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Cerebral Perfusion Monitoring With Transpharyngeal Ultrasonography (TP-Echo)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT01828411
Recruitment Status : Active, not recruiting
First Posted : April 10, 2013
Last Update Posted : March 13, 2018
Information provided by (Responsible Party):
University Hospital Inselspital, Berne

March 27, 2013
April 10, 2013
March 13, 2018
April 2013
May 2018   (Final data collection date for primary outcome measure)
accuracy of cerebral flow velocity measurement [ Time Frame: intraoperative phase, expected to be ca. 4 hours ]
Cerebral blood flow velocity measurements will be performed using the pulsed wave Doppler technique. Doppler peak flow velocities (obtained at the same intraoperative phase and at the same time) will be compared between the different Doppler techniques.
Same as current
Complete list of historical versions of study NCT01828411 on Archive Site
clinical feasibility [ Time Frame: intraoperative phase, expected to be ca. 4 hours ]
Clinical feasibility will be assessed by analyzing the accuracy of data concordance, i.e. location of cerebral blood vessel, blood flow velocity and cerebral vessel area between the different Doppler techniques. Data will be plotted using Bland-Altman analysis.
Same as current
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Cerebral Perfusion Monitoring With Transpharyngeal Ultrasonography
Monitoring the Brain in On-pump Cardiovascular Surgery: The Role of Transpharyngeal Ultrasonography as a Non-invasive Adjunct to Assess Cerebral Perfusion

This prospective observational pilot study investigates transpharyngeal ultrasonography (TPU) as an additional neuromonitoring strategy to assess cerebral perfusion during on-pump cardiovascular surgery.

In the first part of the study the investigators will investigate the feasibility of TPU for visualization of aortic arch branches including the innominate and the carotid arteries in twenty patients undergoing coronary artery bypass grafting with extracorporeal circulation (cohort 1.). In the second part the investigators plan to adopt the investigators previous experiences on TPU to a selected population of twelve patients undergoing ascending aortic and/or arch repair in deep hypothermic circulatory arrest (DHCA, cohort 2.). In contrast to cohort 1., patients in cohort 2. are exposed intraoperatively to intermittent cerebral perfusion stops or reductions due to surgical procedure, perfusion technique and their underlying disease (aortic dissection or aortic aneurysm).

The investigators hypothesize that cerebral perfusion monitoring using TPU as a non-invasive technique provides a simple and real-time adjunct to assess blood flow velocity in the extracranial cephalic vessels with Doppler ultrasound. Especially in aortic arch surgery with its inherent risk of cerebral hypoperfusion TPU might be a valuable adjunct to routine.


Cerebral hypo- or malperfusion during cardiovascular surgery can lead to grave consequences including transient cerebral ischemia or stroke impairing patient`s daily life and affect surgical outcome. For this reason a multimodal neuromonitoring strategy using a variety of devices (evoked potentials, near-infrared spectroscopy, transcranial Doppler ultrasonography) with different technologies has been recommended by medical societies. These techniques have various limitations and cannot be used in all clinical situations. In contrast, transpharyngeal ultrasonography (TPU) represents a simple and readily available technique: the transesophageal echocardiography probe, routinely placed in most cardiac surgical patients for monitoring and assessment of surgical results, will be withdrawn into the upper esophagus making the visualization of supraaortic branches possible.

To date, there are several reports about imaging of aortic arch branches using TPU. The utility of this technique, however, for systematic cerebrovascular monitoring has not have been investigated so far.


The aim of this study is to investigate TPU as a cerebrovascular monitoring adjunct in two cohorts of on-pump cardiac surgery procedures. Clinical feasibility and diagnostic accuracy of antegrade carotid flow detection are compared to the established reference methods of Duplex sonography and transcranial Doppler ultrasound.


All patients receive anesthetic and surgical management according to institutional standards. Patient enrollment in the study occurs consecutively and unblinded for surgical procedure.

All patients receive TPU, Duplex sonography and transcranial Doppler examination after anesthesia induction preoperatively, during extracorporeal circulation and after weaning from cardiopulmonary bypass. In addition, the patients in cohort 2.(ascending aortic repair with DHCA) receive above mentioned noninvasive ultrasound / Doppler measurements also during the period of DHCA with and without antegrade cerebral perfusion.

Image acquisition and data extraction are conducted by different persons to avoid investigator-related bias.

Observational Model: Case-Only
Time Perspective: Cross-Sectional
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Probability Sample
Patients undergoing cardiac surgery at the University Hospital Bern.
Cardiopulmonary Bypass
  • Device: Transpharyngeal ultrasonography
    Transpharyngeal Dopplerultrasonography (Device: iE33 xMatrix Philips). Assessment of cerebral blood flow by detection of blood flow velocities in the extracranial carotid arteries.
  • Device: Duplex sonography
    Assessment of cerebral blood flow by detection of blood flow velocities in the extracranial carotid and middle cerebral arteries during coronary artery bypass grafting.
  • Cardiopulmonary bypass group
    Patients requiring normothermic (or mild hypothermic) cardiopulmonary bypass.
    • Device: Transpharyngeal ultrasonography
    • Device: Duplex sonography
  • Hypothermic Cardiopulmonary Bypass Group
    Patients requiring (deep) hypothermic cardiopulmonary bypass.
    • Device: Transpharyngeal ultrasonography
    • Device: Duplex sonography

*   Includes publications given by the data provider as well as publications identified by Identifier (NCT Number) in Medline.
Active, not recruiting
September 2018
May 2018   (Final data collection date for primary outcome measure)

Inclusion Criteria:

  • Signed informed consent
  • Cardiopulmonary bypass procedure (normo-(group 1) or hypothermic (group 2))

Exclusion Criteria

  • Contraindication for transesophageal echocardiography
  • Carotid artery stenosis
Sexes Eligible for Study: All
18 Years and older   (Adult, Senior)
Contact information is only displayed when the study is recruiting subjects
Not Provided
Not Provided
University Hospital Inselspital, Berne
University Hospital Inselspital, Berne
Not Provided
Study Chair: Balthasar Eberle, Prof., MD. University Hospital Bern, Dep. of Anesthesiology and Pain therapy
University Hospital Inselspital, Berne
March 2018