Effect of antifibrinolytic drugs on transfusion requirement and blood loss during orthotopic liver transplantation: Results from a single center

Safety and Efficacy of Tranexamic Acid to Minimise Perioperative Bleeding in Hepatic Surgery: A Systematic Review and Meta-Analysis

INTRODUCTION

Perioperative bleeding poses a major risk during liver surgery, which can result in increased transfusion requirements, morbidity, and mortality. Tranexamic acid (TXA) effectively reduces perioperative bleeding and transfusion requirements in trauma patients. However, there remains a lack of evidence of its use in liver surgery. This meta-analysis of randomised controlled trials evaluated the efficacy and safety of TXA in liver resection and transplantation.

METHOD

A comprehensive search of Medline, Embase, CENTRAL and Clinicaltrials.gov databases was undertaken to identify studies from January 1947 to September 2021. The outcomes of the need for blood transfusion, thromboembolic events and mortality were extracted from the included studies. Quantitative pooling of data was based on the random effects model.

RESULTS

Six studies reporting on 429 patients were included. TXA reduced the need for perioperative blood transfusion in liver resection and transplantation (OR 0.09; 95% CI 0.01 to 0.72). More importantly, TXA did not increase the incidence of thromboembolic events (OR 2.22; 95% CI 0.47 to 10.43) and mortality (OR 0.60; 95% CI 0.13 to 2.76).

CONCLUSION

TXA safely reduces the need for blood transfusion in patients undergoing liver resection and transplantation.

The effect of tranexamic acid on hidden bleeding in older intertrochanteric fracture patients treated with PFNA

OBJECTIVE

To investigate the effect of tranexamic acid (TXA) on hidden bleeding in older intertrochanteric fracture patients treated with intramedullary nails.

METHOD

Between January 2016 and January 2017, 100 cases of intertrochanteric fractures eligible for the study were treated with proximal femoral nail antirotation (PFNA) in our hospital. All patients were divided into two groups of 50 patients each: the TXA group and a blank control group. In the TXA group, all patients received TXA at a dose of 10 mg/kg^-1 intravenously, 10 min preoperatively and 5 h postoperatively. The control group did not receive TXA. We recorded the volume of intraoperative blood loss and postoperative drainage, and the need for postoperative blood transfusion and transfusion volume for all patients. Blood routine examination was performed on the day of surgery and 2 days postoperatively. We calculated the total blood loss and hidden blood loss in the two groups separately according to the Gross equation. All patients underwent deep vein ultrasound of the lower limbs preoperatively and 1 week postoperatively to detect thrombosis.

RESULTS

Compared with controls, patients in the TXA group had lower: overt bleeding (50.59 ml; p = .012), total blood loss (181.58 ml; p = .005), hidden blood loss (130.64 ml; p = .037), volume of blood transfusion (110.0 ml; p = .019), and 20% lower transfusion rate compared with the control group. Patients receiving short-nail fixation had significantly lower hidden blood loss compared with patients receiving long-nail fixation (p < .05). However, we found no statistically significant difference in the incidence of deep vein thrombosis in the lower limbs between the two groups (p = .938).

CONCLUSION

TXA significantly reduced hidden blood loss in older intertrochanteric fracture patients treated with intramedullary nails without an increased risk of thrombosis in lower limb deep veins.

Pyrolo[1,2:4,5]-1,4-dioxopyrazino[1,2:1,6]pyrido[3,4-b]indoles: a group of urokinase inhibitors, their synthesis, and stereochemistry-dependent activity

Antifibrinolytic agents are required during complex surgeries to decrease bleeding; their pro-thrombotic potency and efficacy in causing hemostasis has attracted much attention. To discover new inhibitors of urokinase with high selectivity for antifibrinolytic effects over pro-thrombotic effects, the 12-position of (5aS,12S,14aS)- and (5aS,12R,14aS)-5,14-dioxo-1,2,3,5,5a,6,11, 12,14,14a-decahydro-5H,14H-pyrolo[1,2:4,5]pyrazino[1,2:1,6]pyrido[3,4-b]indoles were modified with L-Ala, L-Asp, L-Phe, L-Trp, L-Lys, L-Ser, Gly, and L-Leu to provide 16 (5aS,12S,14aS) and (5aS,12R,14aS) derivatives. In a murine bleeding model, the (5aS,12S,14aS) derivatives containing L-Ala, L-Asp, L-Phe, and L-Trp induced blood coagulation for the treated mice; they also stimulated thrombus formation in a rat thrombosis model, but the other derivatives inhibited thrombosis. The most potent compound, the L-Asp derivative, showed a good therapeutic window: the minimum effective dose for coagulation was <1 nmol kg(-1), whereas at 10 nmol kg(-1), no pro-thrombotic effect was observed. This type of coagulation action was correlated with a mechanism of urokinase inhibition, and these results could lead to the discovery of novel urokinase inhibitors.

Antifibrinolytics in liver surgery

Hyperfibrinolysis, a known complication of liver surgery and orthotopic liver transplantation (OLT), plays a significant role in blood loss. This fact justifies the use of antifibrinolytic drugs during these procedures. Two groups of drug namely lysine analogues [epsilon aminocaproic acid (EACA) and tranexamic acid (TA)] and serine-protease-inhibitors (aprotinin) are frequently used for this purpose. But uniform data or guidelines on the type of antifibrinolytic drugs to be used, their indications and correct dose, is still insufficient. Antifibrinolytics behave like a double-edged sword. On one hand, there are benefits of less transfusion requirements but on the other hand there is potential complication like thromboembolism, which has been reported in several studies. We performed a systematic search in PubMed and Cochrane Library, and we included studies wherein antifibrinolytic drugs (EACA, TA, or aprotinin) were compared with each other or with controls/placebo. We analysed factors like intraoperative red blood cell and fresh frozen plasma requirements, the perioperative incidence of hepatic artery thrombosis, venous thromboembolic events and mortality. Among the three drugs, EACA is least studied. Use of extensively studied drug like aprotinin has been restricted because of its side effects. Haemostatic effect of aprotinin and tranexamic acid has been comparable. However, proper patient selection and individualized treatment for each of them is required. Purpose of this review is to study various clinical trials on antifibrinolytic drugs and address the related issues like benefits claimed and associated potential complications.

From Cerius² based stereoview to mouse and enzyme: the model systems for discovery of novel urokinase inhibitors

Antifibrinolytic therapy during major complex surgery could reduce blood loss and allogeneic transfusion. Novel antagonists of the plasminogen activator and the corresponding model system are of clinical importance. In this paper (1S,2'S,3S)-1-[2-(S)-carboxylindolemethylenemethineaminoeth-1-yl]-2,3,4,5-tetrahydropyrolo[1,2:1,6]pyrazino[3,4:2,3]-1,2,3,4-tetrahydrocarboline-2,5-dione (CIPPC) was presented as a novel antagonist of plasminogen activator, and its blood coagulation and action mechanism were investigated by using a model system which consisted of a mouse-tail bleeding assay, in vitro and in vivo fibrinolysis inhibition assays, a thrombus formation assay and a plasminogen (PLG) electrophoresis assay.