The clinical relevance of the anhepatic phase during liver transplantation

The outcomes and biliary complications of a staged biliary reconstruction in living donor liver transplantation: a propensity score matched analysis

BACKGROUND

Uncontrolled massive bleeding and bowel edema are critical issues during liver transplantation. Temporal intra-abdominal packing with staged biliary reconstruction (SBR) yields acceptable outcomes in deceased donor liver transplantation; however, data on living donor liver transplantation (LDLT) are scarce.

METHODS

A retrospective analysis of 1269 patients who underwent LDLT was performed. After one-to-two propensity score matching, patients who underwent LDLT with SBR were compared with those who underwent LDLT with one-stage biliary reconstruction (OSBR). The primary outcomes were graft survival (GS) and overall survival (OS), and the secondary outcomes were postoperative biliary complications.

RESULTS

There were 55 and 110 patients in the SBR and OSBR groups, respectively. The median blood loss was 6500 mL in the SBR and 4875 mL in the OSBR group. Patients receiving SBR-LDLT had higher incidence of sepsis (69.0% vs. 43.6%; P < 0.01) and intra-abdominal infections (60.0% vs. 30.9%; P < 0.01). Biliary complication rates (14.5% vs. 19.1%; P = 0.47) and 1-and 5-year GS (87.27%, 74.60% vs. 83.64%, 72.71%; P = 0.98) and OS (89.09%, 78.44% vs. 84.55%, 73.70%; P = 0.752) rates were comparable between the two groups.

CONCLUSIONS

SBR could serve as a life-saving procedure for patients undergoing complex critical LDLT, with GS, OS, and biliary outcomes comparable to those of OSBR.

Incidence and Risk Factors of Acute Kidney Injury in Pediatric Liver Transplant Patients: A Retrospective Study

Background

Acute kidney injury (AKI) significantly contributes to the mortality and morbidity rates among pediatric liver transplant (LT) recipients.

Objective

Our study aimed to assess the potential factors contributing to AKI in pediatric LT patients and to analyze the impact of AKI on postoperative mortality and hospitalization duration.

Materials and methods

About 235 pediatric LT patients under the age of 18 between the years 2015 and 2021 were evaluated retrospectively. The relationship between preoperative and intraoperative variables of the patients and AKI developed when the early postoperatıve period was assessed.

Results

A correlation was found between the patients' preoperative age, albumin levels, and AKI. AKI was found to be associated with the duration of surgery and intraoperative blood transfusion.

Conclusion

Our findings revealed that the severity of AKI in pediatric LT patients is linked to extended surgical durations and increased blood transfusions resulting from hemodynamically compromised blood loss. Furthermore, independent risk factors for AKI were identified as prolonged warm ischemia and the overall duration of the operation.

How to cite this article

Demiroz D, Colak YZ, Ozdes OO, Ucar M, Ali Erdogan M, Toprak HI, et al. Incidence and Risk Factors of Acute Kidney İnjury in Pediatric Liver Transplant Patients: A Retrospective Study. Indian J Crit Care Med 2024;28(1):75-79.

Liver transplantation using magnetic anastomosis in pigs

Magnetic anastomosis substantially shortens the duration of vascular anastomosis. We aimed to apply magnetic anastomosis technology (MAT) to donor liver implantations in pig orthotopic liver transplantation (OLT). Twenty healthy adult pigs were randomly divided into donors and recipients, and major vascular anastomosis was performed using MAT during OLT. Recipient liver and kidney function was measured pre-surgery and 12, 24 and 72 h post-surgery. Vascular anastomoses examinations were performed using ultrasound or angiography weekly post-surgery, and pathological examinations of vascular anastomoses were performed during autopsy after animal euthanasia. All recipients survived 24 h after surgery, which is considered as successful transplantation. Anhepatic duration was only 13 min, and no anastomotic obstruction or stenosis, magnetic displacement and anastomotic angulation, or distortion was found upon postoperative examinations of major liver vasculature. Aspartate aminotransferase, alanine aminotransferase, and total bilirubin serum levels increased considerably postoperatively. The follow-up period for this study was 1 year, and the median survival time of all recipients was 115 d (interquartile range = 11-180 d). The main causes of death were liver failure, immune rejection, infection, and arterial anastomotic bleeding. Moreover, vascular anastomoses healed well with a survival time of more than two weeks. We developed a novel magnetic device to create a fast and safe technique to perform major vascular anastomoses in pig liver transplantations. Additionally, the liver graft implantation using MAT considerably shortened the recipient warm ischemia time, which will reduce the extent of ischemia-reperfusion injury. We conclude that MAT is an effective method for donor liver fast implantation in OLT in pigs.

Application of extended criteria donor grafts in liver transplantation for acute-on-chronic liver failure: A retrospective cohort study

BACKGROUND

There is no consensus on the usage of extended criteria donor (ECD) grafts in liver transplantation (LT) for acute-on-chronic liver failure (ACLF) patients.

AIM

To summarize the experience of using ECD livers in ACLF-LT.

METHODS

A retrospective cohort study was conducted, enrolling patients who underwent LT at the First Affiliated Hospital of Sun Yat-Sen University from January 2015 to November 2021. The patients were divided into ECD and non-ECD groups for analysis.

RESULTS

A total of 145 recipients were enrolled in this study, of which ECD and non-ECD recipients accounted for 53.8% and 46.2%, respectively. Donation after cardiac death (DCD) recipients accounted for the minority compared with donation after brain death (DBD) recipients (16.6% vs 83.4%). Neither overall survival nor graft survival significantly differed between ECD and non-ECD and DCD and DBD recipients. ECD grafts were associated with a significantly higher incidence of early allograft dysfunction (EAD) than non-ECD grafts (67.9% vs 41.8%, P = 0.002). Postoperative outcomes between DCD and DBD recipients were comparable (P > 0.05). ECD graft (P = 0.009), anhepatic phase (P = 0.034) and recipient gamma glutamyltransferase (P = 0.016) were independent risk factors for EAD. Recipient preoperative number of extrahepatic organ failures > 2 (P = 0.015) and intraoperative blood loss (P = 0.000) were independent predictors of poor post-LT survival.

CONCLUSION

Although related to a higher risk of EAD, ECD grafts can be safely used in ACLF-LT. The main factors affecting post-LT survival in ACLF patients are their own severe preoperative disease and intraoperative blood loss.

Risk factors for myocardial injury during living donor liver transplantation in pediatric patients with biliary atresia

BACKGROUND

Cold ischemia-reperfusion of the liver is an inevitable occurrence in liver transplantation that may also cause damage to the heart. Perioperative myocardial injury during liver transplantation can increase the incidence of postoperative mortality, but there is little research on the incidence of myocardial injury in children who undergo living donor liver transplantation (LDLT). Therefore, this study mainly explores the independent risk factors for myocardial injury in children who undergo LDLT.

AIM

To analyze the data of children who underwent LDLT to determine the risk factors for intraoperative myocardial injury.

METHODS

We retrospectively analyzed the inpatient records of pediatric patients who underwent LDLT in Tianjin First Central Hospital from January 1, 2020, to January 31, 2022. Recipient-related data and donor-related data were collected. The patients were divided into a myocardial injury group and a nonmyocardial injury group according to the value of the serum cardiac troponin I at the end of surgery for analysis. Univariate analysis and multivariate logistic regression were used to evaluate the risk factors for myocardial injury during LDLT in pediatric patients.

RESULTS

A total of 302 patients met the inclusion criteria. The myocardial injury group had 142 individuals (47%), and the nonmyocardial injury group included 160 patients (53%). Age, height, and weight were significantly lower in the myocardial injury group (P < 0.001). The pediatric end-stage liver disease (PELD) score, total bilirubin, and international standardized ratio were significantly higher in the myocardial injury group (P < 0.001). The mean arterial pressure, lactate, hemoglobin before reperfusion, duration of the anhepatic phase, cold ischemic time, incidence of postreperfusion syndrome (PRS), and fresh frozen plasma transfusion were significantly different between the two groups (P < 0.05). The postoperative intensive care unit stay and peak total bilirubin values in the first 5 d after LDLT were significantly higher in the myocardial injury group (P < 0.05). The pediatric patients with biliary atresia in the nonmyocardial injury group who underwent LDLT had a considerably higher one-year survival rate than those in the myocardial injury group (P = 0.015). Multivariate logistic regression revealed the following independent risk factors for myocardial injury: a high PELD score [odds ratio (OR) = 1.065, 95% confidence interval (CI): 1.013-1.121; P = 0.014], a long duration of the anhepatic phase (OR = 1.021, 95%CI: 1.003-1.040; P = 0.025), and the occurrence of intraoperative PRS (OR = 1.966, 95%CI: 1.111-3.480; P = 0.020).

CONCLUSION

A high PELD score, a long anhepatic phase duration, and the occurrence of intraoperative PRS were independent risk factors for myocardial injury during LDLT in pediatric patients with biliary atresia.

Emerging strategies to bypass transplant rejection via biomaterial-assisted immunoengineering: Insights from islets and beyond

Novel transplantation techniques are currently under development to preserve the function of impaired tissues or organs. While current technologies can enhance the survival of recipients, they have remained elusive to date due to graft rejection by undesired in vivo immune responses despite systemic prescription of immunosuppressants. The need for life-long immunomodulation and serious adverse effects of current medicines, the development of novel biomaterial-based immunoengineering strategies has attracted much attention lately. Immunomodulatory 3D platforms can alter immune responses locally and/or prevent transplant rejection through the protection of the graft from the attack of immune system. These new approaches aim to overcome the complexity of the long-term administration of systemic immunosuppressants, including the risks of infection, cancer incidence, and systemic toxicity. In addition, they can decrease the effective dose of the delivered drugs via direct delivery at the transplantation site. In this review, we comprehensively address the immune rejection mechanisms, followed by recent developments in biomaterial-based immunoengineering strategies to prolong transplant survival. We also compare the efficacy and safety of these new platforms with conventional agents. Finally, challenges and barriers for the clinical translation of the biomaterial-based immunoengineering transplants and prospects are discussed.

Development and validation of a nomogram model for predicting chronic kidney disease after liver transplantation: a multi-center retrospective study

Chronic kidney disease (CKD) is a frequent complication after liver transplantation (LT) and associated with poor prognosis. In this study, we retrospectively analyzed 515 adult patients who underwent LT in our center. They were randomly divided into a training set (n = 360) and an internal test set (n = 155). Another 118 recipients in other centers served as external validation set. Univariate and multivariate COX regression analysis were used to determine risk factors. A nomogram model was developed to predict post-LT CKD. The incidence of post-LT CKD in our center was 16.9% (87/515) during a median follow-up time of 22.73 months. The overall survival of recipients with severe CKD (stage IV and V) were significantly lower than those with non or mild CKD (stage III) (p = 0.0015). A nomogram model was established based on recipient's age, anhepatic phase, estimated glomerular filtration rate and triglyceride levels at 30 days after LT. The calibration curves for post-LT CKD prediction in the nomogram were consistent with the actual observation in both the internal and external validation set. In conclusion, severe post-LT CKD resulted in a significantly reduced survival in liver recipient. The newly established nomogram model had good predictive ability for post-LT CKD.

A Single-Center's Early Surgical Outcomes of Living Donor Liver Transplantation

BACKGROUND

Living donor liver transplantation (LDLT) has become an increasingly common surgical option because the number of cadaveric donors is insufficient to fulfill the organ needs of patients facing end-stage cirrhosis. Many centers are investigating different surgical techniques to achieve lower complication rates. We aimed to examine our complication rates in light of demographic data, graft data, and perioperative findings as a single-center experience.

METHODS

The study included one hundred and three patients who underwent LDLT for end-stage liver cirrhosis. Demographic data; sex; age; blood group; Model for End-Stage Liver Disease score; Child score; etiology; liver side; graft-to-recipient weight ratio; hepatic artery, portal vein, and bile anastomosis type rates; anhepatic phase; cold ischemia time; operation time; and blood product transfusion rates were analyzed. Biliary complications in patients with single or multiple biliary anastomoses, right or left liver transplants, and with or without hepatic artery thrombosis were analyzed statistically.

RESULTS

There was no significant difference in biliary complications between patients who underwent single or multiple bile anastomosis (P = .231) or patients receiving right lobe and left lobe transplants (P = .315). Although there was no statistically significant difference in the rate of portal vein thrombosis between the regular and reconstructed portal vein anastomosis groups (P = .693), the postoperative portal vein thrombosis rate was statistically higher in patients with left lobe transplants (P = .044).

CONCLUSIONS

Vascular and biliary complication rates can be reduced with increasing experience.

Factors associated with immediate and early extubation in pediatric living-donor liver transplant recipients

BACKGROUND

The practice of prompt extubation after adult liver transplantation has increasingly been applied in the pediatric population. Therefore, the factors contributing to this intervention should be identified in order to minimize failures.

AIMS

We sought to determine the factors associated with immediate and early extubation in pediatric living-donor liver transplant recipients.

METHODS

The medical records of pediatric liver transplant recipients at our center from January 2013 to December 2021, a 9-year period, were retrospectively collected and divided into early or delayed extubation groups. Factors associated with early extubation were determined using univariate and multivariate analyses, as the primary outcome. Comparisons of the postoperative management and outcomes between groups were evaluated as secondary outcomes.

RESULTS

Seventy-nine patients were included in the analysis, of whom 19 (24%) were immediately extubated in the operating room while 12 patients (15%) were extubated early, within 24 h postoperatively. These 31 patients (39%) were assigned to the early extubation group, whereas the others were assigned to the delayed extubation group. Shorter anhepatic time was the only factor associated with early extubation (adjusted odds ratio = 0.52; 95% confidence interval: 0.30, 0.89 per 30-min increment; p-value = .018) in patients with the same characteristics, including diagnosis, total operative time, and intraoperative volume of albumin and packed red blood cells. The length of intensive care unit stay was shorter in the early extubation group than in the delayed extubation group (p = .001). The rates of total and early medical complications and total reintubation in 30 days were significantly higher in the delayed extubation group than in the early extubation group (p-value = .002, .044, and .006 respectively). There were no significant differences in the length of hospital stay between the groups.

CONCLUSION

Our findings indicated that 39% of the pediatric living donor-liver transplantation patients tolerated early extubation and that the only associated factor was anhepatic time. Early extubation significantly reduces the number of days of intensive care unit stay but may not change the length of hospital stay.

Antithrombin supplementation for prevention of vascular thrombosis after pediatric liver transplantation

AIMS

After liver transplantation (LT), synthesis of coagulation factors by the graft recovers faster for pro thrombotic than anti thrombotic factors, resulting in a potential pro thrombotic imbalance. We studied the thrombotic and hemorrhagic complications in our pediatric LT series, providing supplementation of fresh frozen plasma (FFP) and/or antithrombin (AT) in the prophylactic antithrombotic regimen.

METHODS

This was a retrospective observational single center study. All isolated pediatric LTs performed between 1/11/2009 and 31/12/2019 (n = 181) were included. Postoperatively, in addition to low molecular weight heparin, 22 patients (12%) received FFP (10 ml/kg twice daily for 10 days), 27 patients (15%) were given FFP (reduced duration) and AT (50-100 IU/kg/day if AT activity remained <70%), and 132 (73%) received AT only. Complications, outcome, and coagulation profiles in postoperative days 0-10 were analyzed.

RESULTS

In all three treatment groups, AT activity normalized by day 4 while prothrombin remained <70% of normal until day 9. Hepatic artery thrombosis (HAT), portal vein thrombosis (PVT), and hemorrhagic complications occurred in 2.8%, 3.3%, and 3.9% of LTs. One- and 5-year patient and graft survival were 88% (±2.4% Standard Error) and 84% (±2.5%), and 86% (±2.6%) and 84% (±2.7%), respectively, without difference between groups. HAT were associated with low AT on days 0 and 1, and PVT with low AT on day 0.

CONCLUSIONS

Low antithrombin activity after LT was associated with postoperative thromboses. FFP and/or AT supplementation allowed early normalization of AT activity, while thrombotic or hemorrhagic complications were rare, suggesting efficient and safe management of post-LT coagulopathy.

Magnetic-assisted laparoscopic liver transplantation in swine

BACKGROUND

Although laparoscopic technology has achieved rapid development in the surgical field, it has not been applied to liver transplantation, primarily because of difficulties associated with laparoscopic vascular anastomosis. In this study, we introduced a new magnetic-assisted vascular anastomosis technique and explored its application in laparoscopic liver transplantation in pigs.

METHODS

Two sets of magnetic vascular anastomosis rings (MVARs) with different diameters were developed. One set was used for anastomosis of the suprahepatic vena cava (SHVC) and the other set was used for anastomosis of the infrahepatic vena cava (IHVC) and portal vein (PV). Six laparoscopic orthotopic liver transplantations were performed in pigs. Donor liver was obtained via open surgery. Hepatectomy was performed in the recipients through laparoscopic surgery. Anastomosis of the SHVC was performed using hand-assisted magnetic anastomosis, and the anastomosis of the IHVC and PV was performed by magnetic anastomosis with or without hand assistance.

RESULTS

Liver transplants were successfully performed in five of the six cases. Postoperative ultrasonographic examination showed that the portal inflow was smooth. However, PV bending and blood flow obstruction occurred in one case because the MVARs were attached to each other. The durations of loading of MVAR in the laparoscope group and manual assistance group for IHVC and PV were 13 ± 5 vs. 5 ± 1 min (P < 0.01) and 10 ± 2 vs. 4 ± 1 min (P < 0.05), respectively. The durations of MVAR anastomosis in the laparoscope group and manual assistance group for IHVC and PV were 5 ± 1 vs. 1 ± 1 min (P < 0.01), and 5 ± 1 vs. 1 ± 1 min (P < 0.01), respectively. The anhepatic phase was 43 ± 4 min in the laparoscope group and 23 ± 2 min in the manual assistance group (P < 0.01).

CONCLUSIONS

Our study showed that magnetic-assisted laparoscopic liver transplantation can be successfully carried out in pigs.

Adhesive anastomosis for organ transplantation

The recent development of tough tissue adhesives has stimulated intense interests among material scientists and medical doctors. However, these adhesives have seldom been tested in clinically demanding surgeries. Here we demonstrate adhesive anastomosis in organ transplantation. Anastomosis is commonly conducted by dense sutures and takes a long time, during which all the vessels are occluded. Prolonged occlusion may damage organs and even cause death. We formulate a tough, biocompatible, bioabsorbable adhesive that can sustain tissue tension and pressurized flow. We expose the endothelial surface of vessels onto a gasket, press two endothelial surfaces to the adhesive using a pair of magnetic rings, and reopen the bloodstream immediately. The time for adhesive anastomosis is shortened compared to the time for sutured anastomosis. We have achieved adhesive anastomosis of a great vein in transplanting the liver of a pig. After the surgery, the adhesive is absorbed, the vein heals, and the pig lives for over one month.

•

Use tough hydrogel to achieve adhesive anastomosis of a great vein in porcine liver transplantation.

•

The time for adhesive anastomosis is shortened compared to the time for sutured anastomosis.

•

The tough hydrogel can be bioabsorbed and enable the vessel to heal.

Primary Nonfunction of the Liver Allograft

Severe allograft dysfunction, as opposed to the expected immediate function, following liver transplantation is a major complication, and the clinical manifestations of such that lead to either immediate retransplant or death are the catastrophic end of the spectrum. Primary nonfunction (PNF) has declined in incidence over the years, yet the impact on patient and healthcare teams, and the burden on the organ pool in case of the need for retransplant should not be underestimated. There is no universal test to define the diagnosis of PNF, and current criteria are based on various biochemical parameters surrogate of liver function; moreover, a disparity remains within different healthcare systems on selecting candidates eligible for urgent retransplantation. The impact on PNF from traditionally accepted risk factors has changed somewhat, mainly driven by the rising demand for organs, combined with the concerted approach by clinicians on the in-depth understanding of PNF, optimal graft recipient selection, mitigation of the clinical environment in which a marginal graft is reperfused, and postoperative management. Regardless of the mode, available data suggest machine perfusion strategies help reduce the incidence further but do not completely avert the risk of PNF. The mainstay of management relies on identifying severe allograft dysfunction at a very early stage and aggressive management, while excluding other identifiable causes that mimic severe organ dysfunction. This approach may help salvage some grafts by preventing total graft failure and also maintaining a patient in an optimal physiological state if retransplantation is considered the ultimate patient salvage strategy.

Preclinical models of acute liver failure: a comprehensive review

Acute liver failure is marked by the rapid deterioration of liver function in a previously well patient over period of days to weeks. Though relatively rare, it is associated with high morbidity and mortality. This makes it a challenging disease to study clinically, necessitating reliance on preclinical models as means to explore pathophysiology and novel therapies. Preclinical models of acute liver failure are artificial by nature, and generally fall into one of three categories: surgical, pharmacologic or immunogenic. This article reviews preclinical models of acute liver failure and considers their relevance in modeling clinical disease.

Intraoperative systemic biomarkers predict post-liver transplantation acute kidney injury

OBJECTIVE

Liver transplant (LT) is a definitive therapeutic option for patients with chronic liver disease. However, acute kidney injury after LT (post-LT AKI) is a frequent complication that may lead to graft dysfunction and decrease life expectancy. Delay in AKI detection by traditional biomarkers boosted research with new biomarkers for post-LT AKI as neutrophil gelatinase-associated lipocalin (NGAL) and syndecan-1. We aim to evaluate associations of intraoperative systemic NGAL and syndecan-1 levels with post-LT AKI.

METHODS

This is a prospective study conducted in 46 patients selected for LT. Patients were evaluated preoperatively and blood samples were collected intraoperatively: T1 (after induction of anesthesia), T2 (anhepatic phase) and T3 (2 h after reperfusion of the graft).

RESULTS

The mean age was 54 ± 12 years and 60% were male. Post-LT AKI was observed in 24 (52%) patients of which 12% needed dialysis. Serum NGAL and syndecan-1 increased along surgical phases. Mostly, increment values of serum NGAL of T2 to T3 and syndecan-1 at T3 were importantly associated with post-LT AKI. Into a multivariate model with model for end-stage liver disease score, age, gender, warm ischemia, cold ischemia and surgery time, syndecan-1 levels at T3 remains capable to predict post-LT AKI. Serum NGAL had significance only with increment values calculated by the ratio of 'T3/T2'. Finally, serum syndecan-1 at T3 had a better diagnostic performance in receiver operating characteristic curve analysis.

CONCLUSION

Serum syndecan-1 levels in 2 h after reperfusion were most useful in early post-LT AKI diagnosis and may be used to construct new risk groups in this context.

Application of various surgical techniques in liver transplantation: a retrospective study

Background

Surgical techniques of liver transplantation have continually evolved and have been modified. We retrospectively analyzed a single-center case series and compared the advantages and disadvantages of each method.

Methods

Six-hundred and seventy-four recipients’ perioperative data were assessed and analyzed stratified by different surgical technics [modified classic (MC), modified piggyback (MPB) and classic piggyback (CPB)].

Results

MELD score and Child-Pugh scores was significantly higher in CPB groups (P=0.008 and 0.003, respectively). Anhepatic time in MPB group was longer than those in CPB group (P<0.05). The operation duration in MPB group was significantly longer than those in MC group and CPB group (P=0.003). Three patients had outflow obstruction (P=0.035). The overall survival in MPB group were better than those in MC group and CPB group in general comparison (P<0.001). In patients with preoperative creatine >120 µmol/L, the overall survival in MC group was worst (P<0.001). In patients with a high MELD score (>24), the overall survival in MPB group tended to be the best (P<0.001).

Conclusions

The advantages and disadvantages are different for these three surgical techniques. A reasonable operation technique should be adopted considering the patient's unique condition to ensure the stability of hemodynamics.

Biocompatibility and patency of a novel titanium vascular anastomotic device in a pig jugular vein

This study aimed to evaluate the biocompatibility and patency of our newly developed titanium vascular anastomotic device (TVAD) in a pig jugular vein. TVAD was made of commercially pure grade 2 titanium. The patency and anastomotic time were simultaneously confirmed in an ex-vivo system developed by the authors and in vivo using pig jugular veins. Five 8-month-old pigs, with body weights of 50–60 kg, underwent anastomosis of both jugular veins using the device. Graft patency was evaluated for 12 weeks by biplane angiography and sonography. All tissue biopsy samples were analysed by histology. In all 10 cases, the anastomosis was completed in < 5 min. The vessel lumen was not damaged, and the inner vessel wall was completely endothelialised at the anastomotic site. No foreign body reactions were observed at the vessel lumen, vessels, and outer vessel walls by histopathologic analysis. Patency and absence of leakage at the anastomotic site of the follow-up period were confirmed clearly by angiography and sonography. This preliminary animal study proved that our newly developed device is a very promising tool for intima-to-intima contact anastomosis. TVAD can be used as a feasible and safe medical tool for vessel anastomosis.

Immediate Postoperative Extubation Decreases Pulmonary Complications in Liver Transplant Patients

BACKGROUND

Fast-track anesthesia in liver transplantation (LT) has been discussed over the past few decades; however, factors associated with immediate extubation after LT surgery are not well defined. This study aimed to identify predictive factors and examine impacts of immediate extubation on post-LT outcomes.

METHODS

A total of 279 LT patients between January 2014 and May 2017 were included. Primary outcome was immediate extubation after LT. Other postoperative outcomes included reintubation, intensive care unit stay and cost, pulmonary complications within 90 days, and 90-day graft survival. Logistic regression was performed to identify factors that were predictive for immediate extubation. A matched control was used to study immediate extubation effect on the other postoperative outcomes.

RESULTS

Of these 279 patients, 80 (28.7%) underwent immediate extubation. Patients with anhepatic time >75 minutes and with total intraoperative blood transfusion ≥12 units were less likely to be immediately extubated (odds ratio [OR], 0.48; 95% confidence interval [CI], 0.26-0.89; P = 0.02; OR, 0.11; 95% CI, 0.05-0.21; P < 0.001). The multivariable analysis showed immediate extubation significantly decreased the risk of pulmonary complications (OR, 0.34; 95% CI, 0.15-0.77; P = 0.01). According to a matched case-control model (immediate group [n = 72], delayed group [n = 72]), the immediate group had a significantly lower rate of pulmonary complications (11.1% versus 27.8%; P = 0.012). Intensive care unit stay and cost were relatively lower in the immediate group (2 versus 3 d; P = 0.082; $5700 versus $7710; P = 0.11). Reintubation rates (2.8% versus 2.8%; P > 0.9) and 90-day graft survival rates (95.8% versus 98.6%; P = 0.31) were similar.

CONCLUSIONS

Immediate extubation post-LT in appropriate patients is safe and may improve patient outcomes and resource allocation.

An Alternative Surgical Technique of Native Hepatectomy in Liver Transplantation

Background

Orthotopic liver transplantation has become the procedure of choice for end-stage liver disease. There are 3 commonly used methods of vena cava anastomosis. Here, we report a new technique for native hepatectomy.

Material/Methods

The data of 12 patients who underwent orthotopic liver transplantation using a new surgical technique were retrospectively collected for analysis. The new separation and reconstruction surgical technique mainly involved the second portal isolation and hepatectomy that followed. We performed recipient liver resection without the occlusion of the inferior vena cava, which was then followed by classic, piggyback, modified piggyback, or side-to-side orthotopic liver transplantation. The graft function index and complications were collected after transplantation.

Results

The length of the anhepatic phase was 30.92±9.1 min. Alanine transaminase (ALT) levels were 138 to 2027 U/L, with a median of 361.5 U/L. The ALT levels of all patients gradually decreased to normal levels 7 to 10 days after surgery. Only 2 recipients had elevated levels of ALT higher than 1000 U/L. Four of 12 patients did not require red blood cell transfusion during surgery. Four patients appeared to have early allograft dysfunction, while others recovered smoothly.

Conclusions

This new surgical technique may shorten the anhepatic phase and decrease blood loss volume, aiding the success of liver transplant surgery. It can be used for most patients and does not increase the risk of complications or impair prognosis.

Impact of prolonged clamping of the portal vein during liver transplantation in infants with biliary atresia: renewed interest in a long-standing issue

PURPOSE

Various approaches to portal vein (PV) reconstruction have been described; however, there is still scope to improve the safety and efficiency of how PV anastomosis is performed in infants.

METHODS

We analyzed, retrospectively, the predictive factors for PV reanastomosis during living donor liver transplantation (LDLT) in 117 infants (< 1 year old) with biliary atresia (BA).

RESULTS

Twenty-six infants required PV reanastomosis because of intraoperative PV thrombosis in 21 and insufficient PV flow in 5. Univariate analysis identified multiple previous laparotomies and a prolonged anhepatic phase (AHP) as significant risk factors for repeated PV anastomosis. The AHP cutoff value for identifying patients requiring PV reanastomosis was 134 min. Multivariate analysis revealed prolonged AHP > 134 min (odds ratio, 15.98; 95% confidence interval, 5.05-50.6; P < 0.001) as an independent risk factor for repeated PV anastomosis. The plasma D-dimer and fibrinogen degradation product concentration just after reperfusion were significantly higher in patients requiring PV reanastomosis (P < 0.001). Patients requiring reanastomosis of the PV had a higher incidence of PV complications after LDLT than those who did not need PV reanastomosis (P = 0.01).

CONCLUSION

Attempting to minimize the AHP is indispensable for successful LDLT in infants with BA.

Association Between Serum Lactate and Unsatisfactory Outcomes in Critically Ill Children in the Immediate Post-operative Period of Liver Transplantation

OBJECTIVES

Serum lactate is a useful biomarker of tissue perfusion in critically ill patients. We evaluated the behavior of serum lactate in children in the pediatric intensive care unit (PICU) immediately after liver transplantation and its association with surgical complications, graft dysfunction and 90-day mortality.

MATERIALS AND METHODS

A prospective observational study carried out between November 2009 and December 2019. Multidisciplinary PICU at the University Children's Hospital, Fundación Cardioinfantil-IC, Bogotá, Colombia.

MEASUREMENTS AND MAIN RESULTS

Patients between 1 month and 18 years of age who were in the immediate post-operative period following living-donor or cadaveric liver transplantation were included. A total of 145 patients with a median age of 14 months (IQR 8-60) met the inclusion criteria. Biliary atresia was the main diagnosis in 56.5% of the cases. A serum lactate level > 3.0 mmol/L on admission to the PICU was associated with biliary complications (AUC 0.73 95% CI 0.54-0.93; p = 0.05) and mortality (AUC 0.72 95% CI 0.63-0.8; p = 0.01). A lactate level > 2 mmol/L after 6 h in the PICU was associated with mortality (AUC 0.70 95% CI 0.54-0.83; p = 0.02). Higher lactate levels and lack of clearance were associated with the presence of tardus et parvus waveforms (p = 0.001) on liver Doppler, primary dysfunction (p < 0.001), arterial thrombosis (p < 0.001) and neurological complications (p = 0.04). There was an inverse correlation between admission lactate and the volume of fluids administered during surgery (rho = 0.36; p < 0.001). A total procedure time > 350 min, along with a vasopressor score > 7 and elevated lactate, were associated with worse outcomes (p < 0.001).

CONCLUSIONS

In post-operative pediatric liver transplant patients, the level of serum lactate is associated with post-operative surgical complications and mortality.

Incidence and risk factors of primary non-function after liver transplantation using grafts from uncontrolled donors after circulatory death

BACKGROUND

Graft primary non-function (PNF) is the most severe complication after orthotopic liver transplantation (OLT) and is frequently associated with livers from uncontrolled circulatory death (uDCD).

METHODS

We reviewed retrospectively the incidence, risk factors, and outcome of patients showing PNF after receiving uDCD liver grafts. The series comprises 75 OLT performed during 11 years.

RESULTS

The incidence of PNF using uDCD livers was 8%. We compared patients who developed PNF (n = 6) vs. patients without PNF (n = 69). Mean pump flow of donors during normothermic regional perfusion (NRP) was significantly lower in PNF (p = .032). Day 1 post-OLT levels of transaminases and the incidence of renal complications and postoperative mortality were also significantly higher in the PNF group, but 5-year patient survival was similar in both groups (66.7% in PNF and 68.5% in non-PNF). All PNF patients underwent re-OLT, and 2 died. PNF incidence has decreased in the last 5-years. Binary logistic regression analysis confirmed final ALT value >4 times the normal value as risk factor for PNF, and median donor pump flow >3700 ml/min as protective effect.

CONCLUSIONS

Adequate donor pump flow during NRP was a protective.

Poor prognosis of liver transplantation for acute liver failure with acute pancreatitis: Two case reports

INDUCTION

Liver transplantation (LT) is the only final therapy for patients with acute liver failure (ALF) that cannot be controlled by conservative treatment. Acute pancreatitis (AP) is a recognized complication of ALF. The pathogenesis of AP in ALF patients has not yet been elucidated. The appearance of AP complicates the patients condition and causes a significantly increased risk of mortality.

PATIENT CONCERNS

We report 2 fatal cases who were both admitted with yellowing of skin and sclera with general weakness lasting for 2 weeks.

DIAGNOSIS

After admission, the laboratory examination of case 1 showed liver dysfunction with serum levels of total bilirubin (TB) 270 μmol/l, alanine aminotransferase (ALT) 106 U/l. Abdominal computed tomography (CT) showed pelvic and peritoneal cavity fluids, occupation of left lateral lobe of liver and unclear margin of pancreas. The clinical laboratory findings of case 2 revealed TB 351.1 μmol/l, ALT 252 U/l, blood lactic acid 18 mmol/l, ammonia 209 μmol/l. And abdominal CT showed pancreatic exudation. They were both diagnosed with acute liver failure, hepatic encephalopathy and AP which was confirmed during the operation.

INTERVENTIONS

They were both received a routine orthotopic LT.

OUTCOMES

After the surgery, their liver functions recovered well, and they received conventional conservative treatment for pancreatitis. However, the treatment was not adequately effective, and the infection was too serious and both died of multiple organ failure despite emergency rescue efforts on day 21 and day 19 after LT.

CONCLUSION

AP is a serious complication that can contribute to prohibitive morbidity and mortality in LT patients. For this reason, the vulnerable state of the pancreas and the scoring system must be defined to help clinicians decide whether a patient is suitable for liver transplantation, and the clinical experience in the treatment of pancreatitis after LT needs to be summarized as an optimal treatment guideline to facilitate better treatment.

Risk factors and associated outcomes of early acute kidney injury in pediatric liver transplant recipients: A retrospective study

BACKGROUND

Acute kidney injury (AKI) may contribute to high mortality rates after liver transplantation. Few studies have investigated AKI in pediatric liver transplantation. This retrospective study was conducted to investigate the risk factors for and associated outcomes of AKI in pediatric liver transplant recipients.

METHODS

Eighty pediatric liver transplant patients were included. The occurrence of AKI was defined by the KDIGO Clinical Practice Guidelines for Acute Kidney Injury. A multivariate regression analysis model was used to investigate risk factors for AKI in the pediatric liver recipients.

RESULTS

The final multivariable regression model showed that biliary atresia (odds ratio [OR] = 0.097, p = 0.03), increased time of the anhepatic phase (OR = 0.871, p = 0.005) and lower postoperative jaundice clearance (OR = 13.936, p = 0.02) were independently associated with the development of AKI in pediatric patients. Additionally, cumulative 3-year patient (p = 0.15) and graft (p = 0.26) survival rates between the non-acute kidney injury (NAKI) and AKI groups were 95.2% vs 86.8% and 90.5% vs 84.2%, respectively.

CONCLUSION

Pediatric liver transplant recipients with a presence of biliary atresia, increased time of anhepatic phase, and a lower postoperative jaundice clearance had an increased risk of AKI. The long-term outcomes of patients who developed AKI appears to be worse compared with those having NAKI.

TYPE OF STUDY

Prognosis study.

LEVEL OF EVIDENCE

Level III.

Indocyanine green fluorescence imaging to evaluate graft perfusion during liver transplantation

BACKGROUND

Primary graft dysfunction (PGD) is a leading cause of graft loss after liver transplantation. There is no reliable method to anticipate this complication intraoperatively. Indocyanine green (ICG) fluorescence imaging is a technique used in hepatobiliary surgery for detection of liver malignancies, but has never been reported in the setting of liver transplantation (LT) for function assessment. We hypothesized that there could be an association between the type of fluorescence and the occurrence of PGD.

METHODS

We retrospectively analyzed 72 patients who underwent LT at our center. An assessment of the liver graft with the ICG fluorescence technique was carried out. A classification comprising 3 types of fluorescence was created after evaluation of the recorded images. We assessed the relationship between the type of fluorescence and the occurrence of PGD.

RESULTS

Crosstabulation analysis of the fluorescent types and occurrence of PGD yielded a statistically significant association (p = 0.002). Univariate analysis showed that an abnormal ICG fluorescence pattern was a risk factor for the occurrence of PGD after LT.

CONCLUSIONS

Our findings suggest that there could be an association between ICG fluorescence imaging and graft function. This intraoperative tool could be useful to detect patients at risk of developing PGD after LT.

Assessment of the Learning Process After Introducing a New Liver Transplantation Procedure in a Center With Extensive Experience in Kidney Transplantation

BACKGROUND

Liver transplantation (LTx) is one of the most complex transplant procedures. The aim of the present study was to determine whether the learning process can be observed after the introduction of LTx in a center with extensive previous experience in renal transplantation.

METHODS

This retrospective analysis included 264 primary LTx procedures performed with the piggyback technique (2005-2016). The procedures were divided into 4 equal groups. The characteristics of the recipients, data related to the surgery, and the postoperative course and complications were analyzed.

RESULTS

We observed a significant reduction in surgical time and in the anhepatic phase duration between Group 1 and the other groups (median surgical time was 455 minutes vs 415 minutes, 410 minutes and 387 minutes, respectively, P < .05; median anhepatic phase duration was 75 min vs 60 min, 62 min, 60 min, respectively, P < .05). There was a decrease in the number of transfused blood units (median in Group 1 of 6 packs vs 3 packs in Group 4, P < .05) and a decrease in blood recovered from the operating field using the Cell Saver system (median in Group 1 of 1570 mL vs 1057 mL, 1123 mL, and 1045 mL, respectively, P < .05). A significant reduction in the number of hemorrhages was found (1.5% in Group 4 vs 13.6%, 10.6%, and 7.6% in the other groups P < .05). The remaining studied parameters were not statistically significant.

CONCLUSIONS

Extensive previous transplantation experience affected the lack of typical features of the learning process.

A simplified multivisceral transplantation procedure for patients with combined end-stage liver disease and type 2 diabetes mellitus

In liver transplant patients with type 2 diabetes mellitus (DM), the disease worsens after transplantation because of longterm use of diabetogenic immunosuppressive drugs, making management of those patients a great challenge. The objective of our study was to evaluate the safety and efficacy of a simplified multivisceral transplantation (SMT) procedure for the treatment of patients with end-stage liver disease and concurrent type 2 DM. Forty-four patients who had pretransplant type 2 DM were included. A total of 23 patients received SMT, and 21 patients received orthotopic liver transplantation (OLT). Patient and graft survivals, complications, diabetic control, and quality of life (QOL) were retrospectively analyzed in both groups. The 1-, 3-, and 5-year cumulative patient and graft survival rates were 91.5%, 75.4%, and 75.4% in the SMT group and were 94.4%, 64.4%, and 64.4% in the OLT group, respectively (P = 0.70). Interestingly, 95.7% (22/23) of patients achieved complete remission from DM after SMT compared with 16.7% (3/18) of patients after OLT. The occurrence of biliary complication was significantly higher in the OLT group than that in the SMT group (23.8% versus 0.0%; P = 0.01). Moreover, better QOL was observed in the SMT group than that in the OLT group. In conclusion, the SMT procedure we described here is a safe and viable option for patients with end-stage live disease and concurrent type 2 DM. This SMT procedure offers excellent transplant outcomes and QOL. Liver Transplantation 23 1161-1170 2017 AASLD.

Improving the Diagnostic Criteria for Primary Liver Graft Nonfunction in Adults Utilizing Standard and Transportable Laboratory Parameters: An Outcome-Based Analysis

Current diagnostic criteria for primary nonfunction (PNF) of liver grafts are based on clinical experience rather than statistical methods. A retrospective, single-center study was conducted of all adults (n = 1286) who underwent primary liver transplant (LT) 2000-2008 in our center. Laboratory variables during the first post LT week were analyzed. Forty-two patients (3.7%) had 2-week graft failure. Transplant albumin, day-1 aspartate aminotransferase (AST), day-1 lactate, day-3 bilirubin, day-3 international normalized ratio (INR), and day-7 AST were independently associated with PNF on multivariate logistic regression. PNF score =(0.000280*D1AST)+ (0.361*D1 Lactate)+(0.00884*D3 Bilirubin)+(0.940*D3 INR)+(0.00153*D7 AST)-(0.0972*TxAlbumin)-4.5503. Receiver operating curve analysis showed the model area under receiver operating curve (AUROC) of 0.912 (0.889-0.932) was superior to the current United Kingdom (UK) PNF criteria of 0.669 (0.634-0.704, p < 0.0001). When applied to a validation cohort (n = 386, 34.4% patients), the model had AUROC of 0.831 (0.789-0.867) compared to the UK early graft dysfunction criteria of 0.674 (0.624-0.721). The new model performed well after exclusion of patients with marginal grafts and when modified to include variables from the first three post-LT days only (AUROC of 0.818, 0.776-0.856, p = 0.001). This model is superior to the current UK PNF criteria and is based on statistical methods. The model is also applicable to recipients of all types of grafts (marginal and nonmarginal).

The anhepatic phase extended by temporary portocaval shunt does not affect anesthetic sensitivity and postoperative cognitive function: A case-control study

Temporary portocaval shunt (TPCS) prolongs the duration of the anhepatic phase, during which anesthetic sensitivity is highest among the 3 phases of living donor liver transplantation (LDLT). Cognitive dysfunction has been associated with increased anesthetic sensitivity and poor hepatic function. Therefore, we assessed anesthetic sensitivity to desflurane and perioperative cognitive function in patients undergoing LDLT, in whom the duration of the anhepatic phase was extended by TPCS to test the hypothesis that the prolonged anhepatic phase increases anesthetic sensitivity and causes postoperative cognitive decline.This case-control study was conducted in 67 consecutive patients undergoing LDLT from February 2014 to January 2016. Anesthesia was maintained at a 0.6 end-tidal age-adjusted minimum alveolar concentration of desflurane. The bispectral index (BIS) was maintained at less than 60 and averaged at 1-minute intervals. The mini-mental state examination (MMSE-KC) was performed 1 day before and 7 days after the LDLT. All parameters were compared between the patients undergoing TPCS (TPCS group) and the remaining patients (non-TPCS group).TPCS was performed in 16 patients (24%). TPCS prolonged the duration of the anhepatic phase (125.9 ± 29.4 vs 54.9 ± 20.5 minutes [mean ± standard deviation], P < 0.0001). The averaged BIS values during the 3 phases were comparable between the 2 groups. No significant interval changes in the averaged BIS values were observed during the 3 consecutive phases. Similarly, there were no significant differences in MMSE-KC score assessed 1 day before and 7 days after LDLT between the 2 groups. The preoperative MMSE-KC scores were unchanged postoperatively in the 2 groups.The extension of the anhepatic phase did not affect anesthetic sensitivity and postoperative cognitive function.

Key Points in Establishing a Model of Mouse Liver Transplantation

The explosion of interest in research into the mouse genome and immune system has meant that the mouse orthotopic liver transplantation (MOLT) model has become a popular means of studying transplantation immunity, organ preservation, ischemia-reperfusion injury, and surgical techniques, among others. Although numerous modifications and refinements of surgical techniques have simplified the operation, the relatively short duration of postoperative survival after MOLT remains an obstacle to longer-term follow-up studies. Here, we summarize the scientific basis of MOLT and our experience improving and refining the model in six key areas: anesthesia, operative technique, perfusion and preservation of the liver, cuff technique, anhepatic time, and the value of rearterialization for the liver graft. We also compare the characteristics of different surgical techniques, and give recommendations for the best means of tailoring technique to the objectives of a study. In doing so, we aim to assist other investigators in establishing and perfecting the MOLT model in their routine research practice.

Predictive factors of short term outcome after liver transplantation: A review

Liver transplantation represents a fundamental therapeutic solution to end-stage liver disease. The need for liver allografts has extended the set of criteria for organ acceptability, increasing the risk of adverse outcomes. Little is known about the early postoperative parameters that can be used as valid predictive indices for early graft function, retransplantation or surgical reintervention, secondary complications, long intensive care unit stay or death. In this review, we present state-of-the-art knowledge regarding the early post-transplantation tests and scores that can be applied during the first postoperative week to predict liver allograft function and patient outcome, thereby guiding the therapeutic and surgical decisions of the medical staff. Post-transplant clinical and biochemical assessment of patients through laboratory tests (platelet count, transaminase and bilirubin levels, INR, factor V, lactates, and Insulin Growth Factor 1) and scores (model for end-stage liver disease, acute physiology and chronic health evaluation, sequential organ failure assessment and model of early allograft function) have been reported to have good performance, but they only allow late evaluation of patient status and graft function, requiring days to be quantified. The indocyanine green plasma disappearance rate has long been used as a liver function assessment technique and has produced interesting, although not univocal, results when performed between the 1^th and the 5^th day after transplantation. The liver maximal function capacity test is a promising method of metabolic liver activity assessment, but its use is limited by economic cost and extrahepatic factors. To date, a consensual definition of early allograft dysfunction and the integration and validation of the above-mentioned techniques, through the development of numerically consistent multicentric prospective randomised trials, are necessary. The medical and surgical management of transplanted patients could be greatly improved by using clinically reliable tools to predict early graft function.

Inferior graft survival of hepatitis B core positive grafts is not influenced by post-transplant hepatitis B infection in liver recipients--5-year single-center experience

Nonoptimal liver grafts, and among them organs from anti-HBc+ donors, are increasingly used for liver transplantation. In this retrospective study including 1065 adult liver transplantations performed between 1977 and 2012, we analyzed long-term patient and graft survival and occurrence of HBV infection. A total of 52 (5.1%) patients received an anti-HBc+ graft. The 10-year graft and patient survival of these recipients were 50.9% and 59.0% compared to 72.0% and 76.5% (P = 0.001; P = 0.004) of patients receiving anti-HBc- grafts, respectively. Cox regression model showed that high urgency allocation (P = 0.003), recipient age (P = 0.027), anti-HCV+ recipients (P = 0.005), and anti-HBc+ organs (P = 0.048) are associated with decreased graft survival. Thirteen of 52 (25.0%) patients receiving anti-HBc+ grafts developed post-transplant HBV infection within a mean of 2.8 years. In this study, antiviral prophylaxis did not have significant impact on HBV infection, but long-term survival (P = 0.008). Development of post-transplant HBV infection did not affect adjusted 10-year graft survival (100% vs. 100%; P = 1). Anti-HBc+ liver grafts can be transplanted with reasonable but inferior long-term patient and graft survival. The inferior graft survival is not, however, related with post-transplant HBV infection as long as early diagnosis and treatment take place.

Extended Ischemia Times Promote Risk of HCC Recurrence in Liver Transplant Patients

BACKGROUND

There is increasing evidence that ischemia-reperfusion injury (IRI) promotes vasculogenesis and tumor outgrowth in the liver. Hepatic IRI is exaggerated by prolongation of ischemia times.

AIMS

The aim of this retrospective analysis was to assess the impact of ischemia times on risk of hepatocellular carcinoma (HCC) recurrence after liver transplantation (LT). Subgroup analysis focused on patients with (18)F-fluoro-deoxy-glucose ((18)F-FDG)-avid HCC on pretransplant positron emission tomography (PET).

METHODS

A total of 103 liver transplant patients with HCC were included in this study. The impact of cold (CIT), warm (WIT), and total ischemia times (TIT) along with other prognostic variables on posttransplant outcome was analyzed in uni- and multivariate analysis.

RESULTS

Twenty-four patients (23.3 %) developed tumor relapse after LT. Mean durations of CIT (468.0 vs. 375.5 min; P = 0.001), WIT (58.4 vs. 45.7 min; P = 0.001), and TIT (525.8 vs. 422.0 min; P < 0.001) were significantly longer in patients with compared to those without HCC recurrence. In multivariate regression analysis, (18)F-FDG-avid HCC (odds ratio [OR] 73.4), WIT >50 min (OR 52.5), alpha-fetoprotein level >400 IU/ml (OR 11.1), and Milan Out status (OR 7.4) were identified as independent predictors of HCC recurrence. In the subgroup of patients with PET-positive HCC, WIT remained the only independent variable to predict HCC recurrence (OR 15.5).

CONCLUSION

Prolongation of ischemia times promotes the risk of HCC recurrence after LT, especially in patients with unfavorable tumor biology on PET imaging.

A score model for the continuous grading of early allograft dysfunction severity

Early allograft dysfunction (EAD) dramatically influences graft and patient outcomes. A lack of consensus on an EAD definition hinders comparisons of liver transplant outcomes and management of recipients among and within centers. We sought to develop a model for the quantitative assessment of early allograft function [Model for Early Allograft Function Scoring (MEAF)] after transplantation. A retrospective study including 1026 consecutive liver transplants was performed for MEAF score development. Multivariate data analysis was used to select a small number of postoperative variables that adequately describe EAD. Then, the distribution of these variables was mathematically modeled to assign a score for each actual variable value. A model, based on easily obtainable clinical parameters (ie, alanine aminotransferase, international normalized ratio, and bilirubin) and scoring liver function from 0 to 10, was built. The MEAF score showed a significant association with patient and graft survival at 3-, 6- and 12-month follow-ups. Hepatic steatosis and age for donors; cold/warm ischemia times and postreperfusion syndrome for surgery; and intensive care unit and hospital stays, Model for End-Stage Liver Disease and Child-Pugh scores, body mass index, and fresh frozen plasma transfusions for recipients were factors associated significantly with EAD. The model was satisfactorily validated by its application to an independent set of 200 patients who underwent liver transplantation at a different center. In conclusion, a model for the quantitative assessment of EAD severity has been developed and validated for the first time. The MEAF provides a more accurate graft function assessment than current categorical classifications and may help clinicians to make early enough decisions on retransplantation benefits. Furthermore, the MEAF score is a predictor of recipient and graft survival. The standardization of the criteria used to define EAD may allow reliable comparisons of recipients' treatments and transplant outcomes among and within centers.

Factors associated with early mortality after living-donor liver transplant

OBJECTIVES

We sought to identify the risk factors associated with the early mortality after a living-donor liver transplant.

MATERIALS AND METHODS

Two hundred eighteen patients were recruited in this study. Potential risk factors were analyzed using univariate and multivariate analyses. A C statistic equivalent to the area under the receiver operating characteristic curve was used to assess the ability of the model to predict mortality risk during the first 3 months after a living-donor liver transplant.

RESULTS

Twenty-six recipients died within the first 3 months after a living-donor liver transplant. On a multivariate analysis, intraoperative allogeneic red blood cell transfusion and the preoperative creatinine levels were independently associated with early postoperative mortality. A prognostic model was proposed in this study (early mortality risk score = 0.107 × intraoperative allogeneic red blood cells transfusion [U] + 0.005 × preoperative creatinine concentration [μmol/L]). Three-month survival rates of patients with high and low scores were 69.8% and 95.5% (P < .001).

CONCLUSIONS

Transfusion of intraoperative allogeneic red blood cell and preoperative creatinine levels are associated with the early mortality after living-donor liver transplant. A model to predict early mortality after a living-donor liver transplant based on these risk factors was proposed in this study.

A review of various techniques of mouse liver transplantation

OBJECTIVES

Liver transplantation in a mouse model is a valuable tool for studying transplantation immunobiology and clinic-relevant issues. However, the successful establishment is highly technical and demanding, impeding its widespread use. Herein, the aims of this study were to review and analyze the various techniques of liver transplantation in mice to circumvent pitfalls and minimize the incidence of complications.

MATERIALS AND METHODS

A search of PubMed was made by using the key words "mouse liver transplantation" for articles published between January 1973 and July 2012. Of the 473 publications identified, 14 were shown to be closely associated with mouse liver transplantation and 4 articles discussed specific microsurgical techniques. Through reviewing these articles, a series of potential factors were collected and analyzed in combination with other murine transplantation models, which might influence successfully establishing a mouse model for liver transplantation.

RESULTS

A mouse liver transplantation model is feasible and practical for experimental studies. Mouse strain, type of anesthesia, type of perfusion and storage solution, and reconstruction of bile duct are relevant factors but not determinants for a successful transplantation. Cold and warm ischemia time should be less than 4.0 hours and 20 minutes, respectively.

CONCLUSIONS

The cuff preparation, reconstruction of the hepatic artery, and length of the anhepatic phase play critical roles in successfully establishing a liver transplantation model in mice.

Primary graft dysfunction after liver transplantation

BACKGROUND

Primary graft dysfunction (PGD) causes complications in liver transplantation, which result in poor prognosis. Recipients who develop PGD usually experience a longer intensive care unit and hospital stay and have higher mortality and graft loss rates compared with those without graft dysfunction. However, because of the lack of universally accepted definition, early diagnosis of graft dysfunction is difficult. Additionally, numerous factors affect the allograft function after transplantation, making the prediction of PGD more difficult. The present review was to analyze the literature available on PGD and to propose a definition.

DATA SOURCE

A search of PubMed (up to the end of 2012) for English-language articles relevant to PGD was performed to clarify the characteristics, risk factors, and possible treatments or interventions for PGD.

RESULTS

There is no pathological diagnostic standard; many documented definitions of PGD are different. Many factors, such as donor status, procurement and transplant process and recipient illness may affect the function of graft, and ischemia-reperfusion injury is considered the direct cause. Potential managements which are helpful to improve graft function were investigated. Some of them are promising.

CONCLUSIONS

Our analyses suggested that the definition of PGD should include one or more of the following variables: (1) bilirubin ≥ 10 mg/dL on postoperative day 7; (2) international normalized ratio ≥ 1.6 on postoperative day 7; and (3) alanine aminotransferase or aspartate aminotransferase >2000 IU/L within 7 postoperative days. Reducing risk factors may decrease the incidence of PGD. A majority of the recipients could recover from PGD; however, when the graft progresses into primary non-function, the patients need to be treated with re-transplantation.

A randomized clinical trial testing the anti-inflammatory effects of preemptive inhaled nitric oxide in human liver transplantation

Decreases in endothelial nitric oxide synthase derived nitric oxide (NO) production during liver transplantation promotes injury. We hypothesized that preemptive inhaled NO (iNO) would improve allograft function (primary) and reduce complications post-transplantation (secondary). Patients at two university centers (Center A and B) were randomized to receive placebo (n = 20/center) or iNO (80 ppm, n = 20/center) during the operative phase of liver transplantation. Data were analyzed at set intervals for up to 9-months post-transplantation and compared between groups. Patient characteristics and outcomes were examined with the Mann-Whitney U test, Student t-test, logistic regression, repeated measures ANOVA, and Cox proportional hazards models. Combined and site stratified analyses were performed. MELD scores were significantly higher at Center B (22.5 vs. 19.5, p<0.0001), surgical times were greater at Center B (7.7 vs. 4.5 hrs, p<0.001) and warm ischemia times were greater at Center B (95.4 vs. 69.7 min, p<0.0001). No adverse metabolic or hematologic effects from iNO occurred. iNO enhanced allograft function indexed by liver function tests (Center B, p<0.05; and p<0.03 for ALT with center data combined) and reduced complications at 9-months (Center A and B, p = 0.0062, OR = 0.15, 95% CI (0.04, 0.59)). ICU (p = 0.47) and hospital length of stay (p = 0.49) were not decreased. iNO increased concentrations of nitrate (p<0.001), nitrite (p<0.001) and nitrosylhemoglobin (p<0.001), with nitrite being postulated as a protective mechanism. Mean costs of iNO were $1,020 per transplant. iNO was safe and improved allograft function at one center and trended toward improving allograft function at the other. ClinicalTrials.gov with registry number 00582010 and the following URL:http://clinicaltrials.gov/show/NCT00582010.

Coagulopathy management in liver transplantation

Risk of bleeding and transfusion in liver transplantation is determined by age, severity of liver disease, as well as hemoglobin and plasma fibrinogen values. During the hepatectomy and the anhepatic phase, the coagulopathy is related to a decrease in clotting factors caused by surgical bleeding, facilitated by the increased portal hypertension and esophageal-gastric venous distension. Corrections of hematologic disturbances by administration of large volumes of crystalloid, colloid, or blood products may worsen the coagulopathy. Also, impaired clearance of fibrinolytic enzymes released from damaged cells can lead to primary fibrinolysis. At time of graft reperfusion further deterioration may occur as characterized by global reduction among all coagulation factors, decreased plasminogen activator inhibitor factors, and simultaneous generation of tissue plasminogen activator. In situations with inherent risk of bleeding, hypofibrinogenemia must be corrected. Concern about unwanted events is a major limitation of preventive therapy. There is some evidence for the efficacy of antifibrinolytic drugs to reduce red blood cell requirements. A guide for antifibrinolytic therapy are clot firmness in trhomboelastometry or alternatively, diffuse bleeding associated to a fibrinogen value less than 1 g/L. Because thrombin generation is limited in severe thrombocytopenia, platelet administration is recommended when active bleeding coexists with a platelet count below 50,000/mm(3). When the administration of hemoderivates and antifibrinolytic drugs does not correct severe bleeding, consumption coagulopathy and secondary fibrinolysis should be suspected. Treatment of affected patients should be based upon correcting the underlying cause, mostly related to tissue hypoxia due to critical hypoperfusion.

Effects of ω-3 fish oil lipid emulsion combined with parenteral nutrition on patients undergoing liver transplantation

BACKGROUND

The effect of parenteral nutrition (PN) support supplemented with ω-3 fatty acids was investigated in a randomized, controlled clinical trial at the Affiliated Drum Tower Hospital, Medical School of Nanjing University.

MATERIALS AND METHODS

Ninety-eight patients with the diagnosis of end-stage liver disease or hepatic cellular carcinoma were admitted for orthotopic liver transplantation at the Affiliated Drum Tower Hospital. The patients were randomly divided into 3 groups: diet group (n = 32), PN group (n = 33), and polyunsaturated fatty acid (PUFA) group (n = 33). Patients in the PN and PUFA groups received isocaloric and isonitrogenous PN for 7 days after surgery. Venous heparin blood samples were obtained for assay on days 2 and 9 after surgery. A pathological test was performed after reperfusion of the donor liver and on day 9.

RESULTS

Alanine aminotransferase levels were improved significantly by PUFA treatment compared with traditional PN support (P < .05). Compared with the results on day 9 in the PN group, a significant difference was seen in the extent of increase of the prognostic nutrition index and prealbumin in the PUFA group. The pathological results also showed that ω-3 fatty acid supplementation reduced hepatic cell injury. PUFA therapy also decreased the incidence of infectious morbidities and shortened the posttransplant hospital stay significantly.

CONCLUSION

Posttransplant PN support can greatly improve metabolism of protein and nutrition states of patients. ω-3 fatty acid-supplemented PN significantly reduces injury of the transplanted liver, decreases the incidence of infectious morbidities, and shortens posttransplant hospital stay.

Postreperfusion syndrome during orthotopic liver transplantation: a single-center experience

BACKGROUND

Marked hemodynamic alteration, commonly referred to as postreperfusion syndrome (PRS), often occurs after revascularization of the donor organ during orthotopic liver transplantation (OLT) and is associated with poor outcomes. This study aimed to investigate the incidence, predictive factors and clinical outcomes of PRS in Chinese patients following OLT at a liver transplantation center in China.

METHODS

Over a 5-year period, 330 consecutive patients who had undergone OLT for hepatocellular carcinoma or cirrhosis were included in this retrospective study. PRS was defined as a >30% decrease in the mean arterial pressure compared with that before revascularization for more than 1 minute during the first 5 minutes of graft reperfusion. The patients were divided into 2 groups according to the development of PRS: group 1 (patients with PRS, n=56) and group 2 (patients without PRS, n=274). The demographic characteristics, operative and postoperative courses, and outcomes of the patients were analyzed using SPSS version 18.0.

RESULTS

Multivariate regression analysis showed that left ventricular diastolic dysfunction determined by echocardiography and prolonged cold ischemia time were the independent risk factors for PRS. More patients in group 1 showed postoperative renal dysfunction than those in group 2 (19.23% vs 8.4%). Moreover, patients in group 1 also had higher intraoperative (7.14% vs 0%) and postoperative mortalities (26.92% vs 12.04%).

CONCLUSION

Left ventricular diastolic dysfunction and prolonged cold ischemia time contribute to a high incidence of PRS, which is associated with adverse outcomes in Chinese patients following OLT.

Orthotopic liver transplantation without venovenous bypass using the conventional and piggyback techniques

INTRODUCTION

Orthotopic liver transplantation is a widely used procedure for the treatment of irreversible liver diseases for which there is no possibility of medical treatment. When this procedure is performed by the conventional technique, the retrohepatic vena cava is removed along with the native liver. The inferior vena cava (IVC) remains clamped until the revascularization of the graft, and in this period there is a reduction in the venous return, which may induce a fall by up to 50% in the cardiac output with hemodynamic instability and a fall in renal perfusion pressure. The use of a portal-femoral-axillary venovenous bypass system, in which the blood from the femoral and portal veins returns to the heart via the axillary vein propelled by a centrifugal pump, is intended to minimize the effects of the IVC clamping. In the piggyback (PB) technique, the native liver is removed and the IVC of the recipient is preserved and only partially clamped. We have employed both techniques without the use of venovenous bypass for 10 years. The objective of this study was to compare the results obtained from the use of the two techniques.

PATIENTS AND METHODS

A retrospective analysis was performed of 195 patients transplanted between 1999 and 2008: 125 by the conventional technique and 70, the PB technique. The intraoperative parameters were analyzed (surgical time, ischemia time, use of blood products, and diuresis), as well as intensive care support (duration of stay in intensive care unit and use of vasoactive drugs), period of intubation, length of hospital stay, renal function, graft function, postoperative complications, retransplantation, and patient survival.

RESULTS

The PB group showed a reduction in surgical time, warm ischemia time, the use of packed red blood cells concentrates, and fresh frozen plasma, as well as mortality at 30 days (P<.05). There were no differences in relation to cold ischemia time, intraoperative diuresis; length of stay and use of vasoactive drugs in the intensive care unit; the period of intubation; the duration of hospital stay; the renal function; the graft function; the need for reoperation; the incidence of sepsis, biliary complications, vascular complications; need for retransplantation; and 1-year mortality. The cumulative survival rate at 1 year was significantly better among the PB patients.

CONCLUSION

Orthotopic liver transplantation can be performed without venovenous bypass with good results, using either the conventional technique or the PB technique. Provided that there is no technical contraindication and a long ischemia period is not foreseen, the PB technique should be the technique of choice.

Early graft dysfunction after liver transplantation

Liver transplantation has become the treatment of choice for fulminant hepatic failure and end-stage liver diseases. Several factors have been described to be predictors of graft function. Since early graft dysfunction dramatically influences graft and patient outcomes after liver transplantation, prevention of this event is mandatory. Donor-, procurement-, operative- and recipient-related factors influence the development of graft dysfunction. We have presented herein a review of the impact of these factors on graft dysfunction.