Cerebral Perfusion PressureNCT07317258
Evaluation of Cerebral Perfusion in Supine and Steep Trendelenburg Positions During Robotic Prostatectomy
An observational study of Cerebral Perfusion Pressure and Trendelenburg, run by Hanife Kabukcu at 1 site in Turkey (Türkiye).
Trial summary
Evaluation of Cerebral Perfusion in Supine and Steep Trendelenburg Positions During Robotic Prostatectomy Robotic endoscopic radical prostatectomy requires pneumoperitoneum and the steep Trendelenburg position to ensure optimal surgical visualization. Read more about this study
- Who is it for?
- Ages 18 to 80 years, men only
- Conditions the study is for
- Cerebral Perfusion Pressure, Trendelenburg
- How many people
- 60 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 1 Jan 2026to Nov 2026
- How long will I take part?
- 1 Day
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 80 years
- Men only
- No healthy volunteers
- Adult, Older adult
Study population: Male patients aged 18 to 80 years undergoing robotic prostate surgery under general anesthesia.
Who may be able to join
- Male patients aged 18 to 80 years
- ASA physical status I-III
- Scheduled for robotic prostate surgery under general anesthesia
- Able and willing to provide written informed consent
Who cannot join
- Decline or inability to provide informed consent
- Age <18 years or >80 years
- Inability to perform ultrasonographic measurements or to maintain the required surgical position
- Presence of intracranial space-occupying lesions
- History of cerebrovascular accident (CVA) or carotid artery occlusion
- Known neurological disorders (e.g., epilepsy)
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Turkey (Türkiye)1 site
Akdeniz University
Antalya, Antalya
Sinem Omca, +905061187398, snmomca@gmail.com
Hanife Kabukcu, +905337319555, hanifekabukcu@akdeniz.edu.tr
About this study
Evaluation of Cerebral Perfusion in Supine and Steep Trendelenburg Positions During Robotic Prostatectomy Robotic endoscopic radical prostatectomy requires pneumoperitoneum and the steep Trendelenburg position to ensure optimal surgical visualization. However, this combination may increase intracranial pressure (ICP) and alter cerebral blood flow and oxygenation.
This study aimed to evaluate cerebral perfusion changes in patients undergoing robotic prostatectomy by using Transcranial Doppler (TCD) and Near-Infrared Spectroscopy (NIRS). Cerebral blood flow velocity in the middle cerebral artery and pulsatility index (PI) were measured to estimate ICP, while NIRS was used to assess cerebral oxygen saturation.
Read more
Additionally, arterial blood gas parameters (PCO₂, PO₂, Hb), end-tidal CO₂, and mean arterial pressure (MAP) were recorded. Pre- and postoperative Mini-Mental State Examination (MMSE) scores were compared to evaluate potential cognitive effects.
The aim was to determine the relationship between ICP estimation, cerebral oxygenation, and hemodynamic variables during supine and steep Trendelenburg positions in robotic prostatectomy.
Read the detailed description
The use of robotic endoscopic radical prostatectomy has the potential to improve surgical outcomes and reduce complications compared to open radical prostatectomy. Robotic endoscopic abdominal surgery involves carbon dioxide (CO₂) insufflation to create pneumoperitoneum and requires the Trendelenburg position to provide adequate surgical visualization.
An increase in intra-abdominal pressure due to pneumoperitoneum leads to various physiological changes. The combination of steep Trendelenburg positioning and pneumoperitoneum during robotic prostatectomy is known to cause intracranial hypertension. The elevation of intra-abdominal pressure and Trendelenburg positioning increases intracranial pressure (ICP) and alters cerebral blood flow (CBF). These changes in cerebral hemodynamics may have detrimental effects on cerebral oxygenation.
Several invasive and non-invasive techniques are available for monitoring ICP and cerebral perfusion pressure (CPP). Among non-invasive methods, Transcranial Doppler ultrasonography (TCD) and Near-Infrared Spectroscopy (NIRS) are reliable and safe monitoring tools.
TCD measures blood flow velocities in the major arteries of the Circle of Willis. Based on TCD-derived data, several formulas have been proposed to estimate ICP, such as the Pulsatility Index (PI) and Resistance Index (RI).
PI is calculated using the formula:
PI = (Peak systolic velocity - End diastolic velocity) / Mean velocity. A normal PI typically ranges between 0.5 and 1.2. Under normal systemic hemodynamic conditions, an elevated PI (particularly >2) suggests reduced cerebral perfusion pressure (CPP).
RI is calculated as:
RI = (Peak systolic velocity - End diastolic velocity) / Peak systolic velocity.
An RI greater than 0.75-0.8 is considered abnormal. RI is conceptually similar to PI (both increase in cases of low CPP), although PI is more widely used in clinical practice.
Normal ICP values vary with age and body position, but are generally 5-15 mmHg in healthy supine adults, 3-7 mmHg in children, and 1.5-6 mmHg in infants.
In cases of elevated ICP or circulatory hypotension, cerebral perfusion pressure (CPP) decreases. CPP is calculated as the difference between mean arterial pressure (MAP) and ICP. MAP is obtained by adding one-third of the pulse pressure (the difference between systolic and diastolic pressure) to the diastolic pressure.
NIRS technology was recently developed to enable continuous and non-invasive monitoring of regional cerebral tissue oxygen saturation for various clinical indications. The differing absorption spectra of oxygenated and deoxygenated hemoglobin at different light wavelengths allow for assessment of the balance between cerebral oxygen supply and demand.
In this study, the correlation between cerebral oxygen saturation measured by NIRS and estimated ICP calculated from TCD-derived middle cerebral artery (MCA) flow velocity and pulsatility index was evaluated. In addition, arterial blood gas parameters (PCO₂, PO₂, hemoglobin), end-tidal CO₂ (EtCO₂), and mean arterial pressure (MAP) were included in the analysis.
Preoperative and postoperative Mini-Mental State Examination (MMSE) tests were administered to assess potential cognitive changes and to compare our non-invasive monitoring results with clinical outcomes.
- Conditions
- Cerebral Perfusion Pressure, Trendelenburg
- Keywords
- TRANSCRANİAL DOPPLER USG, CEREBRAL PERFUSİON, TRENDELENBURG, NIRS, EEG, PATİENT STATE İNDEKS, ROBOTİC SURGERY, PROSTATEKTOMİ
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Patients Robotic Prostate Surgery | Men aged 18 to 80 undergoing robotic prostate surgery |
What is being measured
The primary outcome is the main question the study is designed to answer.
Cerebral Oxygenation Measured by Near-Infrared Spectroscopy (NIRS)
Cerebral oxygenation will be assessed using near-infrared spectroscopy (NIRS). Regional cerebral oxygen saturation (%) will be continuously monitored, and values will be recorded at predefined perioperative time points.
Measured: 1.Upon arrival in the operating room (baseline) 2.10 minutes after endotracheal intubation 3.30 minutes after placement in the Trendelenburg position 4.10 minutes before returning to the supine position 5. Postoperative 1 hour
Middle Cerebral Artery Blood Flow Velocity Measured by Transcranial Doppler Ultrasonography (TCD)
Middle cerebral artery (MCA) blood flow velocity will be measured using transcranial Doppler ultrasonography (TCD). MCA mean flow velocity (cm/s) will be recorded at predefined perioperative time points.
Measured: 1.Supine position, 10 minutes after endotracheal intubation 2.30 minutes after placement in the Trendelenburg position 3.10 minutes before returning to the supine position 4.After returning to the supine position 5.Postoperative 1 hour
Secondary outcomes (2)
Mean Arterial Pressure (MAP) at Predefined Perioperative Time Points
Mean arterial pressure (mmHg) will be recorded continuously and extracted at predefined perioperative time points to assess hemodynamic changes associated with patient positioning.
Measured: 1.Upon arrival in the operating room 2.10 minutes after endotracheal intubation 3.30 minutes after placement in the Trendelenburg position 4.10 minutes before returning to supine 5.Postoperative 1 hour
End-Tidal CO₂ (EtCO₂) at Predefined Perioperative Time Points
End-tidal carbon dioxide (mmHg) will be monitored continuously and documented at several standardized perioperative time points to assess potential effects of Trendelenburg positioning and pneumoperitoneum on ventilation.
Measured: 1.Upon arrival in the operating room 2.10 minutes after endotracheal intubation 3.30 minutes after placement in the Trendelenburg position 4.10 minutes before returning to supine 5.Postoperative 1 hour
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted5 Jan 2026
- Study start1 Jan 2026 (estimated)
- Primary completion30 Oct 2026 (estimated)
- Study completionNov 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (2)Papers the sponsor has linked to this study.
- Other trials for Cerebral Perfusion PressureStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 60 participants (estimated)
- Target duration
- 1 Day
Sponsor and investigators
- Lead sponsor
- Hanife Kabukcu
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor-investigator, Hanife Kabukcu, Akdeniz University
- Investigators
- Hanife Kabukcu, Study director, Akdeniz UniversitySinem Omca, Principal investigator, Akdeniz University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07317258
- Sponsor's protocol ID
- Cerebral Perfusion in Position
- Status last verified
- Nov 2025
- First submitted
- 17 Nov 2025
- Last updated
- 5 Jan 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: IPD used in publishing the results
Publications
Kalmar AF, Dewaele F, Foubert L, Hendrickx JF, Heeremans EH, Struys MM, Absalom A. Cerebral haemodynamic physiology during steep Trendelenburg position and CO(2) pneumoperitoneum. Br J Anaesth. 2012 Mar;108(3):478-84. doi: 10.1093/bja/aer448. Epub 2012 Jan 17.
PubMed 22258202Kalmar AF, Foubert L, Hendrickx JF, Mottrie A, Absalom A, Mortier EP, Struys MM. Influence of steep Trendelenburg position and CO(2) pneumoperitoneum on cardiovascular, cerebrovascular, and respiratory homeostasis during robotic prostatectomy. Br J Anaesth. 2010 Apr;104(4):433-9. doi: 10.1093/bja/aeq018. Epub 2010 Feb 18.
PubMed 20167583
Study at a glance
From the registry record, last updated by the sponsor on 5 Jan 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Evaluation of Cerebral Perfusion in Supine and Steep Trendelenburg Positions During Robotic Prostatectomy
- ClinicalTrials.gov ID
- NCT07317258
- Acronym / sponsor ID
- Cerebral Perfusion in Position
- Conditions
- Cerebral Perfusion Pressure, Trendelenburg
- Keywords
- TRANSCRANİAL DOPPLER USG, CEREBRAL PERFUSİON, TRENDELENBURG, NIRS, EEG, PATİENT STATE İNDEKS, ROBOTİC SURGERY, PROSTATEKTOMİ
- Study type
- Observational
- Recruitment status
- Not yet recruiting
- Enrolment
- 60 participants (estimated)
- Lead sponsor
- Hanife KabukcuUniversity, hospital or other
- Study start
- 1 Jan 2026 (estimated)
- Primary completion
- 30 Oct 2026 (estimated)
- Study completion
- Nov 2026 (estimated)
- First posted
- 5 Jan 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Evaluation of Cerebral Perfusion in Supine and Steep Trendelenburg Positions During Robotic Prostatectomy Robotic endoscopic radical prostatectomy requires pneumoperitoneum and the steep Trendelenburg position to ensure optimal surgical visualization. However, this combination may increase intracranial pressure (ICP) and alter cerebral blood flow and oxygenation.
This study aimed to evaluate cerebral perfusion changes in patients undergoing robotic prostatectomy by using Transcranial Doppler (TCD) and Near-Infrared Spectroscopy (NIRS). Cerebral blood flow velocity in the middle cerebral artery and pulsatility index (PI) were measured to estimate ICP, while NIRS was used to assess cerebral oxygen saturation.
Additionally, arterial blood gas parameters (PCO₂, PO₂, Hb), end-tidal CO₂, and mean arterial pressure (MAP) were recorded. Pre- and postoperative Mini-Mental State Examination (MMSE) scores were compared to evaluate potential cognitive effects.
The aim was to determine the relationship between ICP estimation, cerebral oxygenation, and hemodynamic variables during supine and steep Trendelenburg positions in robotic prostatectomy.
Detailed description
The use of robotic endoscopic radical prostatectomy has the potential to improve surgical outcomes and reduce complications compared to open radical prostatectomy. Robotic endoscopic abdominal surgery involves carbon dioxide (CO₂) insufflation to create pneumoperitoneum and requires the Trendelenburg position to provide adequate surgical visualization.
An increase in intra-abdominal pressure due to pneumoperitoneum leads to various physiological changes. The combination of steep Trendelenburg positioning and pneumoperitoneum during robotic prostatectomy is known to cause intracranial hypertension. The elevation of intra-abdominal pressure and Trendelenburg positioning increases intracranial pressure (ICP) and alters cerebral blood flow (CBF). These changes in cerebral hemodynamics may have detrimental effects on cerebral oxygenation.
Several invasive and non-invasive techniques are available for monitoring ICP and cerebral perfusion pressure (CPP). Among non-invasive methods, Transcranial Doppler ultrasonography (TCD) and Near-Infrared Spectroscopy (NIRS) are reliable and safe monitoring tools.
TCD measures blood flow velocities in the major arteries of the Circle of Willis. Based on TCD-derived data, several formulas have been proposed to estimate ICP, such as the Pulsatility Index (PI) and Resistance Index (RI).
PI is calculated using the formula:
PI = (Peak systolic velocity - End diastolic velocity) / Mean velocity. A normal PI typically ranges between 0.5 and 1.2. Under normal systemic hemodynamic conditions, an elevated PI (particularly >2) suggests reduced cerebral perfusion pressure (CPP).
RI is calculated as:
RI = (Peak systolic velocity - End diastolic velocity) / Peak systolic velocity.
An RI greater than 0.75-0.8 is considered abnormal. RI is conceptually similar to PI (both increase in cases of low CPP), although PI is more widely used in clinical practice.
Normal ICP values vary with age and body position, but are generally 5-15 mmHg in healthy supine adults, 3-7 mmHg in children, and 1.5-6 mmHg in infants.
In cases of elevated ICP or circulatory hypotension, cerebral perfusion pressure (CPP) decreases. CPP is calculated as the difference between mean arterial pressure (MAP) and ICP. MAP is obtained by adding one-third of the pulse pressure (the difference between systolic and diastolic pressure) to the diastolic pressure.
NIRS technology was recently developed to enable continuous and non-invasive monitoring of regional cerebral tissue oxygen saturation for various clinical indications. The differing absorption spectra of oxygenated and deoxygenated hemoglobin at different light wavelengths allow for assessment of the balance between cerebral oxygen supply and demand.
In this study, the correlation between cerebral oxygen saturation measured by NIRS and estimated ICP calculated from TCD-derived middle cerebral artery (MCA) flow velocity and pulsatility index was evaluated. In addition, arterial blood gas parameters (PCO₂, PO₂, hemoglobin), end-tidal CO₂ (EtCO₂), and mean arterial pressure (MAP) were included in the analysis.
Preoperative and postoperative Mini-Mental State Examination (MMSE) tests were administered to assess potential cognitive changes and to compare our non-invasive monitoring results with clinical outcomes.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Target follow-up
- 1 Day
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Patients Robotic Prostate Surgery | – | –Men aged 18 to 80 undergoing robotic prostate surgery |
Who may qualify
- Ages
- 18 to 80 years
- Sex
- Male only
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Male patients aged 18 to 80 years undergoing robotic prostate surgery under general anesthesia.
Key inclusion criteria (4 listed)
- Male patients aged 18 to 80 years
- ASA physical status I-III
- Scheduled for robotic prostate surgery under general anesthesia
- Able and willing to provide written informed consent
Key exclusion criteria (6 listed)
- Decline or inability to provide informed consent
- Age <18 years or >80 years
- Inability to perform ultrasonographic measurements or to maintain the required surgical position
- Presence of intracranial space-occupying lesions
- History of cerebrovascular accident (CVA) or carotid artery occlusion
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Cerebral Oxygenation Measured by Near-Infrared Spectroscopy (NIRS)
Time frame: 1.Upon arrival in the operating room (baseline) 2.10 minutes after endotracheal intubation 3.30 minutes after placement in the Trendelenburg position 4.10 minutes before returning to the supine position 5. Postoperative 1 hour
Cerebral oxygenation will be assessed using near-infrared spectroscopy (NIRS). Regional cerebral oxygen saturation (%) will be continuously monitored, and values will be recorded at predefined perioperative time points.
Middle Cerebral Artery Blood Flow Velocity Measured by Transcranial Doppler Ultrasonography (TCD)
Time frame: 1.Supine position, 10 minutes after endotracheal intubation 2.30 minutes after placement in the Trendelenburg position 3.10 minutes before returning to the supine position 4.After returning to the supine position 5.Postoperative 1 hour
Middle cerebral artery (MCA) blood flow velocity will be measured using transcranial Doppler ultrasonography (TCD). MCA mean flow velocity (cm/s) will be recorded at predefined perioperative time points.
2 secondary outcomes
Mean Arterial Pressure (MAP) at Predefined Perioperative Time Points
Time frame: 1.Upon arrival in the operating room 2.10 minutes after endotracheal intubation 3.30 minutes after placement in the Trendelenburg position 4.10 minutes before returning to supine 5.Postoperative 1 hour
End-Tidal CO₂ (EtCO₂) at Predefined Perioperative Time Points
Time frame: 1.Upon arrival in the operating room 2.10 minutes after endotracheal intubation 3.30 minutes after placement in the Trendelenburg position 4.10 minutes before returning to supine 5.Postoperative 1 hour
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 5 Jan 2026.
- Results publication: PubMed 22258202Kalmar AF, Dewaele F, Foubert L, Hendrickx JF, Heeremans EH, Struys MM, Absalom A. Cerebral haemodynamic physiology during steep Trendelenburg position and CO(2) pneumoperitoneum. Br J Anaesth. 2012 Mar;108(3):478-84. doi: 10.1093/bja/aer448. Epub 2012 Jan 17.
- Results publication: PubMed 20167583Kalmar AF, Foubert L, Hendrickx JF, Mottrie A, Absalom A, Mortier EP, Struys MM. Influence of steep Trendelenburg position and CO(2) pneumoperitoneum on cardiovascular, cerebrovascular, and respiratory homeostasis during robotic prostatectomy. Br J Anaesth. 2010 Apr;104(4):433-9. doi: 10.1093/bja/aeq018. Epub 2010 Feb 18.
- Individual participant dataSharing planned: Yes. IPD used in publishing the results
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Hanife Kabukcu study director
Akdeniz University
Sinem Omca principal investigator
Akdeniz University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Cerebral Perfusion Pressure and Trendelenburg, run by Hanife Kabukcu at 1 site in Turkey (Türkiye).
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 5 Jan 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Turkey (Türkiye). Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Hanife Kabukcu (+905337319555, hanifekabukcu@akdeniz.edu.tr), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Cerebral Oxygenation Measured by Near-Infrared Spectroscopy (NIRS) (time frame: 1.Upon arrival in the operating room (baseline) 2.10 minutes after endotracheal intubation 3.30 minutes after placement in the Trendelenburg position 4.10 minutes before returning to the supine position 5. Postoperative 1 hour). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07317258, which also lists 2 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 5 Jan 2026.