Small-for-size syndrome in adult-to-adult living-related liver transplantation

Portal hypertension-like pattern in coronavirus disease 2019 acute respiratory distress syndrome

OBJECTIVES

Although respiratory failure is the most common feature in coronavirus disease 2019 (COVID-19), abdominal organ involvement is likewise frequently observed. To investigate visceral and thoracic circulation and abdominal organ damage in COVID-19 patients.

MATERIALS AND METHODS

A monocentric observational study was carried on. In COVID-19 patients affected by acute respiratory distress syndrome (ARDS) (n = 31) or mild pneumonia (n = 60) thoracoabdominal circulation was evaluated using Doppler-ultrasound and computed tomography. The study also included non-COVID-19 patients affected by ARDS (n = 10) or portal hypertension (n = 10) for comparison of the main circulatory changes.

RESULTS

Patients affected by COVID-19 ARDS showed hyperdynamic visceral flow and increased portal velocity, hepatic artery resistance-index, and spleen diameter relative to those with mild-pneumonia (p = 0.001). Splanchnic circulatory parameters significantly correlated with the main respiratory indexes (p < 0.001) and pulmonary artery diameter (p = 0.02). The chest and abdominal vascular remodeling pattern of COVID-19 ARDS patients resembled the picture observed in the PH group, while differed from that of the non-COVID ARDS group. A more severe COVID-19 presentation was associated with worse liver dysfunction and enhanced inflammatory activation; these parameters both correlated with abdominal (p = 0.04) and chest imaging measures (p = 0.03).

CONCLUSION

In COVID-19 ARDS patients there are abdominal and lung vascular modifications that depict a portal hypertension-like pattern. The correlation between visceral vascular remodeling, pulmonary artery enlargement, and organ damage in these critically ill patients is consistent with a portal hyperlfow-like syndrome that could contribute to the peculiar characteristics of respiratory failure in these patients.

CLINICAL RELEVANCE STATEMENT

our data suggest that the severity of COVID-19 lung involvement is directly related to the development of a portal hyperflow-like syndrome. These observations should help in defining the need for a closer monitoring, but also to develop dedicated therapeutic strategies.

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.

Dual Graft Living Donor Liver Transplantation for High Acuity Patients: A Single-Center Experience

Background

The outcomes of dual graft living donor liver transplantation (DGLDLT) in high acuity patients remain underreported. The objective of this study was to report long-term outcomes from a single center in this select group of patients.

Methods

This was a retrospective review of patients who underwent DGLDLT between 2012 and 2017 (n = 10). High acuity patients were defined as patients with model for end stage liver disease (MELD) ≥30 or Child Pugh score ≥11. We looked at 90-day morbidity and mortality and 5-year overall survival (OS).

Results

The median MELD score and Child Pugh score were 30 (26.7-35) and 11 (11-11.2). The median recipient weight was 105 (95.2-113.7) and ranged from 82 to 132 kg. Out of 10 patients, 4 (40%) required perioperative renal replacement therapy, and 8 (80%) required hospital admission for optimization. The estimated graft to recipient weight ratio (GRWR) with right lobe graft alone was <0.8 in all patients, between 0.75 and 0.65 in 5 (50%) patients, and <0.65 in 5 (50%) patients. The 90-day mortality was 3/10 (30%), and there were 3/10 (30%) deaths during long-term follow-up. Among 155 high acuity patients, the 1-year OS with standard LDLT, standard LDLT with GRWR <0.8, and DGLDLT was 82%, 76%, and 58%, respectively (P = 0.123). With a median follow-up of 40.6 (1.9-74.4) months, the 5-year OS for DGLDLT was 50%.

Conclusion

The use of DGLDLT in high acuity patients should be prudent and low GRWR grafts should be considered a viable alternative in selected patients.

Platelets mediate acute hepatic microcirculatory injury in a protease-activated-receptor-4-dependent manner after extended liver resection

BACKGROUND

Small-for-size syndrome (SFSS) is a major complication following extended liver resection. The role of platelets in the early development of SFSS remains to be cleared. We aimed to investigate the impact of platelets and PAR-4, a receptor for platelet activation, on the acute phase microcirculatory injury after liver resection by in vivo microscopy analyzing the changes in leukocyte recruitment, platelet-neutrophil interaction, and microthrombosis-induced perfusion failure.

METHODS

Sixty-percent partial hepatectomy (PH) models using C57BL/6 mice receiving platelet depletion with anti-GPIbα, PAR-4 blockade with tcY-NH2, or vehicle treatment with saline were used. Sham-operated animals served as controls. Epifluorescence microscopic analysis was performed 2 h after PH to quantify the leukocyte recruitment and microcirculatory changes. Sinusoidal neutrophil recruitment, platelet-neutrophil interaction, and microthrombosis were evaluated using two-photon microscopy. ICAM-1 expression and liver liver injury were assessed in tissue/blood samples.

RESULTS

The increments of leukocyte recruitment in post-sinusoidal venules and sinusoidal perfusion failure, the upregulation of ICAM-1 expression, and the deterioration of liver function 2 h after 60% PH were alleviated in the absence of platelets or by PAR-4 blockade. Intensified platelet-neutrophil interaction and microthrombosis in sinusoids were observed 2 h after 60% PH, which significantly attenuated after PAR-4 blockade.

CONCLUSION

Platelets play a critical role in acute liver injury after extended liver resection within 2 h. The deactivation of platelets via PAR-4 blockade ameliorated liver function deterioration by suppressing early leukocyte recruitment, platelet-neutrophil interaction, and microthrombosis in hepatic sinusoids.

Liver Transplantation for Unresectable Intrahepatic Cholangiocarcinoma: The Role of Sequencing Genetic Profiling

Intrahepatic cholangiocarcinoma (iCCA) is a rare and aggressive primary liver tumor, characterized by a range of different clinical manifestations and by increasing incidence and mortality rates even after curative treatment with radical resection. In recent years, growing attention has been devoted to this disease and some evidence supports liver transplantation (LT) as an appropriate treatment for intrahepatic cholangiocarcinoma; evolving work has also provided a framework for better understanding the genetic basis of this cancer. The aim of this study was to provide a clinical description of our series of patients complemented with Next-Generation Sequencing genomic profiling. From 1999 to 2021, 12 patients who underwent LT with either iCCA or a combined hepatocellular and cholangiocellular carcinoma (HCC-iCCA) were included in this study. Mutations were observed in gene activating signaling pathways known to be involved with iCCA tumorigenesis (KRAS/MAPK, P53, PI3K-Akt/mTOR, cAMP, WNT, epigenetic regulation and chromatin remodeling). Among several others, a strong association was observed between the Notch pathway and tumor size (point-biserial rhopb = 0.93). Our results are suggestive of the benefit potentially derived from molecular analysis to improve our diagnostic capabilities and to devise new treatment protocols, and eventually ameliorate long-term survival of patients affected by iCCA or HCC-iCCA.

Association of Plasma Fibrinogen Levels on Postoperative Day 1 with 2-Year Survival of Orthotopic Liver Transplantation for HBV-Related HCC

OBJECTIVE

To clarify the prognostic values of hemostatic parameters to predict the survival of patients undergoing orthotopic liver transplantation (OLT) for hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC).

METHODS

The data of 182 consecutive adult patients who underwent OLT for HBV-related HCC were subjected to univariate and multivariate analyses.

RESULTS

Ascites and fibrinogen levels on postoperative day (POD) 1 were independent predictors of postoperative 2-year mortality (both P <.05). Kaplan-Meier survival analysis showed that the higher the fibrinogen level on POD 1, the better the 1- and 2-year survival of patients with ascites (P <.05), whereas the fibrinogen level on POD 1 was associated with 1-year (P <.05) but not 2-year survival of patients without ascites.

CONCLUSION

Fibrinogen on POD 1 is a predictor of 2-year post-OLT survival of patients with HBV-related HCC with ascites.

[Liver regeneration: resolved and problem issues]

Liver is an exceptional organ due to unique anatomical and physiological features, as well as advanced regenerative ability. Discovery of molecular mechanisms governing liver regeneration allowed researchers to use them to enhance liver regeneration. However, significant progress in this area was achieved through the introduction of gene therapy. In this manuscript, the authors consider stem cells for cell therapy and tissue engineering, as well as an alternative to liver transplantation.

Adult to Adult Living Donor Liver Transplantation in Recipients with Low MELD: A Strategy Intended to Overcome Donor Shortage

Recent series have demonstrated advantages of living donor over deceased donor liver transplantation, with particular benefit for those with low model for end-stage liver disease score. The logic underlying the transplantation of patients before they become too sick is intuitive. It reduces mortality and drop outs from the waiting list and makes transplant surgery less demanding. Those principles have to be balanced with donor safety and transplant benefit for the recipient avoiding early, futile transplantation. The authors report a case of adult to adult right lobe living donor liver transplantation performed for a recipient affected by primary biliary cirrhosis with MELD score of 15, in a transplant center located in an area of Europe characterized by chronic organ shortage.

Near Infra-Red Technology to Evaluate Segment IV in Split Liver Transplantation

BACKGROUND

Indocyanine green injected intravenously has been employed in many fields of hepatobiliary surgery such as liver and biliary tree mapping, tumor detection, and graft evaluation in liver transplant. This latter application has, in our opinion, particular potentials when a split liver transplantation is performed 1-3.

METHODS

In this study, we used infrared technology to evaluate in real-time the segment 4 region in a recipient of extended right lobe transplantation. Donor data: 50 years old male, brain death, height, 1.70 mt, weight 69 kg; surgical technique employed was in situ standard split liver procurement. Recipient data: 46 years old male, height 1.75 mt; weight 67 k 23 g, affected by cirrhosis secondary HCV infection, with MELD Na 33. Standard orthotopic liver transplantation was performed with indocyanine green intravenous injection at 15 min after arterial reperfusion.

RESULTS

Infrared technology, showed in this video, demonstrates progressive improvement of segment IV viability which was confirmed by the post-operative contrast-enhanced CT scan performed before discharge. The transplant procedure was uneventful and the patient discharged to home 10 days after surgery.

CONCLUSION

The case reported in this video is, to the best of our knowledge, the first in the English literature showing how near infrared technology has predictive value on the evaluation of a split graft. Fast diffusion of the colorant allows dynamic early evaluation and may confirm the presence of intra-hepatic venous shunt, which will determine a full recovery of the originally ischemic area. On the contrary, a permanent absence of the staining might be predictive of dysfunction.

Laparoscopic Microwave Thermal Ablation for the Treatment of Hepatocellular Carcinoma in Chronic Hepatic Patients

Background: Laparoscopic microwave thermal ablation (LMWTA) is a well-established alternative treatment to liver resection for treatment of liver tumors. The aim of this study was to describe our experience in LMWTA for hepatocellular carcinoma (HCC) in chronic hepatic patients. Materials and Methods: A study group of 61 consecutive HCC patients treated with LMWTA from January, 2013 to May, 2020 were considered for this study. Patient characteristics, liver function test, operational characteristics, and complications were recorded. Results: Of the 61 patients who underwent LMWTA, median age was 64 (interquartile range [IQR]: 58-71) years, mean body mass index was 26.2 (IQR: 23.2-29.4); 44 patients (72%) presented with an hepatitis C virus etiology, 46 (75%) were Child-Pugh Class A, median model for end-stage liver disease (MELD) score was 8.0 (IQR: 7.0-9.4). Viral infection was confirmed to be the most important risk factor in determining progressive cirrhotic evolution with HCC expression. Conclusions: LMWTA is a safe alternative treatment to traditional surgery, and can be combined with surgery.

Application of Pediatric Donor Livers After Circulatory Death in Adult Liver Transplantation: A Single-Center Experience

OBJECTIVES

This study aimed to investigate the outcomes of adult liver transplant procedures using grafts from pediatric donors after circulatory death.

MATERIALS AND METHODS

We retrospectively analyzed the data of 19 pediatric-to-adult liver transplant procedures from July 2013 to May 2016 in our hospital. Nineteen adult liver transplant procedures were performed using livers from pediatric donors after circulatory death.

RESULTS

We performed 18 orthotopic and 1 piggyback liver transplant procedure. The median graft-to-recipient weight ratio was 1.26% (range, 0.86% to 2.46%). The median warm and cold ischemia times were 11 minutes (range, 8-20 min) and 638 minutes (range, 200-843 min), respectively. Complications after the operation included postoperative pulmonary infection (8 patients), fungal infection (1 patient), cytomegalovirus infection (1 patient), hepatic artery thrombosis and biliary stricture (1 patient), portal vein stenosis (1 patient), and graft failure (2 patients). For patients with graft failure, 1 patient received retransplant and 1 died. The patients were followed for 22.44 months (range, 9.63-44.07 mo) after transplant and showed normal liver function and good health. The 3-year survival rates of grafts and patients were 89.47% and 94.74%, respectively.

CONCLUSIONS

Appropriate evaluation of donors and recipients and accurate intraoperative and postoperative treatment can ensure successful application of livers from pediatric donors after circulatory death in adult recipients.

Perioperative von Willebrand factor dynamics are associated with liver regeneration and predict outcome after liver resection

von Willebrand Factor (vWF) was found to mediate platelet influx during the early phase of liver regeneration in mice. Furthermore, increased vWF-antigen (vWF-Ag) levels were shown to be predictive for outcome of patients with chronic liver disease. Accordingly, we aimed to assess the relevance of perioperative vWF-Ag dynamics in terms of liver regeneration and clinical outcome in patients undergoing liver resection (LR). Accordingly, we observed that vWF-Ag and its activity-estimated by ristocetin cofactor measurement-increased immediately after induction of liver regeneration and was associated with platelet accumulation within the liver. However, a significant vWF-Ag burst was only observed in patients with unaffected postoperative liver regeneration. E-selectin, as an established marker for endothelial cell activation, was found to correlate with vWF-Ag in the liver vein after induction of liver regeneration (R = 0.535, P = 0.022). Preoperative vWF-Ag levels significantly predicted postoperative liver dysfunction (LD; N = 95; area under the curve, 0.725; P = 0.009). Furthermore, a cutoff of vWF-Ag ≥182% was defined to identify patients with a higher risk for postoperative LD or morbidity. This was confirmed within an independent mulitcenter validation cohort (N = 133). Ultimately, multivariable analysis revealed that vWF-Ag was an independent predictor of postoperative LD and morbidity.

CONCLUSION

Within this study, we were able to provide evidence that an initial vWF burst is required to allow for adequate platelet accumulation and concomitant liver regeneration post-LR and might be abolished as a consequence of intrahepatic endothelial cell dysfunction. We were further able to reveal and validate the potential of preoperative vWF-antigen levels to predict poor postoperative outcome in patients undergoing LR. Despite the pathophysiological relevance of our findings, vWF-Ag seems to be a valuable tool for preoperative risk assessment in patients undergoing LR. (Hepatology 2018;67:1516-1530).

Effects of splanchnic vasoconstrictors on liver regeneration and survival after 90% rat hepatectomy

Purpose

Posthepatectomy liver failure is a serious complication and considered to be caused by increased portal pressure and flow. Splanchnic vasoactive agents and propranolol are known to decrease portal pressure. The aim of this study was to identify optimal candidates with potential for clinical use among somatostatin, terlipressin, and propranolol using rats with 90% hepatectomy.

Methods

Rats were divided into 5 groups: sham operation (n = 6), control (n = 20), propranolol (n = 20), somatostatin (n = 20), and terlipressin group (n = 20). Seven-day survival rates and portal pressure change were measured, and biochemical, histologic, and molecular analyses were performed.

Results

Portal pressure was significantly decreased in all 3 treatment groups compared to control. All treatment groups showed a tendency of decreased liver injury markers, and somatostatin showed the most prominent effect at 24 hours postoperatively. Histologic liver injury at 24 hours was significantly decreased in propranolol and terlipressin groups (P = 0.016, respectively) and somatostatin group showed borderline significance (P = 0.056). Hepatocyte proliferation was significantly increased after 24 hours in all treatment groups. Median survival was significantly increased in terlipressin group compared to control group (P < 0.01).

Conclusion

Terlipressin is considered as the best candidate, while somatostatin has good potential for clinical use, considering their effects on portal pressure and subsequent decrease in liver injury and increase in liver regeneration.

Small-for-Size Syndrome: Bridging the Gap Between Liver Transplantation and Graft Recovery

In living donor liver transplantation, optimal graft size is estimated from values like graft volume/standard liver volume and graft/recipient body weight ratio but the final functional hepatic mass is influenced by other donor and recipient factors. Grafts with insufficient functional hepatic mass can produce a life-threatening condition with rapidly progressive liver failure called small-for-size syndrome (SFSS). Diagnosis of SFSS requires careful surveillance for signs of inadequate hepatocellular function, residual portal hypertension, and systemic inflammation that suggest rapidly progressive liver failure. Early diagnosis, symptom control, and addressing the cause of SFSS may prevent the need for retransplantation. With increased attention to avoiding donor risk, intensivists will be confronted with more SFSS recipients. In this review, we aim to outline a systematic approach to the medical management of patients with SFSS by providing a concise synopsis of general supportive care—neurological, cardiovascular, and renal support, mechanical ventilation, nutritional support, infection control, and tailored immunosuppression—with an aim to avoid end-organ damage or death and a review of current interventions including liver support devices, portal flow modulating drugs, and other experimental interventions that aim to preserve existing hepatic mass and improve conditions for hepatic regeneration. We examine evidence for SFSS interventions to provide the reader with information that may assist in clinical decision making. Points of controversy in care are purposefully highlighted to identify areas where additional experimental work is still needed. A full understanding of the pathophysiology of SFSS and measures to support liver regeneration will guide effective management.

Perioperative Non-Invasive Indocyanine Green-Clearance Testing to Predict Postoperative Outcome after Liver Resection

Background

Postoperative liver dysfunction may lead to morbidity and mortality after liver resection. Preoperative liver function assessment is critical to identify preexisting liver dysfunction in patients prior to resection. The aim of this study was to evaluate the predictive potential of perioperative indocyanine green (ICG)-clearance testing to prevent postoperative liver dysfunction and morbidity using standardized outcome parameters in a routine Western-clinical-setting.

Study Design

137 patients undergoing partial hepatectomy between 2011 and 2013, at the general hospital of Vienna, were included. ICG-clearance was recorded one day prior to surgery as well as on the first and fifth postoperative day. Postoperative liver dysfunction was defined according to the International Study Group of Liver Surgery and evaluation of morbidity was based on the Dindo-Clavien classification. Statistical analyses were based on non-parametric tests.

Results

Preoperative reduced ICG—plasma disappearance rate (PDR) as well as increased ICG—retention rate at 15 min (R15) were able to significantly predict postoperative liver dysfunction (Area under the curve = PDR: 0.716, P = 0.018; R15: 0.719, P = 0.016). Furthermore, PDR <17%/min. or R15 >8%, were able to accurately predict postoperative complications prior to surgery. In addition to this, ICG-clearance on postoperative day 1 comparably predicted postoperative liver dysfunction (Area under the curve = PDR: 0.895; R15: 0.893; both P <0.001), specifically, PDR <10%/min or R15 >20% on postoperative day 1 predicted poor postoperative outcome.

Conclusion

PDR and R15 may represent useful parameters to distinguish preoperative high and low risk patients in a Western collective as well as on postoperative day 1, to identify patients who require closer monitoring for potential complications.

Dysfunction in Patients With Small-for-Size Grafts After Living Donor Liver Transplantation

The relationship between postoperative percentage fall of platelet (PLT) counts and graft dysfunction after living donor liver transplantation (LDLT) in recipients with small-for-size (SFS) graft has not been fully evaluated. We retrospectively studied 50 adult-to-adult LDLT recipients with a graft-to-recipient weight ratio of <0.8% between 1999 and 2011. Graft dysfunction was defined as the presence of hyperbilirubinemia, coagulopathy, or ascites on 3 consecutive days during the first postoperative week. Each clinical sign of dysfunction was assigned 1 point. Postoperative percentage fall in PLT counts, graft dysfunction score, and postoperative complications according to the Clavien-Dindo classification were investigated. Overall, 31 patients (62%) exhibited a PLT count fall of more than 50%, and 19 (38%) patients exhibited a PLT count fall of less than 50% at postoperative day (POD) 3. Receiver operating characteristic curve analysis indicated that at POD 3, the cutoff value of PLT count fall was 56% for a graft dysfunction score of 2 or 3 (sensitivity, 70%; specificity, 63.3%). Fourteen of 20 patients (70%) with a dysfunction score of 2 or 3 and 11 of 30 patients (37%) with a dysfunction score of 0 or 1 showed a fall in PLT count >56% at POD 3 (P = 0.021). Grade 2 to 5 complications were more observed in patients with a dysfunction score of 2 or 3 than in patients with a dysfunction score of 0 or 1 (P < 0.001). The fall of PLT count at POD 3 >56% is an ominous sign that can predict the graft dysfunction after LDLT in recipients with SFS graft.

Does the development of chronic kidney disease and acute kidney injury affect the prognosis after living donor liver transplantation?

BACKGROUND AND AIMS

Chronic kidney disease (CKD) and acute kidney injury (AKI) have been discussed as complications following living donor liver transplantation (LDLT). The aim of this study was to clarify the relationships among CKD, AKI, and the prognosis after LDLT.

METHODS

This study included 118 patients who underwent LDLT in our department. A low eGFR (<60 mL/min/1.73 m(2) ) was regarded to indicate CKD. AKI 1 and AKI 2 were characterized by an increase in the serum creatinine level of 0.5 and 1.0 mg/dL, respectively, within one wk after LDLT. We investigated the risk factors for and the relevance of CKD and AKI on the prognosis.

RESULTS

AKI 1 was associated with sepsis and intra-operative bleeding (p = 0.0032, p = 0.001). AKI 2 was associated with sepsis and hepatitis C infection (p < 0.001, p = 0.027). A pre-operative eGFR of 60-89 and diabetes were the risk factors for the development of CKD in POY 2 (p = 0.018, p = 0.002). AKI 2, sepsis, and diabetes were the risk factors for the patient death within one yr after LDLT (p = 0.010, p = 0.002, p = 0.022). AKI 2 and sepsis were the risk factors for death within two yr after LDLT (p = 0.005, p = 0.018).

CONCLUSIONS

Recognizing the risk factors and careful management for preventing both AKI and CKD may improve the prognosis of patients following LDLT.

Octreotide prevents liver failure through upregulating 5'-methylthioadenosine in extended hepatectomized rats

BACKGROUND & AIMS

Insufficient liver regeneration and hepatocyte injury caused by excessive portal perfusion are considered to be responsible for post-hepatectomy liver failure (PLF) or small-for-size syndrome in living-donor liver transplantation. Somatostatin can decrease portal vein pressure (PVP) but simultaneously inhibits liver regeneration. This interesting paradox motivated us to investigate the outcome of PLF in response to somatostatin treatment.

METHODS

Rats receiving extended partial hepatectomy (90% PH) were treated with octreotide, a somatostatin analogue, or placebo. Animal survival, serum parameters and hepatic histology were evaluated. Metabolomic analysis was performed to investigate the effect of octreotide on hepatocyte metabolism.

RESULTS

Despite significantly inhibiting early regeneration, octreotide application noticeably improved the hepatic histology, liver function and survival after PH but did not decrease the PVP level. Metabolomic analysis exhibited that octreotide profoundly and exclusively altered the levels of five metabolites that participate in or closely associate with the methionine cycle, a biochemical reaction that uniquely produces S-adenosylmethionine (SAMe), an active methyl residual donor for methyltransferase reactions. Among these metabolites, 5'-methylthioadenosine (MTA), a derivate of SAMe, increased three-fold and was found independently improve the hepatic histology and reduce inflammatory cytokines in hepatectomized rats.

CONCLUSIONS

Octreotide exclusively regulates the methionine cycle reaction and augments the MTA level in hepatocytes. MTA prominently protects hepatocytes against shear stress injury and reduces the secondary inflammation, thereby protecting rats from PLF.

Assessment of Graft Selection Criteria in Living-Donor Liver Transplantation: The Jikei Experience

In living-donor liver transplantation, graft selection is especially important for the safety of the live donor and an acceptable outcome for the recipient. The essential medical requirements for living liver donation at Jikei University Hospital are as follows: an adult aged 65 years or younger, in good general condition, with partial liver volume of more than 35% of the standard liver volume (SLV) for the recipient, and without severe liver steatosis. Based on our criteria, we performed 13 living-donor liver transplantations between 2007 and 2013, including 1 retransplantation. Three cases were outside our standard donor criteria, including age (18 and 66 years) and 33% graft volume (GV) to SLV ratio for the recipient on preoperative volumetry using computed tomography. In 2 cases, the actual GV to SLV ratio at transplantation was less than 35%. Median postoperative hospital stay was 11 days for the donors, and 29 days for the recipients. All donors returned to their preoperative status, and all recipients were discharged in good condition. Our medical requirements for living liver donation seem to be acceptable because of the good outcome.

Role of the spleen in liver regeneration in relation to transforming growth factor-β1 and hepatocyte growth factor

BACKGROUND

Optimizing the hepatic regenerative capacity is an immediate priority after partial hepatectomy (PH). Recent reports have indicated improvement in liver regeneration after splenectomy, raising interest on the role of the spleen in liver regeneration. However, little is known about the exact mechanism underlying these effects.

MATERIALS AND METHODS

Eight-week-old male Sprague-Dawley rats randomly underwent either 70% PH only (PH, n = 25) or 70% PH combined with splenectomy (PHS, n = 25). The specimens, including liver and/or spleen tissues and sera, were collected and evaluated using immunohistochemistry, Western blotting, enzyme-linked immunosorbent assay, and serum biochemical analyses.

RESULTS

PH induced higher transforming growth factor (TGF)-β1 expression in the liver up to 72 h after PH. The PHS group showed significantly higher numbers of proliferating cell nuclear antigen-positive cells, reflecting higher liver regeneration and lower amounts of liver enzymes compared with the PH group. Splenectomy after PH resulted in increased and decreased serum concentrations of hepatocyte growth factor (HGF) and TGF-β1 in the portal vein, respectively. Moreover, the PHS group demonstrated downregulation of TGF-β1 and its receptor TGF-β-RII and upregulation of HGF and its receptor c-Met in the liver.

CONCLUSIONS

The spleen seemed to exhibit an inhibitory effect on liver regeneration by upregulating TGF-β1 and its receptor TGF-β-RII and downregulating HGF and its receptor c-Met in the liver. Therefore, splenectomy can be considered an option for improving liver regeneration in selected patients with reduced regenerative capacity of the liver.

Liver regeneration

The liver is unique in its ability to regenerate in response to injury. A number of evolutionary safeguards have allowed the liver to continue to perform its complex functions despite significant injury. Increased understanding of the regenerative process has significant benefit in the treatment of liver failure. Furthermore, understanding of liver regeneration may shed light on the development of cancer within the cirrhotic liver. This review provides an overview of the models of study currently used in liver regeneration, the molecular basis of liver regeneration, and the role of liver progenitor cells in regeneration of the liver. Specific focus is placed on clinical applications of current knowledge in liver regeneration, including small-for-size liver transplant. Furthermore, cutting-edge topics in liver regeneration, including in vivo animal models for xenogeneic human hepatocyte expansion and the use of decellularized liver matrices as a 3-dimensional scaffold for liver repopulation, are proposed. Unfortunately, despite 50 years of intense study, many gaps remain in the scientific understanding of liver regeneration.

Liver, pancreas and small bowel transplantation: current ethical issues

We describe the medical state of the art in liver, pancreas and small bowel transplantation, and portray the ethical issues. Although most ethical questions related to these transplantations are not specific for liver, pancreas and small bowel, they do challenge ethical analysis as well as new policies and clinical procedures. Firstly, outcomes continue to be of utmost concern, as information is only limited available, is developing over time and is surrounded by many uncertainties. Secondly, characteristics of donors and recipients should be carefully evaluated. The question of what qualifies a donor and a recipient should be considered against the background of a quest for extended criteria, embracing marginal cases, and a judgment with regard to what counts as a good enough outcome. Thirdly, ethical principles of autonomy and fairness are pushed, given the circumstance of severe scarcity, towards limits that can easily be crossed.

Right hepatic lobe living donation: a 12 years single Italian center experience

Mini invasive techniques are taking over conventional open liver resections in the setting of left lateral segmentectomy for living liver donation, and hydride procedure are being implemented for the living related right hepatectomy. Our center routinely performs laparoscopic left lateral segmentectomy for pediatric recipient and has been the first in the Europe performing an entirely robotic right hepatectomy. Great emphasis is posed on living donor safety which is the first priority during the entire operation, then the most majority of our procedures are still conventional open right hepatectomy (RHLD), defined as removal of a portion of liver corresponding to Couinaud segments 5-8, in order to obtain a graft for adult to adult living related liver transplant. During this 10 years period some changes, herein highlighted, have occurred to our surgical techniques. This study reports the largest Italian experience with RHLD, focused on surgical technique evolution over a 10 years period. Donor safety must be the first priority in right-lobe living-related donation: the categorization of complications of living donors, specially, after this "highly sensitive" procedure, reflects the need for prompt and detailed reports.

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.

Smoothing the path: reducing biliary complications, addressing small-for-size syndrome, and making other adaptations to decrease the risk for living donor liver transplant recipients

1. Over the course of the past 2 decades, living donor liver transplantation (LDLT) has become increasingly successful because many of the technical issues plaguing it have been resolved. 2. Although donor safety remains a concern, most challenges related to the recipient's surgery are now better understood, and they appear surmountable. 3. The following concepts need to be addressed for optimal recipient outcomes to be achieved: a. Reduction of the risk of small-for-size syndrome in LDLT (ie, the management of 4 factors: the recipient status, the portal pressure and inflow, the venous outflow, and the graft-to-recipient weight ratio/graft quality). b. Reduction of the risk of surgical complications (biliary complications, reconstitution of the middle hepatic vein outflow in the right lobe graft, and safe hepatic artery and portal vein reconstruction). c. Other adaptations for improving recipient outcomes (adaptations related to LDLT and adaptations common to deceased donor liver transplantation and LDLT).

[Small-for-size: experimental findings for liver surgery]

The characteristics of the hepatic macrocirculation, i.e., the parallel portal-venous and arterial blood supply, is of utmost relevance for liver surgery. With extended hepatectomy or transplantation of a reduced-size liver the remaining or transplanted liver tissue is overperfused because the liver fails to regulate the portal-venous inflow. This portal hyperperfusion is responsible for the initiation of liver cell proliferation but represents at the same time one of the substantial events in the pathogenesis of the small-for-size syndrome. Portal-venous hyperperfusion, the so-called hepatic arterial buffer response, which describes the semi-reciprocal relationship between the portal-venous and hepatic arterial blood flows, leads to an arterial hypoperfusion of the small-for-size liver. In this article experimental and clinical data are discussed which underline the high but so far overseen relevance of this arterial underperfusion in the development of a small-for-size syndrome.

Beneficial effects of splenectomy on liver regeneration in a rat model of massive hepatectomy

BACKGROUND

Small-for-size syndrome is a widely recognized clinical complication after living donor liver transplantation or extended hepatectomy due to inadequate liver mass. The purpose of this study was to investigate the role of splenectomy in rats after massive hepatectomy, a surrogate model of small-for-size graft.

METHODS

Rats were divided into eight groups, each with 20 animals: 50% hepatectomy (50% Hx), 50% hepatectomy+splenectomy (50% Hx+Sp), 60% Hx, 60% Hx+Sp, 70% Hx, 70% Hx+Sp, 90% Hx and 90% Hx+Sp. The following parameters were evaluated: liver function tests (ALT, AST and TBIL), liver regeneration ratio, DNA synthesis, proliferation cell nuclear antigen, hepatic oxygen delivery (HDO2) and hepatic oxygen consumption (HVO2).

RESULTS

The liver regeneration ratio was enhanced in the Hx+Sp groups (P<0.05). In addition, compared with the Hx groups, the Hx+Sp groups had better liver functions (P<0.05). DNA synthesis and proliferation cell nuclear antigen were also increased in the Hx+Sp groups compared with the Hx groups (P<0.05). Furthermore, in the Hx+Sp groups, HDO2 and HVO2 were increased over those in the Hx groups (P<0.05), and were positively correlated with the liver regeneration ratio.

CONCLUSIONS

Splenectomy significantly improved liver function, and enhanced DNA synthesis and proliferation cell nuclear antigen after massive hepatectomy in rats. This operation could be mediated through increased HDO2 and HVO2, which facilitate liver regeneration.

Subrenal capsule assay: feasibility of transporting tissues to a central facility for testing

Hepatic hemangioma patients with Kasabach-Merritt syndrome have reportedly been cured by liver transplantation. However, liver transplantation as a potential cure for a stable patient without Kasabach-Merritt syndrome remains debatable. We report the case of a 27-year-old female patient with a giant hepatic hemangioma. The hemangioma measured 50 × 40 × 25 cm in size and weighed 15 kg, which is the largest and heaviest hemangioma reported in the literature. The patient showed jaundice, ascites, anemia, and appetite loss; but no disseminated intravascular coagulation was observed through laboratory findings. We successfully operated using a right lobe graft without the middle hepatic vein from a 55-year-old donor. At the long-term follow-up, the patient experienced two acute rejections, which were confirmed by biopsy. However, the patient still survives with good graft function after 50 months.