Assessment of the Cerebral Perfusion During the Period of Deep Hypothermia at 18°C in Patient Undergoing Pulmonary Endarterectomy Surgery. (HYPO-TEP)

February 22, 2024 updated by: Fondation Hôpital Saint-Joseph

Cardiopulmonary bypass (CPB) surgery present risk of acute postoperative neurological complications. These complications are most often postoperative cognitive dysfunction (confusion, cognitive disorders, executive disorders) with a prevalence of up to 40% at 5 years, and ischemic (stroke) with an incidence of between 0.4 and 14%. The causes are usually multifactorial, but altered cerebral perfusion during CPB surgery is an important prognostic factor. Data regarding the effect of deep hypothermia on cerebral perfusion during CPB in adult are scarce. Currently, aortic arch replacement following aortic dissection or aneurysm, and pulmonary artery endarterectomy (PAE) in the treatment of pulmonary hypertension of post embolic origin are performed under deep hypothermia.

In this latter indication, the need to obtain a completely bloodless operating field necessitates complete circulatory arrest during short period of time to enable the surgeon to optimally remove the clot materials located into the pulmonary arteries.

To protect the brain and avoid irreversible brain injury during circulatory arrest(s), body temperature is lowered at 18-20°C. Deep hypothermia can lead to significant arterial vasoconstriction, which can reduce the blood supply to the brai. It also increases the solubility of CO2 in the blood, leading to respiratory alkalosis, which can also lead to vasoconstriction of cerebral vessels, increasing the risk of ischemic lesions.

In adult there is no consistent data on the cerebral perfusion during PAE surgery under deep hypothermia at 18-20°C. Animal studies showed that cerebral regulation seems to be preserved under these conditions. A better understanding of the effect of deep hypothermia on cerebral perfusion during PAE surgery is essential to adapt our management to limit the occurrence of postoperative neurological complications.

Study Overview

Study Type

Interventional

Enrollment (Estimated)

80

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

  • Name: Sylvain DIOP, Dr
  • Phone Number: +33140948637
  • Email: sdiop@ghpsj.fr

Study Locations

      • Le Plessis-Robinson, France, 92350
        • Recruiting
        • Hôpital Marie Lannelongue
        • Contact:
        • Principal Investigator:
          • Sylvain DIOP

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Scheduled for pulmonary artery thromboendarterectomy surgery.
  • Patient with free, written and informed consent.
  • Patient affiliated to a social security scheme (beneficiary or beneficiary's beneficiary).
  • French-speaking patient.

Exclusion Criteria:

  • Patient refusing to participate in the study.
  • Patient under guardianship.
  • Patient deprived of liberty.
  • Pregnant or breast-feeding women.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Other
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Patients with thromboendarterectomy surgery

Anesthesia was induced with sufentanil 0.3 g/kg, etomidate 0.3-0.4 mg/kg, rocuronium 0.4 mg/kg and maintained with continuous infusion Propofol and sufentanil. A pulmonary arterial catheter was inserted in all patients. Patients were cooled by means of the oxygenator heat exchanger at a rate of one degree Celsius every three minutes. Rewarming was achieved at a rate of one degree Celsius every five to ten minutes.

The following measures were performed:

Measure 1: In normo-thermia after induction of general anesthesia Measure 2: On CPB, before circulatory arrest and in hypothermia at 18-20°C Measure 3: On bypass, after circulatory arrest and in hypothermia at 18-20°C Measure 4: At the end of the procedure, after weaning from the bypass and in normothermia.

For each measure mean arterial pressure, cardiac output, PaCO2, pH, bilateral NIRS value were also recorded.

Velocity measurements in the middle cerebral artery are made using an ultrasound probe applied to the patient's temple during surgery.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Assessment of cerebral blood perfusion during deep hypothermia
Time Frame: M1: Baseline-normothermia after induction of general anesthesia (H0) M2: During CPB-at 18°C-before cardiac arrest (H2) M3: After cardiac arrest-at 18°C before (H4) M4: End of surgery-normothermia (H6)
Cerebral blood perfusion during deep hypothermia (18-20°C) will be assessed by measuring mean blood flow velocities in the middle cerebral arteries (MCAs) using trans-cranial Doppler ultrasound (DTC) at different time of the surgery (Four measures in total). All measure are performed during the time of the surgery. The first measure (M1) is baseline to which the other measure will be compared to.
M1: Baseline-normothermia after induction of general anesthesia (H0) M2: During CPB-at 18°C-before cardiac arrest (H2) M3: After cardiac arrest-at 18°C before (H4) M4: End of surgery-normothermia (H6)

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Correlation between NIRS and middle cerebral arteries velocity values for each measure.
Time Frame: M1: Baseline-normothermia after induction of general anesthesia (H0) M2: During CPB-at 18°C-before cardiac arrest (H2) M3: After cardiac arrest-at 18°C before (H4) M4: End of surgery-normothermia (H6)
For each measure of middle cerebral arteries blood flow velocity performed during the surgery, the value of the near infrared spectroscopy (NIRS) is recorded. A total of four measures is performed during the time of the surgery.
M1: Baseline-normothermia after induction of general anesthesia (H0) M2: During CPB-at 18°C-before cardiac arrest (H2) M3: After cardiac arrest-at 18°C before (H4) M4: End of surgery-normothermia (H6)
Seek for post-circulatory arrest hyperemia
Time Frame: M2: During CPB after cooling at 18°C before cardiac arrest (H2). M3: After cardiac arrest at 18°C before rewarming period (H4).
Comparison of the middle cerebral arteries blood flow velocities during the period of hypothermia, before and after cardiac arrest.
M2: During CPB after cooling at 18°C before cardiac arrest (H2). M3: After cardiac arrest at 18°C before rewarming period (H4).

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

August 24, 2023

Primary Completion (Estimated)

February 24, 2025

Study Completion (Estimated)

May 24, 2025

Study Registration Dates

First Submitted

January 12, 2024

First Submitted That Met QC Criteria

January 31, 2024

First Posted (Actual)

February 9, 2024

Study Record Updates

Last Update Posted (Estimated)

February 26, 2024

Last Update Submitted That Met QC Criteria

February 22, 2024

Last Verified

August 1, 2023

More Information

Terms related to this study

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Clinical Trials on Pulmonary Hypertension

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