Transpharyngeal Doppler Sonography for Cerebral Perfusion Monitoring

Study Overview
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Brief Summary
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This prospective interventional study investigates transpharyngeal sonography (TPS) as an additional neuromonitoring strategy to assess cerebral perfusion during cardiovascular surgery. In the first part of the study the investigators will investigate the feasibility of TPS for visualization of aortic arch branches including the innominate and the carotid arteries in patients undergoing cardiac surgery with cardiopulmonary bypass. In the second part the investigators plan to adopt the investigators previous experiences on TPS to a selected population of patients undergoing ascending aortic and/or arch repair in hypothermic circulatory arrest (HCA).

Official Title
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Evaluation of Transpharyngeal Doppler Sonography as a Cerebral Monitoring Tool in Cardiac Surgery

Conditions
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Cerebral Perfusion

Intervention / Treatment
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* Diagnostic Test: Transpharyngeal Doppler sonography (TPS)
* Diagnostic Test: Conventional colour-coded Duplex sonography (CDS)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Cardiovascular Surgery Age > 18 yrs Informed Consent Exclusion Criteria: Contraindication for TPS Carotid artery stenosis

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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Design Details

Primary Purpose: Diagnostic
Allocation: Non-Randomized
Intervention Model: Sequential Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: 20 patients (1-20) validation arm<br>Accuracy of cerebral flow measurement between TPS and CDS in 20 patients undergoing cardiovascular surgery with cardiopulmonary bypass | Diagnostic Test: Transpharyngeal Doppler sonography (TPS)<br>* Usage of transpharyngeal Doppler to assess cerebral perfusion during cardiovascular surgery<br>Diagnostic Test: Conventional colour-coded Duplex sonography (CDS)<br>* Usage of conventional colour-coded Duplex sonography (CDS) to assess cerebral perfusion during cardiovascular surgery<br>|
| Experimental: 20 patients (21-40) HCA arm<br>Assessment and comparison of TPS and CDS in hypothermic circulatory arrest (HCA) during cardiovascular surgery | Diagnostic Test: Transpharyngeal Doppler sonography (TPS)<br>* Usage of transpharyngeal Doppler to assess cerebral perfusion during cardiovascular surgery<br>Diagnostic Test: Conventional colour-coded Duplex sonography (CDS)<br>* Usage of conventional colour-coded Duplex sonography (CDS) to assess cerebral perfusion during cardiovascular surgery<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Accuracy of cerebral flow velocity measurement | Cerebral blood flow velocity measurements will be performed with transpharyngeal Doppler sonography (TPS) and conventional colour-coded Duplex sonography (CDS). Doppler flow velocities (obtained at the same intraoperative phase and at the same time) will be compared between TPS and CDS TPS and different Doppler techniques. | intraoperative phase, expected to be ca. 4 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Hypothermic Circulatory Arrest | Doppler flow velocities (obtained with both methods in the Phase of hypothermic circulatory arrest - intraoperatively) will be compared between TPS and CDS TPS and different Doppler techniques. | intraoperative phase, expected to be ca. 4 hours |