Blood loss in orthotopic liver transplantation: a retrospective analysis of transfusion requirements and the effects of autotransfusion of cell saver blood in 164 consecutive patients

Efficacy of intraoperative blood salvage and autotransfusion in living-donor liver transplantation: a retrospective cohort study

BACKGROUND

Liver transplantation (LT) may be associated with massive blood loss and the need for allogeneic blood transfusion. Intraoperative blood salvage autotransfusion (IBSA) can reduce the need for allogeneic blood transfusion. This study aimed to investigate the effectiveness of blood salvage in LT.

METHODS

Among 355 adult patients who underwent elective living-donor LT between January 1, 2019, and December 31, 2022, 59 recipients without advanced hepatocellular carcinoma received IBSA using Cell Saver (CS group). Based on sex, age, model for end-stage liver disease (MELD) score, preoperative laboratory results, and other factors, 118 of the 296 recipients who did not undergo IBSA were matched using propensity score (non-CS group). The primary outcome was the amount of intraoperative allogenic red blood cell (RBC) transfusion. Comparisons were made between the two groups regarding the amount of other blood components transfused and postoperative laboratory findings.

RESULTS

The transfused allogeneic RBC for the CS group was significantly lower than that of the non-CS group (1,506.0 vs. 1,957.5 ml, P = 0.026). No significant differences in the transfused total fresh frozen plasma, platelets, cryoprecipitate, and estimated blood loss were observed between the two groups. The postoperative allogeneic RBC transfusion was significantly lower in the CS group than in the non-CS group (1,500.0 vs. 2,100.0 ml, P = 0.039). No significant differences in postoperative laboratory findings were observed at postoperative day 1 and discharge.

CONCLUSIONS

Using IBSA during LT can effectively reduce the need for perioperative allogeneic blood transfusions without causing subsequent coagulopathy.

Thromboelastography characteristics in critically ill patients with liver disease

OBJECTIVE

The purpose of this study was to determine how thromboelastography (TEG) parameters differ by various clinical conditions that commonly occur in patients with cirrhosis, including sepsis, acute on chronic liver failure (ACLF), alcohol-associated hepatitis (AAH) and portal vein thrombosis (PVT).

BACKGROUND

TEG, a whole blood assay, is used to assess several parameters of coagulation and is becoming increasingly used in clinical practice.

STUDY

This study was a retrospective chart review of 155 patients admitted to the ICU with decompensated cirrhosis from 2017 to 2019.

RESULTS

The R time was significantly shorter in patients when they were septic compared to when they were not and longer in patients with vs. without ACLF grade 3. Alpha angle and maximum amplitude was decreased in patients with severe AAH compared to those without severe AAH; and maximum amplitude was increased in patients with acute PVT compared to those with chronic PVT. R time was positively correlated with Chronic Liver Failure Consortium Organ Failure and Chronic Liver Failure Consortium ACLF scores (rho = 0.22, P = 0.020), while alpha angle and maximum amplitude were negatively correlated with MELD-NA.

CONCLUSION

Findings suggest TEG parameters vary in several clinical conditions in patients with decompensated cirrhosis who are admitted to the ICU. Prospective research is needed to confirm our findings and to determine how this knowledge can be used to guide clinical practice, as well as blood product transfusions in the setting of bleeding or prior to invasive procedures.

Viscoelastic Management of Coagulopathy during the Perioperative Period of Liver Transplantation

Viscoelastic testing (VET) in liver transplantation (LT) has been used since its origin, in combination with standard laboratory testing (SLT). There are only a few, small, randomized controlled trials that demonstrated a reduction in transfusion rates using VET to guide coagulation management. Retrospective analyses contrasting VET to SLT have demonstrated mixed results, with a recent concern for overtreatment and the increase in postoperative thrombotic events. An oversight of many studies evaluating VET in LT is a single protocol that does not address the different phases of surgery, in addition to pre- and postoperative management. Furthermore, the coagulation spectrum of patients entering and exiting the operating room is diverse, as these patients can have varying anatomic and physiologic risk factors for thrombosis. A single transfusion strategy for all is short sighted. VET in combination with SLT creates the opportunity for personalized resuscitation in surgery which can address the many challenges in LT where patients are at a paradoxical risk for both life-threatening bleeding and clotting. With emerging data on the role of rebalanced coagulation in cirrhosis and hypercoagulability following LT, there are numerous potential roles in VET management of LT that have been unaddressed.

The Coagulation Profile of End-Stage Liver Disease and Considerations for Intraoperative Management

The coagulopathy of end-stage liver disease results from a complex derangement in both anticoagulant and procoagulant processes. With even minor insults, cirrhotic patients experience either inappropriate bleeding or clotting, or even both simultaneously. The various phases of liver transplantation along with fluid and blood product administration may contribute to additional disturbances in coagulation. Thus, anesthetic management of patients undergoing liver transplantation to improve hemostasis and avoid inappropriate thrombosis in the perioperative environment can be challenging. To add to this challenge, traditional laboratory tests of coagulation are difficult to interpret in patients with end-stage liver disease. Viscoelastic coagulation tests such as thromboelastography (Haemonetics Corporation, Braintree, MA) and rotational thromboelastometry (TEM International, Munich, Germany) have helped to reduce transfusion of allogeneic blood products, especially fresh frozen plasma, but have also lead to the increased use of fibrinogen-containing products. In general, advancements in surgical techniques and anesthetic management have led to significant reduction in blood transfusion requirements during liver transplantation. Targeted transfusion protocols and pharmacologic prevention of fibrinolysis may further aid in the management of the complex coagulopathy of end-stage liver disease.

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.

Flushing the liver with urokinase before transplantation does not prevent nonanastomotic biliary strictures

The aim of the present study was to assess whether flushing the donor liver with urokinase immediately before implantation reduces the incidence of nonanastomotic biliary strictures (NASs) after liver transplantation, without causing increased blood loss, analyzed as a historical cohort study. Between January 2005 and October 2012, all liver (re-)transplantations were included. Of the 185 liver transplant recipients included, 63 donor livers between January 2010 and October 2012 received urokinase (study group), whereas the donor liver of 122 consecutive recipients, who served as a historical control group, between January 2005 and January 2010 did not receive urokinase. Basic donor (Eurotransplant donor risk index) and recipient (age, body mass index, laboratory Model for End-Stage Liver Disease score) characteristics did not significantly differ in both groups. Thirty-three recipients developed NASs: 22 in the control group (18%) and 11 (17.5%) in the study group (P = 0.68). Analyzed separately for donation after circulatory death (P = 0.42) or donation after brain death (P = 0.89), there was no difference between the groups in incidence of NAS. Of all the recipients developing NAS, 7 (21%) needed retransplantation and all others were treated conservatively. Autologous blood transfusion requirements did not differ significantly between both groups (P = 0.91), whereas interestingly, more heterologous blood transfusions were needed in the control group (P < 0.001). This study has its limitations by its retrospective character. A multi-institutional prospective study could clarify this issue. In conclusion, arterial flushing of the liver with urokinase immediately before implantation did not lead to a lower incidence of NAS in this study, nor did it lead to increased blood loss.

Preoperative hypoalbuminemia and anemia as predictors of transfusion in radical nephrectomy for renal cell carcinoma: a retrospective study

Background

The only curative therapy for renal cell carcinoma is the complete removal of malignant tissue. Surgical bleeding during radical nephrectomy may require blood transfusion. Blood transfusion, however, is associated with postoperative morbidity and mortality. This study investigated predictive factors of transfusion requirement in patients undergoing radical nephrectomy, as well as the effects of transfusion on postoperative outcomes.

Methods

This study retrospectively enrolled 526 patients who underwent open radical nephrectomy for renal cell carcinoma between 2010 and 2012. Univariate and multivariate logistic regression analyses were used to determine independent predictive factors of a requirement for packed red blood cell (PRBC) transfusion. Postoperative outcomes included an admission to the intensive care unit (ICU) and lengths of ICU and hospital stay.

Results

Of the 526 patients, 93 (17.7 %) required PRBC transfusion, with these patients requiring a mean 5.5 units. Preoperative hypoalbuminemia (serum albumin <3.5 g/dL) was observed in 75 (14.3 %) patients, and preoperative anemia (hemoglobin <12.0 g/dL) in 121 (23.0 %). Multivariate logistic regression analysis showed that preoperative hypoalbuminemia, preoperative anemia, and a high cancer stage were independent factors significantly associated with PRBC transfusion in open radical nephrectomy. The transfused group had higher incidence of ICU admission and longer lengths of ICU and hospital stay than the non-transfused group.

Conclusions

Preoperative hypoalbuminemia and anemia are important predictors of PRBC transfusion during radical nephrectomy for renal cell carcinoma. Furthermore, transfusion is associated with poor postoperative outcomes.

Preoperative predictors of blood component transfusion in living donor liver transplantation

Context:

Extensive bleeding associated with liver transplantation is a major challenge faced by transplant surgeons, worldwide.

Aims:

To evaluate the blood component consumption and determine preoperative factors that predict the same in living donor liver transplantation (LDLT).

Settings and Design:

This prospective study was performed for a 1 year period, from March 2010 to February 2011.

Materials and Methods:

Intra- and postoperative utilization of blood components in 152 patients undergoing LDLT was evaluated and preoperative patient parameters like age, gender, height, weight, disease etiology, hemoglobin (Hb), hematocrit (Hct), platelet count (Plt), total leukocyte count (TLC), activated partial thromboplastin time (aPTT), international normalized ratio (INR), serum bilirubin (T. bilirubin), total proteins (T. proteins), albumin to globulin ratio (A/G ratio), serum creatinine (S. creatinine), blood urea (B. urea), and serum electrolytes were assessed to determine their predictive values. Univariate and stepwise discriminant analysis identified those factors, which could predict the consumption of each blood component.

Results:

The average utilization of packed red cells (PRCs), cryoprecipitates (cryo), apheresis platelets, and fresh frozen plasma was 8.48 units, 2.19 units, 0.93 units, and 2,025 ml, respectively. Disease etiology and blood component consumption were significantly correlated. Separate prediction models which could predict consumption of each blood component in intra and postoperative phase of LDLT were derived from among the preoperative Hb, Hct, model for end-stage liver disease (MELD) score, body surface area (BSA), Plt, T. proteins, S. creatinine, B. urea, INR, and serum sodium and chloride.

Conclusions:

Preoperative variables can effectively predict the blood component requirements during liver transplantation, thereby allowing blood transfusion services in being better prepared for surgical procedure.

Risk factors and outcomes of massive red blood cell transfusion following living donor liver transplantation

OBJECTIVES

To identify the factors influencing blood loss and secondary blood transfusion and to investigate the outcomes of patients who underwent a massive blood transfusion (MBT) following living donor liver transplantation (LDLT).

METHODS

Patients who underwent primary adult-to-adult right hepatic lobe LDLT were included in the study, and were divided into the MBT group [≥6 red blood cell (RBC) units in 24 h] and the non-massive blood transfusion (NMBT) group (<6 RBC units in 24 h). All potential risk factors, length of intensive care unit (ICU) stay and long-term survival rate of the patients in the two groups were analyzed.

RESULTS

The data of 181 eligible patients were retrospectively analyzed. A decreased long-term survival rate, a higher incidence of postoperative infection and prolonged ICU stay were observed in the MBT group. No significant difference was observed in survival rate between patients having platelet transfusion>2 units and ≤2 units. Hemoglobin<100 g/L, platelet counts<70×10(9)/L, fibrinogen level<1.5 g/L and history of upper abdominal surgery were found to be independent risk factors.

CONCLUSIONS

Blood transfusion during LDLT can be predicted using preoperative variables. Massive RBC transfusion may lead to poor long-term survival, higher postoperative infection rate and prolonged ICU stay. Platelet transfusion may not be a risk factor for long-term survival.

Liver transplantation for hepatocellular carcinoma--is there a risk of recurrence caused by intraoperative blood salvage autotransfusion?

BACKGROUND/AIMS

The use of intraoperative blood salvage autotransfusion (IBSA) during surgical approaches may contribute to tumour cell dissemination. Therefore, IBSA should be avoided in cases of malignancy. However, the risks of IBSA might be acceptable in liver transplantation (LT) for selected small hepatocellular carcinoma (HCC).

METHODS

In total, 136 recipients of LT with histologically proven HCC in the explanted liver were included in this analysis. With regard to tumour recurrence, 40 patients receiving IBSA despite HCC (IBSA group) were compared to 96 patients without IBSA (non-IBSA group).

RESULTS

Milan criteria as assessed in the explanted liver were fulfilled in 24 of 40 IBSA patients and 58 of 96 non-IBSA patients (p = 0.85). Five of 40 patients in the IBSA group and 18 of 96 patients in the non-IBSA group experienced tumour recurrence (p = 0.29). In spite the theoretical risk of tumour cell dissemination, the recurrence rate was not increased in the IBSA group.

CONCLUSION

Our results indicate that IBSA does not modify the risk of HCC recurrence. Therefore, in highly selected HCC patients undergoing LT, the use of IBSA appears to be justified.

Rebalanced hemostasis in patients with liver disease: evidence and clinical consequences

Patients with liver disease frequently acquire a complex disorder of hemostasis secondary to their disease. Routine laboratory tests such as the prothrombin time and the platelet count are frequently abnormal and point to a hypocoagulable state. With more sophisticated laboratory tests it has been shown that patients with liver disease may be in hemostatic balance as a result of concomitant changes in both pro- and antihemostatic pathways. Clinically, this rebalanced hemostatic system is reflected by the large proportion of patients with liver disease who can undergo major surgery without any requirement for blood product transfusion. However, the hemostatic balance in the patient with liver disease is relatively unstable as evidenced by the occurrence of both bleeding and thrombotic complications in a significant proportion of patients. Although it is still common practice to prophylactically correct hemostatic abnormalities in patients with liver disease before invasive procedures by administration of blood products guided by the prothrombin time and platelet count, we believe that this policy is not evidence-based. In this article, we will provide arguments against the traditional concept that patients with liver failure have a hemostasis-related bleeding tendency. Consequences of these new insights for hemostatic management will be discussed.

How to minimize blood loss during liver surgery in patients with cirrhosis

Patients with liver disease frequently have substantial changes in their haemostatic system. This is reflected in abnormal test results on routine coagulation screening assays such as the prothrombin time (PT), activated thromboplastin time (APTT) and platelet count. Traditionally, attempts were made to correct abnormalities in the haemostatic system as measured by routine coagulation assays prior to invasive procedures by infusion of platelets or fresh frozen plasma (FFP). Recent laboratory and clinical data have indicated that the haemostatic reserve in cirrhotic patients is relatively well maintained although the coagulation screening assays suggest otherwise. Pre-procedural correction of coagulation tests with blood products may therefore not be necessary, and may even have harmful side-effects. In particular, fluid overload resulting in exacerbation of portal hypertension by infusion of blood products may in fact promote bleeding. In recent years, it has become clear that reduction of the central and portal venous pressure by fluid restriction and avoidance of blood product transfusion is a beneficial strategy in minimizing bleeding during liver surgery in cirrhotic patients. Some investigators have even taken this a step further and suggested pre-procedural phlebotomy in liver transplant recipients. The aim of this review is to provide an overview of recent studies and developments which have changed our understanding of the clinical relevance of abnormal coagulation tests in patients with cirrhosis, and which have contributed to a reduction in blood loss and transfusion requirements when liver surgery is needed in these patients.

The clinical relevance of the anhepatic phase during liver transplantation

This study assesses the relation between the anhepatic phase duration and the outcome after liver transplantation. Of 645 patients who underwent transplantation between 1994 and 2006, 194 were recipients of consecutive adult primary piggyback liver transplants using heart-beating donors. The anhepatic phase was defined as the time from the physical removal of the liver from the recipient to recirculation of the graft. Other noted study variables were the cold and warm ischemia times, donor and recipient age, donor and recipient body mass index, perioperative red blood cell (RBC) transfusion, indication for transplantation, and Model for End-Stage Liver Disease score. The primary outcome parameter was graft dysfunction, which was defined as either primary nonfunction or initial poor function according to the Ploeg-Maring criteria. The median anhepatic phase was 71 minutes (37-321 minutes). Graft dysfunction occurred in 27 patients (14%). Logistic regression analysis showed an anhepatic phase over 100 minutes [odds ratio (OR), 4.28], a recipient body mass index over 25 kg/m(2) (OR, 3.21), and perioperative RBC transfusion (OR, 3.04) to be independently significant predictive factors for graft dysfunction. One-year patient survival in patients with graft dysfunction was 67% versus 92% in patients without graft dysfunction (P < 0.001). A direct relation between the anhepatic phase duration and patient survival could, however, not be established. In conclusion, this study shows that liver transplant patients with an anhepatic phase over 100 minutes have a higher incidence of graft dysfunction. Patients with graft dysfunction have significantly worse 1-year patient survival.

Changing trends in transfusion practice in liver transplantation

PURPOSE OF REVIEW

Prevention of excessive blood loss is an important issue in the perioperative management of liver transplantation. This review describes changing trends in blood products use, risk predicting of blood transfusion, variability in use and practices, as well as transfusion safety during liver transplantation.

RECENT FINDINGS

Over the last 20 years, the average use of blood products per case has considerably decreased. There are marked interinstitutional differences in blood use. Differences in patient population characteristics and surgical techniques are a partial explanation, but differences in transfusion practices probably account for a substantial part of the variability. Recent data have sparked off ongoing controversy relating to volume replacement therapy and its impact on blood loss. New studies emphasize the risks associated with transfusion in liver transplantation.

SUMMARY

Recent studies call for continuing every reasonable effort to minimize the use of blood components and can guide us in new approaches to this vital problem.

Intraoperative massive transfusion decreases survival after liver transplantation

Patients undergoing liver transplantation often experience coagulopathy and massive intraoperative blood loss that can lead to morbidity and reduced survival. The aim of this study was to verify the survival rate and discover predictive factors for death among liver transplant patients who received massive intraoperative blood transfusions. This cohort study was based on prospective data collected retrospectively from January 2004 to July 2006. The 232 patients were distributed according to their blood requirements, (namely, more or less than 6 units), including red blood cell saver. The statistical analyses were performed using Student t test, Cox hazard regression, and the Kaplan-Meier method (log-rank test). The massively transfused cohort displayed higher Child-Pugh classifications (10.2 vs 9.6; P = .03); model for end-stage liver disease (MELD) scores (19 vs 17; P = .02); recipient weights (75.4 vs 71 kg; P = .03); as well as warm ischemia times (70.7 vs 56.4 minutes; P < .001) and surgery times (584.6 vs 503.4 minutes; P < .05). The proportional hazard (Cox) regression analysis showed that the risk of death increased 2.1% for each unit of donor sodium and 1.6% for each additional year of donors age over 50. The survival rates at 6, 12, 60, and 120 months for > or = 6 vs <6 U of blood transfusion of 63.8% vs 83.3%; 53.9% vs 76.3%; 40% vs 60%; 34.5% vs 49.2%. In conclusion, we observed that patients receiving over 6 red blood cell units intraoperatively displayed reduced survival. Predictive factors for this risk factor were high donor level of sodium and of age.

Intraoperative blood salvage during liver transplantation in patients with hepatocellular carcinoma: efficiency of leukocyte depletion filters in the removal of tumor cells

BACKGROUND

Intraoperative blood salvage (IBS) reduces homologous transfusion in orthotopic liver transplantation (OLT), but may carry with it the risk of reinfusing tumor cells in patients with hepatocellular carcinoma (HCC). The use of leukocyte depletion filters (LDFs) for the removal of tumor cells is rarely reported in clinical OLT. The aims of this study were to evaluate the frequency of tumor cell contamination in surgical field during OLT for HCC recipients and to investigate the efficiency of additional LDFs for eliminating tumor cells from IBS.

METHODS

Thirty-two HCC patients with preoperatively elevated serum alpha-fetoprotein (AFP) underwent OLT. The blood from the surgical field was collected and processed by an autotransfusion device (Cell Saver 5), followed by 2 consecutive LDF filtrations. The HCC cells in IBS samples and filtered samples were determined using a nested RT-PCR technique to detect the AFP mRNA.

RESULTS

The shed blood samples from 20 (62.5%) of the 32 HCC patients were contaminated with HCC cells and 15 of them remained positive after Cell Saver processing. Patients within the Milan or UCSF criteria were less likely to have HCC cell contamination and the contaminated HCC cells were more likely to be removed by the Cell Saver in these patients as compared to other patients (P<0.01). After filtration through an additional LDF, most cases (13/15) became negative except for those with ruptured tumors (P<0.05).

CONCLUSIONS

Our results suggest that blood filtration with the LDF can efficiently remove tumor cells and the use of an additional LDF after use of the Cell Saver could markedly reduce the risk of tumor cell reintroduction during the OLT in HCC recipients with nonruptured tumors.

The prevalence of a heparin-like effect shown on the thromboelastograph in patients undergoing liver transplantation

It has been known for several decades that thromboelastographic analysis of the blood of patients undergoing liver transplantation may show a heparin-like effect (HLE) at the time of reperfusion. However, the prevalence of HLE and the origin of these heparin-like substances remain largely unstudied. The primary aim of this retrospective observational analysis was to determine the prevalence of the HLE in 211 consecutive patients having liver transplantation in our institution at various stages throughout the transplant. One of the secondary aims was to analyze the prevalence of HLE with respect to the various etiologies of liver disease. Paired Thromboelastograph traces (native and heparinase) were examined at 5 stages of the transplant: the baseline stage, dissection stage, anhepatic stage, reperfusion stage, and end of the case. HLE was defined as a reduction in the reaction and coagulation times of greater than 50% by the addition of heparinase to the sample. Thirty-one percent of patients had evidence of an HLE at baseline, and this increased to 75% after reperfusion of the donor graft. This HLE resolved spontaneously in 47% by the end of the case. Patients with fulminant liver failure were more likely to demonstrate HLE at baseline than those with chronic liver disease (45.8% compared to 29%). There was no difference in the prevalence of HLE after reperfusion. In conclusion, prior to transplantation, there is a significant difference in the prevalence of HLE with respect to etiology. However, this difference disappears after reperfusion as the majority of patients then develop HLE. Although it is clear that there are both endogenous and exogenous sources of heparin contributing to the HLE, the clinical significance of these findings remains unclear.

Efficacy of intraoperative cell saver in decreasing postoperative blood transfusions in instrumented posterior lumbar fusion patients

STUDY DESIGN

A retrospective study.

OBJECTIVE

To determine the efficacy of using intraoperative cell saver in decreasing the need for blood transfusion.

SUMMARY OF BACKGROUND DATA

Lumbar spine surgery is associated with potential large intraoperative blood loss, which may put patients at risk for blood transfusions. Preoperative autologous blood donation mitigates the need for allogenic blood transfusion, but does not eliminate it. Cell-saver use has been advocated to further reduce the need for transfusion, but recent reports have called its efficacy into question.

METHODS

Data were collected from 188 patients undergoing consecutive instrumented lumbar laminectomy and fusion. One hundred and forty-one of these patients had cell saver used during their procedures, whereas 47 did not. In addition, previously published data from similarly treated patients were used for analysis. Operative blood loss, autologous and allogenic blood transfusions, discharge hematocrit, and patient factors were analyzed.

RESULTS

A significant increase in the number of blood transfusions was found in the cell-saver group. The cell-saver group also had a significantly increased blood loss compared with the non-cell-saver group. Using analysis of covariance, we determined the effect of blood loss on the need for transfusion. The results showed that correcting for blood loss eliminated the significance in the transfusion difference, but cell saver still was not able to decrease the transfusion need. Comparing our current results with our previously published results also demonstrated no benefit of cell saver use.

CONCLUSION

Use of cell saver in instrumented lumbar fusion cases was not able to decrease the need for blood transfusion. Cell-saver use was associated with a significantly higher blood loss.

Evaluation of cell salvage autotransfusion utility during liver transplantation

BACKGROUND

Orthotopic liver transplantation (OLT) may be associated with massive blood loss and the need for allogenic blood product transfusions. Cell salvage autotransfusion (CS) is an attractive alternative to allogenic red blood cell (RBC) transfusion. However, controversy surrounds its usefulness during OLT; some studies stated that CS decreased transfusions of allogenic blood products and others stated that blood loss was increased. The aim of this study was to evaluate the efficiency of the CS during OLT.

PATIENTS AND METHODS

After approval by the institutional ethics committee, a prospective survey was undertaken. A total of 150 consecutive OLTs were included in the study. Two groups of patients were formed. Period 1 included patients 1-75 with no CS use. Period 2 comprised patients 76-150 with systematic CS use.

RESULTS

Patients from both periods were comparable. CS was used in all cases in period 2, and there was enough salvaged blood to retransfuse 65% of these OLTs. The mean volume of retransfused blood was 338+/-339 ml. The transfusion rate did not change from period 1 to period 2. The mean number of RBC units transfused per patient was 0.4+/-0.9 vs 0.4+/-1.2 with 78.7% vs 81.3% of cases not receiving transfusion of any blood product. The threshold for RBC transfusions was the same. The length of surgery and blood loss were greater in period 2 than in period 1 (associated with the arrival of two junior surgeons), but the hemoglobin (Hb) value was also higher at the end of surgery (93.8+/-19.3 g/L vs 85.2+/-17.8 g/L, p<0.0001).

CONCLUSION

Despite increased blood loss in period 2, CS saved 21 g/L of Hb per patient or two RBC unit transfusions. As long as we cannot predict with accuracy which patients will bleed, we will continue to use the CS for all OLTs.

New insights into the coagulopathy of liver disease and liver transplantation

The liver is an essential player in the pathway of coagulation in both primary and secondary haemostasis. Only von Willebrand factor is not synthetised by the liver, thus liver failure is associated with impairment of coagulation. However, recently it has been shown that the delicate balance between pro and antithrombotic factors synthetised by the liver might be reset to a lower level in patients with chronic liver disease. Therefore, these patients might not be really anticoagulated in stable condition and bleeding may be caused only when additional factors, such as infections, supervene. Portal hypertension plays an important role in coagulopathy in liver disease, reducing the number of circulating platelets, but platelet function and secretion of thrombopoietin have been also shown to be impaired in patients with liver disease. Vitamin K deficiency may coexist, so that abnormal clotting factors are produced due to lack of gamma carboxylation. Moreover during liver failure, there is a reduced capacity to clear activated haemostatic proteins and protein inhibitor complexes from the circulation. Usually therapy for coagulation disorders in liver disease is needed only during bleeding or before invasive procedures. When end stage liver disease occurs, liver transplantation is the only treatment available, which can restore normal haemostasis, and correct genetic clotting defects, such as haemophilia or factor V Leiden mutation. During liver transplantation haemorrage may occur due to the pre-existing hypocoagulable state, the collateral circulation caused by portal hypertension and increased fibrinolysis which occurs during this surgery.

Derivation of a risk index for the prediction of massive blood transfusion in liver transplantation

Massive blood transfusion (MBT) remains a serious and common occurrence in liver transplantation surgery. This retrospective cohort study was undertaken to identify preoperative predictors of MBT and to develop a risk index for MBT in liver transplantation. Data were retrospectively collected on all liver transplantations carried out at a single institution between January 1998 and March 2004. Multivariable logistic regression analysis was used to identify independent predictor variables of MBT, defined as >/=6 units of red blood cell concentrate (RBC) in the first 24 hours of surgery. The model was internally validated by bootstrapping. Of the 460 liver transplant recipients, 193 (42%) received >/=6 units of RBC within 24 hours of surgery. Unadjusted analyses identified 12 preoperative predictors of MBT: age, height, gender, repeat transplantation, etiology of liver failure, and preoperative laboratory values (hemoglobin concentration, platelet count, international normalized ratio for prothrombin activity [INR], albumin, total bilirubin, and creatinine). In multivariable logistic regression, 7 independent predictors of MBT were identified: age (>40 years), hemoglobin concentration (</=10.0 g/dL), INR (1.2-1.99, and >2.0), platelet count (</=70 x 10(9)/L), creatinine (>/=110 micromol/L for female subjects and >/=120 micromol/L for male subjects), albumin (< 28 g/L), and repeat transplantation. The area under the receiver-operating characteristic curve (ROC) for the model was 0.82. By using the regression beta coefficients to derive weights for each of these predictors, a risk index was developed that assigned each patient a score between 0 and 8. The ROC for this risk index was 0.79. MBT in liver transplantation surgery can be accurately predicted by 7 readily available preoperative predictors.

Analysis of differences in outcome of two European liver transplant centers

Authors analyzed the differences in the outcome of two European liver transplant centers differing in case volume and experience. The first was the Transplantation and Surgical Clinic, Semmelweis University, Budapest, Hungary (SEB) and the second the University Medical Center Groningen, Groningen, The Netherlands (UMCG). We investigated if such differences could be explained. The 1-, 3- and 5-year patient survival in the UMCG was 86%, 80%, and 77% compared with 65%, 56%, and 55% in SEB. Graft survival at the same time points was 79%, 71%, and 66% in the UMCG and 62%, 55%, and 53% in SEB. Significant differences were present regarding the donor and recipient age, diagnosis mix, disease severity and operation variables, per-operative transfusion rate, vascular complications, postoperative infection rate, and need for renal replacement. To determine factors correlating with survival, a separate uni- and multivariate analysis was performed in each center individually, between study parameters and patient survival. In both centers, peri-operative red blood cell (RBC) transfusion rate was a significant predictor for patient survival. The difference in blood loss can be explained by different operation techniques and shorter operation time in SEB, with consequently less time spent on hemostasis. It was jointly concluded that measures to reduce blood loss by adapting the operation technique might lead to improved survival and reduced morbidity.

Avoiding blood products during liver transplantation

Liver transplantation is a major surgical procedure usually requiring large amount of blood products (red cells, platelets, fresh-frozen plasma). We developed a multidisciplinary transfusion-free protocol for liver transplantation in Jehovah's witnesses who refuse the use of blood products but accept organ transplantation. Between September 1998 and November 2004, 9 of 29 Jehovah's witnesses evaluated for liver transplantation were transplanted after medical preparation. None of these patients received any blood product during the surgical procedure. This experience may be beneficial for the entire liver transplantation population, as excessive transfusion has been linked to increased morbidity and mortality in liver transplantation.

Liver transplantation in Jehovah's witnesses

For religious reasons, Jehovah's witnesses refuse transfusion of blood products (red cells, platelets, plasma), but may accept organ transplantation. The authors developed a multidisciplinary protocol for liver transplantation in Jehovah's witnesses. In a 6-year period, nine Jehovah's witness patients were listed for liver transplantation. They received preoperative erythropoietin therapy, with iron and folic acid that allowed significant haematocrit increase. Two patients underwent partial spleen embolization to increase platelet count. Seven patients underwent cadaveric whole liver transplantation, and two right lobe living-related liver transplantation, using continuous circuit cell saving system and high dose aprotinin. No patient received any blood product during the surgical procedure. One patient suffering from deep anaemia after living-related liver transplantation was transfused as required by his family, but died from aspergillus infection. One 6-year-old child was transfused against her parent's will. The authors demonstrated that it is possible to increase haematocrit and platelet levels in cirrhotic patients awaiting liver transplantation. They were able to reduce intraoperative need for blood products, allowing liver transplantation in prepared Jehovah's witness patients. This experience may be beneficial for non-Jehovah's witness liver transplant recipients.

Single pretransplant bolus of recombinant activated factor VII ameliorates influence of risk factors for blood loss during orthotopic liver transplantation

Large blood loss and transfusions during liver transplantation (LTx) may lead to serious complications and have a negative impact on post-transplant mortality and morbidity. In the retrospective study we compared two groups of recipients of primary cadaveric liver transplantation: group I (study group), consisted of 28 patients with preoperative risk of high intraoperative blood loss, including severe uncorrected coagulopathy. This group was given a bolus of recombinant activated factor VII (rFVIIa) just before LTx. Group II (control group) included 61 patients without a particular risk for increased intraoperative blood loss. These patients were not given rFVIIa. We analyzed both groups for: coagulation parameters before, during and after surgery (INR, APTT, factor VII activity), blood and FFP transfusions, operative time, postoperative complications (vascular thrombosis, reoperation for bleeding), postoperative ICU stay, post-transplant hospitalization time and mortality. Patients from the study group (I) had significantly worse coagulation parameters than patients in the control group (II) at the start of the surgical procedure; however, after administration of a bolus of rFVIIa there was immediate correction of coagulation in all recipients. No significant differences in intraoperative blood transfusions were observed between study and control groups (1980 +/- 311.4 mL vs. 1527 +/- 154.2 mL, respectively), operating time (8.7 h vs. 8.9 h) or ICU and hospital stay (7.03 days vs. 6.15 days and 40.89 days vs. 41.1 days). Re-exploration because of bleeding was performed in three patients from group I (10.7%) and in seven patients (11.5%) from group II. No single case of vascular thrombosis was observed in the study group, while in the control group there were three hepatic artery thromboses, two portal vein thromboses and one hepatic vein thrombosis. We conclude that rFVIIa given preoperatively to liver transplant recipients with several risk factors for high intraoperative bleeding adjusts these patients to a normal risk group, without an increased risk for thrombotic complications.

Can a leukocyte depletion filter (LDF) reduce the risk of reintroduction of hepatocellular carcinoma cells?

During liver transplantation for hepatocellular carcinoma (HCC) patients, HCC could theoretically be introduced into the systemic circulation when salvaged blood is used with an autotransfusion device. Several reports have shown that some types of leukocyte depletion filters (LDFs) could completely reduce the risk for reintroducing some types of tumor cells. In this study, we tested the ability of the LDF (RCEZ1T, Pall Biomedical Co, NY, USA) to reduce the risk for reintroducing HCC cells in vitro by using a very sensitive detection method. We divided the test group into 6 groups: group I was 10 cells, group II was 20 cells, group III was 2 x 10(3) cells, group IV was 2 x 10(5) cells, group V was 2 x 10(6) cells, and group VI was 2 x 10(7) cells. The counted cells in 200 mL saline were passed through the RCEZ1T using the force of gravity. To identify the presence of cells, the pellet was resuspended, and polymerase chain reaction (PCR) was performed. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH), a housekeeping gene, was used as a primer. In groups I and II, the HCC cells were completely filtered in all experiments. However, in groups III, IV, and V, the HCC cells were not completely filtered in a few of the repeated experiments, with the unfiltered rate of tumor cells being between 8% and 20%. In group VI, the HCC cells were not completely filtered in all the repeated experiments. In conclusion, the RCEZ1T filter markedly reduced the risk for reintroduction of HCC cells. However, at high HCC cell load the filter cannot completely remove all the tumor cells. Further studies are required to assess the impact in clinical settings.

The management of coagulopathy and blood loss in liver surgery

Liver surgery has long been associated with massive perioperative blood loss and high rates of postsurgery morbidity and mortality. Recent advances in our knowledge of hepatic segmental anatomy have led to the evolution of liver resection, and a growing awareness of the coagulopathy present in cirrhotic patients has produced a greater understanding of the factors influencing surgical hemostasis. This review will examine the risk factors for perioperative hemorrhage in liver disease patients, and will describe current pharmacological, surgical, and radiological methods available for controlling bleeding and achieving effective hemostasis during liver resection and orthotopic liver transplantation (OLT). The potential role of recombinant factor VIIa (rFVIIa) in providing safe hemostasis during such procedures will also be explored. Today, due to careful monitoring and correction of coagulopathy, improved surgical techniques, and judicious patient selection, liver surgery is no longer a high-risk specialty with an unfavorable risk profile, but a safe and widely practiced procedure.

Recombinant activated factor VII (NovoSeventm): addition to replacement therapy in acute, uncontrolled and life-threatening bleeding

BACKGROUND AND OBJECTIVES

Recombinant activated factor VII (rFVIIa, NovoSeven) has been used off-label for various conditions. A protocol for its use in acute, uncontrolled life-threatening bleeding, was devised and employed. A haematologist/transfusion specialist was assigned as a member of the team.

MATERIALS AND METHODS

The clinical data were reviewed and summarized. A scoring system for the assessment and monitoring of coagulopathy was employed. Each parameter of prothrombin time (PT), activated partial thromboplastin time (aPTT), platelet number and fibrinogen level was allocated points according to the degree of abnormality. Three scoring levels emerged.

RESULTS

Between April 2001 and April 2003, 13 patients received rFVIIa for acute, uncontrolled life-threatening bleeding. Nine of 13 patients remained alive for 15 days or longer after rFVIIa infusion. All patients who experienced a reduction or cessation of bleeding after rFVIIa infusion, also had a lower coagulopathy score after replacement therapy, prior to rFVIIa infusion, compared with their score at rFVIIa request. There was a reduction in the average use of blood products after rFVIIa infusion. The coagulopathy score was statistically predictive of response to rFVIIa and survival.

CONCLUSIONS

In an area where very little data exists, we report the usefulness of rFVIIa. We propose that transfusion replacement should aim to correct coagulopathy before infusion of rFVIIa and that a haematologist/transfusion specialist should be involved in the management of these patients. A prognostically significant coagulopathy scoring system is offered.

Perioperative normovolemic anemia is safe in pediatric living-donor liver transplantation

BACKGROUND

Perioperative normovolemic anemia was applied in pediatric living-donor liver transplant (LDLT) recipients with the aim of reducing the use of blood products and decreasing transfusion-related risk.

METHODS

The anemic state was allowed to occur by replacing intraoperative blood and transudate loss with colloid solutions and a discriminate use of packed red blood cells. When blood transfusion was required, the amount of blood replacement was calculated to target a hemoglobin level not higher than 8 to 9 g/dL.

RESULTS

Forty-eight pediatric patients underwent LDLT. Their mean hemoglobin and hematocrit levels were maintained below 9 g/dL and 27%, respectively, at the end of the operation, at the time of extubation, postoperative days 3, 10, and 20, and at the time of discharge. The mean ventilatory support time was 15.7 hr, and no patient required reintubation. Graft function normalized within the first week posttransplant in all patients, and there was no documented case of acute hepatic artery thrombosis. All the patients were discharged with acceptable liver function, and 98% of them remain alive to date.

CONCLUSION

Routine application of perioperative normovolemic anemia in pediatric LDLT has allowed the sparing use of blood products. Approximately half of our patients (42%) did not require intraoperative blood transfusion; 31% of the patients went home without receiving any blood products except 5% albumin. There were no adverse effects with this maneuver, and graft function was good in all patients.

Recombinant factor VIIa in orthotopic liver transplantation: influence on parameters of coagulation and fibrinolysis

The effect of recombinant factor VIIa (rFVIIa) on blood loss was evaluated in cirrhotic patients undergoing orthotopic liver transplantation. In the present study, we explored the effect of rFVIIa on coagulation and fibrinolysis during orthotopic liver transplantation. Coagulation factors, parameters of thrombin generation and parameters of fibrinolysis were measured in six patients who had received a single dose of 80 micro g/kg rFVIIa and in ten controls, during and after orthotopic liver transplantation. Baseline concentrations and course of coagulation factors were similar in patients and controls. Thrombin generation did not rise after the administration of rFVIIa, but showed a sharp increase after reperfusion in patients, as compared with controls. No difference in fibrinolysis was apparent between patients and controls. No evidence of diffuse intravascular coagulation was seen. We conclude that the use of rFVIIa in orthotopic liver transplantation seems to enhance thrombin generation in a localized and time-limited matter, without causing systemic coagulation.

Institutional variability in transfusion practice for liver transplantation

We prospectively evaluated the institutional variability in perioperative transfusion therapy in orthotopic liver transplantation (OLT). Adult OLTs completed during a 12-mo period were studied until the 48th postoperative hour at 8 centers. A multivariate analysis using mixed-effects logistic regression included variables predisposing to blood loss and a center random effect. In addition, the influence of the calculated perioperative hemoglobin (Hb) loss on the individual probability of receiving red blood cells (RBCs), fresh frozen plasma (FFP), and platelets in excess of the overall median were explored. The analysis was performed on 301 cases. The overall median numbers transfused were 5 RBC units, 6 FFP units, and the median platelet dose was 5.10(11), with significant intercentric differences in the proportions of cases given more than the overall median. Intercentric differences remained significant after adjustment for factors independently associated with a large blood component use. Intercentric differences in RBCs, FFP, and platelet use decreased but persisted after adjustment for the perioperative Hb loss. Intercentric differences in RBC use disappeared after adjustment for the postoperative Hb concentration. The significant heterogeneity in transfusion therapy mandates reassessment of the rational use of blood products in OLT.

Review of the clinical practice literature on patient characteristics associated with perioperative allogeneic red blood cell transfusion

There is evidence to suggest that there exists considerable variation in red blood cell (RBC) transfusion practices, especially in the surgical specialties. This is in large part related to difficulties in defining specific transfusion threshold criteria, given that there is no minimum acceptable hemoglobin threshold concentration and there is variability in assigning importance to patient factors. The purpose of this study is to identify patient-related factors that might be associated with the need for allogeneic RBC transfusion in surgical patients. We systematically identified, selected, and reviewed all observational or interventional studies describing patient-specific or related variables associated with the need for allogeneic RBC transfusion in the surgical patient population. We also evaluated the methodological characteristics of the individual studies. Sixty-two studies met our inclusion criteria and were analyzed for this review. Most of these studies were conducted in patients undergoing cardiac surgery (n = 30) and orthopedic surgery (n = 16). Decreased preoperative red cell reserve was most frequently associated with RBC transfusions, being identified as a significant variable in 46 studies. The other factors commonly associated with transfusion were advancing age (n = 28), female gender (n = 21), and small body size (n = 14). Only 2 studies attempted to prospectively validate a predictive model for RBC transfusion based on the variables identified. This systematic review shows that preoperative anemia, advancing age, female gender, and small body size are often associated with perioperative allogeneic RBC transfusion. However, the retrospective nature of most of the studies and the small sample sizes make it difficult to formulate a clinically useful prediction rules regarding allogeneic RBC transfusion. Ongoing research in designing large prospective cohort studies evaluating transfusion patterns are needed to further elucidate how patient characteristics impact the transfusion threshold.

Safety and efficacy of recombinant factor VIIa in patients with liver disease undergoing laparoscopic liver biopsy

BACKGROUND & AIMS

Activated recombinant factor VII (rFVIIa) has been shown to be effective in correcting prolonged prothrombin time (PT) in cirrhotic patients. The main objective of this study was to evaluate the effect of 4 (5, 20, 80, and 120 microg/kg) doses of rFVIIa on correction of PT and the time to achieve hemostasis in cirrhotic patients with coagulopathy who are undergoing laparoscopic liver biopsy.

METHODS

Seventy-one patients (parts I and II) with advanced liver disease (Child-Turcotte B or C), platelet count > or =60,000/mm3, and PT in the range of 3-15 seconds above normal were included in the study. Efficacy endpoints were normalization of PT and time to hemostasis.

RESULTS

PT was corrected to normal levels (<13.1 seconds) in the majority of patients. The duration of normalization of PT was longer in patients treated with higher doses of rFVIIa. Forty-eight (74%) of 65 patients (part II) achieved hemostasis within 10 minutes. No correlation between the time to hemostasis and duration of correction of PT was observed. None of the patients required operative intervention or transfusion of blood/blood products to control bleeding. One thrombotic event and one case of disseminated intravascular coagulation were reported, but both events were considered by the investigator as unlikely to be related to treatment with rFVIIa.

CONCLUSIONS

The results of this study suggest that treatment with rFVIIa may offer benefit for patients with liver disease undergoing laparoscopic biopsy.

Effects of recombinant activated factor VII on coagulation measured by thromboelastography in liver transplantation

Besides the conventional laboratory tests, thromboelastography (TEG) is used to monitor hemostasis during liver transplantation. A previous pilot study suggested a beneficial effect of recombinant activated factor VII (rFVIIa) on transfusion requirements in liver transplantation. In the present study, we assess the effects of rFVIIa on coagulation variables and TEG. In six study patients, the prothrombin time (PT), the activated partial thromboplastin time (aPTT) and TEG variables [reaction time (r), kinetic time (k), or clot formation time, alpha angle (alpha), and maximal amplitude (MA)] were recorded before and after the administration of a bolus of 80 microg/kg rFVIIa. These patients were compared with six controls who did not receive rFVIIa. In contrast with the control group, a significant shortening of PT (P = 0.028) and aPTT (P = 0.028), r (P = 0.046) and k (P = 0.043) values, and a significant incline of the alpha angle (P = 0.028) were noticed after injection of rFVIIa, whereas MA increased not significantly (P = 0.075). rFVIIa rapidly improved coagulation variables in liver transplant patients including PT and aPTT. Of the TEG variables, r, k and alpha angle significantly improved, and MA showed a trend to increase. These data suggest that rFVIIa not only influences the speed of clot formation, but also the physical properties of the clot, which cannot be detected by routine coagulation tests.

Intraoperative blood losses and transfusion requirements during adult liver transplantation remain difficult to predict

PURPOSE

To identify preoperative factors associated with high blood losses during liver transplantation for chronic end-stage liver disease.

METHODS

Four hundred and ten consecutive patients were included in this retrospective study. Blood losses were calculated, based on transfusion requirements. The population was divided into two groups: the upper quartile was defined as the high blood loss (HBL) group and the lower three quartiles as the low blood loss group. Fourteen preoperative variables were collected. Qualitative variables consisted of the type of hepatopathy, Child-Pugh's classification, sex, the surgical team's experience, previous abdominal surgery and portal hypertension. Quantitative variables were age, hemoglobin concentration Hb, platelet count, prothrombin time, activated partial thromboplastin time, fibrinogen concentration, fibrin degradation products (FDP) and euglobulin lysis time. Univariate analysis and stepwise multivariate analysis were conducted.

RESULTS

Patients in the HBL group required 12 units of red blood cell or more to maintain a Hb >/= 100g*L(-1). HBL was associated with severe liver disease, previous abdominal surgery, use of a venovenous bypass and little surgical experience in orthotopic liver transplantation (OLT). In the HBL group several hemostatic parameters were more disturbed before surgery. The multivariate analysis disclosed three independent variables associated with HBL: Hb and FDP concentrations and previous upper abdominal surgery. When combined, these resulted in a high specificity (98%) but low sensitivity to predict blood loss.

CONCLUSION

Despite our efforts we were unable to identify predictive risk factors of bleeding during OLT even in a homogeneous population. Centres should evaluate their practice individually in an attempt to identify patients at high risk of being transfused.

Reduced transfusion requirements by recombinant factor VIIa in orthotopic liver transplantation: a pilot study

BACKGROUND

Large transfusion requirements, i.e., excessive blood loss, during orthotopic liver transplantation (OLT) are correlated with increased morbidity and mortality. Recombinant factor VIIa (rF-VIIa) has been shown to improve hemostasis in a variety of conditions, but has never been studied in liver transplantation.

METHODS

We performed a single-center, open-label, pilot study in adult patients undergoing OLT for cirrhosis Child-Pugh B or C, to assess efficacy and safety of rFVIIa. rFVIIa (80 microg/kg) was administered at the start of the operation, to be repeated according to predefined criteria. Packed red blood cells (RBC), fresh-frozen plasma, and platelet concentrates were administered according to predefined criteria. Perioperative transfusion requirements in study patients were compared with matched controls.

RESULTS

Six patients were enrolled in the study. All received a single dose of rFVIIa. Transfusion requirements (given as median, with range in parentheses) were lower in the study group than in matched controls: 1.5 (0-5) vs. 7 (2-18) units of allogeneic RBC (P=0.006), 0 (0-2) vs. 3.5 (0-23) units of autologous RBC (P=0.043), total amount of RBC 3 (0-5) vs. 9 (4-40) units (P=0.002). Transfused fresh-frozen plasma was 1 (0-7) vs. 8 (2-35) units (P=0.011). Blood loss was 3.5 L (1.4-5.3) vs. 9.8 L (3.7-35.0) (P=0.004). One study patient developed a hepatic artery thrombosis at day 1 postoperatively.

CONCLUSIONS

A single dose of 80 microg/kg rFVIIa significantly reduced transfusion requirements during OLT. Further study is needed to establish the optimally effective and safe dose of rFVIIa in orthotopic liver transplantation.