“Someone in the United States has a
stroke every 40 seconds. Every 4 minutes, someone dies of stroke (6).”
The highest death rates from stroke are in the southeastern United States, thus
being titled the “Stroke Belt.” Kentucky, being part of the Southeastern United
States, is part of this statistic. A stroke is a vascular disease in the brain
that causes a lack of oxygen to part of the brain, hindering metabolic activity
in neurons (6).There are two types of strokes; ischemic and
hemorrhagic. An ischemic stroke is where the blood supply to certain parts of
the brain is blocked due to either narrowing of arteries due to plaque
(atherosclerosis) or thrombotic (blood clot) (1). A hemorrhagic
stroke is due to the rupture of an artery allowing blood flow to pool out of
the arteries into the skull (1) .
 |
| Source: Blumenthal M.D., R. S., 23 November 2016) |
Out of the two types of strokes, an
ischemic stroke is the most common type accounting for 88% of all strokes (6).
Many things cause ischemic strokes including atrial fibrillation, cigarette
smoking, alcohol abuse, obesity, carotid stenosis, diabetes and hypertension(7).
These factors increase the chances at which an individual will produce a blood
clot. Many situations can influence the production of a blood clot; surgery,
intravenous line, flying for long periods of time and a sedentary lifestyle are
only a few. A thrombosis is a clot that is formed in an artery(7).
An embolism is a piece of a blood clot or circulatory material that has been
dislodged and trapped in an artery, blocking blood flow(7). People
with plaque, cholesterol, in their arteries create a perfect environment for
these embolisms to get stuck.
Stroke is the leading cause of disability
in adults(6). With this information in mind the treatment for
strokes is incredibly important. The treatment for strokes depend on what type
of stoke is occurring. Once an emergency doctor determines that the patient is
having a stroke, they order for a CT angiogram. The CT angiogram is a type of
imaging that uses contrast to determine whether or not the stroke is
hemorrhagic or ischemic. A hemorrhagic stroke has much less treatment plans
than an ischemic stroke. A hemorrhagic stroke is treated by either; putting in
a ventricular drain directly under the skull to relieve pressure or removing
part of the skull to relieve pressure(6).
An ischemic stroke is due to a
blockage, giving doctors the choice to perform a mechanical thrombectomy or
introduce tPA (8). Many ischemic strokes are not candidates for a
thrombectomy because the clot must be located in a large vessel. Tissue
Plasminogen Activator (tPA) is an intravenous medication that degrades the
thrombus (4). tPA is a serine protease found in endothelial cells
(cells that line the blood vessels) (4). In the presence of fibrin, tPA
works by cleaving the plasminogen enzyme into a protease plasmin (9).
The plasmin degrades the fibrin clot into fibrinogen degradation products (5) . tPA also works by enhancing
the catalytic efficiency by localizing the active site of fibrin to the clot (9).
According to diapharma.com, “rt-PA is probably the most effective thrombolytic
agent…”
 |
| Flow chart showing the fibrinolytic system, Diapharma.com |
Although this idea of having a
“clot busting” medication is great, there is a timeline involved when
administering tPA. The countdown begins once the signs and symptoms of the
stroke begin and physicians only have 4.5 hours to diagnose and treat the
patient with tPA (3). Studies have shown that a broader range of 6.0
hours is still acceptable but the risk of secondary hemorrhaging greatly
increases (4). Unfortunately, even with administration in a timely
manner, tPA can still cause hemorrhaging as a side effect (3). The
patient must be strictly monitored after tPA is given to evaluate any changes
showing a secondary hemorrhage (4).
Tissue Plasminogen Activator is not
a perfect solution for acute ischemic strokes, it has serious side effects.
However, according to Paek, “IV-TPA treatment within 4.5 h was associated with
an improvement of functional disability with an acceptable risk.” When
administered tPA, mortality rates have reduced by 25% (4). Although
tPA is a great medication to treat an acute ischemic stroke, when possible,
prevention is the best treatment. Maintaining a healthy weight, eating a heart
healthy diet, quitting smoking, exercise regularly and managing cholesterol
levels can inhibit many ischemic strokes (8).
References
1. Blumenthal M.D., R. S.(23 November 2016). “What is a
stroke?” Health After 50; University of California, Berkeley, School of Public
Health. Retrieved by https://www.healthcentral.com/article. Accessed on
September 20th, 2019.
2. Cerebral Angiography (n.d.). National Institute of
Neurological Disorders and Stroke. Retrieved by http://www.strokecenter.org/professionals/stroke-diagnosis/guide-to-imaging-techniques-in-stroke-diagnosis/cerebral-angiography/
3. Gravanis I, Tsirka SE (February 2008). "Tissue-type plasminogen
activator as a therapeutic target in stroke". Expert Opinion on Therapeutic Targets. 12 (2): 159–70. doi:10.1517/14728222.12.2.159.
4. Paek, Y. M.,
Lee, J. S., Park, H.-K., et. al. (1 June, 2019). Intravenous Thrombolysis with
Tissue-Plasminogen Activator in Small Vessel Occlusion. Journal
Of Clinical Neuroscience: Official Journal Of The Neurosurgical Society Of
Australasia, 64, 134–140.
https://doi-org.ezproxy.uky.edu/10.1016/j.jocn.2019.03.036
5. Parsons J. C. (1 June 2012). Fibrinolysis
pathway. Retrieved from http://www.pathologyoutlines.com/topic/coagulationfibrinolysis.html.
Accessed September 21st, 2019.
6. Stroke (May 13, 2019). Centers for Disease Control and
Prevention. Received by https://www.cdc.gov/stroke/index.htm.
Accessed September 19th,
2019.
7. Stroke; also called: Brain Attack, CVA. 21 August 2019.
Medline Plus. Retrieved from https://medlineplus.gov/stroke.html.
8. Stroke Treatment. (n.d). American Stroke Association.
Retrieved from https://www.stroke.org/en/about-stroke/treatment.
9. Tissue Plasminogen Activator (n.d.). Diapharma. Retrieved
from https://diapharma.com/tissue-plasminogen-activator-tpa/#Thrombolytic%20therapy.
Accessed September 19, 2019.
Considering how often strokes occur, I am surprised that tPA is really the only common treatment for acute ischemic strokes. I have known multiple people who have had a stroke but were unable to identify the sensation as a stroke or waited to go to the doctor until the next day, making them ineligible to receive any kind of treatment for the stroke they had had. After reading into ischemic strokes some more, I found that it is actually quite common that stroke patients are unable to be treated with tPA because they don't arrive to the hospital within the 4.5 hour window. I think it is important to raise more awareness on how common strokes are, preventable causes of strokes, and how to properly identify if you or someone you know is having a stroke so they can receive treatment before any serious damage occurs.
ReplyDeleteThis is a very strong treamtment option that can easily be dosed in wrong amounts depending on the severity of the stroke and its location. tPA is mostly used for older individuals in part because they have a much higher chance of stroking and having blood clots. tPA is dangerous in young adults and kids so the likelihood they would be administered for any kind of anti coagulation is only used in very small amounts. It is basically a strong antagonist to the extrinsic and intrinsic clotting pathways tPA can bind plasminogen, cleaving off the bound plasmin from it. Plasmin, another type of protease, can either be bound by a plasmin inhibitor, or work to degrade fibrin clots, which is the highest utilized and desired pathway. since t-PA is synthesized mainly in vascular endothelial cells it gets secreted into the plasma continuously. and also through the acute release of t-PA. The latter situation occurs upon stimulation of certain endothelial cell receptors. Different regions of the vascular system secrete different amounts of t-PA. Upper extremities secrete about four times more t-PA than that of the lower extremities. This is why the amount of fibrin and the amount of tPA needed to treat different types of strokes in patients with varying age and gender.
ReplyDeleteGreat work, your blog post is very insightful! Being from a generally unhealthy area in eastern Kentucky, it is fascinating to understand a prevalent medical condition that plagues my area. Despite the narrow window, tPA is a very reliable option. However strokes can vary significantly between people depending on many factors such as age or weight. In my hometown, there are many campaigns making the signs of strokes much more well known. This has had a very positive impact and has reduced the stroke related deaths in my area. While the overall health is still very poor, its definitely a step in the right direction. Understanding the physiological causes of strokes as well as the proper treatments will be a huge benefit to any future physicians.
ReplyDeleteYour blog is extremely interesting! I love that you chose a topic that is so prevalent in our area. I can personally think of a few people who have experienced a stroke and did not know they were having a stroke. One of them ended up having severe brain damage because she was not treated fast enough. I had no idea that the treatment window for tPA was so narrow, or that it could only be administered within 4.5-6 hours after the stroke symptoms began. It is also very interesting that because tPA breaks down the thrombus, that it can help restore some of the functional disability in the brain. After reading about strokes a little more, I found that when tPA dissolves the clot, it collectively works to restore the blood flow to the brain. The restoration of blood flow ultimately prevents other brain cells from dying, which is why the functional disability of the patient can be improved. Your blog post has definitely made me more interested about this topic and the treatment of tPA. Educating the people in our area more about strokes, the symptoms associated with them, and the narrow treatment window of tPA could be beneficial. I definitely think that educating individuals about these things could make stroke patients seek treatment at a faster rate.
ReplyDeleteIt has typically been know that with strokes “TIME IS BRAIN”, because if a person who has or is showing signs of strokes can be saved. There are many studies and correlations between how ischemic stroke and many advances have been made in the field. Besides the tPA use there have been other treatments, such as the mechanical thrombectomy (MT), large vessel occlusion (LVO), and intravenous thrombolysis (IVT). 1 The study by Weber et al, looked at how MT and IVT with recombination tissue plasminogen activator (rt-PA) would help with patients in Germany to see how to improve stroke care. 1 The authors note that there is a direct impact of the MT rate and IVT as a treatment option. They found that in Germany strokes are on a rise and the use of IVT and MT is helping but a need for neuro-interventional centers will help and strengthen the use of MT. 1
ReplyDeleteAnother study by Young-Saver et al, examined how ischemic strokes due to large vessel occlusions can be treated with the use of MT and IVT versus the use of neither.2 They found that with the use of IV thrombolysis and MT is beneficial to help with patients in LVO. 2 It seems that patients who get both the IV and MT have a better outcomes in 1 of every 2 patients. 2 Furthermore, it seems hat IVT alone provides better outcome as well where 1 in every 5 patients get better. So it seems that the use of MT, IVT, and tPA ae very important for helping patients with strokes.
1. Weber, Ralph, et al. “Distribution and Evolution of Acute Interventional Ischemic Stroke Treatment in Germany from 2010 to 2016.” Neurological Research and Practice, vol. 1, no. 1, 2019, pp. Neurological Research and Practice, 12/2019, Vol.1(1).
2. Young-Saver, Dashiell F, Gornbein, Jeffrey, Starkman, Sidney, & Saver, Jeffrey L. (2018). Abstract TMP5: Acute Ischemic Stroke due to Large Vessel Occlusions: Incremental Benefits of IV tPA Alone and Mechanical Thrombectomy Added to IV tPA. Stroke., 49(Suppl_1), ATMP5.
This is a very interesting topic! Given how often strokes occur and the burden it creates, it is interesting to consider future directions with treatment. I was curious about extending the time window of treatment and administration of IV-TPA, and how that might improve patient outcome and recovery. Extending the window might aid in the development of more tools that may help clinicians to effectively stratify patients by risk and by predicted treatment response that go beyond the information provided by knowing the time after symptom onset. “Currently, the Extending the time for Thrombolysis in Emergency Neurological Deficits (EXTEND/ECASS-IV) trial is enrolling patients presenting within 3 to 9 hours of stroke onset or with wake-up stroke within 9 hours from midpoint of sleep duration who have significant penumbral mismatch on either MRI or CT imaging. These studies are a response to the imperfect but often readily available information provided by the symptom onset time.”1 With further refinement and validation of penumbral imaging or other diagnostic techniques, it is conceivable that physicians may be able to further tailor management by identifying patients for whom IV-TPA in the extended window and beyond would be safe and effective. “Extended time windows for thrombolysis may allow more patients to receive acute thrombolysis therapy, the goal of achieving revascularization as soon as safely possible remains a central tenet of acute stroke care.”1 Given the great heterogeneity in strokes, and the accompanying co-morbidities that patients often have, there exists many obstacles in the way of stroke research.
ReplyDelete1. Cheng, Natalie T, and Anthony S Kim. “Intravenous Thrombolysis for Acute Ischemic Stroke Within 3 Hours Versus Between 3 and 4.5 Hours of Symptom Onset.” The Neurohospitalist vol. 5,3 (2015): 101-9. doi:10.1177/1941874415583116
Great job erin, very informative blog post. As a tech in the emergency department, I encountered several stroke patients throughout the years. I know you mentioned strict monitoring post tPA administration, but I just wanted to mention a little of what this entails first hand. The patient is required to lay flat for 24, and must have advanced neuroassesments every 15 minutes, gradually increases to q30 and then q1hr over the first 24hrs. This is due to the enormous anticoagulant affects of tPA. The patient must also not have any invasive procedures, including venipuncture.
ReplyDeleteGreat post, Erin. Very informative and thorough! I have witnessed firsthand the increasing prevalence of stroke in rural Appalachia, and tPA - when administered properly - is an invaluable tool for treating ischemic stroke patients. But as you mentioned, tPA is a very time-sensitive drug that comes with potentially dangerous side effects.
ReplyDeleteThis time-sensitive nature of stroke treatment can be a great obstacle for patients in rural areas, especially throughout Kentucky. A new solution for those seeking treatment in so-called "health care deserts" is a form of telemedicine for stroke, specifically known as "Telestroke" (Adcock, 2019.)
Telestroke allows specialists to instantly connect with patients in health care settings where physicians and resources may be scarce. At West Virginia University, the implementation of Telestroke resulted in a 173% increase in total patients receiving tPA in a timely manner for ischemic stroke from 2015 to 2018 (Adcock.)
With all this being said, I agree with you that ultimately our best solution to combat stroke is to promote prevention through healthy lifestyle changes and education of that nature.
Adcock, AK et al. "Expanding Acute Stroke Care in Rural America: A Model for Statewide Success." Telemed J E Health. (2019 October 9.) doi: 10.1089/tmj.2019.0087
Well written and informative post, Erin! I have not had a lot of experience with stroke care or treatment, and this is pretty new information to me. tPA sounds like a very effective and helpful method to manage an ischemic stroke if it is caught early on. The time window drawback is certainly an issue, and the power of the anticoagulant properties of tPA makes me wonder about any prior patient conditions that would increase the risk of a hemorrhagic event, so I looked into it. It appears that risk factors include age, male gender, obesity, increased stroke severity, diabetes, hyperglycemia, uncontrolled hypertension, combination antiplatelet use, large areas of early ischemic change, atrial fibrillation, congestive heart failure, and leukoariosis (1). It was surprising to me to find that being male was associated with higher risk of intercerebral hemorrhage. There is also apparently a higher mortality rate for males treated with tPA, though the article I read did not offer any possible explanation for this.
ReplyDelete1: Miller, D. J., Simpson, J. R., & Silver, B. (2011). Safety of thrombolysis in acute ischemic stroke: a review of complications, risk factors, and newer technologies. The Neurohospitalist, 1(3), 138–147. doi:10.1177/1941875211408731
I loved the post Erin! I especially appreciate the relevance to our state. Living a large portion my life in a rural Kentucky town the I know all too well the high prevalence of risk factors in our state. Most everyone I know has smoked cigarettes at one time, if they don't still currently smoke. Also our adult obesity rate has continued to claim since 1990. In 1990 the rate was 12.7%, this rose to 21.7% in 2000 and 36.6.% in 2018. From what seems to be a perpetuating pattern of passing on unhealthy habits in our state, strokes, diabetes, cardiovascular disease and much more have become a normal occurrence for our communities. This sparks the question in myself of why we haven't attacked unhealthy life style choices more aggressively in our state and I hope statistics and posts like your own spark this question in more of us.
ReplyDelete“State Briefs.” The State of Childhood Obesity, https://stateofchildhoodobesity.org/states/ky/.
Jen Eccleston
ReplyDeleteConsidering the causes of stoke that you mentioned, I became curious of how chronic stress could play a role in increasing a person’s risk of stroke. Everyone deals with some level of stress in their lifetime, but I wondered if persistently high stress levels contributed to stroke risk. In a research study published by the National Heart Association, just over 6,000 people of various age ranges were evaluated to first establish their relative anxiety and depression levels. By tracking strokes from hospitals or other medical centers, they then determined that people who fell in the higher anxiety category had a 33% higher stroke risk. If you think about it too, people dealing with anxiety and/or depression may try to manage their emotions by smoking, eating more (potentially leading to obesity/diabetes), and abusing alcohol. Based on the risk factors you presented, it makes sense that stress, anxiety, and depression may all contribute to their risk of stroke later in life.
“Anxiety Linked to Long Term Stroke Risk.” https://www.stroke.org/en/about-heart-disease-in-women/latest-research/anxiety-linked-to-long-term-stroke-risk.
A therapy that I was just educated on in my job, was the use of EKOS MicroLysUS infusion catheter, which is much different than tPA. The physician places a catheter with ultrasound properties into the femoral vein and when hooked into the small EKOS machine, it breaks up the clot. It is more so used for pulmonary embolisms, but there is study where they used it for embolic strokes. This therapy does not require high dose medications such as tPA (it does require heparin), but it works by using ultrasound waves to to break up the clot to promote revascularization. Again, this may not work for every case, but when it can be used the patient is at a much lower risk for bleeding and the hospital stay is usually shorter. Of course, more studies are being done. Here is the study link if you would like to learn more about it: http://www.ajnr.org/content/24/3/534
ReplyDeleteGreat post Erin! I really appreciate your effort in explaining the different types of strokes that can happen. When I worked in the stroke unit, I saw so many patients who received tPA and they had to be monitored closely. We also received so many patients who arrived too late and were no longer able to receive tPA which is extremely scary. I think it is just as important to emphasize how to recognize the symptoms of stroke as it is to teach people how to prevent them. Like you mentioned, tPA is not the perfect medication. According to the American Academy of Emergency Medicine (AAEM), that 1 out of 18 patients who received tPA had a brain bleed which has a 45% fatality rate. Also, the risk of stroke increases with age and the complications of administering tPA also increase when used on patients over the age of 70. On the other hand, the AAEM states that 8 out of 18 patients who received tPA recovered after three months with any significant issues. Overall, I think it is critical the patients and physicians understand the risks and benefits associated with tPA. Thank you for your eye-opening post. I enjoyed reading it!
ReplyDelete"tPA for Stroke – Potential Benefit, Risk and Alternatives." https://www.aaem.org/UserFiles/file/tpaedtool-AAEM.pdf
I really like that you pointed out the region of concern for this disease. It is important to understand where certain conditions rise from in order to truly understand the reasoning behind the formation of the disease. I believe that due the long distances a person must travel for medical issues is very much unreasonable in the Southeastern states. I have traveled and lived in many of the Southeastern states during my childhood and when I had any health problems, most of the time the local clinic was not able to fix it and they would end up reffering me to a huge hospital somewhere in a major city of the state. For people who cannot travel far (health/age/disease factors) or cannot afford to do so, the rate of disease increases for that area.
ReplyDeleteAlso, most of the causes listed for ischemic strokes are listed as the top 10 diseases in the U.S. Such as heart disease (atrial fibrillation), cancer (from smoking), obesity, and diabetes. It is obvious for there to be correlation since one health issue leads to another. Looking at the list of diseases, I feel that science should intensify their focus on preventing the diseases rather than mainly discovering the new drugs for diagnosis or treatment.
A primary injury is the direct result of an initial insult, caused by a stroke, spinal cord damage, or a traumatic injury to the brain/head. An example of a primary insult is the vascular occlusion causing a stroke resulting in an infarct region of dead brain tissue. While this primary injury is the initial blow causing severe damage to the brain, the secondary injury can be just as detrimental to the patient. A secondary injury is defined as the neuronal and microvascular injury caused by a cascade of pathophysiological events that exacerbate the damage caused by the original injury. This damage typically leads to the death and deterioration of the surrounding viable tissue in the absence of treatment, because of sustained compromised blood flow. Usually, patients are not prepared for a primary injury, making the treatment of secondary injury a prime target for therapeutic agents. Reducing the severity of the secondary injury is known as neuroprotection.
ReplyDeleteWith an understanding of secondary damage, a greater appreciation for the potential antagonist pathways of neuroprotective drugs is possible. For instance, a neuroprotective agent like a corticosteroid works to minimize the inflammatory response by preventing the release of cytokines. Statins could also be effective in antagonizing inflammation following a stroke or TBI. Statins may also improve blood flow by increasing the availability of oxygen. Maintaining enough blood flow is one of the prime focuses of neuroprotective therapy, along with statins, fibrinolytic agents can also be beneficial in combating the reduced blood flow caused by clots. For instance, tPA (tissue plasminogen activator) is known to dissolve blood clots, thus restoring blood flow to the tissues and brain. tPA does this by activating plasminogen which then produces a cleaved product, plasmin. Plasmin breaks down fibrin which is the main component providing blood clots with structural integrity. Blood flow to the brain is vital to its survival, primarily because blood is the primary transporter of oxygen. Therefore, agents like hematopoietic growth factors that increase erythrocyte volume can have significant neuroprotective effects following a stroke or CNS injury. As a consequence of increasing the blood cell count and hemoglobin availability, these agents would not only increase oxygen supply but also encourage neuron survival, prevent cerebral ischemia, reduce inflammation, and inhibit the formation of free radicals. Constricting vessels is not the only way blood flow is reduced, as previously stated vasogenic blood vessels can result in the unintended release of blood vessels. Therapies like albumin can combat this release of the vascular contents. Albumin is a protein found in blood plasma, and it is capable of binding to several components like water, ions, and hormones which makes it a suitable regulator of oncotic blood pressure. These properties enable compounds, like albumin, to antagonize the leakage of fluid from the vasculature and maintain the homeostasis of ion pumps.
The only fibrinolytic agent approved to treat ischemic stroke is tPa. As you mentioned Erin there is a large set of criteria that must be met for treatment with tPa to be considered. Another treatment of ischemic stroke is mechanical thrombectomy, which is done in cases where fibrinolysis cannot be done. From my understanding, researchers are having a difficult time in producing successful experimental stroke treatments. One problem with stroke research is that the stroke conditions simulated in the laboratory cannot be translated as an accurate representation of a stroke. Many factors during experimental treatments are highly regulated which is not the case of normally occurring strokes.
Niamh Costello
Hall, Edward D. PhD. (2018). Ischemic and Hemorrhagic Stroke Models. ANA650: CNS Injury and Repair. University of Kentucky, Lexington.
Bix, Gregory. MD., Ph.D., F.A.H.A. (2018). Stroke - Clinical. ANA780: Special Topic in Neurobiology. University of Kentucky, Lexington.
Hey Erin, I really enjoyed your blog post. This post makes me wonder if it is possible to really win while treating a stroke. As you say, once a stroke occurs there is very little time to either surgically or pharmacologically confront the stroke, and both options confer great risk to the patient. This is, of course, not to say that it is better to leave the stroke untreated as a patient’s quality of life is decreased dramatically or mortally by ischemic death of brain tissue. In the case of surgical intervention or thrombectomy there are many additional factors that one must consider including migration of the clot and reperfusion injuries. Even allowing blood to flow back into the brain tissue too quickly can result in severe injury or further hemorrhagic stroke. Similarly, tPA and other drugs that “bust clots” work as blood thinners that prevent clotting and degrade existing clots. These drugs can also induce hemorrhagic stroke following ischemic stroke. At the same time, if strokes are effectively treated in a very narrow window of time following the onset of the stroke, most physical and cognitive functions can be recovered. Outside of this window this is not the case so there is no time to waste when confronting a stroke. So, with such high risk and potentially high return the treatment of strokes can be a gamble for sure.
ReplyDeleteNour, M., Scalzo, F., & Liebeskind, D. S. (2012). Ischemia-Reperfusion Injury in Stroke. Interventional Neurology, 1(3-4), 185–199. doi: 10.1159/000353125
I thought this post was very informative. I appreciated how you chose to outline both types of strokes and their treatments before delving into tPA as a treatment for ischemic strokes in cases where the blockage is located in a smaller blood vessel. I would have really enjoyed some more information on the aftermath of strokes, being that so many people, especially in Kentucky are affected. Regarding the timing of administration for tPA, I wondered the statistics of patients who arrived to the hospital within that timeframe versus those who did not. I think it is important to educate the public on the major signs of stroke and remind them that it is better to be safe than sorry. Unfortunately, there are many people who think ignorance is bliss when it comes to their heath, but they cannot afford to have that mindset when there is such a small timeframe for something so serious and permanent to be rectified. Ultimately, I think public education is of such importance in these scenarios, and when it comes to tPA specifically, each patient should know the risks (such as cranial hemorrhaging) but also understand the great reward of minimal permanent damage.
ReplyDelete-Alivia Larkin
There are some alternative therapies that are currently being investigated. Most involve surgical intervention to physically remove the clot, although this often remains an incomplete solution, which must be similarly attacked in a short time. This is usually combined with other thrombolytics. All of these treatments are aimed at reperfusion. It is important to do this in as short a time as possible in order to limit damage from lack of oxygenation in the ischemic areas. Hopefully some of these therapies will turn out to be viable alternatives to tPA, since it comes with such a high risk of hemorrhage and has so many restrictions for use.
ReplyDeleteBarreto, Andrew D, and Andrei V Alexandrov. “Adjunctive and Alternative Approaches to Current Reperfusion Therapy.” Stroke, U.S. National Library of Medicine, Feb. 2012, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3268680/.
This was a really informative post! I have never really looked into the mechanisms behind strokes and I was defineitly surprised to see that the treatment window is so small. Since the medication is used to clear blood clots, I was interested in it’s use for clots occurring in other parts of the body such as deep vein thrombosis in the legs. I quickly learned that this has been explored for some time. In a study done on adolescents, the majority of clots were cleared. However, there were many complications including hemorrhaging as you mentioned. The study came to the conclusion that it can be used to resolve thrombosis. However, it is not a safe method due to its very low margin of safety and side effects. I will admit that I have not gone in depth with researching the drugs mechanism, but I’m curious to see if tPA will become an agent that is sparingly used compared to alternatives or if researchers will further research to attempt to resolve some of its complications.
ReplyDeleteGupta, A. A., Leaker, M., Andrew, M., Massicotte, P., Liu, L., Benson, L. N., & McCrindle, B. W. (2001). Safety and outcomes of thrombolysis with tissue plasminogen activator for treatment of intravascular thrombosis in children. The Journal of pediatrics, 139(5), 682-688.