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RecruitingNCT07491198ONSD-RALPUpdated Sep 10, 2026

Effect Of Trendelenburg Position And Pneumoperitoneum On Optic Nerve Sheath Diameter In Robot-Assisted Prostatectomy

An observational study in Prostate Cancer, Optic Nerve Sheath Diameter and Robot-Assisted Radical Prostatectomy, sponsored by Ege University. Recruiting at 1 site in Turkey (Türkiye). Open to male participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-09-10.

Sponsored by Ege University · Observational

From the registry’s dates

  • Started Jan 2026; still recruiting 10 months later.
Study type
Observational
Model
Cohort
Time perspective
Prospective
Enrollment
50
Ages
18 Years and older
Sex
Male
01

Study summary

This prospective study aims to evaluate the effect of steep Trendelenburg position and pneumoperitoneum on optic nerve sheath diameter in patients undergoing robot-assisted laparoscopic radical prostatectomy and open radical prostatectomy under general anesthesia. Increased intracranial pressure may occur during robotic surgery due to pneumoperitoneum and head-down positioning. Optic nerve sheath diameter measured by ocular ultrasonography is a non-invasive method used to assess intracranial pressure changes. Hemodynamic and respiratory parameters will also be recorded during surgery. The results of this study may help to better understand the physiological effects of surgical position and pneumoperitoneum during prostatectomy procedures.

Read the detailed description

Robot-assisted laparoscopic radical prostatectomy requires steep Trendelenburg positioning and carbon dioxide pneumoperitoneum to improve the surgical field. These conditions may lead to increased intracranial pressure due to venous congestion and elevated intrathoracic pressure. Optic nerve sheath diameter measurement by ultrasonography is a noninvasive method that can be used to estimate changes in intracranial pressure during surgery.

In this prospective study, patients undergoing robot-assisted laparoscopic radical prostatectomy will be compared with patients undergoing open radical prostatectomy. Optic nerve sheath diameter will be measured at predefined time points during surgery using ocular ultrasonography. Hemodynamic parameters, respiratory variables, intra-abdominal pressure, duration of surgery, blood loss, and administered fluids will also be recorded.

The aim of this study is to evaluate the effect of pneumoperitoneum and steep Trendelenburg position on optic nerve sheath diameter and to determine the relationship between optic nerve sheath diameter and intraoperative physiological changes.

02

Conditions studied

  • Prostate Cancer
  • Optic Nerve Sheath Diameter
  • Robot-Assisted Radical Prostatectomy
  • Steep Trendelenburg Position With Penumoperitoneum in Robot Assisted Laparoscopic Prostatectomy

Keywords

  • Optic Nerve Sheath Diameter
  • Trendelenburg Position
  • Pneumoperitoneum
  • Robot-Assisted Radical Prostatectomy
03

In context

Prostatic Neoplasms

7,046 studies on the registry are indexed under Prostatic Neoplasms; 1,580 are open to participants now.

This study's planned enrollment of 50 is below the median of 200 across 1,310 observational studies indexed under Prostatic Neoplasms.

Browse Prostatic Neoplasms studies →

Lead sponsor

Ege University is the lead sponsor of 377 studies on the registry; 48 are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years and older
Sexes eligible
Male
Accepts healthy volunteers
No
Sampling method
Non-probability sample

Study population

Adult male patients aged 18 years and older with ASA physical status I-III who are scheduled for robot-assisted laparoscopic radical prostatectomy or open radical prostatectomy under general anesthesia at Ege University Faculty of Medicine Hospital will be included in this prospective observational study.

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  • Age ≥ 18 years
  • I-III
  • Patients scheduled for robot-assisted laparoscopic radical prostatectomy or open radical prostatectomy under general anesthesia
  • Written obtained

Exclusion criteria

Exclusion Criteria:

  • History of intracranial surgery or intracranial lesion
  • Known ocular disease (glaucoma, retinal detachment, diabetic retinopathy, previous ocular surgery, etc.)
  • Intraocular pressure greater than 30 mmHg
  • Refusal to participate in the study
Terms in these criteria, in plain language(2)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

ASA physical status

The anaesthetists’ scale of health before surgery: I is healthy, II has a mild illness that is under control, III a severe one, IV a severe illness that is a constant threat to life. V and VI are used for the critically ill and for organ donors.

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.

05

Study design

Observational model
Cohort
Time perspective
Prospective
Enrollment
50 participants (estimated)
Patient registry
No

Groups and cohorts

  • Robot-Assisted Radical Prostatectomy

    Patients undergoing robot-assisted laparoscopic radical prostatectomy under general anesthesia.

  • Open Radical Prostatectomy

    Patients undergoing open radical prostatectomy under general anesthesia.

06

What researchers measure

Primary outcomes

  1. Optic Nerve Sheath Diameter

    Measurement of optic nerve sheath diameter using ocular ultrasonography during surgery.

    Time frame: During surgery at predefined intraoperative time points

07

Study locations

1 of 1 sites recruiting
08

References and documents

Individual participant data

Plan to share: No — Individual participant data will not be shared due to privacy and institutional restrictions.

No publications or documents are linked to this record.

09

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Sep 10, 2026, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT07491198
Lead sponsor
Ege University
Responsible party
Nursen Karaca (Anesthesiologist, MD, Ege University) — Principal investigator
First posted
Mar 24, 2026
Start date
Jan 5, 2026
Primary completion
Oct 1, 2026 (estimated)
Completion
Dec 2026 (estimated)
Last update
Sep 10, 2026

Study contacts

Nursen Karaca, MD
Contact
dr.nursenkaraca@hotmail.com
+902323902142 ext. 2142
NURSEN KARACA, MD
principal investigator · Ege University

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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