Study on Stroke Treatments: Alteplase vs. Thrombectomy

Overview of Stroke Mechanisms

A comprehensive stroke research study conducted by the University of Calgary in Canada examined the effectiveness of intravenous alteplase compared to thrombectomy for treating arterial clots. The National Stroke Association defines a stroke as an event where blood flow to a specific area of the brain is interrupted. The absence of oxygen leads to cell death and adversely affects the functions controlled by that brain region. Even minimal brain damage can result in muscle weakness, while larger strokes can cause significant brain damage and potential paralysis on one side of the body.

Types of Strokes

Strokes are categorized into two main types. Hemorrhagic strokes occur when weakened blood vessels in the brain leak or burst, cutting off blood flow. Ischemic strokes, which account for over 80% of strokes, occur when arterial clots obstruct normal blood flow.

Treatment Approaches for Ischemic Strokes

Importance of Prompt Treatment

Rapid removal of clots and restoration of blood flow to the brain is crucial for optimizing patient outcomes. This can be achieved through a mechanical thrombectomy, where a specialized catheter is used to extract the clot from an artery in the groin. Alternatively, intravenous medications like alteplase (tPA) can be administered to dissolve the clot.

Diagnostic Procedures

When a patient presents with stroke symptoms, a computed tomographic (CT) angiogram is utilized to assess the brain’s blood vessels and identify the cause and location of the blockage. However, physicians often face challenges in determining the most suitable treatment option for individual patients.

Research Findings on Treatment Efficacy

Study Details and Participant Demographics

A recent study published in JAMA explored the effectiveness of alteplase (tPA) compared to thrombectomy for arterial clots. Researchers recruited 575 participants from 12 medical centers across Canada, the Czech Republic, South Korea, Spain, and Turkey. Participants, with an average age of 72 and comprising 51.5% males, underwent CT-angiograms that indicated intracranial arterial blockage.

Treatment Groups and Outcomes

Among the participants, 275 (47.8%) received only intravenous alteplase, 195 (33.9%) received a combination of alteplase and thrombectomy, 48 (8.3%) underwent only thrombectomy, and 57 (9.9%) received no treatment. The findings revealed that arterial clots exhibited varying compositions. In certain cases, administering intravenous alteplase was nearly as effective as thrombectomy, particularly when clots were permeable. In these instances, intravenous alteplase resulted in the dissolution of 50% or more of the clot within two hours. However, for clots located in the carotid artery, thrombectomy remained necessary.

Insights from Research

Dr. Demchuk, one of the researchers, emphasized that these findings offer physicians crucial evidence supporting the timely administration of alteplase once a stroke due to a clot is confirmed.

Conclusion and References

This study highlights the importance of personalized treatment strategies for acute ischemic strokes, presenting valuable insights into the effectiveness of alteplase compared to thrombectomy.

Written by Debra A. Kellen, PhD

References:
Menon, B. K., Al-Ajlan, F. S., Najm, M., Puig, J., Castellanos, M., Dowlatshahi, D., … & Mikulik, R. (2018). Association of Clinical, Imaging, and Thrombus Characteristics With Recanalization of Visible Intracranial Occlusion in Patients With Acute Ischemic Stroke. JAMA, 320(10), 1017-1026. doi:10.1001/jama.2018.12498

National Stroke Association. Understand Stroke. [Cited Oct. 3, 2018] Available from http://www.stroke.org/understand-stroke/what-stroke