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SEGA Trial

Sedation versus General Anesthesia for Endovascular Therapy in Acute Ischemic Stroke – a Randomized Comparative Effectiveness Trial.

The purpose of this page is to inform the public about a clinical trial in which patients with acute ischemic stroke undergoing endovascular therapy may be enrolled without prior consent. This clinical trial will recruit patients at Memorial Herman Hospital - Texas Medical Center and at Baylor College of Medicine. 

What is the purpose of this research study?

The majority of strokes are the result of blood clots in the main vessels that provide blood to the brain. When people suffer from a stroke, these blood clots produce a blockage to the normal flow of blood, which can cause brain tissue to be damaged. This often produces symptoms such as weakness or numbness to one side of the body, changes in vision, or changes in people’s abilities to speak or be understood.

Although the body may break up the blood clots on its own, doctors also use a clot-busting drug called rt-PA for patients with certain types of stroke. Unfortunately, rt-PA is not always successful in breaking up clots. Larger clots can also be removed from the brain by performing an emergency surgery called endovascular therapy which can restore normal blood flow. Endovascular therapy with stent retrievers have been shown to improve outcomes in acute stroke patients. However, there is still some controversy about the best type of anesthesia – general anesthesia (GA) vs sedation (CS) to be used during endovascular therapy.

The purpose of this study is to study whether GA during endovascular therapy results in better outcomes compared with CS during endovascular therapy among acute ischemic stroke patients.

Why is it not possible to get patient’s consent before including them in the study?

The trial compares two anesthesia approaches for EVT delivered as usual care.  Participation in SEGA should never delay the time-sensitive nature of providing urgent endovascular therapy in acute ischemic stroke.  Many of the severe stroke patients are air-transported to the comprehensive stroke centers and family members must drive from the outlying hospital to the center.  In our experience, we have noticed that a majority of patients suffer from either language disturbance of either comprehension or expression or are unable to understand or acknowledge they are suffering a stroke.  Hence, the majority of patients will be unable to provide informed consent due to lack of capacity.  Unfortunately, the majority of legal next of kin fail to arrive before the endovascular procedures are started; including the transfer from the emergency department to the angio suite for endovascular therapy.

Hence, informed consent in this patient population is rarely feasible.  If we only enroll the small number of patients who are able to give consent, the trial would recruit at a very slow pace and enrollments will be predominantly a less-severe subgroup of strokes.  It is well established across clinical research that the patients who benefit the most from effective interventions are usually those most severely affected.  We believe that participation in a clinical trial could directly benefit the patient and ultimately society if one of the treatments (GA vs. CS) is better than the other .  The inability to participate in promising research for the most severely affected patients is sometimes interpreted as a breach of the ethical principle of justice.  The basic concept of distributive justice, as it relates to clinical research, should not categorically exclude certain subgroups with clinically relevant characteristics such as disease severity, sex, age, etc.  This discrimination is unjust and results in skewed generalizable knowledge that guides health care practices. 

We recognize that emergency research such as this trial or any research that requires study-related research outcomes will require subsequent written consent from the patient of legal next of kin.  The study doctors and study staff will make attempts to reach family members that are available in the hospital or will be arriving within 15 minutes.  If patients were enrolled into the study before consent was obtained, the study doctors and study staff will talk with the patients and/or family members as soon as possible after the procedure to obtain consent for continued participation in the research. 

When will the study start?

This study began early 2018 and has enrolled over 100 patients at various clinical sites around US. We hope to finish enrollment by mid 2022. 

Who will be included in this research study?

Adult patients with an acute ischemic stroke due to large occlusions who are being considered for endovascular therapy will be included in this research study.

How many patients will be included in this research study?

We plan to enroll 250 acute ischemic stroke patients at 10 – 15 centers all around the country. Of these 250 patients, 125 will be randomized to receiving general anesthesia and 125 to sedation during the endovascular therapy treatment.

What are the other study procedures?

The study doctors and study staff will collect information on medical history, physical exam, vital signs, laboratory tests; CT scans and arterial vessel imaging from the patients’ medical records. After 7-days or at discharge (whichever occurs first), the study staff will collect information on vital signs and physical examination. There will be a follow up visit about 3 months after the stroke to assess stroke recovery and quality of life.

What are the risks of using general anesthesia versus sedation during endovascular therapy?

Both sedation and anesthesia are generally considered to be very safe. Most people can undergo general anesthesia or sedation without serious problems.

Serious, but rare, complications can occur with all methods of anesthesia. Some of these risks are breathing and heart problems, drug reactions, nerve damage, cardiac arrest, brain damage, paralysis, or death. Sedation carries a risk of a necessity to convert to general anesthesia. General anesthesia has additional risks of injury to the vocal cords, teeth, lips, or eyes and awareness during the procedure.

If I do not wish to be included in this research study, how can make my wish known?

If you do not wish to participate in this research study, please email us at We will be happy to provide you with an ‘opt-out’ bracelet that you should wear for the duration of the study.