Optic Nerve Sheath DiameterLap Optic NervNCT07262125
Effect of Carbon Dioxide Pressure on Optic Nerve Sheath Diameter in Laparoscopic Transperitoneal Nephrectomy
A study testing Optic Nerve Sheath Diameter Measurement in people with Optic Nerve Sheath Diameter and Laparoscopic Nephrectomy, run by Fatih Sultan Mehmet Training and Research Hospital at 1 site in Turkey (Türkiye).
Trial summary
Nephrectomy is a surgical procedure performed for various indications, and with the development and increasing availability of advanced diagnostic techniques, its incidence has been rising. Read more about this study
- Who is it for?
- Ages 31 to 69 years
- Conditions the study is for
- Optic Nerve Sheath Diameter, Laparoscopic Nephrectomy
- What is being tested?
- Optic Nerve Sheath Diameter Measurement
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 100 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 1 Dec 2024to 1 Jan 2026
- Phase
- Interventional
- 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 31 to 69 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Male and female patients aged 31-69 years.
- Diagnosis of renal cancer (ICD Code C64).
- Planned laparoscopic radical or partial nephrectomy based on current guidelines and patient consent in the Urology Council.
Who cannot join
- Presence of any condition that prevents transorbital measurement of the optic nerve sheath (e.g., orbital trauma, severe periorbital edema, or ocular abnormalities affecting optic nerve imaging)
- Presence of a medical condition that precludes positioning the patient in a 45-degree lateral decubitus position (e.g., severe scoliosis, respiratory compromise, or spinal instability)
- Known or suspected intracranial pathology that may independently elevate intracranial pressure (e.g., intracranial tumors, hydrocephalus, recent traumatic brain injury)
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
Fatih Sultan Mehmet Research and Training Hospital
Istanbul, Ataşehir, 34100
About this study
Official title: Effect of CO2 Pressure on Optic Nerve Sheath Diameter in Laparoscopic Transperitoneal Nephrectomy
Nephrectomy is a surgical procedure performed for various indications, and with the development and increasing availability of advanced diagnostic techniques, its incidence has been rising. Today, in appropriate cases, laparoscopic surgery is recommended due to its minimally invasive nature and its surgical success rates being comparable to those of open surgery. In laparoscopic surgery, to achieve optimal visualization, a 45° lateral decubitus position is applied, followed by the creation of a pneumoperitoneum using carbon dioxide gas. While the cardiopulmonary effects of this procedure have been shown to be minimal, studies on its intracranial effects are limited. Cerebral perfusion pressure is defined as the difference between mean arterial pressure and either central venous pressure or intracranial pressure, whichever is higher. Intracranial pressure can be assessed non-invasively using ultrasonographic measurement of the Optic Nerve Sheath Diameter (ONSD). The retrobulbar segment of the optic nerve is surrounded by a distensible subarachnoid space, which expands in response to increased intracranial pressure. The effect of increased intra-abdominal pressure during laparoscopic surgery on intracranial pressure, and its impact on ONSD, will be evaluated non-invasively.
In patients scheduled for laparoscopic kidney surgery, the Optic Nerve Sheath Diameter will be measured transorbitally using ultrasonography by the investigator at various stages of the surgery (before anesthesia, after anesthesia, in the lateral decubitus position, during pneumoperitoneum, and at routine intraoperative pressure levels). Additionally, standard monitoring parameters such as pulse rate, blood pressure, oxygen saturation, and End-Tidal CO₂ will be recorded. The Optic Nerve Sheath Diameter, which serves as an indicator of increased intracranial pressure, will be compared with variables such as surgical positioning, BMI, ASA score, and other relevant factors.
- Being tested
- Optic Nerve Sheath Diameter Measurement
- Keywords
- optic nerve sheath diameter, laparoscopic nephrectomy
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Optic Nerve Sheath Diameter MeasurementDiagnostic test
Optic Nerve Sheath Diameter Measurement, Oxygen saturation and End Tidal CO2 measurements when Pre-operational Supine position, after intubation, Lateral decubitus position, after Pneumoperitoneum, CO2 pressure level at 14-16-18-20 and Post-operational supine position
| Study group | Role | What they receive |
|---|---|---|
| Routine Laparoscopic Pneumoperitoneum | Other | Routine Laparoscopic Pneumoperitoneum of the patients Receives: Diagnostic Test: Optic Nerve Sheath Diameter Measurement |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in optic nerve sheath diameter (ONSD) with increasing intraabdominal CO₂ pressure
Change in optic nerve sheath diameter (ONSD) with increasing intraabdominal CO₂ pressure
Measured: Preop Supine before intubation → During surgery (baseline supine → lateral decubitus positioning → pneumoperitoneum → each pressure level: 14, 16, 18, 20 mmHg → Postop Supine 5 minutes after extubation of the patient
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted3 Dec 2025
- Study start1 Dec 2024
- Primary completion1 Dec 2025 (estimated)
- Study completion1 Jan 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 Optic Nerve Sheath DiameterStudies 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
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 100 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Fatih Sultan Mehmet Training and Research Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Umut Arslan, Fatih Sultan Mehmet Training and Research Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07262125
- Sponsor's protocol ID
- Optic Nerve Sheat Laparoscopy
- Acronym
- Lap Optic Nerv
- Status last verified
- Nov 2025
- First submitted
- 21 Sep 2025
- Last updated
- 3 Dec 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Atasever AG, Salviz EA, Senturk Ciftci H, Bingul ES, Sivrikoz N, Erdem S, Savran Karadeniz M. The Effects of Lateral 45 degrees Head-Down Position and Carbon Dioxide Pneumoperitoneum on the Optic Nerve Sheath Diameter in Patients Undergoing Laparoscopic Transperitoneal Nephrectomies: A Prospective Observational Study. J Laparoendosc Adv Surg Tech A. 2023 Feb;33(2):171-176. doi: 10.1089/lap.2022.0344. Epub 2022 Aug 25.
PubMed 36036829Chin JH, Seo H, Lee EH, Lee J, Hong JH, Hwang JH, Kim YK. Sonographic optic nerve sheath diameter as a surrogate measure for intracranial pressure in anesthetized patients in the Trendelenburg position. BMC Anesthesiol. 2015 Mar 31;15:43. doi: 10.1186/s12871-015-0025-9. eCollection 2015.
PubMed 25861241
Study at a glance
From the registry record, last updated by the sponsor on 3 Dec 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effect of CO2 Pressure on Optic Nerve Sheath Diameter in Laparoscopic Transperitoneal Nephrectomy
- ClinicalTrials.gov ID
- NCT07262125
- Acronym / sponsor ID
- Lap Optic Nerv / Optic Nerve Sheat Laparoscopy
- Keywords
- optic nerve sheath diameter, laparoscopic nephrectomy
- Study type
- Interventional
- Recruitment status
- Enrolling by invitation
- Enrolment
- 100 participants (estimated)
- Lead sponsor
- Fatih Sultan Mehmet Training and Research HospitalUniversity, hospital or other
- Study start
- 1 Dec 2024 (actual)
- Primary completion
- 1 Dec 2025 (estimated)
- Study completion
- 1 Jan 2026 (estimated)
- First posted
- 3 Dec 2025 (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.
Nephrectomy is a surgical procedure performed for various indications, and with the development and increasing availability of advanced diagnostic techniques, its incidence has been rising. Today, in appropriate cases, laparoscopic surgery is recommended due to its minimally invasive nature and its surgical success rates being comparable to those of open surgery. In laparoscopic surgery, to achieve optimal visualization, a 45° lateral decubitus position is applied, followed by the creation of a pneumoperitoneum using carbon dioxide gas. While the cardiopulmonary effects of this procedure have been shown to be minimal, studies on its intracranial effects are limited. Cerebral perfusion pressure is defined as the difference between mean arterial pressure and either central venous pressure or intracranial pressure, whichever is higher. Intracranial pressure can be assessed non-invasively using ultrasonographic measurement of the Optic Nerve Sheath Diameter (ONSD). The retrobulbar segment of the optic nerve is surrounded by a distensible subarachnoid space, which expands in response to increased intracranial pressure. The effect of increased intra-abdominal pressure during laparoscopic surgery on intracranial pressure, and its impact on ONSD, will be evaluated non-invasively.
In patients scheduled for laparoscopic kidney surgery, the Optic Nerve Sheath Diameter will be measured transorbitally using ultrasonography by the investigator at various stages of the surgery (before anesthesia, after anesthesia, in the lateral decubitus position, during pneumoperitoneum, and at routine intraoperative pressure levels). Additionally, standard monitoring parameters such as pulse rate, blood pressure, oxygen saturation, and End-Tidal CO₂ will be recorded. The Optic Nerve Sheath Diameter, which serves as an indicator of increased intracranial pressure, will be compared with variables such as surgical positioning, BMI, ASA score, and other relevant factors.
Study design
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Routine Laparoscopic Pneumoperitoneum | Other | Diagnostic Test: Optic Nerve Sheath Diameter MeasurementRoutine Laparoscopic Pneumoperitoneum of the patients |
Who may qualify
- Ages
- 31 to 69 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- Male and female patients aged 31-69 years.
- Diagnosis of renal cancer (ICD Code C64).
- Planned laparoscopic radical or partial nephrectomy based on current guidelines and patient consent in the Urology Council.
Key exclusion criteria (3 listed)
- Presence of any condition that prevents transorbital measurement of the optic nerve sheath (e.g., orbital trauma, severe periorbital edema, or ocular abnormalities affecting optic nerve imaging)
- Presence of a medical condition that precludes positioning the patient in a 45-degree lateral decubitus position (e.g., severe scoliosis, respiratory compromise, or spinal instability)
- Known or suspected intracranial pathology that may independently elevate intracranial pressure (e.g., intracranial tumors, hydrocephalus, recent traumatic brain injury)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Optic Nerve Sheath Diameter MeasurementOptic Nerve Sheath Diameter Measurement, Oxygen saturation and End Tidal CO2 measurements when Pre-operational Supine position, after intubation, Lateral decubitus position, after Pneumoperitoneum, CO2 pressure level at 14-16-18-20 and Post-operational supine position | Diagnostic test | Routine Laparoscopic Pneumoperitoneum |
Primary outcome
Change in optic nerve sheath diameter (ONSD) with increasing intraabdominal CO₂ pressure
Time frame: Preop Supine before intubation → During surgery (baseline supine → lateral decubitus positioning → pneumoperitoneum → each pressure level: 14, 16, 18, 20 mmHg → Postop Supine 5 minutes after extubation of the patient
Change in optic nerve sheath diameter (ONSD) with increasing intraabdominal CO₂ pressure
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 3 Dec 2025.
- Background: PubMed 36036829Atasever AG, Salviz EA, Senturk Ciftci H, Bingul ES, Sivrikoz N, Erdem S, Savran Karadeniz M. The Effects of Lateral 45 degrees Head-Down Position and Carbon Dioxide Pneumoperitoneum on the Optic Nerve Sheath Diameter in Patients Undergoing Laparoscopic Transperitoneal Nephrectomies: A Prospective Observational Study. J Laparoendosc Adv Surg Tech A. 2023 Feb;33(2):171-176. doi: 10.1089/lap.2022.0344. Epub 2022 Aug 25.
- Background: PubMed 25861241Chin JH, Seo H, Lee EH, Lee J, Hong JH, Hwang JH, Kim YK. Sonographic optic nerve sheath diameter as a surrogate measure for intracranial pressure in anesthetized patients in the Trendelenburg position. BMC Anesthesiol. 2015 Mar 31;15:43. doi: 10.1186/s12871-015-0025-9. eCollection 2015.
- Individual participant dataSharing planned: No
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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.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Optic Nerve Sheath Diameter Measurement in people with Optic Nerve Sheath Diameter and Laparoscopic Nephrectomy, run by Fatih Sultan Mehmet Training and Research Hospital 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 3 inclusion and 3 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: enrolling by invitation, as of the sponsor's last update on 3 Dec 2025. 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?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in optic nerve sheath diameter (ONSD) with increasing intraabdominal CO₂ pressure (time frame: Preop Supine before intubation → During surgery (baseline supine → lateral decubitus positioning → pneumoperitoneum → each pressure level: 14, 16, 18, 20 mmHg → Postop Supine 5 minutes after extubation of the patient). 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 NCT07262125, 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 3 Dec 2025.