Survival rate changes with transfusion of blood products during liver transplantation

2023 Clinical Update in Liver Transplantation

Liver transplantation continues to provide life-saving treatment for patients with end-stage liver disease. Advances in the field of transplant anesthesia continue to support the care of more complex patients. The use of extracorporeal membrane oxygenation has been described in critical care settings and cardiac surgery but may be a valuable option for specific conditions for patients undergoing liver transplantation. Changes to the allocation process for liver grafts now focus on acuity circles to reduce regional disparities. As the number of life-saving transplant surgeries increases, so does the need for specialty knowledge in the anesthetic considerations of these procedures. The specialty of transplant anesthesia continues to grow and develop to meet the demands of complex patients and the increased number of transplants performed. Liver transplantation can be a resource-demanding procedure, and predicting the need for massive transfusion can aid in planning and preparing for significant blood loss.

Normothermic Machine Perfusion Reduces Transfusion Requirements Even After Static Cold Storage: A 1 y Retrospective Single-center Analysis

Background

Normothermic machine perfusion (NMP) of liver grafts has been shown to reduce intraoperative catecholamine consumption and the need for allogenic blood products after reperfusion compared with organs undergoing classical static cold storage (SCS). This study aimed to investigate the effects of an NMP phase after SCS (NMP after SCS) of liver grafts in terms of postreperfusion hemodynamics and transfusion requirements.

Methods

Eighteen recipients of NMP after SCS grafts were matched according to recipient age, donor age, and model for end-stage liver disease score in a 1:2 ratio with recipients of an SCS graft. Postreperfusion hemodynamics and the need for catecholamines, blood products, and clotting factors were compared.

Results

After reperfusion of the organ, patients in the NMP after SCS group showed significantly reduced transfusion requirements for packed red blood cells and platelet concentrates compared with patients of the SCS group (P < 0.001 and P = 0.018, respectively). In addition, patients in the NMP after SCS group received less fibrinogen concentrate (NMP after SCS group 0 [0-1.5] g versus SCS group 2 [0-4] g; P = 0.0163). No differences in postreperfusion hemodynamics could be detected between groups.

Conclusions

This retrospective analysis shows that NMP reduces postreperfusion requirements of red blood cells, platelet concentrates, and fibrinogen concentrate even if installed after a phase of organ SCS, because it may be practiced on most centers where NMP is available.

Anesthesia for Combined Heart-Liver Transplantation: A Narrative Review

In 1984, 21 years after the first liver transplantation, Thomas Starzl achieved a milestone by performing the world's first combined heart-liver transplantation. While still uncommon, the practice of combined heart-liver transplants is on the rise globally. In this review, the authors delve into the current literature on this procedure, highlighting the evolving landscape and key considerations for anesthesiologists. Over the years, there has been a remarkable increase in the number of combined heart-liver transplantations conducted worldwide. This surge is largely attributed to the growing population of adult survivors with single-ventricle physiology, palliated with a Fontan procedure, who later present with late Fontan failure and Fontan-associated liver disease. Research indicates that combined heart-liver transplantation is an effective treatment option, with reported outcomes comparable with isolated heart or liver transplants. Managing anesthesia during a combined heart-liver transplant procedure is challenging, especially in the context of underlying Fontan physiology. International experience in this field remains somewhat limited, with most techniques derived from expert opinions or experiences with single-organ heart and liver transplants. These procedures are highly complex and performed infrequently. As the number of combined heart-liver transplants continues to rise globally, there is a growing need for clear guidance on periprocedural surgical and anesthetic management. Anesthesiologists overseeing these patients must consider multiple factors, balancing various comorbidities with significant hemodynamic and metabolic shifts. An increase in (multicenter) studies focusing on specific interventions to enhance patient and organ outcomes is anticipated in the coming years.

Predictors of intraoperative massive transfusion in orthotopic liver transplantation

BACKGROUND

Although transfusion management has improved during the last decade, orthotopic liver transplantation (OLT) has been associated with considerable blood transfusion requirements which poses some challenges in securing blood bank inventories. Defining the predictors of massive blood transfusion before surgery will allow the blood bank to better manage patients' needs without delays. We evaluated the predictors of intraoperative massive transfusion in OLT.

STUDY DESIGN AND METHODS

Data were collected on patients who underwent OLT between 2007 and 2017. Repeat OLTs were excluded. Analyzed variables included recipients' demographic and pretransplant laboratory variables, donors' data, and intraoperative variables. Massive transfusion was defined as intraoperative transfusion of ≥10 units of packed red blood cells (RBCs). Statistical analysis was performed using SPSS version 17.0.

RESULTS

The study included 970 OLT patients. The median age of patients was 57 (range: 16-74) years; 609 (62.7%) were male. RBCs, thawed plasma, and platelets were transfused intraoperatively to 782 (80.6%) patients, 831 (85.7%) patients, and 422 (43.5%) patients, respectively. Massive transfusion was documented in 119 (12.3%) patients. In multivariate analysis, previous right abdominal surgery, the recipient's hemoglobin, Model for End Stage Liver Disease (MELD) score, cold ischemia time, warm ischemia time, and operation time were predictive of massive transfusion. There was a direct significant correlation between the number of RBC units transfused and plasma (Pearson correlation coefficient r = .794) and platelets (r = .65).

DISCUSSION

Previous abdominal surgery, the recipient's hemoglobin, MELD score, cold ischemia time, warm ischemia time, and operation time were predictive of intraoperative massive transfusion in OLT.

Benefit of living donor liver transplantation in graft survival for extremely high model for end-stage liver disease score ≥35

BACKGROUND AND AIMS

Living liver donation with high model for end-stage liver disease (MELD) score was discouraged despite organ shortage. This study aimed to compare graft survival between living donor liver transplantation (LDLT) and deceased donor liver transplantation (DDLT) recipients with extremely high-MELD (score of ≥35).

METHODS

Between 2008 and 2018, 359 patients who underwent liver transplantation with a MELD score ≥35 were enrolled. We compared graft survival between LDLT and DDLT after propensity score matching (PSM) and performed subgroup analysis according to donor type.

RESULTS

After PSM, there was no statistical difference in graft survival between the LDLT and DDLT groups (p = .466). Old age, acute on chronic liver failure, re-transplantation, preoperative intensive care unit stay and red blood cell (RBC) transfusion during the operation were risk factors for graft failure (p = .046, .005, .032, .015 and .001, respectively). Biliary complications were more common in the LDLT group (p = .021), while viral infection, postoperative uncontrolled ascites, and postoperative hemodialysis were more common in the DDLT group (p = .002, .018, and .027, respectively). In the LDLT group, acute chronic liver failure, intraoperative RBC transfusion, and early postoperative complications were risk factors for graft failure (p = .007, <.001, and .001, respectively).

CONCLUSION

Our study showed that LDLT is not inferior to DDLT in graft survival if appropriate risk evaluation is performed in cases of extremely high-MELD scores. This result will help overcome organ shortages in high-MELD liver transplantation.

Preoperative fibrinogen level and blood transfusions in liver transplantation: A systematic review

BACKGROUND

Orthotopic liver transplantation (OLT) is a major surgery often associated with significant bleeding. We conducted a systematic review to explore the association between preoperative fibrinogen level and intraoperative blood products transfusion, blood loss and clinical outcomes in patients undergoing OLT.

METHODS

We included observational studies conducted in patients undergoing an OLT mostly for end-stage liver disease that reported an association between the preoperative fibrinogen level and our outcomes of interest. Our primary outcome was the intraoperative red blood cell (RBC) transfusion requirements. Our secondary outcomes were intraoperative blood loss, intraoperative transfusion of any blood product, postoperative RBC transfusion, postoperative thrombotic or hemorrhagic complications, and mortality. We used a standardized search strategy. We reported our results mostly descriptively but conducted meta-analyses using random-effect models when judged feasible.

RESULTS

We selected 24 cohort studies reporting at least one of our outcomes. We found that a high preoperative fibrinogen level was associated with fewer intraoperative RBC and other blood products transfusions, and lower blood loss. We also found a lower overall survival in patients with a higher fibrinogen level (pooled hazard ratio [95% CI] of 1.50 [1.23 to 1.84]; 5 studies, n = 1012, I2 = 48%). Only one study formally explored a fibrinogen level threshold effect. Overall, reporting was heterogeneous, and risk of bias was variable mostly because of uncontrolled confounding.

CONCLUSION

A higher preoperative fibrinogen level was associated with fewer intraoperative RBC and other blood products transfusions, lower blood loss, and higher mortality. Further studies may help clarify observed associations and inform guidelines.

Risk factors of massive blood transfusion in liver transplantation: consequences and a new index for prediction including the donor

BACKGROUND

Massive blood transfusion (MBT) is a common occurrence in liver transplant (LT) patients. Recipient-related risk factors include cirrhosis, history of multiple surgeries and suboptimal donors. Despite advances in surgical techniques, anesthetic management and graft preservation have decreased the need for transfusions, this complication has not been completely eliminated.

METHODS

One thousand four hundred and sixty-nine LT were performed at our institution between May 2003 and December 2020, and data was available regarding transfusion for 1198 of them. We divided the patients into two groups, with regards to transfusion of 6 or more units of packed red blood cells in the first 24 h posttransplant, and we analyzed the differences between the groups.

RESULTS

Out of the 1198 patients, 607 (50.7%) met criteria for MBT. Survival was statistically lower at 1, 3, and 5 years when comparing the groups that had MBT to those that did not (92.6%, 85.2% and 79.7%, respectively, in the non MBT group, vs. 78.1%, 71.6% y 66.8%, respectively, in the MBT group). MBT was associated with a 1.5 mortality risk as opposed to non-MBT patients. Logistical regression analysis of our variables yielded the following results for a new model, including serum creatinine (OR 1.97), sodium (OR 1.73), hemoglobin (OR 1.99), platelets (OR 1.37), INR (OR 1.4), uDCD (OR 2.13) and split liver donation.

CONCLUSION

Massive blood transfusion impacts patient survival in a statistically significant way. The most significant risk factors are preoperative hemoglobin, INR and serum creatinine.

Perioperative clinical practice in liver transplantation: a cross-sectional survey

PURPOSE

The objective of this study was to describe some components of the perioperative practice in liver transplantation as reported by clinicians.

METHODS

We conducted a cross-sectional clinical practice survey using an online instrument containing questions on selected themes related to the perioperative care of liver transplant recipients. We sent email invitations to Canadian anesthesiologists, Canadian surgeons, and French anesthesiologists specialized in liver transplantation. We used five-point Likert-type scales (from "never" to "always") and numerical or categorical answers. Results are presented as medians or proportions.

RESULTS

We obtained answers from 130 participants (estimated response rate of 71% in Canada and 26% in France). Respondents reported rarely using transesophageal echocardiography routinely but often using it for hemodynamic instability, often using an intraoperative goal-directed hemodynamic management strategy, and never using a phlebotomy (medians from ordinal scales). Fifty-nine percent of respondents reported using a restrictive fluid management strategy to manage hemodynamic instability during the dissection phase. Forty-two percent and 15% of respondents reported using viscoelastic tests to guide intraoperative and postoperative transfusions, respectively. Fifty-four percent of respondents reported not pre-emptively treating preoperative coagulations disturbances, and 91% reported treating them intraoperatively only when bleeding was significant. Most respondents (48-64%) did not have an opinion on the maximal graft ischemic times. Forty-seven percent of respondents reported that a piggyback technique was the preferred vena cava anastomosis approach.

CONCLUSION

Different interventions were reported to be used regarding most components of perioperative care in liver transplantation. Our results suggest that significant equipoise exists on the optimal perioperative management of this population.

The use of prothrombin complex concentrate in chronic liver disease: A review of the literature

Patients with chronic liver disease (CLD) and cirrhosis present a rebalanced hemostatic system in the three phases of haemostasis. This balance is however unstable and can easily tip towards bleeding or thrombosis. Management of both spontaneous bleeding and bleeding during invasive procedures remains a challenge in this patient population. Transfusion of blood products can result in circulatory overload and thereby worsen portal hypertension. As an alternative to fresh frozen plasma (FFP), prothrombin complex concentrates (PCC) may have merit in patients with liver disease because of their low volume. The impact of PCC in in-vitro spiking experiments of cirrhotic plasma is promising, but also warrants cautious use in light of thromboembolic risk. The majority of existing studies carried-out in CLD patients are retrospective or do not have an adequate control arm. A prospective study (the PROTON trial) was set up in 2013 to investigate the utility of PCC in patients undergoing liver transplantation. However, the study has never recruited the planned number of patients. Robust data on PCC safety in CLD is also required. The limited existing evidence does not seem to indicate an excessive thromboembolic risk. Currently, the utilisation of PCC in CLD cannot be routinely recommended but can provide an option for carefully selected cases in which other measures were not sufficient to control bleeding and after delicately weighing risks and benefits.

Alloimmunization Against RBC Antigens Is Not Associated With Decreased Survival in Liver Transplant Recipients

BACKGROUND

Improvement of liver transplantation (LT) outcomes requires better understanding of factors affecting survival. The presence of RBC alloantibodies (RBCAs) on survival in LT recipients was evaluated.

METHODS

This study was a single-center, retrospective cohort study reviewing transfusion records and all-cause mortality between 2002 and 2021.

RESULTS

Between 2002 and 2021, 2079 LTs were completed, 1,396 of which met inclusion criteria (1,305 RBCA negative; 91 RBCA positive [6.5%]). The cohorts were similar in age (mean [range], 55.8 [17-79] years vs 56.8 [25-73] years; P = .41, respectively) or sex (RBCA negative, 859 [65%] men and 446 [35%] women vs RBCA positive, 51 [56%] men and 40 [44%] women; P = .0684). Of 132 RBCAs detected, 10 were most common were to E (27.27%), Jka (15.91%), K (9.09%), C (8.33%), M (6.06%), D (5.3%), Fya (4.55%), e (2.27%), c (2.27%), and Jkb (2.27%). Twenty-seven patients (29.7%) had more than 1 RBCA; the most common combinations were C with Jka (7.4%) and E with Dia (7.4%). All-cause mortality was increased in men (men, 14.45 years vs women, 17.27 years; P = .0266) and patients 65 years of age and older (≥65 years of age, 10.21 years vs <64 years of age, 17.22 years; P < .0001). The presence of RBCA (≥1) did not affect all-cause mortality (RBCA negative, 14.17 years vs RBCA positive, 15.29 years; P = .4367). The top 5 causes of death were infection (11.9%), primary malignancy (solid) (10.8%), recurrent malignancy (10.5%), cardiovascular arrest (7.1%), and pulmonary insufficiency/respiratory failure (5.7%).

CONCLUSIONS

Survival in RBCA-positive LT recipients is no different from that in RBCA-negative LT recipients.

Preoperative Fibrinogen Level and Bleeding in Liver Transplantation for End-stage Liver Disease: A Cohort Study

BACKGROUND

Liver transplantation is a high-risk surgery associated with important perioperative bleeding and transfusion needs. Uncertainties remain on the association between preoperative fibrinogen level and bleeding in this population.

METHODS

We conducted a cohort study that included all consecutive adult patients undergoing a liver transplantation for end-stage liver disease in 1 center. We analyzed the association between the preoperative fibrinogen level and bleeding-related outcomes. Our primary outcome was intraoperative blood loss, and our secondary outcomes were estimated perioperative blood loss, intraoperative and perioperative red blood cell transfusions, reinterventions for bleeding and 1-y graft and patient survival. We estimated linear regression models and marginal risk models adjusted for all important potential confounders. We used restricted cubic splines to explore potential nonlinear associations and reported dose-response curves.

RESULTS

We included 613 patients. We observed that a lower fibrinogen level was associated with a higher intraoperative blood loss, a higher estimated perioperative blood loss and a higher risk of intraoperative and perioperative red blood cell transfusions (nonlinear effects). Based on an exploratory analysis of the dose-response curves, these effects were observed below a threshold value of 3 g/L for these outcomes. We did not observe any association between preoperative fibrinogen level and reinterventions, 1-y graft survival or 1-y patient survival.

CONCLUSIONS

This study suggests that a lower fibrinogen level is associated with bleeding in liver transplantation. The present results may help improving the selection of patients for further studies on preoperative fibrinogen administration in liver transplant recipients with end-stage liver disease.

Contribution of Salvaged Blood Red Blood Cell Transfusion During Living Donor Liver Transplantation

BACKGROUND

Transfusion of allogeneic blood products can have adverse effects and profoundly influence postoperative liver transplantation outcomes, including graft survival. To minimize allogeneic red blood cell (RBC) transfusion, salvaged blood can be used during liver transplantation. The aim of this study was to determine the contribution of salvaged blood to allogeneic RBC transfusion in living donor liver transplantation (LDLT) recipients.

METHODS

Data of 311 adult-to-adult LDLT recipients between January 2015 and April 2019 were analyzed. The primary outcome was a change in requirement for allogeneic RBCs due to the use of salvaged blood. Additionally, predictors of intraoperative allogeneic RBC transfusion were investigated.

RESULTS

One hundred fifty-three (49.2%) recipients required allogeneic RBC transfusion. If recipients did not receive salvaged blood, 253 (81.4%) recipients would have needed allogeneic RBC transfusion. The total volume of salvaged blood transfused into recipients during surgery was 269,165 mL, which corresponded to 993 units of allogeneic RBCs and accounted for 76.1% of total RBC transfusion volume. Multivariate analysis showed that male recipients, model for end-stage liver disease score, preoperative hemoglobin level, and volume of salvaged blood used during surgery were independent predictors of the need for intraoperative allogenic RBC transfusion.

CONCLUSIONS

Intraoperative use of salvaged blood significantly reduced allogeneic RBC transfusion in LDLT recipients. It can help transplant teams manage transfusion of allogeneic RBCs during liver transplantation.

Validation of 5 models predicting transfusion, bleeding, and mortality in liver transplantation: an observational cohort study

BACKGROUND

Historically, orthotopic liver transplantation (OLT) has been associated with massive blood loss, blood transfusion and morbidity. In order to predict such outcomes five nomograms have been published relating to transfusions and morbidity associated with OLTs. These nomograms, developed on the basis of three cohorts of patients consisting of 406, 750, and 800 having undergone OLTs, aimed to predict a transfusion of ≥1 red blood cell unit (RBC), a transfusion of >2 RBC units, a blood loss of >900 ml, as well as one-month and one-year survival rates. The aim of this study was to validate these five nomograms in a contemporary, independent cohort of patients.

METHODS

Five nomograms were previously developed based on 406, 750, and 800 OLTs. In this study we performed a temporal validation of these nomograms on contemporary patients that consisted of three cohorts of 800, 250, and 200 OLTs. Logistic regression coefficients from the historic development cohorts were applied to the three contemporary temporal validation cohorts.

RESULTS

The most accurate nomogram was able to predict transfusion of ≥1 RBC units with an area under the curve (AUC) was 0.91. The second-best nomogram was able to predict bleeding of >900 ml with an AUC of 0.70. T he AUC of the third nomogram (transfusion of >2 RBC units) was 0.70. However, is temporal validation was suboptimal, due to a low prevalence of OLTs transfused with >2 RBC units. The last 2 nomograms exhibited clearly suboptimal AUC values of 0.54 and 0.61.

CONCLUSION

Two of the five nomograms predict blood transfusion and blood loss with excellent accuracy. Transfusion of ≥1 RBC unit and blood loss of >900 ml can be predicted on the basis of these nomograms. However, these nomograms are not accurate to predict one-month and one-year survival rates. These results should be further cross-validated, ideally prospectively, in additional external independent cohorts.

Viscoelastic Monitoring in Liver Transplantation

Cirrhosis and liver transplantation (LT) surgery are associated with substantial alterations to the patient's coagulation status. Accurate monitoring of these changes during LT can help manage bleeding proactively and potentially reduce transfusion requirements. Unlike conventional coagulation tests (CCTs), viscoelastic monitoring (VEM) can provide an accurate, real-time, point-of-care assessment of coagulation status during LT and hence has become an invaluable tool for anesthetists and intensive care physicians. However, it remains an enigmatic subject for transplantation surgeons who are more conversant with CCTs. This review discusses the principles of VEM, provides a primer to understanding and interpreting its output, and explains how it can be used to make real-world clinical decisions during LT.

Intraoperative phlebotomies and bleeding in liver transplantation: a historical cohort study and causal analysis

BACKGROUND

Liver transplantation is associated with major bleeding and red blood cell (RBC) transfusions. No well-designed causal analysis on interventions used to reduce transfusions, such as an intraoperative phlebotomy, has been conducted in this population.

METHODS

We conducted a historical cohort study among liver transplantations performed from July 2008 to January 2021 in a Canadian centre. The exposure was intraoperative phlebotomy. The outcomes were blood loss, perioperative RBC transfusions (intraoperative and up to 48 hr after surgery), intraoperative RBC transfusions, and one-year survival. We estimated marginal multiplicative factors (MFs), risk differences (RDs), and hazard ratios by inverse probability of treatment weighting both among treated patients and the whole population. Estimates are reported with 95% confidence intervals (CIs).

RESULTS

We included 679 patients undergoing liver transplantations of which 365 (54%) received an intraoperative phlebotomy. A phlebotomy did not reduce bleeding, transfusion risks, or mortality when estimated among the treated but reduced bleeding and transfusion risks when estimated among the whole population (MF, 0.85; 95% CI, 0.72 to 0.99; perioperative RD, -15.2%; 95% CI, -26.1 to -0.8; intraoperative RD, -14.7%; 95% CI, -23.2 to -2.8). In a subgroup analysis on 584 patients with end-stage liver disease, slightly larger effects were observed on both transfusion risks when estimated among the whole population while beneficial effects were observed on the intraoperative transfusion risk when estimated among the treated population.

CONCLUSION

The use of intraoperative phlebotomy was not consistently associated with better outcomes in all targets of inference but may improve outcomes among the whole population.

STUDY REGISTRATION

www.

CLINICALTRIALS

gov (NCT04826666); registered 1 April 2021.

The effect of a viscoelastic-guided bleeding algorithm implementation on blood products use in adult liver transplant patients. A propensity score-matched before-after study

BACKGROUND

Perioperative blood products transfusion is correlated with increased morbidity and mortality in liver transplantation (LTx). The objectives of our study are to assess the effect of a standardized viscoelastic test (VET)-guided bleeding management algorithm implementation on intraoperative bleeding, allogenic blood products and factor concentrates requirements and on early postoperative complications in LTx.

METHODS

Retrospective before-after study comparing two matched cohorts of patients undergoing LTx before (control cohort) and after (intervention cohort) the implementation of a VET-based bleeding algorithm in a single center academic hospital.

RESULTS

After propensity score matching, we included 94 patients in each cohort. Patients in intervention cohort received significantly less blood products, fresh frozen plasma (FFP), and cryoprecipitate (p < 0.001 for each), while the amount of fibrinogen concentrate used was significantly higher (p < 0.001). Postoperatively, intervention cohort patients had significantly lower postoperative hemoglobin and fibrinogen levels and longer prothrombin time compared to control cohort. There were no significant differences in red blood cells transfusions, intraoperative bleeding, early postoperative complications, and short term survival.

CONCLUSIONS

The implementation of a VET-guided bleeding algorithm decreases allogenic blood products requirements, mainly FFP use and allows a more restrictive management of coagulopathy in patients with chronic liver disease undergoing LTx.

Validation of McCluskey Index for Massive Blood Transfusion Prediction in Liver Transplantation

BACKGROUND

The McCluskey index has been used as a tool to predict massive bleeding (>6 red blood cells units) during orthotropic liver transplantation. The objective of this study is to verify its efficacy at our institution.

MATERIALS AND METHODS

Between May 1998 and December 2017, we performed 1216 orthotropic liver transplantations, of which 1016 had sufficient data registered with respect to hemoderivative transfusion. We divided these patients into groups based on the original study of McCluskey. This study was approved by the ethical committee of our Institution and was performed in accordance with the Declaration of Helsinki.

RESULTS

The mean Model for End-Stage Liver Disease score in the 4 groups was 7.5 (range, 7-8) for low risk; 13 (range, 3-32) for medium risk, 17 (range, 8-41) for high risk, and 25 (range, 11-36) for very high risk (P < .001). No significant differences were observed regarding body mass index or hospital stay. No differences have been found in the number of suboptimal donors among the groups. With respect to hemoderivative transfusions, we observed the following for red blood cells: 7 (range, 6-8) units for low risk; 5.5 (range, 0-74) for medium risk; 7 (range, 0-73) for high risk, and 12 (range, 5-30) for very high risk (P < .001) and transfusion of plasma: 12 (range, 10-15) units for low risk; 11 (range, 0-89) for medium risk; 14 (range, 0-76) for high risk, and 13 (range, 3-30) for very high risk (P = .001).

CONCLUSIONS

The McCluskey index is a good indicator of the risk of hemorrhage and hence the necessity of transfusion.

Hemoderivative Transfusion in Liver Transplantation: Comparison Between Recipients of Grafts From Brain Death Donors and Recipients of Uncontrolled Donors After Circulatory Death

INTRODUCTION

Intraoperative bleeding during liver transplantation has been correlated with a higher risk of morbidity and mortality and decrease in patient and graft survival.

MATERIALS AND METHODS

Between January 2006 and December 2016 we performed 783 orthotopic liver transplants. After applying exclusion criteria, we found liver grafts from donors after circulatory death (DCD, group A) were used in 69 patients and liver grafts from donors after brain death (group B) were used in 265 patients.

RESULTS

No difference was found in terms of sex, body mass index, Model for End-Stage Liver Disease score, indication for transplantation, intensive care unit stay, and Child-Pugh score. The mean transfusion of hemoderivates was as follows: red blood cell 9 (0-28) units in group A vs 6 (0-20) units in group B (P = .004) and fresh frozen plasma 10 (0-29) units in group A vs 9.5 (0-23) in group B (P = .000). The only 2 factors related to massive blood transfusion (>6 units of red blood cell) were uncontrolled DCD condition (odds ratio = 2.38; 95% confidence interval, 1.32-4.31; P = .004), and higher Model for End-Stage Liver Disease score (odds ratio = 2.63; 95% confidence interval, 1.53-4.55; P = .001). Survival at 1, 3, and 5 years was 81.3%, 70.2%, and 68.9% in group A vs 89%, 83.7%, and 78% in group B (P = .070).

CONCLUSION

The use of liver grafts from DCDs is associated with increased necessity of transfusion of hemoderivates in comparison with the use of liver grafts from donors after brain death.

Perioperative blood transfusion decreases long-term survival in pediatric living donor liver transplantation

BACKGROUND

The impact of perioperative blood transfusion on short- and long-term outcomes in pediatric living donor liver transplantation (PLDLT) must still be ascertained, mainly among young children. Clinical and surgical postoperative complications related to perioperative blood transfusion are well described up to three months after adult liver transplantation.

AIM

To determine whether transfusion is associated with early and late postoperative complications and mortality in small patients undergoing PLDLT.

METHODS

We evaluated the effects of perioperative transfusion on postoperative complications in recipients up to 20 kg of body weight, submitted to PLDLT. A total of 240 patients were retrospectively allocated into two groups according to postoperative complications: Minor complications (n = 109) and major complications (n = 131). Multiple logistic regression analysis identified the volume of perioperative packed red blood cells (RBC) transfusion as the only independent risk factor for major postoperative complications. The receiver operating characteristic curve was drawn to identify the optimal volume of the perioperative RBC transfusion related to the presence of major postoperative complications, defining a cutoff point of 27.5 mL/kg. Subsequently, patients were reallocated to a low-volume transfusion group (LTr; n = 103, RBC ≤ 27.5 mL/kg) and a high-volume transfusion group (HTr; n = 137, RBC > 27.5 mL/kg) so that the outcome could be analyzed.

RESULTS

High-volume transfusion was associated with an increased number of major complications and mortality during hospitalization up to a 10-year follow-up period. During a short-term period, the HTr showed an increase in major infectious, cardiovascular, respiratory, and bleeding complications, with a decrease in rejection complications compared to the LTr. Over a long-term period, the HTr showed an increase in major infectious, cardiovascular, respiratory, and minor neoplastic complications, with a decrease in rejection complications. Additionally, Cox hazard regression found that high-volume RBC transfusion increased the mortality risk by 3.031-fold compared to low-volume transfusion. The Kaplan-Meier survival curves of the studied groups were compared using log-rank tests and the analysis showed significantly decreased graft survival, but with no impact in patient survival related to major complications. On the other hand, there was a significant decrease in both graft and patient survival, with high-volume RBC transfusion.

CONCLUSION

Transfusion of RBC volume higher than 27.5 mL/kg during the perioperative period is associated with a significant increase in short- and long-term postoperative morbidity and mortality after PLDLT.

Machine Learning for the Prediction of Red Blood Cell Transfusion in Patients During or After Liver Transplantation Surgery

Aim: This study aimed to use machine learning algorithms to identify critical preoperative variables and predict the red blood cell (RBC) transfusion during or after liver transplantation surgery. Study Design and Methods: A total of 1,193 patients undergoing liver transplantation in three large tertiary hospitals in China were examined. Twenty-four preoperative variables were collected, including essential population characteristics, diagnosis, symptoms, and laboratory parameters. The cohort was randomly split into a train set (70%) and a validation set (30%). The Recursive Feature Elimination and eXtreme Gradient Boosting algorithms (XGBOOST) were used to select variables and build machine learning prediction models, respectively. Besides, seven other machine learning models and logistic regression were developed. The area under the receiver operating characteristic (AUROC) was used to compare the prediction performance of different models. The SHapley Additive exPlanations package was applied to interpret the XGBOOST model. Data from 31 patients at one of the hospitals were prospectively collected for model validation. Results: In this study, 72.1% of patients in the training set and 73.2% in the validation set underwent RBC transfusion during or after the surgery. Nine vital preoperative variables were finally selected, including the presence of portal hypertension, age, hemoglobin, diagnosis, direct bilirubin, activated partial thromboplastin time, globulin, aspartate aminotransferase, and alanine aminotransferase. The XGBOOST model presented significantly better predictive performance (AUROC: 0.813) than other models and also performed well in the prospective dataset (accuracy: 76.9%). Discussion: A model for predicting RBC transfusion during or after liver transplantation was successfully developed using a machine learning algorithm based on nine preoperative variables, which could guide high-risk patients to take appropriate preventive measures.

Analysis of the hemostatic therapy in liver transplantation guided by rotational thromboelastometry or conventional laboratory tests

BACKGROUND

Coagulopathy is quite common in chronic liver disease patients undergoing orthotopic liver transplantation (OLT). Diagnosis of intraoperative bleeding disorders is based on conventional laboratory tests (CLTs), and thus, the patients are frequently exposed to unnecessary transfusions of blood products. The present study aimed to analyze the intraoperative administration of blood products in patients undergoing OLT, using rotational thromboelastometry (ROTEM) or CLTs.

PATIENTS AND METHODS

A cohort comprising 153 patients undergoing OLT, of whom 82 were evaluated with ROTEM and 71 by CLTs. Both groups were analyzed intraoperatively: the transfusion of blood products.

RESULTS

The incidence of patients transfused with cryoprecipitate (CRYO) and/or fibrinogen concentrate (54.9 vs. 19.7%; P < 0.001) and prothrombin complex concentrate (PCC) (32.9 vs. 9.9%; P = 0.008) increased significantly in the ROTEM group than in CLT group, respectively. The amount of transfused patient with CRYO (7.6 vs. 1.2; P < 0.001), fibrinogen concentrate (0.8 vs. 0.2; P = 0.004) and PCC (1.4 vs. 0.2; P = 0.002) increased significantly in the ROTEM group than in the CLT group, respectively. In the analysis of fresh-frozen plasma (FFP), the incidence of transfused patients was significantly higher in the CLT group than in the ROTEM group (46.5 vs. 30.5%; P = 0.047, respectively), with a moderate correlation with red blood cells transfusion (r = 0.67, P < 0.001). The incidence of patients receiving antifibrinolytics was significantly higher in the CLT group than in the ROTEM group (85.9 vs. 47.6%; P < 0.001, respectively).

CONCLUSION

Transfusion protocol-based thromboelastometry was able to guide administration of hemostatic factors and reduced administration of FFP and antifibrinolytics.

Importance of Intraoperative Transfusions of Packed Red Blood Cells and Fresh Frozen Plasma in Liver Transplantation for Hepatocellular Cancer

BACKGROUND The impact of packed red blood cells (PRBCs) and fresh frozen plasma (FFP) transfusions in patients with hepatocellular cancer (HCC) undergoing liver transplantation has rarely been evaluated. The aim of the current study was to assess the impact of intraoperative transfusions on posttransplant outcomes. MATERIAL AND METHODS This retrospective cohort study was based on 229 HCC transplant recipients. The primary outcome measure was 5-year recurrence-free survival. Secondary outcome measures comprised overall and long-term survival at 5 years and 90-day mortality. Cox proportional hazard models and logistic regression were used to assess risk factors. RESULTS After adjustment for potential confounders, no association was found with respect to tumor recurrence for PRBCs (P=0.368) or FFP (P=0.081) transfusions. Similarly, PRBC transfusion (P=0.623) and FFP transfusion (P=0.460) had no impact on survival between 90 days and 5 years. PRBC transfusion increased the risk of 90-day mortality (P=0.005), while FFP transfusion was associated with a lower risk (P=0.036). CONCLUSIONS Intraoperative transfusions of blood products does not impair recurrence-free and long-term survival of patients with HCC undergoing liver transplantation. Intraoperative PRBC transfusion increases the risk of early mortality, whereas adequate supplementation of FFP plays a protective role.

Association between intraoperative rotational thromboelastometry or conventional coagulation tests and bleeding in liver transplantation: an observational exploratory study

INTRODUCTION

Liver transplantation is associated with major blood loss and transfusions. Our objective was to evaluate the association between coagulation results (rotational thromboelastometry (ROTEM) and conventional coagulation tests) and intraoperative bleeding or perioperative red blood cell (RBC) transfusions in liver transplantation.

METHODS

We measured ROTEM values and conventional coagulation tests at the beginning of surgery, after graft reperfusion and at the end of surgery. We did bivariate correlation and multivariable regression analyses to explore the association between test results and either intraoperative bleeding or perioperative RBC transfusions.

RESULTS

We enrolled 75 consecutive patients. Median [Q1-Q3] intraoperative blood loss was 1400 mL [675-2300] and 59% of patients did not receive any RBC transfusion either intraoperatively or postoperatively. In multivariable analyses, FIBTEM maximal clot firmness (MCF) measured at the beginning of surgery was associated with lower intraoperative blood loss (ß = -106 mL for each mm; 95% CI, -203 to -9 mL). Both a higher haemoglobin concentration (multiplicative factor = 0.89 for each g/L; 95% CI, 0.84 to 0.95) and FIBTEM MCF measured at the end of surgery (multiplicative factor = 0.68 for each mm; 95% CI, 0.48 to 0.95) were associated with fewer postoperative RBC transfusions.

CONCLUSION

FIBTEM MCF was strongly associated with intraoperative blood loss and postoperative transfusions while other coagulation results were not. This study might inform future clinical trials on ROTEM-based interventions in liver transplantation.

STUDY REGISTRATION

Clinical Trials.gov: NCT02356068.

Blood Markers of Portal Hypertension Are Associated with Blood Loss and Transfusion Requirements during Orthotopic Liver Transplantation

There is increasing evidence that portal hypertension plays a major role in bleeding risk during orthotopic liver transplantation (OLT). We investigated the association between preoperative blood levels of von Willebrand factor (VWF) and soluble CD163 (sCD163), which are established markers of portal hypertension, and blood loss and transfusion requirements during OLT. We measured levels of VWF and sCD163 in preoperative serum samples of 168 adult patients undergoing a primary OLT between 1998 and 2012. Preoperative levels of VWF and sCD163 correlated with the model of end-stage liver disease (MELD) score (r = 0.414, p < 0.001 and r = 0.382, p < 0.001, respectively). Patients with high VWF or sCD163 levels (VWF and sCD163 levels above the median) had a substantially increased risk of needing red blood cell transfusion compared with patients with low VWF or sCD163 levels (VWF and sCD163 levels below the median) (odds ratio 3.5 [95% confidence interval, CI 1.7-7.0] and 2.3 [95% CI 1.1-4.5], respectively). Blood loss was highest in patients with both high VWF or sCD163 levels and a high preoperative international normalized ratio. Elevated blood levels of markers of portal hypertension are associated with increased blood loss and transfusion requirements during OLT and support the notion that portal hypertension is an important contributor to perioperative blood loss.

Management of Hepatic Coagulopathy in Bleeding and Nonbleeding Patients: An Evidence-Based Review

Patients with varying degrees of hepatic dysfunction often present with presumed bleeding diathesis based on interpretation of routine measures of coagulation (prothrombin time [PT], international normalized ratio [INR], and activated partial thromboplastin time). However, standard markers of coagulation do not reflect the actual bleeding risk in this population and may lead to inappropriate administration of hemostatic agents and blood products. The concept of "rebalanced hemostasis" explains both the risk of bleeding and clotting seen in patients with liver dysfunction. The role of pharmacologic agents and blood products for prevention of bleeding during high-risk procedures and treatment of clinically significant bleeding remains unclear. Viscoelastic measurements of the clotting cascade provide information about platelets, fibrinogen/fibrin polymerization, coagulation factors, and fibrinolysis that might better represent hemostasis in vivo and may better inform management strategies. Due to the paucity of available data, firm recommendations for the use of blood products and pharmacologic agents in patients with hepatic coagulopathies are lacking, and thus, these products should not be routinely administered. Traditional laboratory tests such as PT/INR should not be the sole determinant of potential interventions. Rather, clinicians should assess factors such as the severity of bleed or bleeding risk of the procedure, the patient's risk of thromboembolism, and the strength of available evidence for specific agents and blood products to guide decision-making.

Liver Transplantation

The field of liver transplantation has changed since the MELD scoring system became the most widely used donor allocation tool. Due to the MELD-based allocation system, sicker patients with higher MELD scores are being transplanted. Persistent organ donor shortages remain a challenging issue, and as a result, the wait-list mortality is a persistent problem for most of the regions. This chapter focuses on deceased donor and live donor liver transplantation in patients with complications of portal hypertension. Special attention will also be placed on donor-recipient matching, perioperative management of transplant patients, and the impact of hepatic hemodynamics on transplantation.

Successful Treatment of Life-Threatening Small Bowel Bleeding With Thalidomide After Living Donor Kidney Transplantation: A Case Report

Gastrointestinal bleeding after kidney transplantation is a complication that can occur from immunosuppressant use. We present a case of refractory small bowel bleeding treated successfully with thalidomide after multiple failed attempts of conventional treatment. A 65-year-old male patient with diabetic nephropathy underwent living donor kidney transplantation. The surgery was uneventful, however, he developed immunosuppressant-induced melena with unstable vital signs 11 days later. There were a total of 4 bleeding episodes until the 90th postoperative day, and he received a total of 290 units of red blood cell transfusion during this period. Endoscopic clipping, transarterial embolization, and 2 surgical interventions failed to stop the bleeding. A trial of thalidomide 100 mg per day finally stopped the bleeding and the patient was discharged on the 110th postoperative day with a functioning renal graft. This case shows that thalidomide can be a safe option to treat immunosuppressant-induced refractory gastrointestinal bleeding in the setting of kidney transplantation. Additionally, this is the first case that reports the survival of a renal graft after more than 3000 mL of transfusion.

Point-of-care haemostasis monitoring during liver transplantation is cost effective

Background Optimal haemostasis management in orthotropic liver transplant (OLT) could reduce blood loss and transfusion volume, improve patient outcomes and reduce cost. Methods We performed a study including 336 OLTs to evaluate the clinical and cost effectiveness of a new point-of-care (POC)-based haemostatic management approach in OLT patients. Results In terms of health benefit we found that the new approach showed a significant reduction in transfusion requirements (red blood cell transfusion units were reduced from 5.3±4.6 to 2.8±2.9 [p<0.001], free frozen plasma from 3.1±3.3 to 0.4±1.0 [p<0.001] and platelets from 2.9±3.9 to 0.4±0.9 [p<0.001], transfusion avoidance, 9.7% vs. 29.1% [p<0.001] and massive transfusion, 14.5% vs. 3.8% [p=0.001]); we also found a significant improvement in patient outcomes, such, reoperation for bleeding or acute-kidney-failure (8.3% vs. 2.4%, p=0.015; 33.6% vs. 5.4%, p<0.001), with a significant reduction in the length of the hospital total stay (40.6±13.8 days vs. 38.2±14.4 days, p=0.001). The lowest cost incurred was observed with the new approach (€73,038.80 vs. €158,912.90) with significant patient saving associated to transfusion avoidance (€1278.36), ICU-stay (€3037.26), total-stay (€3800.76) and reoperation for bleeding (€80,899.64). Conclusions POC haemostatic monitoring during OLT is cost effective.

Risk Factors for Transfusion after Orthotopic Liver Transplantation

Background

Transfusion of blood products during orthotopic liver transplantation (OLT) is associated with increased morbidity and mortality. Although risk factors associated with intraoperative transfusion requirements have been widely assessed, published data on the prediction of postoperative transfusion requirements are sparse.

Objectives

The aim of this study was to evaluate risk factors for postoperative allogeneic transfusion requirements in OLT.

Methods

Clinical characteristics and intraoperative parameters of 645 consecutive adult patients undergoing OLT were retrospectively reviewed. Multivariate logistic regression was used to determine the main determinants for postoperative transfusion requirements.

Results

Determinants of postoperative transfusion requirements of any blood product in the postoperative period were the number of blood products transfused in the intraoperative period (OR 1.17, 95% CI 1.08-1.28), warm ischemia time (OR 1.05, 95% CI 1.02-1.08), MELD score (OR 1.05, 95% CI 1.01-1.08) and hepatocellular carcinoma (OR 0.45, 95% CI 0.28-0.72). A dose-dependent effect between the number of units transfused in the intraoperative period and transfusion requirements in the postoperative period was also observed. The relative risk of postoperative allogeneic transfusion of any blood component was 5.9 (95% CI 3.4-10.4) for patients who received 1-2 units in the intraoperative period, 7.3 (95% CI 3.6-14.7) for those who received 3-5 units in the intraoperative period, and 11.1 (95% CI 4.7-26.4) for those who received 6 or more units, when compared to no intraoperative blood transfusion.

Conclusion

Our study demonstrated an association between intraoperative transfusion and warm ischemia time with postoperative transfusion requirements. The identification of risk factors for transfusion in the postoperative period may improve management of these patients by increasing awareness to bleeding complications in this high-risk population and by expanding hemostasis monitoring to the postoperative period.

Impact of MELD Score-Based Organ Allocation on Mortality, Bleeding, and Transfusion in Liver Transplantation: A Before-and-After Observational Cohort Study

OBJECTIVE

The goal of this study was to evaluate the effect of the Model for End-Stage Liver Disease (MELD)-based allocation system on mortality, bleeding, and transfusion requirement in orthotopic liver transplantation (OLT).

DESIGN

OLTs were studied for this observational study (before-and-after observational cohort study).

SETTING

One community hospital.

PARTICIPANTS

The study comprised 686 patients who underwent 750 consecutive OLTs.

INTERVENTION

None.

MEASUREMENTS AND MAIN RESULTS

Patients who underwent OLT in the MELD era had an adjusted lower 1-year mortality (adjusted odds ratio 0.45 [0.24-0.83]) compared with patients who underwent OLT the pre-MELD era. No significant difference in 1-month mortality was observed. Other variables with a significant effect on 1-year mortality in multivariate analysis were preoperative international normalized ratio, intraoperative use of a phlebotomy, total intraoperative volume of crystalloid infused, and retransplantation. Blood loss was greater in the MELD era (median difference 200 mL; p < 0.001), as were red blood cell, fresh frozen plasma, and cryoprecipitate transfusions. More patients in the MELD era received at least 1 transfusion (27% v 20%; p = 0.024).

CONCLUSION

The MELD allocation system did not affect 1-month mortality, but a decrease in 1-year mortality was demonstrated. Blood loss and transfusions increased during OLTs performed in the MELD era. The role of other variables should be explored further to explain postoperative morbidity and mortality.

Utility of prothrombin complex concentrate as first-line treatment modality of coagulopathy in patients undergoing liver transplantation: A propensity score-matched study

BACKGROUND

Transfusion management during liver transplantation (LT) is aimed at reducing blood loss and allogeneic transfusion requirements. Although prothrombin complex concentrate (PCC) has been used satisfactorily in various bleeding disorders, studies on its safety, and efficacy during LT are limited.

METHODS

A retrospective chart review of adult patients who underwent living donor LT at a single institute between October 2016 and January 2018 was carried out. The safety and efficacy of PCC in reducing transfusion requirements intraoperatively in patients who received PCC were compared with patients who did not receive PCC. A propensity score-matching technique was used, at a 1:1 ratio, to remove selection bias.

RESULTS

After completing the 1:1 propensity score-matched analysis, 60 pairs of patients were identified. The use of PCC was associated with significantly decreased red blood cell transfusion requirements (6.2 ± 4.1 vs 8.23 ± 5.18, P < 0.001) and fresh frozen plasma transfusion requirements (2.6 ± 2 vs 6.18 ± 4.1, P < 0.001). The number of patients developing postoperative hemorrhagic complications was higher in the non-PCC group.

CONCLUSIONS

During LT, the use of PCC led to decreased transfusion requirements. No thromboembolic complications related to PCC were noted in this series.

Use of Rotational Thromboelastometry in Liver Transplantation Is Associated With Reduced Transfusion Requirements

OBJECTIVES

Increased transfusion requirements in liver transplantation have been reported to be associated with worsened outcomes, more frequent reinterventions, and higher expenses. Anesthesiologists might counteract this through improved coagulation management. We evaluated the effects of rotational thromboelastometry on transfusion and coagulation product requirements and on outcome measurements.

MATERIALS AND METHODS

Patients who were 14 years or older and who were undergoing liver transplant at Hannover Medical School between January 2005 and December 2009 were included in this retrospective analysis. Demographic, clinical, and laboratory data, use of rotational thromboelastometry, intraoperative need for blood or coagulation products and antifibrinolytic substances, and clinical course were recorded. Correlations were examined using appropriate statistical tests.

RESULTS

Our study included 413 patients. Use of rotational thromboelastometry was associated with less frequent intraoperative administration of red blood cell concentrates, fresh frozen plasma, platelet concentrates, prothrombin complex concentrates, and antithrombin concentrates (all P < .05). In addition, univariate and multivariate tests showed that rotational thromboelastometry was correlated with decreased need for red blood cell concentrates and fresh frozen plasma (all P < .05). Intraoperative administration rates of antifibrinolytic substances and fibrinogen concentrate were significantly increased in patients who received rotational thromboelastometry monitoring (both P < .05). However, use of rotational thromboelastometry was not associated with massive transfusion rates (> 10 units vs less), clinical outcome, or length of stay in the intensive care unit (all P > .05).

CONCLUSIONS

Use of rotational thromboelastometry during liver transplant may reduce the need for intraoperative transfusion and coagulation products. Relevant effects of rotational thromboelastometry on patient outcomes or lengths of stay in the intensive care unit could not be ascertained. However, readjustment of therapeutic thresholds may improve the clinical impact.

Perioperative Single-Donor Platelet Apheresis and Red Blood Cell Transfusion Impact on 90-Day and Overall Survival in Living Donor Liver Transplantation

Background:

Although many previous studies have confirmed that perioperative blood transfusion is associated with poor outcomes after liver transplantation (LT), few studies described the influence of single-donor platelet apheresis transfusion in living donor LT (LDLT). This study aimed to assess the effect of blood products on outcomes for LDLT recipients, focusing on apheresis platelets.

Methods:

This retrospective study included 126 recipients who underwent their first adult-to-adult LDLT. Twenty-four variables including consumption of blood products of 126 LDLT recipients were assessed for their link to short-term outcomes and overall survival. Kaplan-Meier survival curve and the log-rank test were used for recipient survival analysis. A multivariate Cox proportional-hazard model and a propensity score analysis were applied to adjust confounders after potential risk factors were identified by a univariate Cox analysis.

Results:

Patients who received apheresis platelet transfusion had a lower 90-day cumulative survival (78.9% vs. 94.2%, P = 0.009), but had no significant difference in overall survival in the Cox model, compared with those without apheresis platelet transfusion. Units of apheresis platelet transfusion (hazard ratio [HR] = 3.103, 95% confidence interval [CI]: 1.720–5.600, P < 0.001) and preoperative platelet count (HR = 0.170, 95% CI: 0.040–0.730, P = 0.017) impacted 90-day survival independently. Multivariate Cox regression analysis also found that units of red blood cell (RBC) transfusion (HR = 1.036, 95% CI: 1.006–1.067, P = 0.018), recipient's age (HR = 1.045, 95% CI: 1.005–1.086, P = 0.025), and ABO blood group comparison (HR = 2.990, 95% CI: 1.341–6.669, P = 0.007) were independent risk factors for overall survival after LDLT.

Conclusions:

This study suggested that apheresis platelets were only associated with early mortality but had no impact on overall survival in LDLT. Units of RBC, recipient's age, and ABO group comparison were independent predictors of long-term outcomes.

Strategies to avoid empiric blood product administration in liver transplant surgery

Massive blood loss has been a dreaded complication of liver transplantation, and the accompanying transfusion is associated with adverse outcomes in the form of decreased patient and graft survival. With advances in both surgical techniques and anesthetic management during transplantation, blood and blood products requirements reduced significantly. However, transfusion practices vary among different centers. The altered coagulation parameters in patients with liver cirrhosis results in a state of “rebalanced hemostasis” and patients are just as likely to clot as they are to bleed. Commonly used coagulation tests do not always reflect this new state and can, therefore, be misleading. Transfusion of blood products solely to correct abnormal parameters may worsen the coagulation status, thus adversely affecting patient outcome. Point-of-care tests such as thromboelastometry more reliably predict the risk of bleeding in these patients and in addition may provide quicker turnaround times compared to routine tests. Perioperative management should also include the possibility of thrombosis in these patients, and the use of low-molecular-weight heparin correlates with better patient survival. This review article aims to highlight the concept of rebalanced hemostasis, limitation of routine coagulation tests, and harmful effect of empiric transfusion of blood products.

SEALIVE: the use of technical vessel-sealing devices for recipient hepatectomy in liver transplantation: study protocol for a randomized controlled trial

Background

The surgical technique used in liver transplantation has undergone constant evolution in an effort to develop a safe, highly standardized procedure. Despite this, the initial step of recipient hepatectomy has not been the focus of clinical research thus far. Due to advanced coagulopathy in liver transplant recipients, this part of the operation still carries the risk of severe hemorrhage. This trial is designed to compare an electrothermal bipolar vessel sealing device (LigaSure™) and an ultrasound dissector (HARMONIC ACE®+7) with standard surgical techniques during the recipients’ hepatectomy in liver transplantation.

Methods/design

In a single-center, prospective, randomized, controlled, parallel, three-armed, confirmatory, open trial, LigaSure™ and HARMONIC ACE®+7 will be compared with standard surgical techniques that use titanium clips and conventional knot-tying ligations during recipient hepatectomy in liver transplantation. Intraoperative total blood loss is the primary endpoint of the trial. Secondary endpoints include blood loss during hepatectomy, the duration of both the hepatectomy and the entire surgical procedure, and blood transfusion requirements of the procedure. To generate reliable data, intraoperative blood loss will be recorded with respect to all rinse fluids during surgery, ascites, and by weighing used swabs. At 80% power and an alpha of 0.025 for both of the experimental groups, 23 subjects will be analyzed per protocol in each study arm in order to detect clinically relevant reduction of intraoperative blood loss. The intention-to-treat analysis will include 69 patients. The follow-up period for each patient will be 90 days for safety reasons, whereas all clinical outcomes will be measured within the first 10 postoperative days.

Discussion

To our knowledge, this is the first prospective, randomized trial comparing two innovative technical methods of vessel sealing and dissection with standard techniques for recipient hepatectomy. This will be done to detect relevant reduction of intraoperative blood loss during liver transplant. The results of the trial are expected to improve patient outcome and safety after liver transplant and to increase the general safety of this procedure.

Trial registration

ClinicalTrials.gov, NCT 03323242. Registered on October 26, 2017.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-2778-1) contains supplementary material, which is available to authorized users.

Development of a Predictive Model for Blood Transfusions and Bleeding During Liver Transplantation: An Observational Cohort Study

OBJECTIVE

Orthotopic liver transplantation (OLT) frequently is associated with major blood loss and considerable transfusion requirements. The goal of this study was to define the risk factors for multiple transfusions and major bleeding during OLT and to help identify higher risk patients that could benefit from targeted interventions.

DESIGN

OLTs were studied for this observational cohort study.

SETTING

Community hospital.

PARTICIPANTS

A total of 800 consecutive OLTs were studied.

INTERVENTION

No intervention.

MEASUREMENTS AND MAIN RESULTS

Baseline and intraoperative data were gathered. Multivariate logistic regression analyses were performed to find variables associated with 2 outcomes: transfusion of more than 2 units of red blood cells (RBC) and bleeding ≥900 mL. Two nomograms were developed to predict individual risks. The overall intraoperative RBC transfusion was 0.6 ± 1.4 units on average, and 61 surgeries (7.6%) received more than 2 units of RBC (4.5 ± 1.9). Some variables were associated with the outcomes: 5 were associated with transfusion of more than 2 units of RBC (patient's height, starting hemoglobin concentration, starting bilirubin value, the use of a phlebotomy, and central venous pressure [CVP] at the time of vena cava clamping) and 3 with blood loss of ≥900 mL (starting hemoglobin value, Child-Turcotte-Pugh score, and CVP at the time of vena cava clamping). Preclamping CVP showed the strongest association with both outcomes. Nomograms were developed to predict the individual OLT recipients' risk of requiring more than 2 units RBC and suffering from major bleeding. Among the variables associated with multiple RBC transfusions and major bleeding, 3 can lead to interventions: baseline hemoglobin value, the use of a phlebotomy, and the preclamping CVP.

CONCLUSION

Some variables were able to predict the risk of multiple transfusions and major bleeding in this low bleeding liver transplantation population. Further studies based on these variables should be done to better define the role of targeted interventions in higher risk liver transplant recipients.

Survival Predictors in Liver Transplantation: Time-Varying Effect of Red Blood Cell Transfusion

BACKGROUND

Many attempts have been undertaken to better predict outcome after liver transplantation. The aim of this study was to identify the pre- and intraoperative variables that may influence the survival after liver transplantation, at a single institution.

METHODS

Anesthetic records from 543 consecutive patients who underwent liver transplantation from June 2006 to June 2014 were reviewed in this retrospective study. Patients undergoing retransplantation were excluded from the analysis, as were patients with familial amyloid polyneuropathy. Preoperative variables studied were age, sex, Model for End-Stage Liver Disease score, primary diagnosis, cold ischemia time, preoperative international normalized ratio, serum albumin, and and hemoglobin levels. Intraoperative variables included were norepinephrine consumption, blood loss, red blood cell transfusion, and surgical time. Variables significant in the univariate analysis with a P value of <.2 were included in a multivariate Cox regression model.

RESULTS

Only red blood cell transfusion (hazard ratio [HR], 1.16; 95% confidence interval [CI], 1.04-1.29) and female sex (HR, 1.71; 95% CI, 1.10-2.65) were identified as significant independent predictors for survival after liver transplantation. Because of proportionality assumption violation, the multivariate Cox regression model was subsequently upgraded by adding a time-varying interaction between red blood cell transfusion and time since liver transplantation. As a result, we found that at 3 months after liver transplantation, the rate of dying increased 14% (95% CI, 2%-26%) for each unit transfused, and at 6 months it increased 12% (95% CI, 0.3%-24%).

CONCLUSIONS

Red blood cell transfusion ceased to influence survival from 1 year onward.

Comparison of three caval reconstruction techniques in orthotopic liver transplantation: A retrospective review

BACKGROUND

Classic caval reconstruction during liver transplantation involves complete cross-clamping and resection of the recipient inferior vena cava (IVC) followed by donor IVC interposition. Other techniques preserve the IVC, with piggyback (PB) to the hepatic veins or side-to-side (SS) caval anastomosis. Avoidance of cross-clamping may be beneficial for minimizing hemodynamic instability and transfusion requirements.

METHODS

Retrospective review of a provincial transplant database (2007-2011). MELD score was used to measure disease severity. Intraoperative blood loss and volume resuscitation were compared between three caval reconstruction techniques using ANOVA.

RESULTS

200 deceased-donor transplants (Classic:58, PB:72, SS:70) were included. Baseline disease severity was equal. Mean case duration was shorter in the PB technique (Classic:366, PB:306, SS:385 min, p < 0.001). Despite similar blood loss, there was significantly less cell saver return, FFP, platelets, and overall resuscitation volume (Classic:12.8, PB:9.5, SS:13.2 L, p = 0.001) utilized in the piggyback technique.

CONCLUSIONS

The PB technique was faster and used less cell saver return, FFP and platelets, despite similar blood loss. Availability of different caval reconstruction techniques allows for a breadth of options in difficult cases.

Perioperative Predictors of Survival After Liver Transplantation for Familial Amyloid Polyneuropathy in a Portuguese Center

BACKGROUND

Liver transplantation (LT) has been the treatment of choice to halt the progression of familial amyloid polyneuropathy (FAP). Few studies have identified prognostic factors for post-LT survival in FAP. Our aim was to assess survival rate and to identify independent factors for survival after LT.

METHODS

This retrospective cohort study of FAP patients transplanted for the first time analyzed 116 transplantations from 2006 to 2014. The median follow-up period was 45.5 months.

RESULTS

The overall survival rates at 1 month, 1 year, and 5 years were 89%, 82% and 79%, respectively. On multivariate analysis, only number of red blood cell (RBC) units transfused during surgery, operation time, and body mass index were independent prognostic factors for patient survival. Only 30% of patients were transfused during surgery, and, in these, each RBC unit transfused increased mortality by 53%. The operation time increased mortality by 20% for every 15 minutes of surgery.

CONCLUSIONS

This study suggests that operation time and RBC transfused are predominant factors affecting post-LT survival in our FAP patients.

Relationship between Stroke Volume Variation and Blood Transfusion during Liver Transplantation

BACKGROUND

Intraoperative blood transfusion increases the risk for perioperative mortality and morbidity in liver transplant recipients. A high stroke volume variation (SVV) method has been proposed to reduce blood loss during living donor hepatectomy. Herein, we investigated whether maintaining high SVV could reduce the need for blood transfusion and also evaluated the effect of the high SVV method on postoperative outcomes in liver transplant recipients.

METHODS

We retrospectively analyzed 332 patients who underwent liver transplantation, divided into control (maintaining <10% of SVV during surgery) and high SVV (maintaining 10-20% of SVV during surgery) groups. We evaluated the blood transfusion requirement and hemodynamic parameters, including SVV, as well as postoperative outcomes, such as incidences of acute kidney injury, durations of postoperative intensive care unit and hospital stay, and rates of 1-year mortality.

RESULTS

Mean SVV values were 7.0% ± 1.3% in the control group (n = 288) and 11.2% ± 1.8% in the high SVV group (n = 44). The median numbers of transfused packed red blood cells and fresh frozen plasmas in the high SVV group were significantly lower than those in control group (0 vs. 2 units, P = 0.003; and 0 vs. 3 units, P = 0.033, respectively). No significant between-group differences were observed for postoperative outcomes.

CONCLUSIONS

Maintaining high SVV can reduce the blood transfusion requirement during liver transplantation without worsening postoperative outcomes. These findings provide insights into improving perioperative management in liver transplant recipients.

Reducing transfusion requirements in liver transplantation

Liver transplantation (LT) was historically associated with massive blood loss and transfusion. Over the past two decades transfusion requirements have reduced dramatically and increasingly transfusion-free transplantation is a reality. Both bleeding and transfusion are associated with adverse outcomes in LT. Minimising bleeding and reducing unnecessary transfusions are therefore key goals in the perioperative period. As the understanding of the causes of bleeding has evolved so too have techniques to minimize or reduce the impact of blood loss. Surgical “piggyback” techniques, anaesthetic low central venous pressure and haemodilution strategies and the use of autologous cell salvage, point of care monitoring and targeted correction of coagulopathy, particularly through use of factor concentrates, have all contributed to declining reliance on allogenic blood products. Pre-emptive management of preoperative anaemia and adoption of more restrictive transfusion thresholds is increasingly common as patient blood management (PBM) gains momentum. Despite progress, increasing use of marginal grafts and transplantation of sicker recipients will continue to present new challenges in bleeding and transfusion management. Variation in practice across different centres and within the literature demonstrates the current lack of clear transfusion guidance. In this article we summarise the causes and predictors of bleeding and present the evidence for a variety of PBM strategies in LT.

Perioperative effects of high doses of intraoperative thymoglobulin induction in liver transplantation

AIM: To describe our single-centre experience in liver transplantation (LT) with the infusion of high perioperative thymoglobulin doses. The optimal dosage and timing of thymoglobulin^® [antithymocyte globulin (ATG)] administration during LT remains controversial. Cytokine release syndrome, haemolytic anaemia, thrombocytopenia, neutropenia, fever and serum sickness are potential adverse effects associated with ATG infusion.

METHODS: Between December 2009 and December 2010, 16 adult non-randomized patients (ATG group), receiving a liver graft from a deceased donor, received an intraoperative infusion (4-6 h infusion) of thymoglobulin (3 mg/kg, ATG: Thymoglobuline^®). These patients were compared (case control approach) with 16 patients who had a liver transplant without ATG treatment (control group) to evaluate the possible effects of intraoperative ATG infusion. The matching parameters were: Sex, recipient age (± 5 years), LT indication including viral status, MELD score (± 5 points), international normalized ratio and platelet count (as close as possible). The exclusion criteria for both groups included the following: Multi-organ or living donor transplant, immunosuppressive therapy before transplantation, contraindications to the administration of any thymocyte globulin, human immunodeficiency virus seropositivity, thrombocytopenia [platelet < 50000/μL] or leukopenia [white blood cells < 1000/μL]. The perioperative side effects (haemodynamic alterations, core temperature variations, colloids and crystalloids requirements, and surgical time) possibly related to ATG infusion and the thromboelastographic (TEG) evaluation of the ATG effects on coagulation, blood loss and blood product transfusion were analysed during the operation and the first three postoperative days.

RESULTS: Intraoperative ATG administration was associated with longer surgical procedures [560 ± 88 min vs 480 ± 83 min (control group), P = 0.013], an intraoperative core temperature more than 37 °C (50% of ATG patients vs 6.2% of control patients, P = 0.015), major intraoperative blood loss [3953 ± 3126 mL vs 1419 ± 940 mL (control group), P = 0.05], higher red blood cell [2092 ± 1856 mL ATG group vs 472 ± 632 mL (control group), P = 0.02], fresh frozen plasma [671 ± 1125 mL vs 143 ± 349 mL (control group), P = 0.015], and platelet [374 ± 537 mL vs 15.6 ± 62.5 mL (control group), P = 0.017] transfusion, and a higher requirement for catecholamines (0.08 ± 0.07 μg/kg per minutes vs 0.01 ± 0.38 μg/kg per minutes, respectively, in the ATG and control groups) for haemodynamic support. The TEG tracings changed to a straight line during ATG infusion (preanhepatic and anhepatic phases) in 81% of the patients from the ATG group compared to 6.25% from the control group (P < 0.001). Patients from the ATG group compared to controls had higher post-op core temperatures (38 °C ± 1.0 °C vs 37.3 °C ± 0.5 °C; P = 0.02), an increased need of noradrenaline (43.7% vs 6.25%, P = 0.037), received more platelet transfusions (31.5% vs 0%, P = 0.04) and required continuous renal replacement therapy (4 ATG patients vs none in the control group; P = 0.10). ATG infusion was considered the cause of a fatal anaphylactic shock and of a suspected adverse reaction that led to intravascular haemolysis and acute renal failure.

CONCLUSION: The side effects and the coagulation imbalance observed in patients receiving a high dosage of ATG suggest caution in the use of thymoglobulin during LT.