Stroke is a life-threatening medical condition characterized by a sudden catastrophic breakdown in the brain-supporting cerebrovascular system and blood supply, which, in many instances, is followed by an irreversible injury to the brain cells and severe neurological impairment or death.
Notwithstanding a remarkable progress in medical science and technology and associated improvements in clinical practices, stroke continues to constitute the major public health problem in the U.S. and overseas. According to the World Health Organization (WHO), OECD, and governments’ data, approximately 12.0 million to 13.0 million people worldwide suffered a stroke in 2014, of which roughly 75% represented first attacks and 25% were qualified as recurrent attacks. Based on the same sources, almost 3.5 million acute stroke episodes result in death within one year globally, which makes it the third most common cause of death, behind diseases of the heart and cancer.
Stroke is also a leading cause of serious and lasting disability and long-term institutionalized care.
Source: MedMarket Diligence, LLC; Report #C310.
Management of Stroke
Therapeutic management of stroke encompasses a broad scope of prophylactic, palliative and curative treatment modalities that are typically employed in some combinations during the preventive, acute and rehabilitation phases of stroke-related care delivery.
Historically, prevention has been universally regarded as the best form of medicine for dealing with any disease. This old wisdom is especially true in management of acute stroke, which represents a catastrophic event with a largely predetermined clinical progression and outcome that stem from the patient’s preexisting pathologies and can be only marginally altered with available emergent therapies.
Presently, the commonly accepted strategy of primary and secondary stroke prevention is focused on elimination or remedying of the modifiable risk factors that have been shown to create a general predisposition or directly contribute to the onset of acute cerebral ischemia or/and hemorrhage.
Within the context of general population, this strategy is targeting alleviation of certain lifestyle risk factors (such as smoking, obesity, physical inactivity, excessive alcohol consumption, drug abuse, high-fat diet etc.), which could contribute to the development of cardiovascular and other pathologies associated with increased propensity to stroke.
In patient caseloads with preexisting medical conditions (AFib, mechanical prosthetic valves, recent AMI, stoke or TIA, hypertension, diabetes, etc.) which are characterized by a high risk of adverse vascular events potentially leading to stroke, preventive strategy is focused on reducing such risks via a strict control and monitoring of corresponding hemostatic and hemodynamic parameters.
Finally, in persons with diagnosed cerebrovascular pathologies (high grade carotid stenosis, intracranial aneurysms and AVMs) the first line preventive therapy involves their repair or eradication, when technically possible.
The scope of FDA-approved medical and interventional modalities commonly employed in preventive management of stroke includes oral anticoagulation, antiplatelet, and lipid-lowering drug therapies, cerebral aneurysm and AVM repair surgery, carotid endarterectomy, stereotactic radiosurgery, as well as endovascular embolization of intracranial aneurysms and AVMs, carotid artery stenting with embolic protection, left atrial appendage closure, along with rarely used and likely to be abandoned intracranial stenting.
In contrast to causes-oriented therapies used in stroke prevention, therapeutic modalities employed in the emergent management of acute stroke are focused almost exclusively on patients’ cardiopulmonary and hemodynamic support and ad hoc containment of dangerous complications and corresponding brain damage associated with stroke.
Among the life-threatening complications that commonly accompany acute cerebral hemorrhage or ischemia are cerebral edema; hydrocephalus; brain stem compression; vasospasm and pulmonary embolism.
Management of the acute complications of stroke relies on a few proven treatment regimens, including (but not limited to):
- medical therapy and catheter-based ventricular drainage of cerebrospinal fluid to control intracerebral pressure in patients at risk of edema, hydrocephalus or brain stem compression;
- hypertensive hypervolemic hemodilution (or “triple-H” therapy) to treat ischemic neurological deficit from vasospasm following subarachnoid hemorrhage;
- subcutaneous anticoagulation (with heparins or heparinoids) for prophylaxis of pulmonary embolism (which accounts for approximately 10% of deaths following stroke); and
- elective hypothermia for temporary salvaging brain cells from necrosis due to hemorrhagic trauma or acute ischemia (although the latter technique has not been proven efficacious in clinical trials and was not endorsed in the latest, 2007 versions of the AHA hemorrhagic and ischemic stroke guidelines).
The currently available curative treatment options for acute stroke are limited to intravenous t-PA therapy (which has about 30% efficacy and is indicated for a very narrow cohort of eligible ischemic stroke patients only), investigational intra-arterial thrombolytic therapy, transcatheter cerebral thrombectomy (in patients who did not qualify for or failed t-PA therapy), and emergency craniotomy-based or endoscopic removal of stroke-related hematoma (which carries a 50% to 80% risk of mortality and is reserved for rapidly deteriorating young patients with large lobar hemorrhages).
Rehabilitation phase of stroke management relies on general physiotherapeutic techniques commonly used in patients with various physical and neurological disabilities. Prophylactics of recurrent cerebrovascular events in stroke survivors employs medical and interventional regimens referred to in the overview of primary and secondary stroke prevention.
The above is excerpted from, “Emerging Global Market for Neurointerventional Technologies in Stroke, 2014-2019“, published September 2015. For details, see link.