An interventional study of Optic nerve sheath and optic nerve diameter ultrasonography and Transcranial Doppler ultrasonography in Aortic Diseases, Cardiac Surgical Procedures and Aortic Aneurysm, Thoracic, sponsored by Koşuyolu Kartal Heart Training and Research Hospital. Not yet recruiting at 1 site in Turkey (Türkiye). Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-09-02.
Sponsored by Koşuyolu Kartal Heart Training and Research Hospital · Not applicable, Interventional, and Basic science
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.
This single-center prospective study will enroll adults undergoing elective or urgent ascending aortic surgery with planned axillary artery cannulation. Participants are grouped according to whether release of the aortic cross-clamp is required to construct the distal anastomosis, and therefore whether selective antegrade cerebral perfusion is applied. Group membership follows from the intraoperative surgical requirement and is not assigned by the investigators. All participants receive a single protocol-specified general anesthesia and ventilation regimen, identical in both groups, so that variables known to act on optic nerve sheath diameter, in particular arterial carbon dioxide tension, volatile agent concentration and airway pressure, are held constant. Because this regimen is assigned by the protocol, the study is registered as interventional. Bilateral optic nerve sheath diameter and optic nerve diameter will be measured by ultrasonography, and middle cerebral artery mean flow velocity by transcranial Doppler, at three time points: before anesthesia induction (T0), at the end of surgery after hemodynamic stabilization in the operating room (T1), and at postoperative hour 24 in the intensive care unit (T2). Regional cerebral oxygen saturation by near-infrared spectroscopy and the electroencephalographic suppression ratio derived from bispectral index monitoring will be recorded intraoperatively. Delirium will be screened at postoperative hour 24 using the Nursing Delirium Screening Scale (Nu-DESC), with a total score of 2 or more considered a positive screen. The primary outcome is the change in bilateral mean optic nerve sheath diameter across T0, T1 and T2, evaluated as the group-by-time interaction in a linear mixed-effects model.
131 studies on the registry are indexed under Aortic Aneurysm, Thoracic; 33 are open to participants now.
This study's planned enrollment of 134 is above the median of 50 across 62 interventional studies indexed under Aortic Aneurysm, Thoracic.
Browse Aortic Aneurysm, Thoracic studies →Koşuyolu Kartal Heart Training and Research Hospital is the lead sponsor of 3 studies on the registry; 2 are open to participants now.
Compared within Aortic Aneurysm, Thoracic, this study's primary condition as ClinicalTrials.gg classifies it; the registry's first condition term is Aortic Diseases. The counts are of registry records indexed under each term, refreshed daily. How we classify →
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Exclusion Criteria:
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Chronic obstructive pulmonary disease: long-term lung disease that makes it hard to breathe out, including emphysema and chronic bronchitis.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
COPD
Chronic obstructive pulmonary disease: long-term lung disease that makes it hard to breathe out, including emphysema and chronic bronchitis.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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
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
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.
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.
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.
Time frame: From before anesthesia induction to postoperative hour 24
Change in bilateral mean optic nerve diameter (OND) over time
Optic nerve diameter in millimetres, measured at the same level as the sheath diameter between the outer margins of the nerve, excluding the sheath. Three measurements per eye are averaged and the mean of the two eyes is the participant value. 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. Measurements are obtained before anesthesia induction, at the end of surgery after hemodynamic stabilization in the operating room, and at postoperative hour 24 in the intensive care unit.
Time frame: From before anesthesia induction to postoperative hour 24
Change in middle cerebral artery mean flow velocity measured by transcranial Doppler
Mean flow velocity in centimetres per second in the M1 segment of the middle cerebral artery, insonated through the temporal window at approximately 45-55 mm depth. Three consecutive stable measurements per side are averaged and the bilateral mean is the participant value. The endpoint is the trajectory across the three time points, evaluated as the group-by-time interaction in a linear mixed-effects model. This analysis is exploratory. Measurements are obtained before anesthesia induction, at the end of surgery after hemodynamic stabilization in the operating room, and at postoperative hour 24 in the intensive care unit.
Time frame: From before anesthesia induction to postoperative hour 24
Change in regional cerebral oxygen saturation measured by near-infrared spectroscopy
Bilateral regional cerebral oxygen saturation as a percentage, recorded by near-infrared spectroscopy with adhesive frontal sensors. Baseline value, nadir value, percentage change from baseline, number of desaturation episodes at or beyond a 20 percent relative fall from baseline, and total duration of desaturation in minutes are recorded for each side. Values are recorded before anesthesia induction, before cardiopulmonary bypass, before and after selective antegrade cerebral perfusion, at the end of cardiopulmonary bypass, and at the end of surgery.
Time frame: From before anesthesia induction to the end of surgery
Proportion of participants with a positive delirium screen (Nu-DESC >=2)
Delirium screened with the Nursing Delirium Screening Scale, a five-item observational scale scored 0 to 2 per item for a total range of 0 to 10, where higher scores indicate more delirium features. A total score of 2 or more is a positive screen. Screening is performed once the participant is sufficiently awake and communicative; where deep sedation precludes assessment the screen is repeated at an appropriate time and the delay recorded.
Time frame: At postoperative hour 24
Number of participants with a clinical neurological event
Composite of stroke, transient ischemic attack, seizure, or a new focal neurological deficit, ascertained from clinical records and bedside neurological examination. Each component is reported separately in addition to the composite. Events are recorded from the end of surgery to hospital discharge.
Time frame: From end of surgery to hospital discharge, up to 30 days
Cumulative intraoperative electroencephalographic suppression time
Total time in minutes for which the electroencephalogram is suppressed, derived from continuous bispectral index monitoring with an adhesive frontal sensor. Suppression time is accumulated from anesthesia induction to the end of surgery and reported in total and separately for the period of cardiopulmonary bypass and, where applicable, for the period of selective antegrade cerebral perfusion and systemic circulatory arrest. Higher values indicate a longer cumulative duration of an isoelectric electroencephalogram. The proportion of participants with any recorded suppression is reported alongside the duration.
Time frame: From before anesthesia induction to the end of surgery
Plan to share: Yes — De-identified individual participant data underlying the published results may be made available to investigators whose proposed use is judged scientifically appropriate. Requests are directed to the principal investigator and are assessed for scientific merit and for consistency with the consent given by participants. Data are released only after the request has been approved by the institutional clinical research ethics committee, and only in de-identified form. The code linking participants to study numbers is retained by the principal investigator and is never shared. Approved requesters must sign a data use agreement specifying the approved analysis, prohibiting any attempt at re-identification and prohibiting onward transfer to third parties.
Supporting information: Study protocol, Statistical analysis plan, 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.
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Koşuyolu Kartal Heart Training and Research Hospital