Antifibrinolytics in liver surgery

Tranexamic acid versus placebo to reduce perioperative blood transfusion in patients undergoing liver resection: protocol for the haemorrhage during liver resection tranexamic acid (HeLiX) randomised controlled trial

INTRODUCTION

Despite use of operative and non-operative interventions to reduce blood loss during liver resection, 20%-40% of patients receive a perioperative blood transfusion. Extensive intraoperative blood loss is a major risk factor for postoperative morbidity and mortality and receipt of blood transfusion is associated with serious risks including an association with long-term cancer recurrence and overall survival. In addition, blood products are scarce and associated with appreciable expense; decreasing blood transfusion requirements would therefore have health system benefits. Tranexamic acid (TXA), an antifibrinolytic, has been shown to reduce the probability of receiving a blood transfusion by one-third for patients undergoing cardiac or orthopaedic surgery. However, its applicability in liver resection has not been widely researched.

METHODS AND ANALYSIS

This protocol describes a prospective, blinded, randomised controlled trial being conducted at 10 sites in Canada and 1 in the USA. 1230 eligible and consenting participants will be randomised to one of two parallel groups: experimental (2 g of intravenous TXA) or placebo (saline) administered intraoperatively. The primary endpoint is receipt of blood transfusion within 7 days of surgery. Secondary outcomes include blood loss, postoperative complications, quality of life and 5-year disease-free and overall survival.

ETHICS AND DISSEMINATION

This trial has been approved by the research ethics boards at participating centres and Health Canada (parent control number 177992) and is currently enrolling participants. All participants will provide written informed consent. Results will be distributed widely through local and international meetings, presentation, publication and ClinicalTrials.gov.

TRIAL REGISTRATION NUMBER

NCT02261415.

Comparison between epsilon-aminocaproic acid and tranexamic acid for total hip and knee arthroplasty: A meta-analysis

BACKGROUND

The aim was to compare the efficacy and safety of epsilon-aminocaproic acid (EACA) and tranexamic acid (TXA) in total hip arthroplasty (THA) and total knee arthroplasty (TKA).

METHODS

Potential academic articles were identified from the Cochrane Library, Springer, PubMed, and ScienceDirect databases from inception to December 2019. Randomized controlled trials (RCTs) and non-RCTs involving EACA and TXA in THA or TKA were included. Pooled data were analyzed using RevMan 5.1.

RESULTS

Three RCTs and three non-RCTs met the inclusion criteria. The present meta-analysis reveals that EACA is associated with significantly more blood loss than TXA. No significant differences were identified in terms of blood transfusion rate, transfusion units, hemoglobin (Hb) level at discharge, operation time, length of hospital stay, deep venous thrombosis (DVT), or 30-day readmission.

CONCLUSIONS

Compared with TXA, EACA led to more blood loss in patients undergoing THA or TKA. However, there was no significant difference in the blood transfusion rate, transfusion units, Hb level at discharge, operation time, length of hospital stay, DVT, or 30-day readmission between groups.

Association between viscoelastic tests-guided therapy with synthetic factor concentrates and allogenic blood transfusion in liver transplantation: a before-after study

Background

Perioperative bleeding and transfusion are important causes of morbidity and mortality in patients undergoing liver transplantation. The aim of this study is to assess whether viscoelastic tests-guided therapy with the use of synthetic factor concentrates impact transfusion rates of hemocomponents in adult patients undergoing liver transplantation.

Methods

This is an interventional before-after comparative study. Patients undergoing liver transplantation before the implementation of a protocol using thromboelastometry and synthetic factor concentrates were compared to patients after the implementation. Primary outcome was transfusion of any hemocomponents. Secondary outcomes included: transfusion of red blood cells (RBC), fresh frozen plasma (FFP), cryoprecipitate or platelets, clinical complications, length of stay and in-hospital mortality.

Results

A total of 183 patients were included in the control and 54 in the intervention phase. After propensity score matching, the proportion of patients receiving any transfusion of hemocomponents was lower in the intervention phase (37.0 vs 58.4%; OR, 0.42; 95% CI, 0.20–0.87; p = 0.019). Patients in the intervention phase received less RBC (30.2 vs 52.5%; OR, 0.21; 95% CI, 0.08–0.56; p = 0.002) and FFP (5.7 vs 27.3%; OR, 0.11; 95% CI, 0.03–0.43; p = 0.002). There was no difference regarding transfusion of cryoprecipitate and platelets, complications related to the procedure, hospital length of stay and mortality.

Conclusions

Use of a viscoelastic test-guided transfusion algorithm with the use of synthetic factor concentrates reduces the transfusion rates of allogenic blood in patients submitted to liver transplantation.

Trial registration

This trial was registered retrospectively on November 15th, 2018 – clinicaltrials.gov – Identifier: NCT03756948.

Electronic supplementary material

The online version of this article (10.1186/s12871-018-0664-8) contains supplementary material, which is available to authorized users.

Tranexamic acid therapy for postoperative bleeding after bariatric surgery

BACKGROUND

Tranexamic acid reduces blood loss associated with various surgical procedures. Postoperative bleeding caused by dissection or bleeding of the enteric staple lines is a well-known complication following bariatric surgery. Reoperation in order to restore hemostasis is frequently necessary (up to 2.5% in literature). The effect of conservative therapy using tranexamic acid for postoperative hemorrhage after bariatric surgery is still very much a novel technique. The aim is to present our results (reoperation rate and thrombo-embolic complication rate) of tranexamic acid therapy for postoperative bleeding after bariatric surgery in comparison to those in existing literature.

METHODS

We retrospectively reviewed 1388 patients who underwent bariatric surgery (laparoscopic gastric bypass or laparoscopic gastric sleeve). Use of tranexamic acid, reoperation rate, transfusion rate and rate of thrombo-embolic complications were reviewed.

RESULTS

Forty-five of 1388 (3.2%) total patients experienced significant hemorrhage after bariatric surgery. Tranexamic acid was administered in 44 of these patients. A failure of the treatment with tranexamic acid was observed in four patients. The incidence of reoperation was 0.4% for the entire population. No thrombo-embolic complications were registered for patients receiving tranexamic acid.

CONCLUSION

These findings suggest that the administration of tranexamic acid appears to be safe in reducing the reoperation rate for bleeding after bariatric surgery.

Fibrinolytic System Changes in Liver Surgery: A Pilot Observational Study

Introduction: Bleeding occurs frequently in liver surgery. Unbalance between tissue plasminogen activator (t-PA) and plasminogen activator inhibitor-1 (PAI-1) concentrations might increase bleeding. Our aim was to analyze perioperative fibrinolytic changes during liver surgery.

Materials and Methods: We evaluated 15 patients for inclusion into a prospective pilot study of liver surgery. We assessed fibrinolysis by plasma PAI-1 and t-PA: before surgery (T1), before Pringle maneuver (PM;T2), at the end of surgery (T3) and 24 h postoperatively (T4), and registered demographic and laboratory data, extent and duration of surgery, hemodynamic parameters, blood loss, and transfused volumes of blood products. Data presented as mean ± SD. Significance at P < 0.05.

Results: After exclusion of six patients only undergoing biopsies, we included six women and three men aged 49.1 ± 19.6 years; two patients with liver metastases of colorectal cancer and hepatocellular carcinoma, respectively, two with focal nodular hyperplasia, two with hepatic hemangioma, and one with angiomyolipoma. Six patients underwent PM. PAI-1 plasma concentration (n = 9) rose from 6.25 ± 2.25 at T1 through 17.30 ± 14.59 ng/ml at T2 and 28.74 ± 20.4 (p = 0.007) and 22.5 ± 16.0 ng/ml (p = 0.04), respectively, at T3 and T4. Correspondingly, t-PA plasma concentration (n = 9) increased from 4.76 ± 3.08 ng/ml at T1 through 8.00 ± 5.10 ng/ml (p = 0.012) at T2 and decreased to 4.25 ± 2.29 ng/ml and 3.04 ± 3.09 at T3 and T4, respectively. Plasma t-PA level at T2 was significantly different from those at T1, T3, and T4 (p < 0.004). In PM patients, t-PA levels increased from T1, peaked at T2 (p = 0.001), and subsequently decreased at T3 and T4 (p = 0.011 and p = 0.037), respectively. Mean blood loss was 1,377.7 ± 1,062.8 ml; seven patients received blood products. Patients with higher PAI-1 levels at T3 received more fresh frozen plasma (r = 0.79; p = 0.01) and red blood cells (r = 0.88; p = 0.002).

Conclusions: During liver surgery, fibrinolysis increased, as evidenced by rises in plasma PAI-1and t-PA, especially after start of surgery and following PM. Transfused volumes of blood products correlated with higher plasma concentrations of PAI-1. Confirming this tendency requires a larger cohort of patients.

Epsilon-aminocaproic acid prevents high glucose and insulin induced-invasiveness in MDA-MB-231 breast cancer cells, modulating the plasminogen activator system

Obesity and type II diabetes mellitus have contributed to the increase of breast cancer incidence worldwide. High glucose concentration promotes the proliferation of metastatic cells, favoring the activation of the plasminogen/plasmin system, thus contributing to tumor progression. The efficient formation of plasmin is dependent on the binding of plasminogen to the cell surface. We studied the effect of ε-aminocaproic acid (EACA), an inhibitor of the binding of plasminogen to cell surface, on proliferation, migration, invasion, epithelial-mesenchymal transition (EMT), and plasminogen activation system, in metastatic MDA-MB-231 breast cancer cells grown in a high glucose microenvironment and treated with insulin. MDA-MB-231 cells were treated with EACA 12.5 mmol/L under high glucose 30 mmol/L (HG) and high glucose and insulin 80 nmol/L (HG-I) conditions, evaluating: cell population growth, % of viability, migratory, and invasive abilities, as well as the expression of uPA, its receptor (uPAR), and its inhibitor (PAI-1), by real-time reverse transcription-polymerase chain reaction (RT-PCR) and Western blot, MMP-2 and MMP-9 mRNAs were evaluated by RT-PCR. Markers of EMT were evaluated by Western blot. Additionally, the presence of active uPA was studied by gel zymography, using casein-plasminogen as substrates. EACA prevented the increase in cell population, migration and invasion induced by HG and insulin, which was associated with the inhibition of EMT and the attenuation of HG- and insulin-dependent expression of uPA, uPAR, PAI-1, MMP-2, MMP-9, α-enolase (ENO A), and HCAM. The interaction of plasminogen to the cell surface and plasmin formation are mediators of the prometastasic action of hyperglycemia and insulin, potentially, EACA can be employed in the prevention and as adjuvant treatment of breast tumorigenesis promoted by hyperglycemia and insulin.

The prophylactic role of tranexamic acid to reduce blood loss during radical surgery: A prospective study

BACKGROUND

The radical surgical procedures are associated with perioperative blood loss. This study was aimed to evaluate the clinical efficacy and safety of tranexamic acid in reducing perioperative blood loss in patients undergoing radical surgery.

MATERIALS AND METHODS

Sixty ASA class I and II adult consented female patients, scheduled for elective radical surgery and met the inclusion criterion, were blindly randomized into two groups to receive either intravenous 1 g tranexamic acid 20 min before skin incision or an equivalent volume of normal saline as placebo (P). All patient's total blood loss was measured and recorded perioperatively at the 12(th)h postoperatively. The preoperative and postoperative hemoglobin, hematocrit values, serum creatinine, activated thromboplastin time, prothombin time, thrombocyte count, fibrinogen, D-dimer, and symptoms of pulmonary embolism were comparatively evaluated.

RESULTS

The tranexamic acid significantly reduced the quantity of total blood loss, 576 ± 53 mL in study group as compared to 823 ± 74 mL in the control group (P<0.01). Postoperatively hematocrit values were higher in the tranexamic acid group. The coagulation profile did not differ between the groups, but D-dimer concentrations were increased in the control group. No complications or adverse effects were reported in the either group.

CONCLUSION

The prophylactic administration of tranexamic acid has effectively reduced theblood loss and transfusion needs during radical surgery without any adverse effects or complication of thrombosis.

Epsilon-aminocaproic acid improves postrecirculation hemodynamics by reducing intraliver activated protein C consumption in orthotopic liver transplantation

BACKGROUND

Activated protein C (APC) is related to regulating the inflammatory response and hemodynamic stability upon reperfusion in cardiac operations and orthotopic liver transplantation (OLT). Epsilon-aminocaproic acid (EACA) is frequently used to treat fibrinolysis during OLT. It also has inhibitory effects related to the inflammatory response. However, it remains to be determined whether EACA can attenuate intraliver APC consumption and improve hemodynamic stability after reperfusion during OLT.

METHODS

Fifty-nine recipients were randomized to receive either EACA (150 mg kg(-1) given intravenously prior to incision, followed by 15 mg kg(-1) h(-1) infusion until 2 h after the graft reperfusion) or the same volume of saline. Blood samples to assess plasma APC and protein C were obtained immediately before and after reperfusion from the inferior caval effluent or the portal veins for calculation of transliver differences (Δ). Hemodynamics and vasoactive medication use during the reperfusion period were observed in both groups.

RESULTS

No transhepatic changes in protein C were found in either group. Immediately after reperfusion, a marked intraliver consumption of APC was noted in all recipients (P < 0.001), and intraliver consumption of APC in the control group was greater than that in the EACA-treated group (P < 0.05). Fewer requirements for vasoactive medication use after reperfusion and better initial graft function were noted in the EACA-treated group (P < 0.05).

CONCLUSIONS

EACA can attenuate intraliver APC consumption and improve hemodynamic stability after reperfusion and initial graft function during OLT.

Low dose tranexamic acid effect on post-coronary artery bypass grafting bleeding

Objective

This study investigated the effects of low-dose tranexamic acid on post-coronary artery bypass surgery bleeding .

Background

Diffuse microvascular bleeding is still a common problem after cardiac procedures. This study was designed to evaluate the hemostatic effects of low-dose tranexamic acid in on-pump coronary artery bypass graft surgery.

Methods

In this prospective randomized placebo-controlled study, 150 patients who were candidates for coronary artery bypass were enrolled and randomly assigned to 1 of 2 groups (tranexamic acid or placebo). Total drainage volume and the need for transfusion as well as surgical complications were recorded and compared in the 2 groups.

Results

There was significantly less mediastinal chest tube drainage up to 48 h in the tranexamic acid group (432 ± 210 mL) compared to the placebo group (649 ± 235 mL, p = 0.006). In the placebo group, 43 (58%) patients were given allogeneic blood during hospital stay compared to 22 (25%) in the tranexamic acid group ( p < 0.001). No significant difference in postoperative complications was seen.

Conclusion

The use of low-dose tranexamic acid can significantly reduce blood loss and need for transfusion, with no increase in complications.

Blood loss, predictors of bleeding, transfusion practice and strategies of blood cell salvaging during liver transplantation

Blood loss during liver transplantation (OLTx) is a common consequence of pre-existing abnormalities of the hemostatic system, portal hypertension with multiple collateral vessels, portal vein thrombosis, previous abdominal surgery, splenomegaly, and poor “functional” recovery of the new liver. The intrinsic coagulopathic features of end stage cirrhosis along with surgical technical difficulties make transfusion-free liver transplantation a major challenge, and, despite the improvements in understanding of intraoperative coagulation profiles and strategies to control blood loss, the requirements for blood or blood products remains high. The impact of blood transfusion has been shown to be significant and independent of other well-known predictors of posttransplant-outcome. Negative effects on immunomodulation and an increased risk of postoperative complications and mortality have been repeatedly demonstrated. Isovolemic hemodilution, the extensive utilization of thromboelastogram and the use of autotransfusion devices are among the commonly adopted procedures to limit the amount of blood transfusion. The use of intraoperative blood salvage and autologous blood transfusion should still be considered an important method to reduce the need for allogenic blood and the associated complications. In this article we report on the common preoperative and intraoperative factors contributing to blood loss, intraoperative transfusion practices, anesthesiologic and surgical strategies to prevent blood loss, and on intraoperative blood salvaging techniques and autologous blood transfusion. Even though the advances in surgical technique and anesthetic management, as well as a better understanding of the risk factors, have resulted in a steady decrease in intraoperative bleeding, most patients still bleed extensively. Blood transfusion therapy is still a critical feature during OLTx and various studies have shown a large variability in the use of blood products among different centers and even among individual anesthesiologists within the same center. Unfortunately, despite the large number of OLTx performed each year, there is still paucity of large randomized, multicentre, and controlled studies which indicate how to prevent bleeding, the transfusion needs and thresholds, and the “evidence based” perioperative strategies to reduce the amount of transfusion.

Effect of tranexamic acid on surgical bleeding: systematic review and cumulative meta-analysis

OBJECTIVE

To assess the effect of tranexamic acid on blood transfusion, thromboembolic events, and mortality in surgical patients.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Cochrane central register of controlled trials, Medline, and Embase, from inception to September 2011, the World Health Organization International Clinical Trials Registry Platform, and the reference lists of relevant articles.

STUDY SELECTION

Randomised controlled trials comparing tranexamic acid with no tranexamic acid or placebo in surgical patients. Outcome measures of interest were the number of patients receiving a blood transfusion; the number of patients with a thromboembolic event (myocardial infarction, stroke, deep vein thrombosis, and pulmonary embolism); and the number of deaths. Trials were included irrespective of language or publication status.

RESULTS

129 trials, totalling 10,488 patients, carried out between 1972 and 2011 were included. Tranexamic acid reduced the probability of receiving a blood transfusion by a third (risk ratio 0.62, 95% confidence interval 0.58 to 0.65; P<0.001). This effect remained when the analysis was restricted to trials using adequate allocation concealment (0.68, 0.62 to 0.74; P<0.001). The effect of tranexamic acid on myocardial infarction (0.68, 0.43 to 1.09; P = 0.11), stroke (1.14, 0.65 to 2.00; P = 0.65), deep vein thrombosis (0.86, 0.53 to 1.39; P = 0.54), and pulmonary embolism (0.61, 0.25 to 1.47; P=0.27) was uncertain. Fewer deaths occurred in the tranexamic acid group (0.61, 0.38 to 0.98; P = 0.04), although when the analysis was restricted to trials using adequate concealment there was considerable uncertainty (0.67, 0.33 to 1.34; P = 0.25). Cumulative meta-analysis showed that reliable evidence that tranexamic acid reduces the need for transfusion has been available for over 10 years.

CONCLUSIONS

Strong evidence that tranexamic acid reduces blood transfusion in surgery has been available for many years. Further trials on the effect of tranexamic acid on blood transfusion are unlikely to add useful new information. However, the effect of tranexamic acid on thromboembolic events and mortality remains uncertain. Surgical patients should be made aware of this evidence so that they can make an informed choice.