Predictive variables affecting transfusion requirements in orthotopic liver transplantation

Effect of liver transplants with retrograde reperfusion on early postoperative recovery of liver function and its risk factors

BACKGROUND

The purpose of this study was to investigate effect of liver Transplants (LT) with retrograde reperfusion on early postoperative recovery of liver function and its risk factors.

METHODS

We conducted a retrospective analysis of clinical data from 136 liver transplantation (LT) patients at the 900th Hospital of the Chinese People's Liberation Army Joint Support Army, covering the period from January 2015 to January 2021. All participants provided informed consent, adhering to medical ethics guidelines. Patients were stratified into two groups based on the liver perfusion technique used: retrograde reperfusion (RTR, n = 108) and initial portal reperfusion (IPR, n = 28). Our study focused on a subset of 23 patients from each group to compare postoperative liver function recovery. The final analysis included 86 RTR and 28 IPR cases after excluding 8 RTR patients who underwent initial hepatic artery reperfusion and 14 who received simultaneous hepatic artery and portal vein reperfusion. Further subdivision within the RTR group identified 19 patients with early hepatic allograft dysfunction (EAD) and 67 without, allowing for an assessment of the influence of preoperative and intraoperative parameters, as well as perfusion methods, on EAD incidence post-LT.

RESULTS

Alanine aminotransferase (ALT) was 329 (211 ~ 548) and 176 (98 ~ 282) U/L on the 3rd and 7th day after RTR, respectively, which was significantly lower than 451 (288 ~ 918) and 251 (147 ~ 430) U/L in the IPR group (Z =-1.979, -2.299, P = 0.048, 0.021). Aspartate aminotransferase (AST) on postoperative days 3, 5, and 7 was 252 (193, 522), 105 (79, 163), and 93 (41, 135) U/L in the RTR group, respectively; it was also significantly lower than 328 (251, 724), 179 (129, 306), and 150 (91, 200)U/L in the IPR group (Z=-2.212, -3.221, -2.979; P = 0.027, 0.001, 0.003). Logistic regression analysis showed that MELD score was an independent risk factor for EAD after LT.

CONCLUSION

RTR LT is more favorable for patients' early postoperative liver function recovery. For patients undergoing LT for RTR, preoperative MELD score was an independent risk factor for their postoperative development of EAD.

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.

The Association between Prognostic Nutritional Index (PNI) and Intraoperative Transfusion in Patients Undergoing Hepatectomy for Hepatocellular Carcinoma: A Retrospective Cohort Study

BACKGROUND

PNI is significantly associated with surgical outcomes; however, the association between PNI and intraoperative transfusions is unknown.

METHODS

This study retrospectively analyzed 1065 patients who underwent hepatectomy. We divided patients into two groups according to the PNI (<44 and >44) and compared their transfusion rates and surgical outcomes. We performed multivariate logistic and Cox regression analysis to determine risk factors for transfusion and the 5-year survival. Additionally, we found the net reclassification index (NRI) to validate the discriminatory power of PNI.

RESULTS

The PNI <44 group had higher transfusion rates (adjusted odds ratio [OR]: 2.20, 95%CI: 1.06-4.60, p = 0.035) and poor surgical outcomes, such as post hepatectomy liver failure (adjusted [OR]: 3.02, 95%CI: 1.87-4.87, p < 0.001), and low 5-year survival (adjusted OR: 1.68, 95%CI: 1.17-2.24, p < 0.001). On multivariate analysis, PNI <44, age, hemoglobin, operation time, synthetic colloid use, and laparoscopic surgery were risk factors for intraoperative transfusion. On Cox regression analysis, PNI <44, MELD score, TNM staging, synthetic colloid use, and transfusion were associated with poorer 5-year survival. NRI analysis showed significant improvement in the predictive power of PNI for transfusion (p = 0.002) and 5-year survival (p = 0.004).

CONCLUSIONS

Preoperative PNI <44 was significantly associated with higher transfusion rates and surgical outcomes.

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.

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.

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.

A data-driven patient blood management strategy in liver transplantation

BACKGROUND AND OBJECTIVES

Blood utilization during liver transplant has decreased, but remains highly variable due to many complex surgical and physiologic factors. Previous models attempted to predict utilization using preoperative variables to stratify cases into two usage groups, usually using entire blood units for measurement. We sought to develop a practical predictive model using specific transfusion volumes (in ml) to develop a data-driven patient blood management strategy.

MATERIALS AND METHODS

This is a retrospective evaluation of primary liver transplants at a single institution from 2013 to 2015. Multivariable analysis of preoperative recipient and donor factors was used to develop a model predictive of intraoperative red-blood-cell (pRBC) use.

RESULTS

Of 256 adult liver transplants, 207 patients had complete transfusion volume data for analysis. The median intraoperative allogeneic pRBC transfusion volume was 1250 ml, and the average was 1563 ± 1543 ml. Preoperative haemoglobin, spontaneous bacterial peritonitis, preoperative haemodialysis and preoperative international normalized ratio together yielded the strongest model predicting pRBC usage. When it predicted <1250 ml of pRBCs, all cases with 0 ml transfused were captured and only 8·6% of the time >1250 ml were used. This prediction had a sensitivity of 0·91 and a specificity of 0·89. If predicted usage was >2000 ml, 75% of the time blood loss exceeded 2000 ml.

CONCLUSION

Patients likely to require low or high pRBC transfusion volumes were identified with excellent accuracy using this predictive model at our institution. This model may help predict bleeding risk for each patient and facilitate optimized blood ordering.

Risk factors for intraoperative massive transfusion in pediatric liver transplantation: a multivariate analysis

Background: Pediatric liver transplantation (LT) is strongly associated with increased intraoperative blood transfusion requirement and postoperative morbidity and mortality. In the present study, we aimed to assess the risk factors associated with massive transfusion in pediatric LT, and examined the effect of massive transfusion on the postoperative outcomes. Methods: We enrolled pediatric patients who underwent LT between December 1994 and June 2015. Massive transfusion was defined as the administration of red blood cells ≥100% of the total blood volume during LT. The cases of pediatric LT were assigned to the massive transfusion or no-massive transfusion (administration of red blood cells <100% of the total blood volume during LT) group. Univariate and multivariate logistic regression analyses were performed to evaluate the risk factors associated with massive transfusion in pediatric LT. Kaplan-Meier survival analysis, with the log rank test, was used to compare graft and patient survival within 6 months after pediatric LT between the 2 groups. Results: The total number of LT was 112 (45.0%) and 137 (55.0%) in the no-massive transfusion and massive transfusion groups, respectively. Multivariate logistic regression analysis indicated that high white blood cell (WBC) count, low platelet count, and cadaveric donors were significant predictive factors of massive transfusion during pediatric LT. The graft failure rate within 6 months in the massive transfusion group tended to be higher than that in the no-massive transfusion group (6.6% vs. 1.8%, P = 0.068). However, the patient mortality rate within 6 months did not differ significantly between the massive transfusion and no-massive transfusion groups (7.3% vs. 7.1%, P = 0.964). Conclusion: Massive transfusion during pediatric LT is significantly associated with a high WBC count, low platelet count, and cadaveric donor. This finding can provide a better understanding of perioperative blood transfusion management in pediatric LT recipients.

Massive haemorrhage in liver transplantation: Consequences, prediction and management

From its inception the success of liver transplantation has been associated with massive blood loss. Massive transfusion is classically defined as > 10 units of red blood cells within 24 h, but describing transfusion rates over a shorter period of time may reduce the potential for survival bias. Both massive haemorrhage and transfusion are associated with increased risk of mortality and morbidity (need for dialysis/surgical site infection) following liver transplantation although causality is difficult to prove due to the observational design of most trials. The blood loss associated with liver transplantation is multifactorial. Portal hypertension secondary to cirrhosis results in extensive collateral circulation, which can bleed during hepatectomy particular if portal pressures are increased. Avoiding volume loading and maintenance of a low central venous pressure together with the use of vasopressors have been shown to reduce blood loss and transfusion during liver transplantation, but may increase the risk of renal impairment post-operatively. Coagulation defects may be present pre-transplant, but haemostasis is often re-balanced due to a deficit in both pro- and anti-coagulation factors. Further derangement of haemostasis may develop in the anhepatic and neohepatic phases due to absent hepatic metabolic function, hyperfibrinolysis and platelet sequestration in the donor liver. Point-of-care tests of coagulation such as the viscoelastic tests rotation thromboelastometry/thromboelastometry allow and more accurate and rapid assessment of these derangements in coagulation and guide the use of factor replacement and antifibrinolytics. Transfusion protocols guided by these tests have been shown to reduce transfusion rates compared with conventional coagulation tests, but have not shown improvements in mortality or morbidity. Pre-operative factors associated with massive transfusion include previous surgery, re-do transplantation, the aetiology and severity of liver disease. Intra-operatively the use of piggy-back technique and avoiding veno-veno bypass has been shown to reduced blood loss.

Reduced Transfusion During OLT by POC Coagulation Management and TEG Functional Fibrinogen: A Retrospective Observational Study

Patients undergoing orthotopic liver transplantation are at high risk of bleeding complications. Several Authors have shown that thromboelastography (TEG)-based coagulation management and the administration of fibrinogen concentrate reduce the need for blood transfusion.

METHODS

We conducted a single-center, retrospective cohort observational study (Modena Polyclinic, Italy) on 386 consecutive patients undergoing liver transplantation. We assessed the impact on resource consumption and patient survival after the introduction of a new TEG-based transfusion algorithm, requiring also the introduction of the fibrinogen functional thromboelastography test and a maximum amplitude of functional fibrinogen thromboelastography transfusion cutoff (7 mm) to direct in administering fibrinogen (2012-2014, n = 118) compared with a purely TEG-based algorithm previously used (2005-2011, n = 268).

RESULTS

After 2012, there was a significant decrease in the use of homologous blood (1502 ± 1376 vs 794 ± 717 mL, P < 0.001), fresh frozen plasma (537 ± 798 vs 98 ± 375 mL, P < 0.001), and platelets (158 ± 280 vs 75 ± 148 mL, P < 0.005), whereas the use of fibrinogen increased (0.1 ± 0.5 vs 1.4 ± 1.8 g, P < 0.001). There were no significant differences in 30-day and 6-month survival between the 2 groups.

CONCLUSIONS

The implementation of a new coagulation management method featuring the addition of the fibrinogen functional thromboelastography test to the TEG test according to an algorithm which provides for the administration of fibrinogen has helped in reducing the need for transfusion in patients undergoing liver transplantation with no impact on their survival.

Transfusion management and immunohematologic complications in liver transplantation: experience of a single institution

OBJECTIVE

Liver transplantation (LT) has traditionally been associated with major blood loss and consequently high blood transfusion requirements. Our objective was to analyze transfusion management and incidence of immunohematologic complications in patients undergoing LT at our institution.

METHODS

A retrospective analysis of immunohematologic events and transfusion outcomes was carried out at La Fe University Hospital in Valencia. Data from 654 patients were reviewed: 654 underwent only one LT while 36 underwent second LT.

RESULTS

Patients received a median of 3 red blood cell (RBC) concentrates, 2 platelets concentrates (PCs) and 2 fresh frozen plasma units (FFPs). Variables significantly influencing RBC transfusions were: the MELD score, hemoglobin levels, and the platelet counts before LT. 27 patients (4.1%) had a positive antibody screening before transplant. Immunohematologic events occurred in 8% of the patients, mostly in the first month after LT, and involved hemolysis in 13 cases. Mortality was significantly higher in patients developing immunohematologic disorders (42.8 vs. 18.3%; p < 0.001). In the multivariable analysis, only ABO minor incompatibility between donor and recipient significantly increased the appearance of immunohematologic incidences (OR 4.92, 95% CI 2.31-10.50; p < 0.001).

CONCLUSION

Transfusion management of patients that underwent LT can be complicated by immunohematologic problems. Blood banks should implement the DAT test in each transfusion to detect them.

Transfusion and coagulation management in liver transplantation

There is wide variation in the management of coagulation and blood transfusion practice in liver transplantation. The use of blood products intraoperatively is declining and transfusion free transplantations take place ever more frequently. Allogenic blood products have been shown to increase morbidity and mortality. Primary haemostasis, coagulation and fibrinolysis are altered by liver disease. This, combined with intraoperative disturbances of coagulation, increases the risk of bleeding. Meanwhile, the rebalancing of coagulation homeostasis can put patients at risk of hypercoagulability and thrombosis. The application of the principles of patient blood management to transplantation can reduce the risk of transfusion. This includes: preoperative recognition and treatment of anaemia, reduction of perioperative blood loss and the use of restrictive haemoglobin based transfusion triggers. The use of point of care coagulation monitoring using whole blood viscoelastic testing provides a picture of the complete coagulation process by which to guide and direct coagulation management. Pharmacological methods to reduce blood loss include the use of anti-fibrinolytic drugs to reduce fibrinolysis, and rarely, the use of recombinant factor VIIa. Factor concentrates are increasingly used; fibrinogen concentrates to improve clot strength and stability, and prothrombin complex concentrates to improve thrombin generation. Non-pharmacological methods to reduce blood loss include surgical utilisation of the piggyback technique and maintenance of a low central venous pressure. The use of intraoperative cell salvage and normovolaemic haemodilution reduces allogenic blood transfusion. Further research into methods of decreasing blood loss and alternatives to blood transfusion remains necessary to continue to improve outcomes after transplantation.

The effect of gained experience on postoperative complications and mortality in cadaveric liver transplantation: a single-center experience

AIM

Liver transplantation (OLT) has become the treatment of choice for end-stage liver failure, as well as for selected cases of malignancies and metabolic disorders. Decreased postoperative complications and mortality rates are expected to correlate with improvements in the interdisciplinary team approach, the perioperative anesthesiologic and intensive care management, and careful follow-up after transplantation. In this study, we have evaluated the effect of gained experience on postoperative complications and mortality in cadaveric OLT performed in our institution.

MATERIALS AND METHODS

Data from cadaveric OLT patients (n = 34) since 2003 were retrospectively evaluated. Patients were divided into 2 groups: Early (2003-2006; n = 15) and late (2007-2010; n = 19). Age, gender, cold and warm ischemia times, intraoperative transfusion rates, infectious complications, biliary and vascular complication rates, and early and late postoperative mortality rates were compared in the 2 groups.

RESULTS

The age and gender distribution was similar among both groups. Mean cold and warm ischemia times, intraoperative transfusion rates, and operative times were significantly lower in the late period group (P = .004, .012, and 0.008, respectively; CI=%95). T-tube usage was also significantly lower in the late period group (P < .001). There was no significant change for postoperative intensive care period (P = .404), but the overall length of stay in hospital was shorter for the patients in the late period group (P = .019). The nonsurgical early postoperative complication rate was lower (P = .001) and early postoperative mortality was nearly significant (P = .06) in patients who comprised the late period group. There was no difference in terms of biliary and vascular complication rates and overall survival rates between patients in the early and late groups (P = .664, .264, and .107, respectively).

CONCLUSION

Our results indicate that the institutional improvements toward an interdisciplinary team approach in cadaveric OLT correlate with better results in ischemia and operative times and lower intraoperative transfusion rates and hospital stays. Early postoperative complication and mortality rates were found to decline in parallel to the team experience.