Postreperfusion syndrome during liver transplantation for cirrhosis: outcome and predictors

Normothermic Machine Perfusion of Deceased Donor Liver Grafts Is Associated With Improved Postreperfusion Hemodynamics

BACKGROUND

Graft reperfusion poses a critical challenge during liver transplantation and can be associated with hemodynamic instability/postreperfusion syndrome. This is sequel to ischemia-reperfusion injury and normothermic machine preservation (NMP) may affect hemodynamic changes. Herein, we characterize postreperfusion hemodynamics in liver grafts after NMP and traditional cold preservation.

MATERIALS AND METHODS

Intraoperative records of patients receiving grafts after NMP (n = 6; NMP group) and cold storage (CS) (n = 12; CS group) were compared. The mean arterial pressure (MAP) was defined as the average pressure in the radial artery during 1 cardiac cycle by invasive monitoring. Postreperfusion syndrome was defined as MAP drop greater than 30% of baseline, lasting for 1 minute or longer within the first 5 minutes from graft reperfusion.

RESULTS

Donor, recipient, demographics, and surgical parameters were evenly matched. Normothermic machine preservation grafts were perfused for 525 minutes (395-605 minutes) after initial cold ischemic time of 91 minutes (73-117 minutes), whereas in CS group cold ischemic time was 456 minutes (347-685 minutes) (P = 0.001). None developed postreperfusion syndrome in the NMP group against n = 2 (16.7%) in CS group (P = 0.529). Normothermic machine preservation group had better intraoperative MAP at 90 minutes postreperfusion (P = 0.029), achieved with a significantly less vasopressor requirement (P = <0.05) and less transfusion of blood products (P = 0.030) compared with CS group.

CONCLUSIONS

Normothermic machine perfusion is associated with a stable intraoperative hemodynamic profile postreperfusion, requiring significantly less vasopressor infusions and blood product transfusion after graft reperfusion and may have benefit to alleviate ischemia-reperfusion injury in liver transplantation.

Sevoflurane Versus Desflurane on the Incidence of Postreperfusion Syndrome During Living Donor Liver Transplantation: A Randomized Controlled Trial

BACKGROUND

Various interventions to reduce postreperfusion syndrome during liver transplantation have been explored, but the effect of volatile anesthetics used during liver transplantation on the incidence of postreperfusion syndrome has not been evaluated. A randomized controlled trial was performed to compare the incidence of postreperfusion syndrome between 2 commonly used volatile anesthetics, sevoflurane and desflurane.

METHODS

Sixty-two adult liver recipients scheduled for living-donor liver transplantation were randomized to receive either sevoflurane or desflurane for general anesthesia. The incidence of postreperfusion syndrome, use of vasoactive drugs, and postoperative course were compared. The risk factors associated with postreperfusion syndrome were also analyzed.

RESULTS

There was significantly less postreperfusion syndrome in the sevoflurane group compared to the desflurane group (38.7% vs 77.4%, P = 0.004) and less epinephrine was required in the sevoflurane group than the desflurane group (19.4% vs 45.2%, P = 0.030). Postoperative intensive care unit and hospital length of stay and postoperative course were similar between the groups. Multivariate analysis identified desflurane (compared to sevoflurane) as the only risk factor (odds ratio 7.314, P = 0.001) for reperfusion syndrome.

CONCLUSIONS

When using volatile anesthetics for elective living donor liver transplantation, sevoflurane seems to be a better option than desflurane for reducing the incidence of postreperfusion syndrome.

Atrioventricular conduction disturbances immediately after hepatic graft reperfusion and their outcomes in patients undergoing liver transplantation

Hemodynamic perturbation during hepatic graft reperfusion in patients undergoing liver transplantation (LT) is challenging and is frequently accompanied by bradyarrhythmia and even asystole. However, detailed data on electrocardiographic (ECG) changes during reperfusion are almost nonexistent, although the correct diagnosis by record is important for the treatment. We aimed to identify ECG rhythm disturbances during graft reperfusion and to investigate risk factors and outcomes. Data from 1065 consecutive patients who underwent adult LT were analyzed. The incidence, type, and detailed characteristics of ECG changes immediately after graft reperfusion were assessed using an electronically archived intraoperative ECG database. We analyzed risk factors, postoperative outcomes including major cardiovascular events, 30-day and 1-year mortalities of recipients based on the occurrence of atrioventricular (AV) block, and asystole during reperfusion. The typical pattern of postreperfusion bradyarrhythmia was progressive PR interval prolongation until a Mobitz type 1 AV block occurred. The overall incidence of AV block was 5.0% (53/1065), and 30.2% of them (16/53) had initiated as AV block and then progressed into ventricular asystole. Fulminant hepatic failure was a significant predictor for occurrence of AV block (odds ratio [OR], 7.20; 95% confidence interval, 3.38-15.32; P < 0.001). Patients with AV block showed significantly higher incidence of postoperative major cardiovascular events (P < 0.001) and 30-day mortality (P = 0.002) than those without AV block, whereas the 1-year mortality was not different between the 2 groups (P = 0.10). The postreperfusion asystole was consistently preceded by a Mobitz type 1 AV block. The occurrence of AV block and asystole appears to be an important prognosticator. Therefore, maintaining an optimal range of physiological status and gradual unclamping of the vena cava to avoid sudden atrial distension are recommended in high-risk patients during reperfusion period. Liver Transplantation 22 956-967 2016 AASLD.

Postperfusion Syndrome in Cadaveric Liver Transplantations: A Retrospective Study

OBJECTIVE

To evaluate the factors that affects the postperfusion syndrome in cadaveric liver transplantations and the effect of the postperfusion syndrome on discharge from the hospital.

METHODS

Patients who underwent cadaveric liver transplantations between 2007 and 2013 were scanned retrospectively. Intraoperative anaesthesia records, intensive care unit follow-up forms and discharge reports were examined from patient files. Overall, 43 patients having complete data were included in the study. The postperfusion syndrome is defined as asystoli or a decrease in mean arterial pressure of more than 30%, which occurred in the first 5 min of reperfusion and continued for 1 min. Patients were divided into two groups: those who had the postperfusion syndrome and those who did not.

RESULTS

The number of patients who had the postperfusion syndrome was 25 of 43 (58.1%). The MELD score of patients without the postperfusion syndrome was calculated as 16.9±3.2 and that of patients with the postperfusion syndrome was 19.7±3.6. A statistically significant relationship was detected between the postperfusion syndrome occurrence and a high MELD score (p=0.013). The diastolic blood pressure just before reperfusion was statistically lower in the group with the postperfusion syndrome than in the other group (p=0.023, 50±8 vs. 58±11). According to the logistic regression analysis, the MELD score and the decrease in diastolic blood pressure before reperfusion were defined as independent predictive factors.

CONCLUSION

According to the study, the ratio for having the postperfusion syndrome was found to be 58.1%. The independent predictor factors affecting the postperfusion syndrome were detected as the MELD score and the decrease in diastolic blood pressure before reperfusion. The postperfusion syndrome during orthotropic liver transplantation is an important issue for anaesthesiologists. The awareness of the related factors with the postperfusion syndrome may help in the development of various preventive strategies.

Prolonged Intraoperative Cardiac Resuscitation Complicated by Intracardiac Thrombus in a Patient Undergoing Orthotopic Liver Transplantation

We report the case of successful resuscitation after prolonged cardiac arrest during orthotopic liver transplantation. After reperfusion, the patient developed ventricular tachycardia, complicated by intracardiac clot formation and massive hemorrhage. Transesophageal echocardiography demonstrated stunned and nonfunctioning right and left ventricles, with developing intracardiac clots. Treatment with heparin, massive transfusion and prolonged cardiopulmonary resuscitation ensued for 51 minutes. Serial arterial blood gases demonstrated adequate oxygenation and ventilation during cardiopulmonary resuscitation. Cardiothoracic surgery was consulted for potential use of extracorporeal membrane oxygenation, however, the myocardial function improved and the surgery was completed without further intervention. On postoperative day 6, the patient was extubated without neurologic or cardiac impairment. The patient continues to do well 2 years posttransplant, able to perform independent daily activities of living and his previous job. This case underscores the potential for positive outcomes with profoundly prolonged, effective advanced cardiovascular life support in patients who experience postreperfusion syndrome.

Risk analysis of ischemic-type biliary lesions after liver transplant using octogenarian donors

The use of octogenarian donors to increase the donor pool in liver transplantation (LT) is controversial because advanced donor age is associated with a higher risk of ischemic-type biliary lesions (ITBL). The aim of this study was to investigate retrospectively the role of a number of different pre-LT risk factors for ITBL in a selected population of recipients of octogenarian donor grafts. Between January 2003 and December 2013, 123 patients underwent transplantation at our institution with deceased donor grafts from donors of age ≥80 years. Patients were divided into 2 groups based on the presence of ITBL in the posttransplant course. Exclusion criteria were retransplantations, presence of vascular complications, and no availability of procurement liver biopsy. A total of 88 primary LTs were included, 73 (83.0%) with no posttransplant ITBLs and 15 (17.0%) with ITBLs. The median follow-up after LT was 2.1 years (range, 0.7-5.4 years). At multivariate analysis, donor hemodynamic instability (hazard ratio [HR], 7.6; P = 0.005), donor diabetes mellitus (HR, 9.5; P = 0.009), and donor age-Model for End-Stage Liver Disease (HR, 1.0; P = 0.04) were risk factors for ITBL. Transplantation of liver grafts from donors of age ≥80 years is associated with a higher risk for ITBL. However, favorable results can be achieved with accurate donor selection. Donor hemodynamic instability, a donor history of diabetes mellitus, and allocation to higher Model for End-Stage Liver Disease score recipient all increase the risk of ITBL and are associated with worse graft survival when octogenarian donors are used. Liver Transplantation 22 588-598 2016 AASLD.

Post reperfusion syndrome during liver transplantation: From pathophysiology to therapy and preventive strategies

This review aims at evaluating the existing evidence regarding post reperfusion syndrome, providing a description of the pathophysiologic mechanisms involved and possible management and preventive strategies. A PubMed search was conducted using the MeSH database, “Reperfusion” AND “liver transplantation” were the combined MeSH headings; EMBASE and the Cochrane library were also searched using the same terms. 52 relevant studies and one ongoing trial were found. The concept of post reperfusion syndrome has evolved through years to a multisystemic disorder. The implications of the main organ, recipient and procedure related factors in the genesis of this complex syndrome are discussed in the text as the novel pharmacologic and technical approaches to reduce its incidence. However the available evidence about risk factors, physiopathology and preventive measures is still confusing, the presence of two main definitions and the numerosity of possible confounding factors greatly complicates the interpretation of the studies.

Infections After Liver Transplantation: A Retrospective, Single-center Study

OBJECTIVE

To access the incidence of infectious problems after liver transplantation (LT).

DESIGN

A retrospective, single-center study.

MATERIALS AND METHODS

Patients undergoing LT from January 2008 to December 2011 were considered. Exclusion criterion was death occurring in the first 48 hours after LT. We determined the site of infection and the bacterial isolates and collected and compared recipient's variables, graft variables, surgical data, post-LT clinical data.

RESULTS

Of the 492 patients who underwent LT and the 463 considered for this study, 190 (Group 1, 41%) developed at least 1 infection, with 298 infections detected. Of these, 189 microorganisms were isolated, 81 (51%) gram-positive bacteria (most frequently Staphylococcus spp). Biliary infections were more frequent (mean time of 160.4 ± 167.7 days after LT); from 3 months after LT, gram-negative bacteria were observed (57%). Patients with infections after LT presented lower aminotransferase levels, but higher requirements in blood transfusions, intraoperative vasopressors, hemodialysis, and hospital stay. Operative and cold ischemia times were similar.

CONCLUSION

We found a 41% incidence of all infections in a 2-year follow-up after LT. Gram-positive bacteria were more frequent isolated; however, negative bacteria were commonly isolated later. Clinical data after LT were more relevant for the development of infections. Donors' variables should be considered in future analyses.

Clinical outcomes and genetic expression profile in human liver graft dysfunction during ischemia/reperfusion injury

INTRODUCTION

This study aims to compare the molecular gene expression during ischemia reperfusion injury. Several surgical times were considered: in the beginning of the harvesting (T0), at the end of the cold ischemia period (T1), and after reperfusion (T2) and compared with graft dysfunction after liver transplant (OLT).

METHODS

We studied 54 patients undergoing OLT. Clinical, laboratory data, and histologic data (Suzuki classification) as well as the Survival Outcomes Following Liver Transplantation (SOFT) score were used and compared with the molecular gene expression of the following genes: Interleukin (IL)-1b, IL-6, tumor necrosis factor-α, perforin, E-selectin (SELE), Fas-ligand, granzyme B, heme oxygenase-1, and nitric oxide synthetase.

RESULTS

Fifteen patients presented with graft dysfunction according to SOFT criteria. No relevant data were obtained by comparing the variables graft dysfunction and histologic variables. We observed a statistically significant relation between SELE at T0 (P = .013) and IL-1β at T0 (P = .028) and early graft dysfunction.

CONCLUSIONS

We conclude that several genetically determined proinflammatory expressions may play a critical role in the development of graft dysfunction after OLT.

Postreperfusion syndrome during liver transplantation

As surgical and graft preservation techniques have improved and immunosuppressive drugs have advanced, liver transplantation (LT) is now considered the gold standard for treating patients with end-stage liver disease worldwide. However, despite the improved survival following LT, severe hemodynamic disturbances during LT remain a serious issue for the anesthesiologist. The greatest hemodynamic disturbance is postreperfusion syndrome (PRS), which occurs at reperfusion of the donated liver after unclamping of the portal vein. PRS is characterized by marked decreases in mean arterial pressure and systemic vascular resistance, and moderate increases in pulmonary arterial pressure and central venous pressure. The underlying pathophysiological mechanisms of PRS are complex. Moreover, risk factors associated with PRS are not fully understood. Rapid and appropriate treatment with vasopressors, volume replacement, or venesection must be provided depending on the cause of the hemodynamic disturbance when hemodynamic instability becomes profound after reperfusion. The negative effects of PRS on postoperative early morbidity and mortality are clear, but the effect of PRS on postoperative long-term mortality remains a matter of debate.

Hemodynamic recovery following postreperfusion syndrome in liver transplantation

OBJECTIVES

The authors' current understanding of the phenomenon of significant and sustained decrease in arterial pressure following liver graft reperfusion (postreperfusion syndrome [PRS]), is derived from relatively small observational reports, and no large scale analysis of PRS exists up to date. This study investigated its incidence, risk factors, temporal course of hemodynamic recovery, and its impact on functional graft outcome.

DESIGN

Retrospective observational study of 1,024 electronic records of orthotopic liver transplant recipients.

SETTING

Major transplant center.

MEASUREMENTS

Out of 1,024, 715 records satisfied the inclusion criteria. Data were analyzed by multivariable Cox's proportional hazard model to identify risk factors for PRS. Hemodynamic recovery patterns and functional graft outcomes were compared between the cohorts of interest (intraoperative PRS) and control (no intraoperative PRS) after propensity score-matching. Association between donor risk index and hemodynamic recovery after hepatic artery reperfusion was analyzed by a multivariable regression model.

RESULTS

The overall incidence of PRS was 31.6% with associated mortality of 0.3%. Independent risk factors for PRS included older donor age, higher donor risk index, and lower central venous pressure at reperfusion. Hemodynamic recovery after PRS following portal vein reperfusion was delayed until hepatic artery reperfusion. The slope of hemodynamic recovery, expressed as %MAP/min, correlated negatively with donor risk index (p=0.014). Immediate and 1-year graft survival rates were similar in both cohorts.

CONCLUSIONS

Host hemodynamic response to graft reperfusion appeared to be phasic: initial abrupt hypotension after portal vein reperfusion was followed by a period of gradual decline of blood pressure until hepatic artery reperfusion, and sustained hemodynamic recovery afterwards. The slope of hemodynamic recovery correlated negatively with the donor risk index. PRS was not associated with deterioration of post-transplant graft survival and function.

The Risk of End-Stage Renal Disease Among Living Donor Liver Transplant Recipients in the United States

Since initiation of model for end-stage liver disease (MELD)-based allocation for liver transplantation, the risk of posttransplant end-stage renal disease (ESRD) has increased. Recent US data have demonstrated comparable, if not superior survival, among recipients of living donor liver transplants (LDLT) when compared to deceased donor liver transplant (DDLT) recipients. However, little is known about the incidence of ESRD post-LDLT. We analyzed linked Scientific Registry of Transplant Recipients (SRTR) and US Renal Data System (USRDS) data of first-time liver-alone transplant recipients from February 27, 2002 to March 1, 2011, and restricted the cohort to recipients with a laboratory MELD score ≤25 not on dialysis prior to transplantation, in order to evaluate the incidence of ESRD post-LDLT, and to compare the incidence among LDLT versus DDLT recipients. There were 28 707 DDLT and 1917 LDLT recipients included in the analyses. The 1-, 3- and 5-year unadjusted risk of ESRD was 1.7%, 2.9% and 3.4% in LDLT recipients, compared with 1.5%, 3.0% and 4.8% in DDLT recipients (p > 0.05), respectively. In multivariable competing risk Cox regression models, there was no association between receiving an LDLT and risk of ESRD (sub-hazard ratio: 0.99, 95% CI: 0.77-1.26, p = 0.92). In conclusion, the incidence of ESRD post-LDLT in the United States is low, and there are no significant differences among LDLT and DDLT recipients with MELD scores ≤25 at transplantation.

Is there a relationship between intraoperative hemodynamic instability and calcineurin inhibitor-related toxicity, early after liver transplantation? A single-center observational study

This study evaluated the relationship between intraoperative hemodynamic instability (IOHI) and the development of calcineurin inhibitor (CNI) toxicity in the early postoperative period after liver transplantation (LT). Eighty-two patients were enrolled during a 1-year period and a 3-month follow-up. IOHI, requiring continuous infusion of vasopressors, was observed in 31 patients (38%, group 1; control group 2, n = 51). Acute kidney injury (AKI) developed in 28 patients (52% in group 1 vs 24% in group 2, P = .02), and CNI-related neurotoxicity (CNI-NT) in 26 (48% in group 1 vs 22% in group 2, P = .03). Group 1 patients received mainly deceased donor grafts (87% vs 57% in group 2, P < .001). An independent association between IOHI and CNI-NT (P = .029) and AKI (P = .016) was observed. The receiver-operator characteristic curve revealed an area under the curve of 0.63 for IHI (sensitivity 56%; specificity 75%) and 0.65 for AKI (sensitivity 56%; specificity 70.2%). In conclusion, patients undergoing LT with IOHI may be more prone to developing CNI-NT and AKI in the early postoperative period.

Clinical Risk Scoring Models for Prediction of Acute Kidney Injury after Living Donor Liver Transplantation: A Retrospective Observational Study

Acute kidney injury (AKI) is a frequent complication of liver transplantation and is associated with increased mortality. We identified the incidence and modifiable risk factors for AKI after living-donor liver transplantation (LDLT) and constructed risk scoring models for AKI prediction. We retrospectively reviewed 538 cases of LDLT. Multivariate logistic regression analysis was used to evaluate risk factors for the prediction of AKI as defined by the RIFLE criteria (RIFLE = risk, injury, failure, loss, end stage). Three risk scoring models were developed in the retrospective cohort by including all variables that were significant in univariate analysis, or variables that were significant in multivariate analysis by backward or forward stepwise variable selection. The risk models were validated by way of cross-validation. The incidence of AKI was 27.3% (147/538) and 6.3% (34/538) required postoperative renal replacement therapy. Independent risk factors for AKI by multivariate analysis of forward stepwise variable selection included: body-mass index >27.5 kg/m2 [odds ratio (OR) 2.46, 95% confidence interval (CI) 1.32-4.55], serum albumin <3.5 mg/dl (OR 1.76, 95%CI 1.05-2.94), MELD (model for end-stage liver disease) score >20 (OR 2.01, 95%CI 1.17-3.44), operation time >600 min (OR 1.81, 95%CI 1.07-3.06), warm ischemic time >40 min (OR 2.61, 95%CI 1.55-4.38), postreperfusion syndrome (OR 2.96, 95%CI 1.55-4.38), mean blood glucose during the day of surgery >150 mg/dl (OR 1.66, 95%CI 1.01-2.70), cryoprecipitate > 6 units (OR 4.96, 95%CI 2.84-8.64), blood loss/body weight >60 ml/kg (OR 4.05, 95%CI 2.28-7.21), and calcineurin inhibitor use without combined mycophenolate mofetil (OR 1.87, 95%CI 1.14-3.06). Our risk models performed better than did a previously reported score by Utsumi et al. in our study cohort. Doses of calcineurin inhibitor should be reduced by combined use of mycophenolate mofetil to decrease postoperative AKI. Prospective randomized trials are required to address whether artificial modification of hypoalbuminemia, hyperglycemia and postreperfusion syndrome would decrease postoperative AKI in LDLT.

Impact of cytokine release on ventricular function after hepatic reperfusion: a prospective observational echocardiographic study with tissue Doppler imaging

BACKGROUND

Postreperfusion syndrome and haemodynamic instability are predictors for poor outcome after liver transplantation. Cytokine release has been claimed to be responsible for postreperfusion syndrome. However, the underlying pathophysiologic mechanism is not clarified. The aim of this prospective observational study was to correlate cardiac performance (measured by transoesophageal echocardiography (TEE), Doppler and Tissue Doppler Imaging (TDI)) to plasmatic cytokines: IL-6, IL-8, CXCL1, TGF-β and CD40L at 5 different time points during liver transplantation.

METHODS

Seventeen consecutive patients scheduled for orthotopic liver transplantation, age 18 to 75 years without contraindication for transoesophageal echocardiography were included. Patients were monitored with TEE and TDI. Systolic and diastolic cardiac function, MAP, MPAP, CVP, PCWP, CO and blood samples for cytokine assays were recorded or collected after induction, 15 min after vena cava inferior clamping, 2 to 5 min after reperfusion, 60 min after reperfusion and at the end of surgery.

RESULTS

Mean arterial pressure and catecholamine requirements remained unchanged, MPAP, CVP and CO increased, SVR decreased after unclamping. Postreperfusion syndrome did not develop. The haemodynamic parameters and the variations of TEE parameters were consistent with the volume load changes during clamping and declamping and did not reveal systolic or diastolic cardiac dysfunction. All cytokines, except TGF-β, increased.

CONCLUSION

These findings suggest, that significant cytokine release during liver transplantation is not necessarily coincident with haemodynamic instability and impaired cardiac function.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT00547924.

Appraising cardiac dysfunction in liver transplantation: an ongoing challenge

End-stage liver disease (ESLD) is a multisystemic disease that adversely and mutually aggravates other organs such as the heart. Cardiac dysfunction in ESLD encompasses a spectrum of disease that could be aggravated, precipitated or be occurring hand-in-hand with coexisting aetiological factors precipitating cirrhosis. Additionally and more complexly, liver transplantation, the curative modality of ESLD, is responsible for additional intra- and postoperative short- and long-term cardiac morbidity. The phenotypic distinction of the different forms of cardiac dysfunction in ESLD albeit important prognostically and therapeutically is not allowed by the current societal recommendations, due to conceptual, and methodological limitations in the appraisal of cardiac function and structure in ESLD and in designing studies that are based on this appraisal. This review comprehensively discusses the spectrum of cardiac dysfunction in ESLD, discusses the limitations of the current appraisal of cardiac dysfunction in ESLD, and proposes a hypothetical approach for studying cardiac dysfunction in liver transplant candidates.

Review of anesthesia in liver transplantation

Liver transplantation (LT) is a well-accepted treatment modality of many end-stage liver diseases. The main issue in LT is the shortage of deceased donors to accommodate the needs of patients waiting for such transplants. Live donors have tremendously increased the pool of available liver grafts, especially in countries where deceased donors are not common. The main ethical concern of this procedure is the safety of healthy donors, who undergo a major abdominal surgery not for their own health, but to help cure others. The first part of the review concentrates on live donor selection, preanesthetic evaluation, and intraoperative anesthetic care for living liver donors. The second part reviews patient evaluation, intraoperative anesthesia monitoring, and fluid management of the recipient. This review provides up-to-date information to help improve the quality of anesthesia, and contribute to the success of LT and increase the long-term survival of the recipients.

Donation after cardiac death liver transplantation is associated with increased risk of end-stage renal disease

Limited organ supply has led to greater use of liver allografts with higher donor risk indices (DRI) and/or donated after cardiac death (DCD). DCD status is associated with acute kidney injury after liver transplantation; however, less is known about the association between donor quality and end-stage renal disease (ESRD). Using SRTR data, we assembled a cohort of liver transplant recipients from 2/2002 to 12/2010. We fit multivariable Cox regression models for ESRD. Model 1 included total DRI; model 2 included components of DRI, including DCD, as separate variables. Forty thousand four hundred and sixty-three liver transplant recipients were included. Median DRI was 1.40 (IQR 1.14, 1.72); 1822 (5%) received DCD livers. During median follow-up of 3.93 years, ESRD occurred in 2008 (5%) and death in 11 075 (27%) subjects. There was a stepwise increase in ESRD risk with higher DRI (DRI ≥1.14 and <1.40: HR 1.17, P = 0.06; DRI ≥1.40 and <1.72: HR 1.29, P = 0.003; DRI ≥1.72: HR 1.39, P < 0.001, compared with DRI <1.14). Adjusting for DRI components separately, DCD status was most strongly associated with ESRD (HR 1.40, P = 0.008). Higher DRI is associated with ESRD after liver transplantation, driven in part by DCD status. Donor quality is an important predictor of long-term renal outcomes in liver transplant recipients.

Liver transplantation in recipients receiving renal replacement therapy: outcomes analysis and the role of intraoperative hemodialysis

The Model for End-Stage Liver Disease (MELD) system has dramatically increased the number of recipients requiring pretransplant renal replacement therapy (RRT) prior to liver transplantation (LT). Factors affecting post-LT outcomes and the need for intraoperative RRT (IORRT) were analyzed in 500 consecutive recipients receiving pretransplant RRT, including comparisons among recipients not receiving IORRT (No-IORRT, n = 401), receiving planned IORRT (Pl-IORRT, n = 70), and receiving emergent, unplanned RRT after LT initiation (Em-IORRT, n = 29). Despite a median MELD of 39, overall 30-day, 1-, 3- and 5-year survivals were 93%, 75%, 68% and 65%, respectively. Em-IORRT recipients had significantly more intraoperative complications (arrhythmias, postreperfusion syndrome, coagulopathy) compared with both No-IORRT and Pl-IORRT and greater 30-day graft loss (28% vs. 10%, p = 0.004) and need for retransplantation (24% vs. 10%, p = 0.099) compared with No-IORRT. A risk score based on multivariate predictors of IORRT accurately identified recipients with chronic (sensitivity 84%, specificity 72%, concordance-statistic [c-statistic] 0.829) and acute (sensitivity 93%, specificity 61%, c-statistic 0.776) liver failure requiring IORRT. In this largest experience of LT in recipients receiving RRT, we report excellent survival and propose a practical model that accurately identifies recipients who may benefit from IORRT. For this select group, timely initiation of IORRT reduces intraoperative complications and improves posttransplant outcomes.

Hepatopulmonary syndrome: the anaesthetic considerations

Hepatopulmonary syndrome (HPS) is a pulmonary complication observed in patients with chronic liver disease and/or portal hypertension, attributable to an intrapulmonary vascular dilatation that induces severe hypoxaemia. Considering the favourable long-term survival of HPS patients as well as the reversal of the syndrome with a functional liver graft, HPS is now an indication for orthotopic liver transplantation (OLT). Consequently, blood gas analysis and imaging techniques should be performed when cirrhotic patients present with shortness of breath as well as when OLT candidates are placed on the transplant waiting list. If the arterial partial pressure of oxygen (PaO2) is more than 10.7 kPa when breathing room air, HPS can be excluded and no other investigation is needed. When the PaO2 when breathing room air is 10.7 kPa or less, contrast-enhanced echocardiography should be performed to exclude pulmonary vascular dilatation. Lung function tests may also help detect additional pulmonary diseases that can contribute to impaired oxygenation. When contrast-enhanced echocardiography is negative, HPS is excluded and no follow-up is needed. When contrast-enhanced echocardiography is positive and PaO2 less than 8 kPa, patients should obtain a severity score that provides them with a reasonable probability of being transplanted within 3 months. In mild-to-moderate HPS (PaO2 8 to 10.6 kPa), periodic follow-up is recommended every 3 months to detect any further deterioration in PaO2. Although no intraoperative deaths have been directly attributed to HPS, oxygenation may worsen immediately following OLT due to volume overload and postoperative infections. Mechanical ventilation is often prolonged with an extended stay in the ICU. A high postoperative mortality (mostly within 6 months) is observed in this group of patients in comparison to non-HPS patients. However, the recovery of an adequate PaO2 within 12 months after OLT explains the similar outcome of HPS and non-HPS patients following OLT over a longer time period.

Preoperative variables associated with transfusion requirements in orthotopic liver transplantation

BACKGROUND

Patients with end-stage chronic liver disease (CLD) and submitted to orthotopic liver transplantation (OLT) usually require blood transfusion during the procedure or in the post-operative period due to hemorrhage. Risk factors for transfusion need are not fully known. This study aimed to identify the factors associated with blood components requirements.

METHODS

In this retrospective study a total of 166 consecutive patients submitted to OLT with the piggyback technique, between 2001 and 2011, were evaluated for number of blood components transfused during surgical procedure and the four subsequent days (total of 5 days). We evaluated the association between the number of units transfused and clinical variables, such as: Child-Turcotte-Pugh (CTP) and MELD scores, hemoglobin concentration (Hb), INR, serum creatinine, bilirubin and albumin concentrations, and total, hypothermic and normothermic time of graft ischemia.

RESULTS

152 (91.6%) Patients were transfused (median of 24 units of blood components). Risk factors for higher blood transfusion requirements were CTP, INR, Hb and total time of graft ischemia. The group with CTP-A score received less blood components than CTP-B/C (11.5 vs 27; P=0.002). The group with Hb<10 required a higher number of blood units (34.5 vs 23; P=0.003). The group with INR<1.5 received less blood units (20.5 vs 31; P=0.012). The group transplanted with a graft exposed to less than the median of 555 min of ischemia received less transfusion (21 vs 27; P=0.03). MELD score and the other factors were not associated with blood requirements.

CONCLUSION

These results demonstrate that CTP, but not MELD score, hemoglobin concentration, INR, and total time of graft ischemia are preoperative variables associated with blood requirements during OLT and in the subsequent days.

Cardiac arrest during adult liver transplantation: a single institution's experience with 1238 deceased donor transplants

Liver transplantation (LT) is one of the highest risk noncardiac surgeries. We reviewed the incidence, etiologies, and outcomes of intraoperative cardiac arrest (ICA) during LT. Adult cadaveric LT recipients from January 1, 2001 through December 31, 2009 were reviewed. ICA was defined as an event requiring either closed chest compression or open cardiac massage. Cardiac arrest patients who recovered with only pharmacological interventions were excluded. Data included etiologies and outcomes of ICA, intraoperative deaths (IDs) and hospital deaths (HDs), and potential ICA risk factors. ICA occurred in 68 of 1238 LT recipients (5.5%). It occurred most frequently during the neohepatic phase (60 cases or 90%), and 39 of these cases (65.0%) experienced ICA within 5 minutes after graft reperfusion. The causes of ICA included postreperfusion syndrome (PRS; 26 cases or 38.2%) and pulmonary thromboembolism (PTE; 24 cases or 35.3%). A higher Model for End-Stage Liver Disease (MELD) score was found to be the most significant risk factor for ICA. The ID rate after ICA was 29.4% (20 cases), and the HD rate was 50.0% (34 cases). The 30-day patient survival rate after ICA was 55.9%, and the 1-year survival rate was 45.6%: these rates were significantly lower (P < 0.001) than those for non-ICA patients (97.4% and 85.1%, respectively). In conclusion, the incidence of ICA in adult cadaveric LT was 5.5% with an intraoperative mortality rate of 29.4%. ICA most frequently occurred within 5 minutes after reperfusion and resulted mainly from PRS and PTE. A higher MELD score was identified as a risk factor.

Surgical site infections in liver transplant recipients in the model for end-stage liver disease era: an analysis of the epidemiology, risk factors, and outcomes

In recipients of liver transplantation (LT), surgical site infection (SSIs) are among the most common types of infection occurring in the first 60 days after LT. In 2007, the Model for End-Stage Liver Disease (MELD) scoring system was adopted as the basis for prioritizing organ allocation. Patients with higher MELD scores are at higher risk for developing SSIs as well as other health care-associated infections. However, there have been no studies comparing the incidence of SSIs in the pre-MELD era with the incidence in the period since its adoption. Therefore, the objectives of this study were to evaluate the incidence, etiology, epidemiology, and outcomes of post-LT SSIs in those 2 periods and to identify risk factors for SSIs. We evaluated all patients who underwent LT over a 10-year period (2002-2011). SSI cases were identified through active surveillance. The primary outcome measure was an SSI during the first 60 days after LT. Risk factors were analyzed via logistic regression, and 60-day survival rates were evaluated via Cox regression. We evaluated 543 patients who underwent LT 597 times. The SSI rates in the 2002-2006 and 2007-2011 periods were 30% and 24%, respectively (P = 0.21). We identified the following risk factors for SSIs: retransplantation, the transfusion of more than 2 U of blood during LT, dialysis, cold ischemia for >400 minutes, and a cytomegalovirus infection. The overall 60-day survival rate was 79%. Risk factors for 60-day mortality were retransplantation, dialysis, and a longer surgical time. The use of the MELD score modified the incidence and epidemiology of SSIs only during the first year after its adoption. Risks for SSIs were related more to intraoperative conditions and intercurrences after LT than to a patient's status before LT.

Postoperative kidney injury does not decrease survival after liver transplantation

PURPOSE

To explore the effect of acute kidney injury (AKI) on long-term survival after conventional orthotopic liver transplantation (OLT) without venovenous bypass (VVB).

METHODS

A retrospective cohort study was carried out on 153 patients with end-stage liver diseases transplanted by the Department of General Surgery and Liver Transplantation of the University of Pernambuco, from August, 1999 to December, 2009. The Kaplan-Meier survival estimates and log-rank test were applied to explore the association between AKI and long-term patient survival, and multivariate analyses were applied to control the effect of other variables.

RESULTS

Over the 12.8-year follow-up, 58.8% patients were alive with a median follow-up of 4.5-year. Patient 1-, 2-, 3- and 5-year survival were 74.5%, 70.6%, 67.9% and 60.1%; respectively. Early postoperative mortality was poorer amongst patients who developed AKI (5.4% vs. 20%, p=0.010), but long-term 5-year survival did not significantly differed between groups (51.4% vs. 65.3%; p=0.077). After multivariate analyses, AKI was not significantly related to long-term survival and only the intraoperative transfusion of red blood cells was significantly related to this outcome (non-adjusted Exp[b]=1.072; p=0.045).

CONCLUSION

The occurrence of postoperative acute kidney injury did not independently decrease patient survival after orthotopic liver transplantation without venovenous bypass in this data from northeast Brazil.

Role of MELD score and serum creatinine as prognostic tools for the development of acute kidney injury after liver transplantation

Background

The role of the Model for End-Stage Liver Disease (MELD) score in predicting complications, such as Acute Kidney Injury (AKI), after orthotopic liver transplantation (OLT) has yet to be evaluated and serum creatinine may be too heavily weighted in the existing MELD formula, since it has many pitfalls in cirrhotic patients.

Methods

Retrospective data of the perioperative period from consecutive adult OLTs performed from January to December 2009 were recorded. Univariate and multivariate analysis were performed to analyze the risk factors for AKI and mortality after OLT.

Results

There were 114 OLTs performed in the study period, 22 (19,2%) were submitted to dialysis prior OLT and were excluded from the analysis for AKI. The median age was 52 years and 66% were male. Median creatinine value was 0.85mg/dL and MELD was 19. Fifty-two of the 92 patients (56,5%) developed AKI in the first 72 hours after OLT. The only independent risk factor for AKI was calculated MELD and when the components of the MELD score were analyzed, INR had a much stronger impact in predicting AKI then serum creatinine. Overall mortality rate was 32,5% and anesthesia duration was the only variable associated with higher mortality rate.

Conclusions

Although MELD score seems to have a good performance in predicting AKI after OLT, serum creatinine had no impact on its prediction despite its importance on MELD calculation. Modifying the MELD score, which could include novel AKI biomarkers, may improve its prognostic accuracy and provide a better tool for public health planning.

Evaluation of the right ventricular ejection fraction during classic orthotopic liver transplantation without venovenous bypass

BACKGROUND

Right ventricular (RV) function is sensitive to changes in cardiac loading conditions, and RV dysfunction may contribute to hemodynamic instability during orthotopic liver transplantation (OLT). Thus, we evaluated RV function and its role in hemodynamic instability during classic OLT without venovenous bypass (VVB).

METHODS

Thirty patients undergoing classic OLT without VVB were studied. Right ventricular ejection fraction (RVEF) was measured using a modified pulmonary artery catheter. Hemodynamic data were recorded at pre-determined time points: T0, baseline; T1-T3: 5, 15, and 30 min after clamping; T4-T7: 5, 15, 30, and 120 min after reperfusion; T8 and T9: 24 and 48 h after surgery.

RESULTS

The baseline RVEF was lower than normal value. RVEF decreased significantly from T1 to T4 and returned to baseline beginning at T5. At 24 and 48 h after surgery, RVEF was higher than baseline value. RVEF was correlated with stroke volume index and post-reperfusion syndrome during OLT. Compared to the low MELDs group, RVEF in the high MELDs group was lower at T1, T2, and T4.

CONCLUSIONS

Right ventricular function was compromised during the anhepatic and early reperfusion stages in patients undergoing classic OLT without VVB, particularly in the high MELD score patients. Close monitoring of RV function in these patients should be considered.

Anesthesia for Liver Transplantation

Orthotopic liver transplantation is the only definitive treatment for end-stage liver disease. More than 6000 procedures are performed in the United States annually with excellent survival rates. The shortage of donor organs leads to continued interest in techniques to enlarge the potential donor pool. Patients presenting for liver transplant suffer from important cardiovascular, respiratory, renal, neurological, and gastroenterological comorbidity. In the Western world, liver failure is increasingly caused by steatohepatitis, and transplant candidates are thus becoming older and more comorbid. The role of the transplant anesthesiologist is highly important in the preoperative assessment, intraoperative management, and postoperative care of these complex and sick patients. Appropriate investigation and management of comorbidities such as coronary artery disease and portopulmonary hypertension is controversial and differs between programs. The transplant procedure is a major surgery, and although massive transfusion is no longer commonplace, there is potential for significant hemodynamic instability, coagulopathy, and metabolic disturbance. Liver transplant surgery can be divided into the preanhepatic phase, the anhepatic phase, and the reperfusion phase, with important anesthetic considerations at each point.  An understanding of the surgical techniques used for vascular exclusion of the liver and the role of venovenous bypass is crucial for the anesthesiologist. Recent trends in perioperative care include the use of antifibrinolytic drugs and point-of-care coagulation tests, intraoperative renal replacement therapy, and “fast-track” extubation and postoperative care. Care of patients with fulminant hepatic failure or those receiving split-liver grafts requires special consideration.

Sympathetic withdrawal is associated with hypotension after hepatic reperfusion

OBJECTIVE

Post-reperfusion syndrome (PRS), severe hypotension after graft reperfusion during liver transplantation, is an adverse clinical event associated with poorer patient outcomes. The purpose of this study was to determine whether alterations in autonomic control in liver transplant recipients prior to graft reperfusion are associated with the subsequent development of PRS.

METHODS

Heart rate variability (HRV), systolic arterial blood pressure (SBP) variability, and baroreflex sensitivity of 218 liver transplant recipients were evaluated using 5 min of ECG and arterial blood pressure signals 10 min before graft reperfusion along with other clinical parameters. Logistic regression analyses were performed to assess predictors of PRS occurrence.

RESULTS

Seventy-seven patients (35 %) developed PRS while 141 did not. There were significant differences in SBP (110 ± 16 vs. 119 ± 16 mmHg, P < 0.001) and the ratio of low frequency power to high frequency power (LF/HF) of HRV (1.0 ± 1.4 vs. 2.1 ± 3.7, P = 0.003) between the PRS group and No-PRS group. In multivariate logistic regression analysis, predictors were LF/HF (odds ratio 0.817, P = 0.028) and SBP (odds ratio 0.966, P < 0.001).

INTERPRETATION

Low LF/HF and SBP measured before hepatic graft reperfusion were significantly correlated with subsequent PRS occurrence, suggesting that sympathovagal imbalance and depressed SBP may be key factors predisposing to reperfusion-related severe hypotension in liver transplant recipients.

Intrarenal resistance index for the assessment of acute renal injury in a rat liver transplantation model

Background

Acute kidney injury (AKI) is a common complication after liver transplantation (LT) and associated with a high mortality. The renal resistive index (RI) is used to assess early renal function impairment in critical care patients. However, limited data are available concerning changes of renal RI and the development of AKI early after reperfusion. We approached to investigate the changes of renal RI and AKI after reperfusion in a rat liver transplantation model.

Methods

Rats were randomly divided into sham group or LT group. Ten rats in each group were used for the hemodynamic study and twenty for Doppler measurements during the procedure. Ten rats were sacrificed 30 min or 2 h after the reperfusion. We harvested kidneys, serum and urine for further analysis of the renal function.

Results

The intrarenal RI increased significantly in the anhepatic stage and decreased significantly after the reperfusion in the LT group compared with sham group (P < 0.05). AKI was seen after the reperfusion in the LT group. No correlation was noted between the RI and renal function parameters 30 min after reperfusion.

Conclusions

The intrarenal RI increased significantly during the anhepatic stage, and decreased significantly early after the reperfusion. Intrarenal RI was unable to assess renal function in a rat liver transplantation model.

Association between plasma cyclic guanosine monophosphate levels and hemodynamic instability during liver transplantation

The activation of cyclic guanosine monophosphate (cGMP) production in patients with end-stage liver disease (ESLD) has been associated with hemodynamic instability during orthotopic liver transplantation (OLT). The aim of this prospective, observational study was to investigate the involvement of cGMP in the mediation of profound hypotension during liver graft reperfusion. An additional objective was to determine whether preoperative cGMP levels are associated with intraoperative hemodynamic instability. Forty-four consecutive patients undergoing OLT were included in the study. Blood samples for cGMP analysis were obtained from (1) the radial artery before the surgical incision; (2) the radial artery, portal vein, and flush blood during the anhepatic phase; and (3) the radial artery 20 minutes after liver graft reperfusion. On the basis of a statistical analysis, the patients were divided into 2 groups: group 1 (preoperative cGMP level ≥ 0.05 μmol/L) and group 2 (preoperative cGMP level < 0.05 μmol/L). We demonstrated a significant correlation between the preoperative levels of cGMP and the amount of catecholamine required to maintain hemodynamic stability during reperfusion (r = 0.52, P < 0.001), the length of the hospital stay (r = 0.38, P = 0.01), and the length of the intensive care unit (ICU) stay (r = 0.44, P = 0.004). We also demonstrated a significantly higher intraoperative catecholamine requirement (P < 0.001) and a prolonged postoperative ICU stay (P = 0.02) in group 1 patients versus group 2 patients. In conclusion, this study demonstrates increased baseline cGMP production in patients with ESLD, which is significantly associated with severe hypotension during OLT. We suggest that preoperative levels of cGMP correlate with hemodynamic instability during liver graft reperfusion.

The PRAISE study: a prospective, multi-center, randomized, double blinded, placebo-controlled study for the evaluation of iloprost in the early postoperative period after liver transplantation (ISRCTN12622749)

Background

Liver graft dysfunction can deteriorate to complete organ failure and increases perioperative morbidity and mortality after liver transplantation. Therapeutic strategies reducing the rate of graft dysfunction are of current clinical relevance. One approach is the systemic application of prostaglandins, which were demonstrated to be beneficial in reducing ischemia-reperfusion injury. Preliminary data indicate a positive effect of prostacyclin analogue iloprost on allograft viability after liver transplantation. The objective of the study is to evaluate the impact of iloprost in a multi-center trial.

Methods/Design

A prospective, double-blinded, randomized, placebo-controlled multicenter study in a total of 365 liver transplant recipients was designed to assess the effect of intravenous iloprost after liver transplantation. Primary endpoint will be the primary graft dysfunction characterized as presentation of one or more of the following criteria: ALAT or ASAT level > 2000 IU/ml within the first 7 postoperative days, bilirubine ≥ 10 mg/dl on postoperative day 7; INR ≥ 1.6 on postoperative day 7 or initial non-function. Secondary endpoints are parameters of post-transplant morbidity, like rates of infections, biliary complications, need of clotting factors or renal replacement therapy and the graft and patient survival.

Discussion

A well-established treatment concept to avoid graft dysfunction after liver transplantation does not exist at the moment. If the data of this research project confirm prior findings, iloprost would improve the general outcome after liver transplantation.

Trial Registration

German Clinical Trials Register: DRKS00003514. Current Controlled Trials Register: ISRCTN12622749.

Epinephrine and phenylephrine pretreatments for preventing postreperfusion syndrome during adult liver transplantation

Acute hypotension after reperfusion of the liver graft occurs frequently during liver transplantation. A randomized, prospective trial was performed to test the effects of epinephrine and phenylephrine pretreatments for attenuating postreperfusion syndrome (PRS). Ninety-three adult liver recipients were randomly allocated to receive an intravenous bolus of 10 μg of epinephrine, 100 μg of phenylephrine, or normal saline (the control group) at the time of graft reperfusion. The occurrence of PRS, the use of vasoactive drugs, and the postoperative courses were compared. The epinephrine and phenylephrine groups showed PRS less frequently (39% and 48%) than the control group (77%, P = 0.006) as well as higher mean arterial pressures (MAPs) immediately after reperfusion (P < 0.05). An overshoot of MAP was observed in one-third of the pretreated patients with minimal heart rate changes. Only 2 patients in each pretreatment group showed an increase in MAP that was greater than 20% of the baseline value. The intraoperative epinephrine and dopamine requirements were significantly lower in both pretreatment groups. Perioperative laboratory data, postoperative stays, and in-hospital mortality rates were similar for the 3 groups. In conclusion, pretreatment with 10 μg of epinephrine or 100 μg of phenylephrine significantly reduces the occurrence of PRS and vasopressor requirements without immediate or delayed adverse effects in adult liver transplantation.

Temporary intraoperative porto-caval shunt: useless or beneficial in piggy back liver transplantation?

The role of intraoperative porto-caval shunts in orthotopic liver transplantation (OLT) is controversial. Aim of this study was to analyze the effects of an intraoperative, porto-caval catheter-shunt on graft function and survival following cava sparing OLT. Four hundred and forty-eight piggy back liver transplantations with or without a temporary spontaneous porto-caval shunt between 1997 and 2010 were analyzed (shunt n = 274 vs. no shunt n = 174). Lab MELD scores and donor risk indices (DRI) were calculated. Hepatic injury (ALT, AST), -function (bilirubin, prothrombin ratio), postreperfusion liver blood flow and graft survival were registered [mean follow-up: 50.5 (0-163.0) months]. The impact of a shunt on graft survival was determined using multivariate analysis. Usage of a porto-caval shunt was associated with reduced hepatic injury (ALT, AST), whereas graft function was not affected. The shunt group showed a significantly increased portal venous blood flow after reperfusion. Retransplantation rate was decreased (7.7% vs. 20.1%, P = 0.001) and long-term graft survival was significantly increased with a porto-caval shunt (hazard ratio 2.1, P < 0.001). This effect was even more pronounced for marginal organs. Usage of intraoperative porto-caval catheter-shunts is beneficial in cava sparing OLT and is associated with reduced ischemia-reperfusion injury and improved organ survival in particular for recipients of marginal organs.

Anaesthesia for Living Related Liver Transplantation

With the greater success of liver transplantation, livers from deceased donors are insufficient to meet the need for livers required for transplantation. In various parts of Asia, living related liver transplantation is the treatment for patients with end-stage liver disease. An overview of anaesthesia for both the donor and the recipient is described. Controversies involving epidural anaesthesia, blood loss prevention and blood conservation techniques in the donor are discussed. Various aspects in the anaesthetic management of the recipient are also looked at.