The never ending success story of tranexamic acid in acquired bleeding

Tranexamic acid is associated with post-injury mortality in a resource-limited trauma system: Findings from the epidemiology and outcomes of prolonged trauma care cohort study

BACKGROUND

Injury-related deaths claim millions of lives annually, with severe hemorrhage a leading cause. This study assesses tranexamic acid (TXA) administered within 3 h post-injury on mortality in trauma patients.

STUDY DESIGN AND METHODS

We conducted secondary database analysis of EpiC, a multicenter, prospective cohort of trauma patients in South Africa. We compared mortality between severely injured patients at risk for traumatic hemorrhage receiving TXA within 3 h post-injury versus untreated patients. Inverse probability of treatment weighting adjusted for confounders, and multivariate logistic regression assessed 24-h mortality, with extended secondary outcome analyses.

RESULTS

Of 3607 analyzed patients, 502 received TXA within 3 h. TXA reduced 24-h mortality by 38% (marginal odds ratio [mOR], 0.62; 95% confidence interval [CI], 0.49-0.78) versus untreated patients. Similar reductions were observed for longer-term mortality. Subgroup analyses revealed reduced mortality when TXA was given within 2 h post-injury (mOR, 0.57; 95% CI, 0.45-0.73), doses of 1 g of TXA within 3 h (mOR, 0.73; 95% CI, 0.56-0.94), and those with the highest risk of hemorrhage (mOR, 0.40; 95% CI, 0.30-0.53). The 24-h mortality reduction was significant for patients with penetrating injury (mOR, 0.58; 95% CI, 0.43-0.78) but not for blunt injury patients. Sensitivity analyses confirmed the robustness of these findings, with TXA consistently reducing mortality odds by 28%-39% across subgroups.

DISCUSSION

Early TXA administration significantly reduced mortality in trauma patients, especially with penetrating injuries and those with the highest risk of hemorrhage. One-gram dosing was as effective as higher doses, and mortality reduction was notable when TXA was given within 2 h post-injury. These findings support TXA use in resource-limited trauma protocols.

Clinical, Laboratory, and Molecular Aspects of Factor V Deficiency

Factor V (FV) is a glycoprotein that plays a pivotal role in hemostasis, being involved in coagulant and anticoagulant pathways. Congenital FV deficiency is a rare bleeding disorder with an incidence of 1 per million live births, considering the most severe homozygous form. FV deficiency is diagnosed using routine coagulation tests and FV activity assays. Several mutations, including missense, nonsense, and frameshift, have been detected in the F5 gene. Clinical symptoms are variable, ranging from mild ecchymoses and mucosal bleeding to life-threatening intracranial hemorrhage. The mainstay of treatment includes fresh-frozen plasma, preferentially virus-inactivated. In this narrative review, we provide an update of the main laboratory, molecular, clinical, and therapeutic features of inherited FV deficiency.

Tranexamic acid: a narrative review of its current role in perioperative medicine and acute medical bleeding

Purpose

Tranexamic acid (TXA) is the most widely prescribed antifibrinolytic for active bleeding or to prevent surgical bleeding. Despite numerous large multi-center randomized trials involving thousands of patients being conducted, TXA remains underutilized in indications where it has demonstrated efficacy and a lack of harmful effects. This narrative review aims to provide basic concepts about fibrinolysis and TXA's mode of action and is focused on the most recent and important trials evaluating this drug in different hemorrhagic situations.

Methods

We selected every low bias RCT, and we highlighted their strengths and limitations throughout this review.

Principal findings

While TXA appears to have a favorable benefit-risk ratio in most situations (trauma, obstetrics, at-risk for bleeding surgeries) evidence of benefit is lacking in certain medical settings (SAH, digestive bleeding).

Conclusion

Although in some situations the drug's effect on significant outcomes is modest, its favorable safety profile allows it to be recommended for trauma patients, in obstetrics, and in scheduled surgeries at risk of bleeding. However, it cannot be recommended in cases of spontaneous intracranial bleeding, subarachnoid hemorrhage (SAH), or gastrointestinal bleeding.

Tranexamic acid - a promising hemostatic agent with limitations: a narrative review

Tranexamic acid (TXA) is a synthetic antifibrinolytic agent that has been used for several decades to reduce blood loss during surgery and after trauma. TXA was traditionally used to reduce bleeding in various clinical settings such as menorrhagia, hemophilia, or other bleeding disorder. Numerous studies have demonstrated the efficacy of TXA in reducing blood loss and the need for transfusions. Interest in the potential applications of TXA beyond its traditional use has been growing recently, with studies investigating the use of TXA in postpartum hemorrhage, cardiac surgery, trauma, neurosurgery, and orthopedic surgery. Despite its widespread use and expanding indications, data regarding the safe and appropriate use of TXA is lacking. Recent clinical trials have found various potential risks and limitations in the long-term benefits of TXA. This narrative review summarizes the clinical applications and limitations of TXA.

Tranexamic Acid: An Evergreen Hemostatic Agent

Tranexamic acid (TXA) is an important antifibrinolytic agent, which inhibits plasminogen activation and fibrinolysis. Several controlled randomized trials have investigated the role of TXA in preventing or decreasing blood loss across different surgical interventions or medical conditions characterized by excessive bleeding, consistently documenting its effectiveness and safety. Although the first clinical use of TXA dates back to more than 60 years ago, TXA remains the focus of intense research. This narrative review summarizes the more recent results and indications on the clinical use of TXA.

Intrapulmonary administration of recombinant activated factor VII in pediatric, adolescent, and young adult oncology and hematopoietic cell transplant patients with pulmonary hemorrhage

Introduction

Diffuse alveolar hemorrhage (DAH) is a devastating disease process with 50-100% mortality in oncology and hematopoietic cell transplant (HCT) recipients. High concentrations of tissue factors have been demonstrated in the alveolar wall in acute respiratory distress syndrome and DAH, along with elevated levels of tissue factor pathway inhibitors. Activated recombinant factor VII (rFVIIa) activates the tissue factor pathway, successfully overcoming the tissue factor pathway inhibitor (TFPI) inhibition of activation of Factor X. Intrapulmonary administration (IP) of rFVIIa in DAH is described in small case series with successful hemostasis and minimal complications.

Methods

We completed a single center retrospective descriptive study of treatment with rFVIIa and outcomes in pediatric oncology and HCT patients with pulmonary hemorrhage at a quaternary hematology/oncology hospital between 2011 and 2019. We aimed to assess the safety and survival of patients with pulmonary hemorrhage who received of IP rFVIIa.

Results

We identified 31 patients with pulmonary hemorrhage requiring ICU care. Thirteen patients received intrapulmonary rFVIIa, while eighteen patients did not. Overall, 13 of 31 patients (41.9%) survived ICU discharge. ICU survival (n=6) amongst those in the IP rFVIIa group was 46.2% compared to 38.9% (n=7) in those who did not receive IP therapy (p=0.69). Hospital survival was 46.2% in the IP group and 27.8% in the non-IP group (p=0.45). There were no adverse events noted from use of IP FVIIa.

Conclusions

Intrapulmonary rFVIIa can be safely administered in pediatric oncology patients with pulmonary hemorrhage and should be considered a viable treatment option for these patients.

Fibrinolytic-deficiencies predispose hosts to septicemia from a catheter-associated UTI

Catheter-associated urinary tract infections (CAUTIs) are amongst the most common nosocomial infections worldwide and are difficult to treat partly due to development of multidrug-resistance from CAUTI-related pathogens. Importantly, CAUTI often leads to secondary bloodstream infections and death. A major challenge is to predict when patients will develop CAUTIs and which populations are at-risk for bloodstream infections. Catheter-induced inflammation promotes fibrinogen (Fg) and fibrin accumulation in the bladder which are exploited as a biofilm formation platform by CAUTI pathogens. Using our established mouse model of CAUTI, here we identified that host populations exhibiting either genetic or acquired fibrinolytic-deficiencies, inducing fibrin deposition in the catheterized bladder, are predisposed to severe CAUTI and septicemia by diverse uropathogens in mono- and poly-microbial infections. Furthermore, here we found that Enterococcus faecalis, a prevalent CAUTI pathogen, uses the secreted protease, SprE, to induce fibrin accumulation and create a niche ideal for growth, biofilm formation, and persistence during CAUTI.

The application of tranexamic acid in respiratory intervention complicated with bleeding

Tranexamic acid (TA) is a well-established antifibrinolytic agent utilized across various medical scenarios to manage bleeding, including surgical, traumatic, postpartum, and upper gastrointestinal bleeding. Despite its widespread application, the systematic evaluation of TA's efficacy in achieving hemostasis during interventional pulmonary procedures remains limited. This review aims to address this gap by examining the utility and effectiveness of TA in promoting hemostasis during pulmonary interventions, encompassing procedures such as bronchial artery embolization, percutaneous lung biopsy, bronchoscopy, and pleural procedures. By synthesizing existing evidence, this review seeks to provide valuable insights into the potential role of TA in mitigating hemorrhage following interventional pulmonary procedures, thereby informing clinical practice and guiding future research endeavors.

Effectiveness of Tranexamic Acid in Trauma Patients: A Systematic Review

Tranexamic acid (TXA), a fibrinolytic agent, effectively inhibits plasminogen activation, thereby reducing fibrinolysis and hemorrhage. This study focused on its application in trauma patients undergoing emergency surgery, a critical area due to trauma's significant role in mortality. Our investigation involved a meticulous screening of randomized controlled trials from databases including Scopus, PubMed, Web of Science, and Cochrane. The findings indicate that TXA intervention is promising in enhancing outcomes for trauma patients. However, the drug's effectiveness may vary based on the specific nature of the medical condition. In summary, robust evidence suggests that TXA can diminish blood loss, lower transfusion rates, reduce complications, and improve hemoglobin and hematocrit levels in surgical patients. Consequently, TXA should be considered a crucial medication, readily available to mitigate morbidity and mortality in surgical settings. Future research should explore factors influencing TXA's effectiveness in traumatic brain injury cases and across a broad spectrum of surgical scenarios in diverse patient populations. This would further guide clinicians in refining and optimizing the use of TXA.

Fibrinolytic-deficiencies predispose hosts to septicemia from a catheter-associated UTI

Catheter-associated urinary tract infections (CAUTIs) are amongst the most common nosocomial infections worldwide and are difficult to treat due to multi-drug resistance development among the CAUTI-related pathogens. Importantly, CAUTI often leads to secondary bloodstream infections and death. A major challenge is to predict when patients will develop CAUTIs and which populations are at-risk for bloodstream infections. Catheter-induced inflammation promotes fibrinogen (Fg) and fibrin accumulation in the bladder which are exploited as a biofilm formation platform by CAUTI pathogens. Using our established mouse model of CAUTI, we identified that host populations exhibiting either genetic or acquired fibrinolytic-deficiencies, inducing fibrin deposition in the catheterized bladder, are predisposed to severe CAUTI and septicemia by diverse uropathogens in mono- and poly-microbial infections. Furthermore, we found that E. faecalis, a prevalent CAUTI pathogen, uses the secreted protease, SprE, to induce fibrin accumulation and create a niche ideal for growth, biofilm formation, and persistence during CAUTI.

Tranexamic Acid: When is It Indicated in Orthopaedic Surgery?

Tranexamic acid (TXA) has been studied extensively during the last 5-8 years. It inhibits clot dissolution during surgery and can therefore reduce blood loss. However, there has been concern that this could result in more frequent complications, specifically in terms of thromboembolic events. The indications for TXA are widespread, and this review covers the literature on orthopaedic indications such as joint replacement, fracture surgery, and arthroscopic procedures. In general, TXA is safe and can be used in a wide variety of orthopaedic procedures, lowering blood loss without increasing the risk of complications.

Absence of hyperfibrinolysis may explain lack of efficacy of tranexamic acid in hypoproliferative thrombocytopenia

The American Trial Using Tranexamic Acid (TXA) in Thrombocytopenia (A-TREAT, NCT02578901) demonstrated no superiority of TXA over placebo in preventing World Health Organization (WHO) grade 2 or higher bleeding in patients with severe thrombocytopenia requiring supportive platelet transfusion following myeloablative therapy for hematologic disorders. In this ancillary study, we sought to determine whether this clinical outcome could be explained on the basis of correlative assays of fibrinolysis. Plasma was collected from A-TREAT participants (n = 115) before the initiation of study drug (baseline) and when TXA was at steady-state trough concentration (follow-up). Global fibrinolysis was measured by 3 assays: euglobulin clot lysis time (ECLT), plasmin generation (PG), and tissue-type plasminogen activator (tPA)-challenged clot lysis time (tPA-CLT). TXA was quantified in follow-up samples by tandem mass spectrometry. Baseline samples did not demonstrate fibrinolytic activation by ECLT or tPA-CLT. Furthermore, neither ECLT nor levels of plasminogen activator inhibitor-1, tPA, plasminogen, alpha2-antiplasmin, or plasmin-antiplasmin complexes were associated with a greater risk of WHO grade 2+ bleeding. TXA trough concentrations were highly variable (range, 0.7-10 μg/mL) and did not correlate with bleeding severity, despite the fact that plasma TXA levels correlated strongly with pharmacodynamic assessments by PG (Spearman r, -0.78) and tPA-CLT (r, 0.74). We conclude that (1) no evidence of fibrinolytic activation was observed in these patients with thrombocytopenia, (2) trough TXA concentrations varied significantly between patients receiving the same dosing schedule, and (3) tPA-CLT and PG correlated well with TXA drug levels.

The safety of tranexamic acid administration in total knee arthroplasty: a population-based study from Taiwan

Tranexamic acid is an effective treatment to reduce blood loss. We performed a retrospective observational study to evaluate safety in unilateral total knee arthroplasty. We utilised Taiwan's national health insurance database to identify relevant patients and to retrieve information on peri-operative blood transfusions and tranexamic acid administration within 60 days of follow-up. We examined changes in the rate of transfusions and adverse events with respect to tranexamic acid administration using logistic regression. We observed a total of 226,719 knee arthroplasty cases during 2010-2019. Transfusion and tranexamic acid administration rates were 38.9% (88,258) and 42.9% (97,237), respectively. Tranexamic acid was associated with a 50% decrease in blood transfusions (RR: 0.50, 95%CI: 0.48-0.51). After propensity-score matching, tranexamic acid was not associated with pulmonary embolism; deep vein thromboembolism; artery vein thromboembolism; acute myocardial infarction; ischaemic stroke; or in-hospital mortality, but was significantly associated with acute kidney injury. Patients with existing chronic kidney disease suffered a high absolute risk of kidney injury irrespective of tranexamic acid administration (832 per 10,000, 95%CI 797-869). Tranexamic acid was also associated with surgical site infection. There was strong interaction between blood transfusion; tranexamic aid administration; and development of surgical site infection. In conclusion, tranexamic acid use was associated with decreased blood transfusion and was not associated with thromboembolic events. However, careful consideration is required before use in patients with pre-existing renal disease. Further, our observed interaction between patients given tranexamic acid who subsequently require transfusion requires careful consideration with respect to enhanced prophylaxis against surgical site infection.

The usefulness of tranexamic acid for bleeding symptoms of chronic consumptive coagulopathy complicated by aortic disease: a single-institute, retrospective study of 14 patients

BACKGROUND

Tranexamic acid (TXA) is an antifibrinolytic drug that blocks lysine-binding sites on the profibrinolytic enzyme plasminogen. Aortic diseases with chronic consumption coagulopathy may lead to disseminated intravascular coagulation (DIC) and cause fatal bleeding. Although the use of antifibrinolytic agents in DIC is generally not recommended due to enhanced fibrin deposition risking thrombotic symptoms, the efficacy of TXA has been reported in several cases of DIC with aortic diseases. However, the efficacy and safety of TXA for bleeding symptoms of chronic consumption coagulopathy with aortic diseases have not been studied in detail.

METHODS

We evaluated the efficacy of TXA in 14 patients with chronic consumptive coagulopathy due to aortic disease complicated by bleeding symptoms. Changes in coagulation and fibrinolysis parameters from baseline were analyzed with Wilcoxon matched-pairs signed-rank tests, excluding missing values. Kaplan-Meier curves were used to analyze overall survival.

RESULTS

Median age was 78.5 years (range, 66-89 years) and median observation period was 448 days (range, 0-2282 days). Twelve patients had chronic renal failure and 1 patient had chronic liver failure. Before starting treatment, median Japanese Ministry of Health and Welfare DIC diagnostic criteria score was 8 (range, 4-11) and median platelet count was 64 × 10⁹/L (range, 25-97 × 10⁹/L). Twelve patients underwent evaluation of bleeding symptoms after introduction of TXA, and 10 of those 12 patients showed improved bleeding tendencies within 30 days (median, 5.0 days). One patient with chronic liver failure showed worsening of bleeding symptoms. Although only one patient was initiated TXA in combination with anticoagulants, no significant worsening of thrombotic events was observed within 30 days.

CONCLUSIONS

TXA therapy appears effective against chronic consumptive coagulopathy with bleeding due to aortic disease, with few side effects.

Microcluster colloidosomes for hemostat delivery into complex wounds: A platform inspired by the attack action of torpedoes

Complex yet lethal wounds with uncontrollable bleeding hinder conventional hemostats from clotting blood at the source or deep sites of injury vasculature, thereby causing massive blood loss and significantly increased mortality. Inspired by the attack action of torpedoes, we synthesized microcluster (MC) colloidosomes equipped with magnetic-mediated navigation and "blast" systems to deliver hemostats into the cavity of vase-type wounds. CaCO₃/Fe₂O₃ (CF) microparticles functionalized with Arg-Gly-Asp (RGD) modified polyelectrolyte multilayers were co-assembled with oppositely charged zwitterionic carbon dots (CDs) to form MC colloidosomes, which were loaded with thrombin and protonated tranexamic acid (TXA-NH₃ ⁺). The composite microparticles moved against blood flow under magnetic mediation and simultaneously disassembled for the burst release of thrombin stimulated by TXA-NH₃ ⁺. The CO₂ bubbles generated during disassembly produced a "blast" that propelled thrombin into the wound cavity. Severe bleeding in a vase-type hemorrhage model in the rabbit liver was rapidly controlled within ∼60 s. Furthermore, in vivo subcutaneous muscle and liver implantation models demonstrated excellent biodegradability of MC colloidosomes. This study is the first to propose a novel strategy based on the principle of torpedoes for transporting hemostats into vase-type wounds to achieve rapid hemostasis, creating a new paradigm for combating trauma treatment.

In vitro reversal of direct factor Xa inhibitors: Direct comparison of andexanet alfa and prothrombin complex concentrates Cofact and Beriplex/Kcentra

Background

Both andexanet alfa and four-factor prothrombin complex concentrate (4F-PCC) are clinically applied reversal agents for direct factor Xa inhibitors (FXaIs) in emergency situations. Controversy exists whether 4F-PCC is as effective as andexanet alfa in correcting FXaI anticoagulation.

Objective

This in vitro study was designed to directly compare andexanet alfa with two different 4F-PCCs (Cofact and Beriplex/Kcentra) in their ability to correct FXaI anticoagulation.

Method

Normal plasma was spiked with apixaban or rivaroxaban. Reversal of anticoagulation was assessed using a thrombin generation assay and a fibrin generation-clot lysis test.

Results

Andexanet alfa, applied at clinically recommended doses, was effective in restoring thrombin generation as evidenced by correction of thrombin generation lag time, peak thrombin, and endogenous thrombin potential (ETP). Clotting time and clot resistance to fibrinolytic breakdown was corrected over the full range of applied FXaI (0-800 ng/ml). 4F-PCC in increasing doses (0.625, 1.25 and 2 IU/ml; approximately 25, 50, and 80 IU/kg) only partially restored thrombin generation lag time and clotting time. Partial correction to overnormalization of peak thrombin and ETP was observed, depending on FXaI concentration and PCC dose. Clot resistance to fibrinolytic breakdown was dose-dependently improved to above normal. Beriplex/Kcentra was consistently less effective than Cofact.

Conclusion

Both andexanet alfa and 4F-PCC improved coagulation that is hampered by FXaIs. While andexanet alfa corrected all thrombin generation parameters, 4F-PCC predominantly increased peak thrombin and ETP. Especially heparin-free 4F-PCC also improved clot stability against fibrinolytic breakdown. Beriplex/Kcentra contains heparin, and this may have caused reduced effectivity compared to Cofact.

Erythrocyte Membrane-Coated Invisible Acoustic-Sensitive Nanoparticle for Inducing Tumor Thrombotic Infarction by Precisely Damaging Tumor Vascular Endothelium

Selective induction of tumor thrombus infarction is a promising antitumor strategy. Non-persistent embolism due to non-compacted thrombus and activated fibrinolytic system within the tumor large blood vessels and tumor margin recurrence are the main therapeutic bottlenecks. Herein, an erythrocyte membrane-coated invisible acoustic-sensitive nanoparticle (TXA+DOX/PFH/RBCM@cRGD) is described, which can induce tumor thrombus infarction by precisely damaging tumor vascular endothelium. It is revealed that TXA+DOX/PFH/RBCM@cRGD can effectively accumulate on the endothelial surface of tumor vessels with the help of the red blood cell membrane (RBCM) stealth coating and RGD cyclic peptide (cRGD), which can be delivered in a targeted manner as nanoparticle missiles. As a kind of phase-change material, perfluorohexane (PFH) nanodroplets possess excellent acoustic responsiveness. Acoustic-sensitive missiles can undergo an acoustic phase transition and intense cavitation with response to low-intensity focused ultrasound (LIFU), damaging the tumor vascular endothelium, rapidly initiating the coagulation cascade, and forming thromboembolism in the tumor vessels. The drugs loaded in the inner water phase are released explosively. Tranexamic acid (TXA) inhibits the fibrinolytic system, and doxorubicin (DOX) eliminates the margin survival. In summary, a stealthy and acoustically responsive multifunctional nanoparticle delivery platform is successfully developed for inducing thrombus infarction by precisely damaging tumor vascular endothelium.

Treatment of inherited thrombocytopenias

The new techniques of genetic analysis have made it possible to identify many new forms of inherited thrombocytopenias (IT) and study large series of patients. In recent years, this has changed the view of IT, highlighting the fact that, in contrast to previous belief, most patients have a modest bleeding diathesis. On the other hand, it has become evident that some of the mutations responsible for platelet deficiency predispose the patient to serious, potentially life-threatening diseases. Today's vision of IT is, therefore, very different from that of the past and the therapeutic approach must take these changes into account while also making use of the new therapies that have become available in the meantime. This review, the first devoted entirely to IT therapy, discusses how to prevent bleeding in those patients who are exposed to this risk, how to treat it if it occurs, and how to manage the serious illnesses to which patients with IT may be predisposed.

Hemorrhages in polycythemia vera and essential thrombocythemia: epidemiology, description, and risk factors, learnings from a large cohort

BACKGROUND

The management of myeloproliferative neoplasms (MPN) is based on the reduction of thrombosis risk. The incidence, impact, and risk factors of bleedings have been less studied.

METHOD

All patients with polycythemia vera (n=339) or essential thrombocythemia (n=528) treated in our center are included in OBENE cohort (NCT02897297). Major bleeding (MB) and clinically relevant non-major bleeding (CRNMB) occurring after diagnosis were included, except after leukemic transformation.

RESULTS

With a median follow-up of 8.3 years, incidence of hemorrhages was 1.85% patient/year, with an incidence of MB of 0.95% patient/year. The 10-year bleeding-free survival was 89%. The most frequent locations were digestive tractus, "mouth, nose and throat" and muscular hematoma. The case fatality rate of MB was 25%. The proportion of potentially avoidable iatrogenic bleeding was remarkable (17.6%). In multivariable analysis, eight risk factors of bleeding were identified: leukocytes >20 giga/l at diagnosis (HR=5.13 95%CI [1.77;14.86]), secondary hemopathies (HR=2.99 95%CI [1.27;7.04]), aspirin use at diagnosis (HR=2.11 95%CI [1.24;3.6]), platelet count >1000 giga/l at diagnosis (HR=1.93, 95%CI [1.11;3.36]), history of hemorrhage (HR=1.82 95%CI [1.03;3.24]), secondary cancers (HR=1.71 95%CI [1.01;2.89]), atrial fibrillation (HR=1.66, 95%CI [1.01;2.72]) and male gender (HR=1.54, 95%CI [1.02-2.33]). The majority of patients taking hydroxyurea displayed a non-macrocytic median corpuscular value in the months preceding bleeding (51.4%).

DISCUSSION

The morbidity and mortality of bleedings in MPN should not be underestimated, and some patients could beneficiate from cytoreduction in order to reducing bleeding risk. Iatrogenic bleedings represent a substantial proportion of bleeding and could be better prevented.

Longitudinal Trends of Patient Demographics and Morbidity of Different Approaches in Lumbar Interbody Fusion: An Analysis Using the American College of Surgeons National Surgical Quality Improvement Program Database

OBJECTIVE

The aims of this study were to determine the time trend of demographics, complications, and outcomes for patients undergoing posterior lumbar interbody fusion/transforaminal lumbar interbody fusion (PLIF/TLIF) or anterior lumbar interbody fusion/lateral lumbar interbody fusion (ALIF/LLIF) and to compare the differences in the time trends between both procedures.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program database was queried for patients undergoing PLIF/TLIF and ALIF/LLIF procedures. Outcomes were analyzed for differences between 2 time periods in the PLIF/TLIF and ALIF/LLIF cohorts separately (2009-2013 and 2015-2019). Longitudinal time trends of the 2 procedures were determined by difference-in-differences (DID) analysis. Statistical significance was defined as P < 0.05.

RESULTS

For both approaches, there was an increase in age and American Society of Anesthesiologists class over time, accompanied by a significant decrease in blood transfusions and morbidity. The DID analysis showed a greater change in age (DID:-1.8%; P < 0.001), and more patients were rated American Society of Anesthesiologists class 3 (DID: -2.4%; P = 0.033) in the ALIF/LLIF cohort than in the PLIF/TLIF cohort. Length of stay declined significantly over time in both cohorts, with a greater reduction observed for patients who underwent ALIF/LLIF than for patients who underwent PLIF/TLIF (DID: 0.2%; P = 0.014). There were no changes in readmission rates over time in either cohort (PLIF/TLIF DID: 0.6%; P = 0.080; ALIF/LLIF DID: -0.2%; P = 0.696).

CONCLUSIONS

Time trends for PLIF/TLIF and ALIF/LIIF showed a significant increase in the number of older patients with complex medical status undergoing surgery. Despite these trends, there were decreases in overall postoperative morbidity, incidence of blood transfusion, and length of stay, without increasing readmission. These results suggest general improvement in surgical and perioperative management of lumbar fusion over time with greater gains found in ALIF/LLIF-specific care than in PLIF/TLIF.

A Novel Drug Self-Delivery System from Fatty Alcohol Esters of Tranexamic Acid for Venous Malformation Sclerotherapy

Venous malformation (VM), which causes severe damage to patients' appearance and organ function, is one of the most common vascular malformations. At present, many drugs in clinical treatment cause various adverse reactions. Herein, we synthesized cationic amphiphilic gelators (TA6, TA8, and TA9) by introducing saturated carbon chains of different lengths to tranexamic acid (TA), which could self-assemble into low-molecular-weight gels (LMWGs) as drug delivery carriers by hydrogen bonds, van der Waals forces, and hydrophobic interactions. The rheological properties, gelation driving force and drug release profiles of TA6, TA8, and TA9 hydrogels were characterized, and the results indicated that the hydrogels prepared in this study possessed the typical characteristics of a gel and could release drugs slowly. More importantly, the TA9 gelator showed significant pharmacological activity, in that it served as both an active drug compound and a drug carrier. The in vitro experiments demonstrated that TA9 induced HUVECs death and hemolysis by destroying cell membranes in a dose-dependent manner, and caused cell death and hemolysis at a concentration of 0.09 µM/mL. Meanwhile, we found TA9 could interact not only with fibrinogen, but also with other endogenous molecules in the blood. After the administration of TA9 hydrogel for 15 days, macroscopic imaging and histological evaluation in mice and rabbits displayed obvious thrombi, inflammatory reactions, and venous embolization, indicating that the mechanism of the TA9 hydrogel in treating VM was involved in two processes. Firstly, the TA9 hydrogel relied on its mechanical strength to physically block veins and continuously release TA9, in situ, for targeted therapy. Then, TA9 destroyed endothelial cells and damaged venous walls critically, causing thrombi. Most excitingly, TA9 was hydrolyzed to TA by enzymes that inhibited the degradation of thrombi by plasmin to prolong the embolization time and to promote venous fibrosis. Compared with other clinically available sclerosants, the degradation of TA9 also empowered a better biocompatibility and biodegradability for the TA9 hydrogel. In conclusion, we synthesized a potentially safe and effective derivative of TA and developed a low-molecular-weight gel as a self-delivery system for TA in treating VM.

[Cerebral-meningeal hemorrhage secondary to snakebite envenomation: about two cases at the Sourô Sanou Teaching Hospital in Bobo-Dioulasso, Burkina Faso]

Background

Envenomation by snakebite is a public health problem in developing countries. Neurovascular complications are uncommon. We report two cases of hemorrhagic stroke at the Sourô Sanou Teaching Hospital in Bobo-Dioulasso, which complicate an envenomation.

Clinical description

The first patient was a 60-year-old woman with no history, who had been admitted 2 hours after snakebite for gingivorrhagia and consciousness disorders. Clinical examination found coma (GCS 7/15) and tetraparesis. The second patient was a 50-year-old woman with no history, who had been admitted one week after snakebite with digestive bleeding. Clinical examination found right hemiplegia and meningeal syndrome. Both patients presented hemorrhagic stroke on brain CT-scan but hemostasis assessment was normal. They received polyvalent antivenom and symptomatic treatment. The outcome was favorable for survival but with sequelae like tetraparesis for first patient and hemiparesis for second patient.

Discussion - Conclusion

The hemorrhagic strokes are rare complications of snake envenomation. Venomous toxins can directly lead to the rupture of intracranial vessels apart of abnormalities of hemostasis. However, the morbidity and mortality related to envenomation by snake bite remains high in our environment.

Tranexamic Acid for Acute Spontaneous Intracerebral Hemorrhage: A Meta-Analysis of Randomized Controlled Trials

Background: The role of tranexamic acid (TXA) in preventing hematoma expansion (HE) in patients with acute spontaneous intracerebral hemorrhage (ICH) remains unclear. We aim to investigate the efficacy and safety of TXA in acute spontaneous ICH with a particular focus on subgroups.

Methods: Randomized controlled trials (RCTs) were retrieved from CENTRAL, Clinicaltrials.gov, EMBASE, PubMed, and WHO ICTRP. The primary outcome measurement was HE. The secondary outcome measurements included 3-month poor functional outcome (PFO), 3-month mortality, and major thromboembolic events (MTE). We conducted subgroup analysis according to the CT markers of HE (standard-risk population and high-risk population) and the time from onset to randomization (>4.5 and ≤4.5 h).

Results: We identified seven studies (representing five RCTs) involving 2,650 participants. Compared with placebo, TXA may reduce HE on subsequent imaging (odd ratio [OR] 0.825; 95% confidence interval [CI] 0.692–0.984; p = 0.033; I² = 0%; GRADE: moderate certainty). TXA and placebo arms did not differ in the rates of 3-month PFO, 3-month mortality, and MTE. Subgroup analysis indicated that TXA reduced the risk of HE in the high-risk population with CT markers of HE (OR 0.646; 95% CI 0.503–0.829; p = 0.001; I² = 0 %) and in patients who were treated within 4.5 h of symptom onset (OR 0.823; 95% CI 0.690–0.980; p = 0.029; I² = 0%), but this protective effect was not observed in the standard-risk population and patients who were treated over 4.5 h of symptom onset.

Conclusions: Tranexamic acid (TXA) may decrease the risk of HE in patients with acute spontaneous ICH. Importantly, the decreased risk was observed in patients who were treatable within 4.5 h and with a high risk of HE, but not in those who were treatable over 4.5 h and in standard-risk population. However, PFO or mortality at 3 months did not significantly differ between patients who received TXA and those who received placebo. TXA is safe for acute spontaneous ICH without increasing MTE.

Shortening Synthetic Routes to Small Molecule Active Pharmaceutical Ingredients Employing Biocatalytic Methods

Biocatalysis, using enzymes for organic synthesis, has emerged as powerful tool for the synthesis of active pharmaceutical ingredients (APIs). The first industrial biocatalytic processes launched in the first half of the last century exploited whole-cell microorganisms where the specific enzyme at work was not known. In the meantime, novel molecular biology methods, such as efficient gene sequencing and synthesis, triggered breakthroughs in directed evolution for the rapid development of process-stable enzymes with broad substrate scope and good selectivities tailored for specific substrates. To date, enzymes are employed to enable shorter, more efficient, and more sustainable alternative routes toward (established) small molecule APIs, and are additionally used to perform standard reactions in API synthesis more efficiently. Herein, large-scale synthetic routes containing biocatalytic key steps toward >130 APIs of approved drugs and drug candidates are compared with the corresponding chemical protocols (if available) regarding the steps, reaction conditions, and scale. The review is structured according to the functional group formed in the reaction.

Bleeding Disorders in Primary Fibrinolysis

Fibrinolysis is a complex enzymatic process aimed at dissolving blood clots to prevent vascular occlusions. The fibrinolytic system is composed of a number of cofactors that, by regulating fibrin degradation, maintain the hemostatic balance. A dysregulation of fibrinolysis is associated with various pathological processes that result, depending on the type of abnormality, in prothrombotic or hemorrhagic states. This narrative review is focused on the congenital and acquired disorders of primary fibrinolysis in both adults and children characterized by a hyperfibrinolytic state with a bleeding phenotype.

Plasmin, Immunity, and Surgical Site Infection

SSI are a universal economic burden and increase individual patient morbidity and mortality. While antibiotic prophylaxis is the primary preventative intervention, these agents are not themselves benign and may be less effective in the context of emerging antibiotic resistant organisms. Exploration of novel therapies as an adjunct to antimicrobials is warranted. Plasmin and the plasminogen activating system has a complex role in immune function. The immunothrombotic role of plasmin is densely interwoven with the coagulation system and has a multitude of effects on the immune system constituents, which may not always be beneficial. Tranexamic acid is an antifibrinolytic agent which inhibits the conversion of plasminogen to plasmin. Clinical trials have demonstrated a reduction in surgical site infection in TXA exposed patients, however the mechanism and magnitude of this benefit is incompletely understood. This effect may be through the reduction of local wound haematoma, decreased allogenic blood transfusion or a direct immunomodulatory effect. Large scale randomised clinical trial are currently being undertaken to better explain this association. Importantly, TXA is a safe and widely available pharmacological agent which may have a role in the reduction of SSI.

The European Perspective on the Management of Acute Major Hemorrhage and Coagulopathy after Trauma: Summary of the 2019 Updated European Guideline

Non-controlled hemorrhage with accompanying trauma-induced coagulopathy (TIC) remains the most common cause of preventable death after multiple injury. Rapid identification followed by aggressive treatment is the key for improved outcomes. Treatment of trauma hemorrhage begins at the scene, with manual compression, the use of tourniquets and (non) commercial pelvic slings, and rapid transfer to an adequate trauma center. Upon hospital admission, coagulation monitoring and support are to be initiated immediately. Bleeding is controlled surgically following damage control principles. Modern coagulation management includes goal-oriented, individualized therapies, guided by point-of-care viscoelastic assays. Idarucizumab can be used as an antidote to the thrombin inhibitor dabigatran, andexanet alpha as an antidote to factor Xa inhibitors. This review summarizes the key recommendations of the 2019 updated European guideline on the management of major bleeding and coagulopathy following trauma. These evidence-based recommendations may form the backbone of algorithms adapted to local logistics and infrastructure.

Hemorrhage in Essential Thrombocythemia or Polycythemia Vera: Epidemiology, Location, Risk Factors, and Lessons Learned from the Literature

Hemorrhage is a well-known complication of essential thrombocythemia (ET) and polycythemia vera (PV), but evidence-based data on its management and prevention are lacking to help inform clinicians. In this review, appropriate published data from the past 15 years regarding bleeding epidemiology, classification, location, and risk factors are presented and discussed. Research was conducted using the Medline database. The bleeding classifications were heterogeneous among the collected studies. The median incidences of bleeding and major bleeding were 4.6 and 0.79% patients/year, in ET patients and 6.5 and 1.05% patients/year in PV patients, respectively. The most frequent location was the gastrointestinal tract. Bleeding accounted for up to 13.7% of deaths, and cerebral bleeding was the main cause of lethal hemorrhage. Thirty-nine potential risk factors were analyzed at least once, but the results were discrepant. Among them, age >60 years, bleeding history, splenomegaly, myeloproliferative neoplasm subtype, and platelet count should deserve more attention in future studies. Among the treatments, aspirin seemed to be problematic for young patients with ET (especially CALR-mutated ET patients) and anagrelide was also identified as a bleeding inducer, especially when associated with aspirin. Future studies should analyze bleeding risk factors in more homogeneous populations and with common bleeding classifications. More tools are needed to help clinicians manage the increased risk of potentially lethal bleeding events in these diseases.

Acquired von Willebrand syndrome: focused for hematologists

The acquired von Willebrand syndrome (AvWS) is a rare bleeding disorder with laboratory findings similar to those of inherited von Willebrand disease. However, unlike the inherited disease, AvWS occurs in persons with no personal and family history of bleeding and is often associated with a variety of underlying diseases, most frequently lymphoproliferative, myeloproliferative and cardiovascular disorders. After the presentation of a typical case, in this narrative review we discuss the more recent data on the pathophysiology, clinical, laboratory and therapeutic aspects of this acquired bleeding syndrome. We chose to focus particularly on those aspects of greater interest for the hematologist.