4-related complications after SLT are totally independent of the S4 volume, and biliary leakage is inherently an actual mechanism. Adequate intervention with early identification leads to better graft and overall survival, which validates SLT as a treatment option.

A Novel Concept for Partial Liver Transplantation in Nonresectable Colorectal Liver Metastases: The RAPID Concept

OBJECTIVE

Selected patients with nonresectable colorectal liver metastases benefit from liver transplantation and have acceptable 5-year survival rates. However, allocating full-sized grafts to this group of patients is difficult due to the scarcity of grafts. This could be improved by utilizing small partial grafts, which mandates effective strategies to overcome the problems regarding insufficient functional liver mass.

METHODS

We have developed a protocol incorporating previously reported experiences from living donor transplantation and recent developments in liver surgery, facilitating transplantation of very small liver grafts. At the time of transplantation, segments 1 to 3 are resected in the recipient and orthotopically replaced by a segment 2 to 3 allograft. Portal inflow is modulated by redirecting the portal flow to the graft with concomitant focus on keeping the portal vein pressure below 20 mm Hg. A second-stage hepatectomy is performed as soon as the graft has regenerated to a sufficient volume.

RESULTS

A graft weighing 330 g was transplanted to a 50-year-old man weighing 92 kg, and the portal vein to the right remnant liver was closed. The volume of the liver graft was doubled 2 weeks after the first procedure, and it increased further after the second procedure, with extended right hepatectomy performed at day 23 after transplantation. There were no signs of liver failure or small-for-size syndrome.

CONCLUSIONS

The current protocol and ongoing study could represent a possible strategy to increase the availability of liver transplantation to patients with nonresectable liver tumors such as hepatocellular carcinoma and colorectal liver metastases.

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.

Right lobe split liver transplantation versus whole liver transplantation in adult recipients: A systematic review and meta-analysis

Split liver transplantation (SLT) has proven to be an effective technique to reduce the mortality of children on the waiting list, but whether creating 2 split grafts from 1 standard-criteria whole liver would compromise outcomes of adult recipients remains uncertain. We conducted this meta-analysis to compare outcomes of right lobe SLT and whole liver transplantation (WLT) in adult patients. PubMed, Embase, and the Cochrane Library were searched for relevant articles published before December 2014. Outcomes assessed were patient survival (PS), graft survival (GS), and major surgical complications after transplantation. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to synthesize the results. Seventeen studies with a total of 48,457 patients met the full inclusion criteria. PS and GS rates were all found to be equivalent between SLT and WLT recipients. However, SLT was associated with higher rates of overall biliary complications (OR = 1.66; 95% CI = 1.29-2.15; P < 0.001), bile leaks (OR = 4.30; 95% CI = 2.97-6.23; P < 0.001), overall vascular complications (OR = 1.81; 95% CI = 1.29-2.53; P < 0.001), hepatic artery thromboses (OR = 1.71; 95% CI = 1.17-2.50; P = 0.005), and outflow tract obstructions (OR = 4.17; 95% CI = 1.75-9.94; P = 0.001). No significant difference was observed in incidences of biliary stricture, portal vein complications, postoperative bleeding requiring surgical treatments, primary nonfunction, and retransplantations. In subgroup analyses, biliary and vascular complications only increased after ex vivo SLT rather than in situ SLT, and SLT recipients had more retransplantations if they matched with WLT recipients in terms of urgent status. In conclusion, adult right lobe SLT was associated with increased biliary and vascular complications compared with WLT, but it did not show significant inferiority in PSs and GSs.

A prospective policy development to increase split-liver transplantation for 2 adult recipients: results of a 12-year multicenter collaborative study

OBJECTIVE

To analyze in a multicenter study the potential benefit of a new prospective policy development to increase split-liver procedures for 2 adult recipients.

BACKGROUND

Split-liver transplantation is an important means of overcoming organ shortages. Division of the donor liver for 1 adult and 1 pediatric recipient has reduced the mortality of children waiting for liver transplantation but the benefits or disadvantages to survival when the liver is divided for 2 adults (adult-to-adult split-liver transplant, AASLT) compared with recipients of a whole graft have not been fully investigated.

METHODS

We developed a computerized algorithm in selected donors for 2 adult recipients and applied it prospectively over a 12-year period among 7 collaborative centers. Patient and graft outcomes of this cohort receiving AASLT either as full right grafts or full left grafts were analyzed and retrospectively compared with a matched cohort of adults who received a conventional whole-liver transplant (WLT). Univariate and multivariate analysis was done for selected clinical variables in the AASLT group to assess the impact on the patient outcome.

RESULTS

Sixty-four patients who received the AASLT had a high postoperative complication rate (64.1% grade III and IV) and a lower 5-year survival rate than recipients of a WLT (63.3% and 83.1%)

CONCLUSIONS

AASLT should be considered a surgical option for selected smaller-sized adults only in experimental clinical studies in experienced centers.

Ex vivo split-liver transplantation: the true right/left split

BACKGROUND

Successful left lateral segment (sectionectomy) and right trisegmentectomy (trisectionectomy) split-liver transplantation (SLT) have been achieved. However, there are few reports of the use of true right/left splitting in SLT.

METHODS

A single-centre retrospective review of true right/left ex vivo split-liver transplants performed during the period 1993-2010 was conducted. Nine cadaveric liver grafts underwent splitting and the resultant 18 allografts were used in transplants performed at the study centre.

RESULTS

In the nine right lobe recipients, 10-year patient and graft survival rates were both 74%. There were no vascular complications, one biliary complication and one re-exploration. In the nine left lobe recipients, 10-year patient and graft survival rates were 78% and 66%, respectively. Postoperative complications included six biliary complications, four of which required surgical revision and all of which occurred within 5 months of transplantation, and two vascular complications, including one early hepatic artery thrombosis (HAT) and one late HAT, one of which required retransplantation. Five left lobe recipients required re-exploration, and one patient developed small-for-size syndrome following SLT, which resolved with conservative measures.

CONCLUSIONS

True right/left ex vivo SLT remains a viable option for facilitating the expansion of the adult cadaver donor pool and allows for excellent patient and graft survival. Postoperative morbidity remains high, especially in recipients of the left lobe graft, and must be balanced with the benefits to be derived from transplant.

Feasibility of split liver transplantation for 2 adults in the model of end-stage liver disease era

OBJECTIVE

To examine the results of split liver transplantation for 2 adults in the model of end-stage liver disease (MELD) era.

BACKGROUND

In the MELD era, liver allografts are first allocated to recipients with the highest MELD scores. However, the application of split liver transplantation for 2 adults in urgent condition has doubled and has become a matter of concern.

METHODS

Twenty-one deceased liver grafts were split into full right and full left lobes for 42 adult recipients. One of the hemiliver grafts was allocated to the recipient with the highest MELD score in the waiting list. The results of split liver transplantation were examined and compared with those of living donor liver transplantation.

RESULTS

Among 42 recipients, 24 (57.1%) had MELD scores higher than 20. The median (interquartile) MELD score for the recipients with split liver transplantation was 22 (15-30), which was higher than that for the recipients with living donor liver transplantation (P < 0.001). The 1-, 3-, and 5-year survival rates for split liver transplantation were comparable with those of living donor transplantation (P = 0.489). Nevertheless, 10 of 42 split liver recipients died within 3 months after transplantation. By receiver operating characteristic curve analysis, the safe graft-recipient weight ratio was better more than 1% to avoid early patient death for split liver transplantation.

CONCLUSIONS

Although most of the recipients with split liver transplantation had high MELD scores, the results were comparable with those of living donor liver transplantation. Split liver transplantation for 2 adults is still feasible in the MELD era.

Liver Transplantation: East versus West

Liver transplantation (LT) has evolved rapidly since the first successful liver transplant performed in1967. Despite a humble beginning, this procedure gained widespread acceptance in the western world as a suitable option for patients with end stage liver disease (ESLD) by the beginning of the 1980s. At present, approximately 25,000 liver transplants are being performed worldwide every year with approximately 90% one year survival. The techniques of living donor liver transplantation (LDLT) developed in East Asia in the 1990s to overcome the shortage of suitable grafts for children and scarcity of deceased donors. While deceased donor liver transplantation (DDLT) constitutes more than 90% of LT in the western world, in India and other Asian countries, most transplants are LDLT. Despite the initial disparity, outcomes following LDLT in eastern countries have been quite satisfactory when compared to the western programs. The etiologies of liver failure requiring LT vary in different parts of the world. The commonest etiology for acute liver failure (ALF) leading to LT is drugs in the west and acute viral hepatitis in Asia. The most common indication for LT due to ESLD in west is alcoholic cirrhosis and hepatitis C virus (HCV), while hepatitis B virus (HBV) predominates in the east. There is a variation in prognostic models for assessing candidature and prioritizing organ allocation across the world. Model for end-stage liver disease (MELD) is followed in United States and some European centers. Other European countries rely on the Child-Turcotte-Pugh (CTP) score. Some parts of Asia still follow chronological order of listing. The debate regarding the best model for organ allocation is far from over.

Liver transplantation in Indian Armed Forces-initial experience

BACKGROUND

This study retrospectively analyses the initial experience of liver transplantation (LT) in the Indian Armed Forces.

METHODS

Fifty-three patients underwent LT at Army Hospital (R&R) Delhi Cantt. between March 2007 and March 2011. Of these 35 patients underwent deceased donor liver transplantation (DDLT) and living donor liver transplantation (LDLT) was carried out in 18 patients. The surgical techniques, complications and mortality were analysed.

RESULTS

A high consent rate of 35.9% for organ donation was achieved by the Armed Forces Organ Retrieval and Transplantation Authority (AORTA). Biliary complications occurred in five patients (9.4%). However, most of them could be managed by endoscopic interventions. Hepatic artery thrombosis (HAT) occurred in five patients (9.4%). Of these, two DDLT grafts were revascularised following HAT, by creating extra-anatomic arterial conduits with excellent outcome. The overall mortality was 18.8% (n = 10). There was no significant difference in the overall complications or mortality in patients undergoing DDLT or LDLT.

CONCLUSION

The overall survival and morbidity in this study is comparable to those from other centres. Urgent revascularisation of grafts following HAT should be attempted as it can salvage grafts with satisfactory outcome. There is a reduction in the incidence of biliary complications with refinements in surgical techniques.

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

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

Results of liver transplantation from donors over 75 years: case control study

INTRODUCTION

The use of elderly donors can increase the pool of organs available for transplant. The aim of this study was to analyze the outcomes of grafts from donors older than 75 years.

PATIENTS AND METHODS

We selected 29 patients transplanted from January 2003 to January 2010 with livers from donors older than 75 years for comparison with a control group (58 patients), selected among patients transplanted immediately before or after each study case. Data analyzed using SPSS 15.0 were considered statistically significant at P < .05.

RESULTS

Statistically significant differences were evident in the mean age of donors (78.3 ± 2.9 vs 50.4 ± 17.8 years, P < .001), levels of aspartate aminotransferase alanine aminotransferase (30.8 ± 18.13/24.9 ± 14.4 vs 53.81 ± 68.4/39.37 ± 39.94 U/L, P < .05), and waiting list time of (122.4 ± 94.3 vs 169.2 ± 135.5 days, P = .034) of elderly donor versus control graft cohorts. The median follow-up was 32 months (range: 4-88.0) No differences were observed at 1 and 3 years after transplantation: graft survival was 78% and 61% in the older donor group and 83% and 71% in the younger donor group, respectively.

CONCLUSION

The use of expanded donors from elderly subjects can increase the donor pool with good results.

The European experience

This mini-review on European experiences with tackling the problem of organ shortage for transplantation was based on a literature review of predominantly European publications dealing with the issue of organ donation from deceased donors. The authors tried to identify the most significant factors that have demonstrated to impact on donation rates from deceased donors and subsequent transplant successes. These factors include legislative measures (national laws and European Directives), optimization of the donation process, use of expanded criteria donors, innovative preservation and surgical techniques, organizational efforts, and improved allocation algorithms.

Regulation of hepatic blood flow: The hepatic arterial buffer response revisited

The interest in the liver dates back to ancient times when it was considered to be the seat of life processes. The liver is indeed essential to life, not only due to its complex functions in biosynthesis, metabolism and clearance, but also its dramatic role as the blood volume reservoir. Among parenchymal organs, blood flow to the liver is unique due to the dual supply from the portal vein and the hepatic artery. Knowledge of the mutual communication of both the hepatic artery and the portal vein is essential to understand hepatic physiology and pathophysiology. To distinguish the individual importance of each of these inflows in normal and abnormal states is still a challenging task and the subject of ongoing research. A central mechanism that controls and allows constancy of hepatic blood flow is the hepatic arterial buffer response. The current paper reviews the relevance of this intimate hepatic blood flow regulatory system in health and disease. We exclusively focus on the endogenous interrelationship between the hepatic arterial and portal venous inflow circuits in liver resection and transplantation, as well as inflammatory and chronic liver diseases. We do not consider the hepatic microvascular anatomy, as this has been the subject of another recent review.

Hypoperfusion of segment 4 in right in situ split-liver transplantation

To expand the donor pool, split-liver transplantation has been implemented in recent years. In the classic technique, the arterial axis with the artery for segment 4 (S4) coming from the left hepatic artery (HA) is included with the right graft. To give a surgical advantage to pediatric recipients in our center, the left HA, the common HA, and the celiac trunk are generally retained with the left liver. Thus the artery for S4 is sacrificed. We compared the outcomes of S4 in 290 whole grafts (WG; group A) with 28 right in situ split-liver grafts (SSLG; group B), which were transplanted over the past 10 years (January 1999-December 2009). The rates of major biliary and of hemorrhagic complications were similar. In most of cases (16/24, 66%) S4, on computerized tomographic scan appeared to show signs of hypoperfusion, sometimes with a peripheral aspect of hyperperfusion in the arterial phase. S1 showed signs of hypoperfusion in only 2 cases. A biliary collection near the resection line present in 8 cases was treated in 6 of them with percutaneous drainage and in 2 with laparotomy. These complications did not influence graft or patient survival. Graft survivals at 1, 5, and 10 years for WG and SSLG were not different among the groups: 85%, 74%, and 66% vs 89%, 79%, and 63%, respectively (P = .8). Although our technique cannot be considered to be anatomically correct, the ischemia of S4 did not influence the outcome. The rate of retransplantations for hepatic artery thrombosis was 17.9% in RSSG and 3.4% in WG (P = .001), which was probably due at least in part to the insertion of interposition grafts.

Improving the waiting list by using 75-year-old donors for recipients with hepatocellular carcinoma

The best treatment for hepatocellular carcinoma (HCC) associated with liver cirrhosis is liver transplantation and the best results are obtained when the tumors fulfill the Milan criteria. However, although the number of transplants is increasing, the organ deficit is growing, which lengthens time on the waiting list, increasing the risk of tumor progression of and exclusion from the list. The use of elderly donors is a valid option for patients on the transplant waiting list with HCC, reducing time on the waiting list. We report our experience with patients transplanted for HCC associated with hepatic cirrhosis using livers from donors >75 years of age. Our preliminary results supported the use of elderly suboptimal donors making it possible to give priority to these patients. All patients in the series achieved good graft function after a follow-up of 2 years with a 100% disease-free survival rate. More extensive long-term studies are needed to confirm these findings.

Reduction in bile leaks following adult split liver transplant using a fibrin-collagen sponge: A pilot study

INTRODUCTION

Bile leaks are a frequent complication of adult split liver transplantation. We compared surgical complications in patients who had the cut surface of the donor liver treated with a patch to those in whom the cut surface of the liver was treated with fibrin glue.

MATERIAL AND METHODS

Two consecutive cohorts of 16 patients undergoing adult right lobe split liver transplant were compared. In the first cohort, the liver surface was treated with fibrin glue and in the second the liver surface was treated with TachoSil fibrinogen-thrombin-collagen patches. Post-operative complications were analyzed.

RESULTS

Bile leaks were significantly fewer among patients in whom the cut surface of the liver was treated with fibrin-collagen sponge compared to those where fibrin glue was used on the cut surface: 1/16 (6.25%) vs. 7/16 (43.75%), respectively; p=0.03. There were some differences in biliary anastomotic techniques used in the two groups but 7/8 leaks (87.5%) arose from the cut surface, and only one was from the anastomosis.

CONCLUSION

Using a fibrinogen-thrombin-collagen sponge patch may reduce bile leaks from the cut surface of the liver during adult right lobe split liver transplants.

Liver transplantation

Liver transplantation has become a lifesaving procedure for patients who have chronic end-stage liver disease and acute liver failure. The satisfactory outcome of liver transplantation has led to insufficient supplies of deceased donor organs, particularly in East Asia. Hence, East Asian surgeons are concentrating on developing and performing living-donor liver transplantation (LDLT). This review article describes an update on the present status of liver transplantation, mainly in adults, and highlights some recent developments on indications for transplantation, patient selection, donor and recipient operation between LDLT and deceased-donor liver transplantation (DDLT), immunosuppression, and long-term management of liver transplant recipients. Currently, the same indication criteria that exist for DDLT are applied to LDLT, with technical refinements for LDLT. In highly experienced centers, LDLT for high-scoring (>30 points) Model of End-Stage Liver Disease (MELD) patients and acute-on-chronic liver-failure patients yields comparably good outcomes to DDLT, because timely liver transplantation with good-quality grafting is possible. With increasing numbers of liver transplantations and long-term survivors, specialized attention should be paid to complications that develop in the long term, such as chronic renal failure, hypertension, diabetes mellitus, dyslipidemia, obesity, bone or neurological complications, and development of de novo tumors, which are highly related to the immunosuppressive treatment.

Percutaneous Transhepatic Bile Duct Ablation with n-Butyl Cyanoacrylate in the Treatment of a Biliary Complication after Split Liver Transplantation

Biliary complications continue to be a major cause of morbidity after split-liver transplantation (SLT). In this report we describe an uncommon late biliary complication. One year after SLT the patient showed an intrahepatic bile dicy dilatation with severe cholangitis episodes. The segmentary bile duct of hepatic segment VI-VII draining in the left duct was unidentified and tied at the time of the in situ split-liver procedure. We perform a permanent obliteration of the dilated intrahepatic ducts by a percutaneous embolization using an n-butyl cyanoacrylate (NABC). The management of biliary complications after SLT requires a multidisciplinary approach. The use of NBCA in obliteration of a dilated bile duct seems to be a safe procedure with good results providing a less invasive option than hepatic resection and decreasing the morbidity associated with chronic external biliary drainage. Further studies are needed to determine whether this approach is effective and safe and whether it could reduce hospital stay and cost.

Pediatric liver transplantation

In previous decades, pediatric liver transplantation has become a state-of-the-art operation with excellent success and limited mortality. Graft and patient survival have continued to improve as a result of improvements in medical, surgical and anesthetic management, organ availability, immunosuppression, and identification and treatment of postoperative complications. The utilization of split-liver grafts and living-related donors has provided more organs for pediatric patients. Newer immunosuppression regimens, including induction therapy, have had a significant impact on graft and patient survival. Future developments of pediatric liver transplantation will deal with long-term follow-up, with prevention of immunosuppression-related complications and promotion of as normal growth as possible. This review describes the state-of-the-art in pediatric liver transplantation.

Long-term outcomes of donation after cardiac death liver allografts from a single center

Organ shortage continues to be a major challenge in transplantation. Recent experience with controlled non-heart-beating or donation after cardiac death (DCD) are encouraging. However, long-term outcomes of DCD liver allografts are limited. In this study, we present outcomes of 19 DCD liver allografts with follow-up >4.5 years. During 1998-2001, 19 (4.1%) liver transplants (LT) with DCD allografts were performed at our center. Conventional heart-beating donors included 234 standard criteria donors (SCD) and 214 extended criteria donors (ECD). We found that DCD allografts had equivalent rates of primary non-function and biliary complications as compared with SCD and ECD. The overall one-, two-, and five-yr DCD graft and patient survival was 73.7%, 68.4%, and 63.2%, and 89.5%, 89.5%, and 89.5%, respectively. DCD graft survival was similar to graft survival of SCD and ECD in non hepatitis C virus (HCV) recipients (p > 0.370). In contrast, DCD graft survival was significantly reduced in HCV recipients (p = 0.007). In conclusion, DCD liver allografts are durable and have acceptable long-term outcomes. Further research is required to assess the impact of HCV on DCD allograft survival.

Preventable death: children on the transplant waiting list

Children, especially those under 5 years of age, have the highest death rate on the transplant waiting list compared to any other age range. This article discusses the concept, supported by OPTN data, that there is an age range of small pediatric donors, which are almost exclusively transplanted into small pediatric transplant candidates. Allocation policies that allow broader sharing of small pediatric donors into small pediatric candidates are likely to decrease death rates of children on the waiting list. As well, although the number of pediatric deceased donors continues to decline, improving consent rates for eligible pediatric donors, and judicious use of pediatric donors after cardiac death, can enhance the pediatric deceased donor supply.

Should we still offer split-liver transplantation for two adult recipients? A retrospective study of our experience

The role of split-liver transplantation (SLT) for two adult recipients is still a matter of debate, and no agreement exists on indications, surgical techniques, and results. The aim of this study was to retrospectively analyze the outcome of our series of SLT. From May 1999 to December 2006, 16 patients underwent SLT at our unit. We used 9 full right grafts (segments 5-8) and 7 full left grafts (segments 1-4). The splitting procedure was always carried out in situ with a fully perfused liver. Postoperative complications were recorded in 8 (50%) patients: 5 (55%) in full right grafts and 3 (43%) in full left grafts. No one was retransplanted. After a median follow-up of 55.82 months (range, 0.4-91.2), 5 (31%) patients died, and the 1-, 3-, and 5-year overall survival rate for patients and grafts was 69%. We considered as a control group for the global outcome 232 whole liver transplantations performed at our unit in the same period of time. Postoperative complications were recorded in 53 (23%) patients, and after a median follow-up of 57.37 months (mean, 55.11; range, 1-102.83), the 1-, 3-, and 5-year overall patient survival was 87%, 82%, and 80%, respectively. In conclusion, SLT for two adult recipients is a technically demanding procedure that requires complex logistics and surgical teams experienced in both liver resection and transplantation. Although the reported rate of survival might be adequate for such a procedure, more efforts have to be made to improve the short-term outcome, which is inadequate in our opinion. The true feasibility of SLT for two adults has to be considered as still under investigation.