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.

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.

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.

Only female patients are eligible for inclusion, as the surgical procedures under investigation (vNOTES and total laparoscopic hysterectomy) are applicable solely to women undergoing gynecologic surgery.

De-identified individual participant data (IPD), including baseline demographic variables and primary/secondary outcome measures, will be shared.

study completion + 6 months

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."

Due to the nature of the surgical interventions, blinding is not feasible. Both surgeons and outcome assessors are aware of group allocation. Participants may also recognize their assigned intervention based on the operative approach.