Selective Antegrade Cerebral Perfusion and Perioperative Optic Nerve Sheath Diameter in Ascending Aortic Surgery

NCT07800806 | Not Yet Recruiting DMC

• 1 other identifier: SACP-ONSD-2026-01
• Study Type: interventional
• Target: 134
• Locations: 1 country
• Sites: 1

Brief Summary

In ascending aortic surgery the distal anastomosis may be constructed with the aortic cross-clamp maintained, or, where the extent of the aortic pathology and the geometry of the graft require it, after release of the cross-clamp during a period of systemic circulatory arrest. Both are established surgical approaches. Where the cross-clamp is released, selective antegrade cerebral perfusion (SACP) is an established cerebral protection technique and is applied for that purpose. Where release of the cross-clamp is not required, systemic circulatory arrest is avoided and SACP is not applied. Optic nerve sheath diameter (ONSD) measured by ocular ultrasonography is a non-invasive marker of raised intracranial pressure. Cardiopulmonary bypass may increase blood-brain barrier permeability through hypoperfusion, non-pulsatile flow, hemodilution and systemic inflammation, predisposing to cerebral edema. Perioperative increases in ONSD have been reported after open heart surgery and have been associated with postoperative delirium. Data on how SACP influences perioperative ONSD dynamics in ascending aortic surgery, and whether such changes relate to postoperative delirium, are limited.

Conditions

Aortic Diseases; Cardiac Surgical Procedures; Aortic Aneurysm, Thoracic; Delirium - Postoperative; Postoperative Complications; Cerebrovascular Circulation; Postoperative Complications (Cardiopulmonary)

Keywords

Optic nerve sheath diameter; Selective antegrade cerebral perfusion; Ascending aortic surgery; Circulatory arrest; Cardiopulmonary bypass; Postoperative delirium; Nursing Delirium Screening Scale; Transcranial Doppler ultrasonography; Middle cerebral artery mean flow velocity; Near-infrared spectroscopy; Suppression ratio; Cerebral protection

Outcome Measures

Primary Outcomes (1)

• Change in bilateral mean optic nerve sheath diameter (ONSD) over time

  Optic nerve sheath diameter in millimetres, measured by ocular ultrasonography 3 mm posterior to the entry of the optic nerve into the globe in the transverse plane. Three measurements are obtained per eye and averaged; the mean of the right and left eye values is the participant value. Higher values indicate a larger sheath diameter and are interpreted as consistent with a higher intracranial pressure. The endpoint is the trajectory across the three time points, evaluated as the group-by-time interaction term in a linear mixed-effects model with a random intercept for participant.

  From before anesthesia induction to postoperative hour 24

Secondary Outcomes (6)

• Change in bilateral mean optic nerve diameter (OND) over time

  From before anesthesia induction to postoperative hour 24

• Change in middle cerebral artery mean flow velocity measured by transcranial Doppler

  From before anesthesia induction to postoperative hour 24

• Change in regional cerebral oxygen saturation measured by near-infrared spectroscopy

  From before anesthesia induction to the end of surgery

• Proportion of participants with a positive delirium screen (Nu-DESC >=2)

  At postoperative hour 24

• Number of participants with a clinical neurological event

  From end of surgery to hospital discharge, up to 30 days

Study Arms (2)

Group SACP: cross-clamp release required

OTHER

Participants in whom the extent of the aortic pathology and the geometry of the graft require release of the aortic cross-clamp to construct the distal anastomosis, and who therefore undergo a period of systemic circulatory arrest with selective antegrade cerebral perfusion for cerebral protection. Perfusion is delivered through axillary artery cannulation; type (unilateral or bilateral), cannulation site, flow, target pressure and duration are recorded. Membership of this arm follows from the intraoperative surgical requirement and is not assigned by the investigators. The protocol-specified anesthesia and ventilation regimen and all study assessments are applied identically in both arms.

Diagnostic Test: Optic nerve sheath and optic nerve diameter ultrasonography; Diagnostic Test: Transcranial Doppler ultrasonography

Group Non-SACP: cross-clamp release not required

OTHER

Participants in whom release of the aortic cross-clamp is not required, the extent of the aortic pathology and the length of the graft permitting the distal anastomosis to be completed with the cross-clamp maintained. These participants do not undergo systemic circulatory arrest and selective antegrade cerebral perfusion is not applied. Membership of this arm follows from the intraoperative surgical requirement and is not assigned by the investigators. The protocol-specified anesthesia and ventilation regimen and all study assessments are applied identically in both arms.

Diagnostic Test: Optic nerve sheath and optic nerve diameter ultrasonography; Diagnostic Test: Transcranial Doppler ultrasonography

Interventions

Transcranial Doppler ultrasonography DIAGNOSTIC_TEST

Transcranial Doppler ultrasonography with a 2 MHz pulsed-wave probe. The M1 segment of the middle cerebral artery is insonated through the temporal window at approximately 45-55 mm depth, bilaterally where a window is obtainable. Three consecutive stable mean flow velocity measurements are taken per side and averaged. Performed at T0, T1 and T2, and where technically feasible during selective antegrade cerebral perfusion and/or circulatory arrest.

Group Non-SACP: cross-clamp release not required; Group SACP: cross-clamp release required

Optic nerve sheath and optic nerve diameter ultrasonography DIAGNOSTIC_TEST

Ocular ultrasonography with a linear probe of approximately 7-13 MHz, participant supine with the head neutral, eyelids closed, sterile transparent dressing and gel, minimal probe pressure. Optic nerve sheath diameter is measured in the transverse plane 3 mm posterior to the entry of the optic nerve into the globe. Three measurements per eye are averaged, and the mean of the two eyes is recorded. Performed at T0, T1 and T2.

Group Non-SACP: cross-clamp release not required; Group SACP: cross-clamp release required

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Age 18 years or older
• Planned or urgent, hemodynamically stable ascending aortic surgery, including supracoronary ascending aortic replacement, aortic root replacement (Bentall procedure) or valve-sparing root surgery (David procedure), limited to cases involving the ascending aortic segment
• Perfusion planned through axillary artery cannulation
• Written informed consent

You may not qualify if:

• History of intracranial procedure or intracranial pathology
• Previous carotid intervention, or carotid artery stenosis of 50 percent or more on preoperative Doppler ultrasonography
• Advanced chronic obstructive pulmonary disease, defined clinically as advanced stage disease with long-term oxygen therapy or a history of frequent exacerbations
• Baseline arterial carbon dioxide tension of 55 mmHg or higher on preoperative arterial blood gas analysis
• Ocular pathology, ocular surgery or ocular trauma that could affect measurement of the optic nerve sheath or optic nerve, including glaucoma and retinal detachment or fibrosis
• Severe preoperative neurological deficit, including major stroke or severe dementia, or active psychiatric illness
• Hemodynamic instability, or a requirement for extracorporeal membrane oxygenation or intra-aortic balloon counterpulsation, of a degree that prevents measurements during the first 24 postoperative hours
• Known contraindication to any component of the protocol-specified anesthesia regimen

Sponsors & Collaborators

• Koşuyolu Kartal Heart Training and Research Hospital: lead

Study Sites (1)

Kosuyolu Heart Training and Research Hospital

Istanbul, Kartal, 34862, Turkey (Türkiye)

Location

MeSH Terms

Conditions

Aortic Diseases; Aortic Aneurysm, Thoracic; Emergence Delirium; Postoperative Complications

Interventions

Ultrasonography, Doppler, Transcranial

Condition Hierarchy (Ancestors)

Vascular Diseases; Cardiovascular Diseases; Aortic Aneurysm; Aneurysm; Delirium; Confusion; Neurobehavioral Manifestations; Neurologic Manifestations; Nervous System Diseases; Pathologic Processes; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Neurocognitive Disorders; Mental Disorders

Intervention Hierarchy (Ancestors)

Echoencephalography; Neuroradiography; Neuroimaging; Diagnostic Imaging; Diagnostic Techniques and Procedures; Diagnosis; Radiography; Ultrasonography; Ultrasonography, Doppler; Diagnostic Techniques, Neurological; Investigative Techniques

Central Study Contacts

Ebru Girgin Dinc, M.D., DESAIC

CONTACT

905446948852; grgnebru@gmail.com

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NON RANDOMIZED
• Masking: SINGLE
• Who Masked: OUTCOMES ASSESSOR
• Masking Details: Participants, the surgical team and the anesthesia team are not masked, since the cerebral protection strategy is visible intraoperatively. Optic nerve sheath and optic nerve diameter measurements at postoperative hour 24, and offline review of stored ultrasound images, are performed by an assessor masked to arm allocation. Delirium screening at postoperative hour 24 is performed by a nurse or investigator masked to arm allocation. Statistical analysis is performed on a coded dataset in which arm labels are masked until the primary analysis is complete.
• Purpose: BASIC SCIENCE
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: MD

Model Details: All participants receive the same protocol-specified general anesthesia and ventilation regimen, which constitutes the assigned intervention and is identical in both arms. Participants are not allocated to arms by the investigators. Arm membership is determined by whether release of the aortic cross-clamp is required to construct the distal anastomosis, which follows from the extent of the aortic pathology and the geometry of the graft. Participants in whom the cross-clamp is released undergo systemic circulatory arrest with selective antegrade cerebral perfusion; participants in whom the anastomosis can be completed with the cross-clamp maintained do not. The study is classified as interventional because the anesthetic and ventilatory regimen is assigned by the protocol, not because the cerebral protection strategy is assigned.

Study Record Dates

• First Submitted: August 30, 2026
• First Posted: September 2, 2026
• Study Start: September 30, 2026
• Primary Completion (Estimated): September 30, 2028
• Study Completion (Estimated): December 30, 2028
• Last Updated: September 2, 2026

Record last verified: 2026-08

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, ANALYTIC CODE
• Time Frame: Beginning 6 months after publication of the primary results and ending 5 years after that date.
• Access Criteria: Requests are submitted in writing to the principal investigator and must state the scientific question, the proposed analysis plan and the qualifications of the requesting team. The principal investigator assesses each request for scientific merit and for consistency with the consent given by participants. Requests judged appropriate are then submitted to the Kartal Kosuyolu Yuksek Ihtisas Training and Research Hospital Clinical Research Ethics Committee, and data are released only if that committee approves the proposed secondary use. Approved requesters must execute a data use agreement before any data are transferred. Data are supplied in de-identified form only, and the linkage key is not transferred under any circumstances.

Locations

TU (1)