Hemostatic therapy for the treatment of intracranial hemorrhage

Preclinical Evaluation of Safety and Biodistribution of Red Cell Microparticles: A Novel Hemostatic Agent

BACKGROUND

Uncontrollable bleeding is a major cause of mortality and morbidity worldwide. Effective hemostatic agents are urgently needed. Red cell microparticles (RMPs) are a highly promising hemostatic agent. This study evaluated the safety profile of RMPs preliminary to clinical trial.

METHODS AND RESULTS

RMPs were prepared from type O+ human red blood cell by high-pressure extrusion. Male rats were treated with RMPs either a 1 × bolus, or 4 × or 20 × administered over 60 minutes. The vehicle-treated group was used as a control. Effects on physiological parameters were evaluated; namely, blood pressure, body and head temperature, hematocrit, and blood gases. We did not observe any adverse effects of RMPs on these physiological parameters. In addition, brain, heart, and lungs of rats treated with 4 × dose (bolus followed by infusion over 60 minutes) or vehicle were examined histologically for signs of thrombosis or other indications of toxicity. No thrombosis or indications of toxicity in brain, heart, or lungs were observed. Studies revealed that RMPs were distributed mainly in liver, spleen, and lymph nodes, and were potentially excreted through the kidneys.

CONCLUSIONS

Our study indicates that RMP administration appears not to have any negative impact on the parameters studied and did not produce thrombosis in heart, brain, and lungs. However, more detailed long-term studies confirming the safety of RMP as a hemostatic agent are warranted.

The Distribution of Transplanted Umbilical Cord Mesenchymal Stem Cells in Large Blood Vessel of Experimental Design With Traumatic Brain Injury

The authors aim to track the distribution of human umbilical cord mesenchymal stem cells (MSCs) in large blood vessel of traumatic brain injury -rats through immunohistochemical method and small animal imaging system. After green fluorescent protein (GFP) gene was transfected into 293T cell, virus was packaged and MSCs were transfected. Mesenchymal stem cells containing GFP were transplanted into brain ventricle of rats when the infection rate reaches 95%. The immunohistochemical and small animal imaging system was used to detect the distribution of MSCs in large blood vessels of rats. Mesenchymal stem cells could be observed in large vessels with positive GFP expression 10 days after transplantation, while control groups (normal group and traumatic brain injury group) have negative GFP expression. The vascular endothelial growth factor in transplantation group was higher than that in control groups. The in vivo imaging showed obvious distribution of MSCs in the blood vessels of rats, while no MSCs could be seen in control groups. The intravascular migration and homing of MSCs could be seen in rats received MSCs transplantation, and new angiogenesis could be seen in MSCs-transplanted blood vessels.

Management of Postthrombolysis Hemorrhagic and Orolingual Angioedema Complications

Intravenous recombinant tissue plasminogen activator was first approved for the treatment of acute ischemic stroke in the United States in 1996. Thrombolytic therapy has been proven to be effective in acute ischemic stroke treatment and shown to improve long-term functional outcomes. Its use is associated with an increased risk of symptomatic intracerebral hemorrhage as well as orolingual angioedema. Our goal is to outline the management strategies for these postthrombolysis complications.

The fibrinolytic system-more than fibrinolysis?

The fibrinolytic system, known for its ability to regulate the activation of the zymogen plasminogen into active plasmin, has been primarily associated with the removal of fibrin and blood clots. Tissue-type plasminogen activator, the most well-recognized plasminogen activator, was harnessed for therapeutic benefit against thromboembolic disorders more than 30 years ago, whereas inhibition of this system has been proven effective for certain bleeding disorders. However, in recent years, new and unexpected functional roles for this system have been identified mostly in relation to the central nervous system that are both unrelated and independent of fibrin degradation and clot removal. Hence, it seems reasonable to ask whether agents used to modify components or activities of the fibrinolytic system have any clinical consequences unrelated to their intended use in hemostasis. This review will provide an overview of these new features of the fibrinolytic system and will also focus on prospective considerations in the use of fibrinolytic and antifibrinolytic agents.

Management of anticoagulant-related intracranial hemorrhage: an evidence-based review

The increased use of anticoagulants for the prevention and treatment of thromboembolic diseases has led to a rising incidence of anticoagulant-related intracranial hemorrhage (AICH) in the aging western population. High mortality accompanies this form of hemorrhagic stroke, and significant and debilitating long-term consequences plague survivors. Although management guidelines for such hemorrhages are available for the older generation anticoagulants, they are still lacking for newer agents, which are becoming popular among physicians. Supportive care, including blood pressure control, and reversal of anticoagulation remain the cornerstone of acute management of AICH. Prothrombin complex concentrates are gaining popularity over fresh frozen plasma, and reversal agents for newer anticoagulation agents are being developed. Surgical interventions are options fraught with complications, and are decided on a case-by-case basis. Our current state of understanding of this condition and its management is insufficient. This deficit calls for more population-based studies and therapeutic trials to better evaluate risk factors for, and to prevent and treat AICH.

Management of thrombolysis-associated symptomatic intracerebral hemorrhage

BACKGROUND

Symptomatic intracerebral hemorrhage (sICH) is the most devastating complication of thrombolytic therapy for acute stroke. It is not clear whether patients with sICH continue to bleed after diagnosis, nor has the most appropriate treatment been determined.

METHODS

We performed a retrospective analysis of our prospectively collected Get With the Guidelines-Stroke database between April 1, 2003, and December 31, 2007. Radiologic images and all procoagulant agents used were reviewed. Multivariable logistic regression was performed to identify factors associated with in-hospital mortality.

RESULTS

Of 2362 patients with acute ischemic stroke during the study period, sICH occurred in 19 of the 311 patients (6.1%) who received intravenous tissue plasminogen activator and 2 of the 72 (2.8%) who received intra-arterial thrombolysis. In-hospital mortality was significantly higher in patients with sICH than in those without (15 of 20 [75.0]% vs 56 of 332 [16.9%], P < .001). Eleven of 20 patients (55.0%) received therapy for coagulopathy: 7 received fresh frozen plasma; 5, cryoprecipitate; 4, phytonadione (vitamin K(1)); 3, platelets; and 1, aminocaproic acid. Independent predictors of in-hospital mortality included sICH (odds ratio, 32.6; 95% confidence interval, 8.8-120.2), increasing National Institutes of Health Stroke Scale score (1.2; 1.1-1.2), older age (1.3; 1.0-1.7), and intra-arterial thrombolysis (2.9; 1.4-6.0). Treatment for coagulopathy was not associated with outcome. Continued bleeding (>33% increase in intracerebral hemorrhage volume) occurred in 4 of 10 patients with follow-up scans available (40.0%).

CONCLUSIONS

In many patients with sICH after thrombolysis, coagulopathy goes untreated. Our finding of continued bleeding after diagnosis in 40.0% of patients suggests a powerful opportunity for intervention. A multicenter registry to analyze management of thrombolysis-associated intracerebral hemorrhage and outcomes is warranted.

Recombinant factor VIIa and the patient with neurologic bleeding: separating fact from fiction

Notwithstanding its limited Food and Drug Administration-approved indications, rFVIIa has rapidly gained widespread use for the treatment of a variety of hemorrhagic conditions, including intracranial bleeding from spontaneous, traumatic, surgical, and coagulopathic causes. Although it appears that the drug only minimally increases the risk of thromboembolic events, its efficacy remains in question. The idea of finding a universal cure for hemorrhage in a medication bottle remains highly appealing, but enthusiasm for the concept is no replacement for evidence. Neuroscience nurses, who are the interface between patients and rFVIIa, need to balance hope and hype until the facts are all in.