What is thrombectomy (thrombus removal)?

From the Guidelines

Thrombectomy is a medical procedure that involves the mechanical removal of blood clots from the cerebral circulation using endovascular retrieval devices, with the goal of restoring blood flow to the affected area of the brain, minimizing damage, and improving patient outcomes 1.

Key Points

• The procedure is typically performed in patients with acute ischemic stroke caused by a large vessel occlusion, within 6 hours of symptom onset 1.
• Thrombectomy can be performed using various devices, including stent retrievers, such as the Solitaire Flow Restoration Device and the Trevo Retriever, and aspiration devices, such as the Penumbra System 1.
• The procedure involves the following steps:
  • Administering intravenous tissue plasminogen activator (tPA) at a dose of 0.9 mg/kg, with a maximum dose of 90 mg, if the patient presents within 4.5 hours of symptom onset and meets the criteria for tPA 1.
  • Performing thrombectomy as soon as possible, ideally within 1 hour of hospital arrival 1.
  • Using general anesthesia or conscious sedation during the procedure, determined on a case-by-case basis 1.
  • Monitoring for complications, such as hemorrhage or re-occlusion, and managing blood pressure and other medical conditions after the procedure 1.

Benefits and Risks

• Thrombectomy has been shown to improve recanalization rates and clinical outcomes, including reduced mortality and improved functional outcomes, compared to intravenous thrombolysis alone 1.
• However, the procedure also carries risks, including procedural complications, symptomatic intracranial hemorrhage, and device malfunctions 1.

Device Options

• The choice of device for thrombectomy depends on various factors, including the location and characteristics of the occlusion, as well as the patient's overall medical condition 1.
• Studies have compared the efficacy and safety of different devices, including the Solitaire and Trevo retrievers, and the Penumbra System, with varying results 1.

From the FDA Drug Label

CLINICAL STUDIES Three clinical studies were performed in patients with improperly functioning central venous access devices (CVADs) Patients with hemodialysis catheters or a known mechanical occlusion were excluded from both studies Restoration of function was assessed by successful withdrawal of 3 mL of blood and infusion of 5 mL of saline through the catheter

Thrombectomy (thrombus removal) is not directly mentioned in the provided text. However, the text does discuss the restoration of function in occluded catheters using Alteplase, which is a tissue plasminogen activator. The studies described in the text involve the use of Alteplase to restore function to catheters that are not functioning due to occlusion, but the term thrombectomy is not used. The FDA drug label does not answer the question.

From the Research

Definition of Thrombectomy

Thrombectomy, also known as thrombus removal, is a medical procedure used to remove a blood clot from a blood vessel. In the context of acute ischemic stroke, thrombectomy is used to remove a clot that is blocking a large vessel in the brain, restoring blood flow to the affected area.

Types of Thrombectomy

There are two main types of thrombectomy:

• Mechanical thrombectomy: This involves using a device to physically remove the clot from the blood vessel.
• Intravenous thrombolysis: This involves using medication to dissolve the clot.

Indications for Thrombectomy

Thrombectomy is typically indicated for patients with acute ischemic stroke who have a large vessel occlusion in the anterior circulation and can be treated within 6 hours of symptom onset 2, 3. However, recent studies have shown that thrombectomy can be effective in select patients up to 24 hours after symptom onset 2, 4.

Benefits of Thrombectomy

Thrombectomy has been shown to improve clinical outcomes in patients with acute ischemic stroke, including:

• Reduced disability 2, 4
• Improved functional independence 2, 4, 5
• Reduced mortality 2, 4

Combined Therapy

Some studies have investigated the use of combined intravenous thrombolysis and thrombectomy, with mixed results:

• One study found that combined therapy did not provide a significant benefit over thrombectomy alone 6
• Another study found that combined therapy was associated with improved functional outcomes and reduced mortality 4

Key Considerations

When considering thrombectomy for acute ischemic stroke, key considerations include:

• Time from symptom onset to treatment 2, 3
• Location and severity of the clot 2, 3
• Patient's overall health and medical history 2, 3
• Potential risks and complications, such as bleeding or vasospasm 6