Cerebral Hemodynamics and Microemboli During Placement of Relay®Branch Thoracic Stent-Graft System

Study Overview
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Brief Summary
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This is an observational cohort study addressing the incidence of cerebral microemboli and alterations of cerebral hemodynamic physiology of the Relay®Branch thoracic stent-graft system.

Detailed Description
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This study is a prospective multi-center observational study. Eligible patients will be enrolled in RelayBranch (NCT03214601). Participating centers must have capabilities of performing intra-operative TCD monitoring and post-operative TCD monitoring. If sites have performed TCD microembolic monitoring during previous RelayBranch procedures, we will also incorporate these data in our analysis. The primary objective is to assess the number and timing of cerebral microemboli during Relay®Branch thoracic stent-graft deployment, to identify the highest risk portions of the procedure. Secondary objectives include: correlate procedural microembolic burden with neuroimaging and clinical outcome; quantify post-operative microemboli, correlating with neuroimaging and clinical outcome; and quantify the changes in cerebral blood flow and cerebral autoregulation that happens during critical procedural epochs, correlating with neuroimaging and clinical outcome.

Official Title
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Cerebral Hemodynamics and Microemboli During Placement of Relay®Branch Thoracic Stent-Graft System

Conditions
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Thoracic Aortic Aneurysm, Thoracic Aortic Dissection, Microemboli

Intervention / Treatment
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* Other: transcranial Doppler ultrasonography (TCD)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Enrollment in NCT03214601 based on presence of a thoracic aortic aneurysm, penetrating atherosclerotic ulcer, or chronic type B dissection that would require coverage of the brachiocephalic trunk and/or left carotid if a non-branching endograft were implanted Advanced heart failure with plan to treat with LVAD At least 18 years of age Patients enrolled prospectively must sign the informed consent form If patients underwent TCD monitoring during a previous RelayBranch procedure as part of routine clinical care, we will also incorporate their data in our analysis Exclusion Criteria: Skull defect or skull surgery that will preclude monitoring Known lack of TCD temporal acoustic window (if had TCD in past) Expected surgical position will preclude access to the patient's head for monitoring

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Intervention/Treatment |
| --- |
|Other: transcranial Doppler ultrasonography (TCD)|Transcranial Doppler (TCD) is a non-invasive ultrasound-based technique that facilitates insonation of the cerebral arteries. TCD probe design enables continuous monitoring of cerebral blood flow velocity (CBFv). TCD has a variety of clinical applications, including intraoperative monitoring for detection of microemboli. The TCD probe can be comfortably secured to the patient's head by a headframe in order to maintain continuous vessel insonation. Microembolic signals (MES) can be reliably detected based on standard criteria: Brief in duration (<300msec) High intensity (amplitude >3 dB above background) Unidirectional Audible chirp or snap Further, CBFv monitoring during may inform flow perturbations that occur during cardiac or vascular manipulations.|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| number of intra-operative cerebral microemboli | TCD | during RelayBranch procedure | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Post-operative microemboli (seen on post-op day 1 study) | TCD | post-op day 1 | 
| Change in CBFv | TCD | intra-op and post-op day 1 | 
| Change in cerebral autoregulation | TCD | intra-op and post-op day 1 |