ONSD as an ICP Marker in vNOTES and TLH

Effect of Surgical Approach on Optic Nerve Sheath Diameter as a Surrogate Marker of Intracranial Pressure: A Comparison Between vNOTES and Total Laparoscopic Hysterectomy

Patients undergoing conventional total laparoscopic hysterectomy (TLH) are typically placed in the Trendelenburg position with intraabdominal carbon dioxide (CO₂) insufflation. These factors may contribute to intraoperative complications such as lymphedema, impaired pulmonary function, and increased intracranial pressure.

Vaginal Natural Orifice Transluminal Endoscopic Surgery (vNOTES), a novel minimally invasive technique, provides retroperitoneal or transperitoneal access through the vaginal route and offers the potential for shorter operative times and lower intraabdominal pressure requirements.

This study aims to evaluate whether the vNOTES technique can reduce intraoperative and postoperative complications compared with TLH. Particular attention will be given to hemodynamic parameters and changes in optic nerve sheath diameter as an indirect indicator of intracranial pressure.

Study Overview

• Status: Completed
• Conditions: Endometrial Cancer; Myoma;Uterus; Abnormal Uterine Bleeding
• Intervention / Treatment: Procedure: vNOTES; Procedure: TLH

Detailed Description

This study is designed as a single-center, prospective, randomized controlled trial conducted at the Gynecologic Oncology Clinic of Health Sciences University Diyarbakır Gazi Yaşargil Training and Research Hospital. Eligible patients will be women between 18 and 75 years of age, classified as ASA I-II, who are scheduled for elective laparoscopic hysterectomy for gynecologic oncology indications. The study protocol will be initiated after approval by the institutional ethics committee, and written informed consent will be obtained from all participants.

Group vNOTES: Following vaginal exposure with a speculum under general anesthesia, entry will be performed through the posterior vaginal fornix. After posterior colpotomy, the vNOTES port system will be inserted. Pneumoperitoneum will be established with CO₂ insufflation at a maximum pressure of 15 mmHg. The operation will be performed using an endoscopic camera and working channels.

Group TLH: Under general anesthesia, pneumoperitoneum will be created via an umbilical trocar (maximum pressure15 mmHg), followed by placement of 2-3 additional trocars in the lower abdomen. A standard total laparoscopic hysterectomy will then be performed.

Demographic and perioperative data will be collected, including age, diagnosis, ASA score, anesthesia and surgery duration, intraoperative blood loss (by suction and sponge count), total intravenous fluids, systolic and diastolic blood pressure, heart rate, oxygen saturation, respiratory rate, end-tidal CO₂, intra-abdominal pressure, and ventilatory parameters (PEEP, peak and plateau airway pressures).

The primary outcome will be changes in optic nerve sheath diameter (ONSD), measured by ultrasonography at predefined time points as a surrogate marker of intracranial pressure:

T0: before induction of anesthesia

T1: at 10 minutes after Trendelenburg positioning and insufflation

T2: at 30 minutes

T3: at 60 minutes

T4: at 90 minutes

T5: 10 minutes after desufflation and return to neutral position

All ONSD measurements will be performed intraoperatively by a trained anesthesiologist using standardized ultrasound techniques. Hemodynamic and ventilatory parameters will be recorded at 10-minute intervals.

Secondary outcomes will include arterial blood gas analysis, postoperative complications (such as nausea, vomiting, delirium, headache, dizziness, and diplopia), and recovery variables (time to ambulation, return of bowel function, oral intake, and hospital stay).

Among the parameters measured, ONSD evaluation via ultrasound is specific to the study and non-invasive, adding no risk or cost to the patient. All other parameters are part of routine intraoperative monitoring. Data collection will be carried out in the operating room by anesthesiologists and trained ICU/gynecologic oncology nurses.

The investigators hypothesize that the vNOTES approach, due to its shorter operative duration, reduced Trendelenburg requirements, and lower intraabdominal insufflation pressures, will result in less pronounced increases in ONSD compared with TLH. This may lead to greater intraoperative stability and reduced postoperative complications, thereby providing valuable evidence for optimizing surgical strategies in gynecologic oncology.

• Study Type: Interventional
• Enrollment (Actual): 66
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Turkey (Türkiye)
  • Outside of the US
    • Diyarbakır, Outside of the US, Turkey (Türkiye), 21070
      • Saglik Bilimleri Universitesi Gazi Yasargil Training and Research Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• voluntary participation,
• elective laparoscopic hysterectomy scheduled by gynecology-oncology specialists,
• ASA physical status I-II

Exclusion Criteria:

• included unwillingness to participate,
• emergency surgery,
• age <18 years,
• prior major pelvic or abdominal surgery,
• ASA ≥III,
• Chronic pulmonary disease, pulmonary hypertension, glaucoma, diabetic retinopathy, intracranial pathology (mass, hydrocephalus, optic neuritis), prior ocular or intracranial surgery, cardiac failure (EF <40%), active infection, or systemic inflammatory diseases other than malignancy.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: vNOTES Hysterectomy for Assessment of Intraoperative Optic Nerve Sheath Diameter; Vajinal natural orifice transluminal endoscopic surgery (vNOTES): In the vNOTES group, the surgery was performed using a transvaginal approach with a self-retaining vaginal port. Following colpotomy, CO₂ insufflation was applied through the vaginal port, ensuring intra-abdominal pressure did not exceed 15 mmHg. The procedure involved occlusion and ligation of the uterine artery under direct endoscopic visualization, followed by sampling through the vaginal route. Pneumoperitoneum was released before closing the vaginal vault. The uterus was then removed through the vaginal route.	Procedure: vNOTES; vNOTES: In the vNOTES group, the surgery was performed using a transvaginal approach with a self-retaining vaginal port. Following colpotomy, CO₂ insufflation was applied through the vaginal port, ensuring intra-abdominal pressure did not exceed 15 mmHg. The procedure involved occlusion and ligation of the uterine artery under direct endoscopic visualization, followed by sampling through the vaginal route. Pneumoperitoneum was released before closing the vaginal vault. The uterus was then removed through the vaginal route.
Active Comparator: Total Laparoscopic Hysterectomy for Assessment of Intraoperative Optic Nerve Sheath Diameter; Total laparoscopic hysterectomy (TLH): In the TLH group, the surgical procedure was performed under standard laparoscopic conditions using a 10 mm umbilical camera port and two 5 mm accessory trocars. CO₂ insufflation was initiated to maintain intra-abdominal pressure below 15 mmHg. The uterus is dissected using a bipolar vessel sealing device, and the specimen is removed transvaginally. The vaginal cuff and abdominal trocar entries are sutured laparoscopically under direct visualization.	Procedure: TLH; In the TLH group, the surgical procedure was performed under standard laparoscopic conditions using a 10 mm umbilical camera port and two 5 mm accessory trocars. CO₂ insufflation was initiated to maintain intra-abdominal pressure below 15 mmHg. The uterus is dissected using a bipolar vessel sealing device, and the specimen is removed transvaginally. The vaginal cuff and abdominal trocar entries are sutured laparoscopically under direct visualization.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Optic nerve sheath diameter (ONSD) measured	All measurements were performed using a high-resolution ultrasound device equipped with a 7-13 MHz linear probe. The ultrasound gain and depth settings were standardized for all patients (depth: 4-5 cm; focus: at the level of the optic disc). Patient Position: Measurements were obtained with patients in the supine position. The eyes were kept closed, and sterile ultrasound gel was applied without exerting pressure on the globe. The probe was gently placed on the upper eyelid, and measurements were taken in the transverse plane. The optic nerve sheath diameter was measured 3 mm distal to the optic disc, from outer edge to outer edge (outer-to-outer).	From baseline (before induction) to 10, 30, 60, and 90 minutes after Trendelenburg and CO₂ insufflation, and 10 minutes after desufflation.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Blood pressure measurement	Systolic, diastolic and mean arterial pressure measurements will be recorded by invasive arterial monitoring.	It will be recorded 10 minutes before induction of anesthesia and every 15 minutes after intubation until the end of the operation.
Measurement of heart rate	The number of heart beats per minute obtained by electrocardiographic monitoring	It will be recorded 10 minutes before induction of anesthesia and every 15 minutes after intubation until the end of the operation.
Nausea-vomiting	Questioning about the presence/absence of nausea and/or vomiting in the postoperative period	During the 24 hours postoperative period
intraabdominal pressure	The pressure inside the abdominal cavity during CO₂ insufflation.	It will be recorded 10 minutes before induction of anesthesia and every 15 minutes after intubation until the end of the operation.
end-tidal CO₂ (EtCO₂)	The partial pressure of CO₂ at end-expiration measured by capnography	It will be recorded 10 minutes before induction of anesthesia and every 15 minutes after intubation until the end of the operation.
peak airway pressure	The highest pressure reached in the airways during inspiration under mechanical ventilation.	It will be recorded 10 minutes before induction of anesthesia and every 15 minutes after intubation until the end of the operation.
dizziness	Questioning about the presence/absence of dizzines the postoperative period	During the 24 hours postoperative period
diplopia	Questioning about the presence/absence of diplopia the postoperative period	During the 24 hours postoperative period
Incidence of Postoperative Headache	The incidence of postoperative headache will be recorded within the first 24 hours after surgery. Headache will be assessed by direct patient questioning and documented as present or absent.	Within the first 24 hours postoperatively

Collaborators and Investigators

• Sponsor: Saglik Bilimleri Universitesi Gazi Yasargil Training and Research Hospital
• Investigators: Principal Investigator: Fatma Acil, M.D., Saglik Bilimleri Universitesi Gazi Yasargil Training and Research Hospital

Publications and helpful links

General Publications

• Guloglu H, Cetinkaya D, Oge T, Bilir A. Evaluation of the effect of trendelenburg position duration on intracranial pressure in laparoscopic hysterectomies using ultrasonographic optic nerve sheath diameter measurements. BMC Anesthesiol. 2024 Jul 15;24(1):238. doi: 10.1186/s12871-024-02624-4.

Study record dates

Study Major Dates

• Study Start (Actual): November 27, 2025
• Primary Completion (Actual): January 2, 2026
• Study Completion (Actual): January 5, 2026

Study Registration Dates

• First Submitted: November 18, 2025
• First Submitted That Met QC Criteria: November 18, 2025
• First Posted (Estimated): November 26, 2025

Study Record Updates

• Last Update Posted (Actual): January 7, 2026
• Last Update Submitted That Met QC Criteria: January 5, 2026
• Last Verified: January 1, 2026

More Information

Terms related to this study

• Keywords: Optic Nerve Sheath Diameter; vNOTES; Intracranial Pressure; Laparoscopic Hysterectomy
• Additional Relevant MeSH Terms: Urogenital Diseases; Genital Diseases; Pathologic Processes; Urogenital Neoplasms; Neoplasms by Site; Neoplasms; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Connective Tissue Diseases; Neoplasms by Histologic Type; Uterine Diseases; Genital Diseases, Female; Hemorrhage; Genital Neoplasms, Female; Uterine Neoplasms; Neoplasms, Connective and Soft Tissue; Neoplasms, Connective Tissue; Uterine Hemorrhage; Pathological Conditions, Signs and Symptoms; Skin and Connective Tissue Diseases; Endometrial Neoplasms; Myofibroma; Metrorrhagia
• Other Study ID Numbers: 09/05/2025-627

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: De-identified individual participant data (IPD), including baseline demographic variables and primary/secondary outcome measures, will be shared.
• IPD Sharing Time Frame: study completion + 6 months

IPD Sharing Access Criteria

Researchers may request access to the de-identified IPD by contacting the principal investigator at:[acilfatma@gmail.com].

Requests will be evaluated by the investigators, and data will be shared after approval and completion of a data-sharing agreement."

• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; ICF

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No