Deep Neuromuscular Blockade and a Low-Residue Diet for the Surgical Field in vNOTES Hysterectomy (vNOTES_NMBDIET)

July 29, 2026 updated by: MURAT YASSA, Fatih Sultan Mehmet Training and Research Hospital

Effect of Deep Neuromuscular Blockade and a Preoperative Low-Residue Diet on Intra-operative Surgical Field Conditions During Vaginal Natural Orifice Transluminal Endoscopic Surgery (vNOTES) Hysterectomy: A 2×2 Factorial, Assessor-Blinded Randomized Controlled Trial

vNOTES (vaginal natural orifice transluminal endoscopic surgery) hysterectomy is performed entirely through the vagina, with no abdominal incision. A clear surgical view is essential, and the main obstacle to the view is bowel falling into the pelvis. This randomized trial tests whether two simple measures improve the surgical field, individually or in combination: a preoperative low-residue diet for three days, and deeper intra-operative muscle relaxation (deep neuromuscular blockade). No group receives mechanical bowel preparation.

Using a 2×2 factorial design, participants are allocated equally (1:1:1:1) to one of four groups: (1) no diet with standard relaxation; (2) diet with standard relaxation; (3) no diet with deep relaxation; (4) diet with deep relaxation (the "bundle"). The surgical field is measured objectively: during a standardized window the carbon-dioxide insufflation pressure is lowered step by step, and 2-3 blinded assessors score the field from de-identified video. The primary outcome is the lowest pressure at which the field remains adequate; a lower pressure indicates an intrinsically better field.

The trial hypothesis is an interaction - that the combination achieves an adequate field at a meaningfully lower pressure than either measure alone. The final sample size is determined from an internal pilot. Secondary outcomes include the continuous field score, the need for an additional instrument to clear the field, postoperative nausea and vomiting, and routine operative outcomes.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

The field is scored with the vNOTES-OVI, a 3-point index (0 = inadequate, 1 = adequate only with instrument bowel-retraction, 2 = optimal/clear), adapted for vNOTES from the team's prior objective visualisation index in conventional laparoscopy. At each 1 mmHg step a 3-second clip is recorded with a fixed scanning choreography (right adnexa → midline/cephalic boundary → left adnexa); the consensus (median) of the blinded assessors defines, per participant, the lowest pressure at which the field is adequate (OVI ≥ 1; primary) and at which it is optimal (OVI = 2; secondary).

Deep relaxation is rocuronium by continuous infusion to a post-tetanic count of 1-2 (no train-of-four twitches); standard relaxation is rocuronium by intermittent bolus to a train-of-four count of 1-2. Relaxation depth is monitored quantitatively and fully reversed (train-of-four ratio ≥ 0.9 confirmed) before extubation in every participant; the reversal agent is sugammadex in all four groups (neostigmine is not used), and because sugammadex dosing follows block depth (≈ 2 mg/kg moderate, ≈ 4 mg/kg deep) the dose differs by the NMB factor by necessity, so it is recorded per participant and reported by arm (collinear with NMB depth, it is examined only in a sensitivity analysis, not added as a covariate to the factorial nausea model). The step-down field measurement descends from 12 mmHg to 6 mmHg in 1 mmHg steps with a 60-second equilibration at each step. The preoperative low-residue diet (diet arms) restricts daily intake to less than 10 g of dietary fibre for the three days before surgery - permitting refined grains, well-cooked or canned skinless and seedless vegetables, peeled or canned fruit, tender meat, fish, eggs, and moderate dairy, while avoiding whole grains, raw fruits and vegetables, legumes, nuts, seeds, and dried fruit - and participants receive a written diet information sheet; no group receives mechanical bowel preparation. The primary outcome is assessor-blinded (assessors score de-identified video with pressure and group removed); the operating surgeon is blinded to allocation and the data analyst analyses with groups coded; the anaesthesia team is necessarily unblinded to relaxation depth but does not score the outcome. The internal pilot (≈ 10-15 per group) is used for blinded sample-size re-estimation; detecting an interaction typically requires several times the sample size of a main effect.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
160

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.
  • Name: MURAT Y Murat Yassa, MD (Assoc. Prof.) - Principal Investigator, ASSOCIATE PROFESSOR IN OBS GYN
  • Phone Number: +905335106312
  • Email: murat.yassa@acibadem.com

Study Locations

  • Turkey (Türkiye)
    • KARTAL
      • Istanbul, KARTAL, Turkey (Türkiye), 34865
        • Active, not recruiting
        • Kartal Dr. Lütfi Kırdar Şehir Hastanesi
      • Istanbul, KARTAL, Turkey (Türkiye)
        • Recruiting
        • Acibadem Kartal Hospital
        • Contact:
          • MURAT Y Murat Yassa, MD - Principal Investigator, MD, Assoc. Prof.
          • Phone Number: +905335106312
          • Email: murat.yassa@acibadem.com
    • Kütahya
      • Kütahya, Kütahya, Turkey (Türkiye), 43100
        • Active, not recruiting
        • Kütahya Şehir Hastanesi

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Adult women (aged 18 years or older) scheduled for hysterectomy for a benign (non-cancer) indication.
  • Judged suitable for the vNOTES approach by the operating surgeon.
  • Able to understand the study and provide written informed consent.

Exclusion Criteria:

  • Suspected or known gynaecological malignancy.
  • Conditions expected to make the approach or the field assessment non-standard (e.g., anticipated dense pelvic adhesions or severe endometriosis, a contraindication to vNOTES, or an obliterated cul-de-sac).
  • Any medical reason why deep neuromuscular blockade or sugammadex would be unsafe (defined with the anaesthesia team).
  • Any medical reason why a low-residue diet would be unsuitable.
  • Inability to give informed consent.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Factorial Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Arm 2 - Diet + standard NMB
Three-day preoperative low-residue diet with standard (moderate) neuromuscular blockade. No mechanical bowel preparation.
Drug: Standard (moderate) neuromuscular blockade

Rocuronium by intermittent bolus to maintain a train-of-four count of 1-2 (usual care); reversed with sugammadex and confirmation of full recovery (train-of-four ratio ≥ 0.9) before extubation.

Cross-reference to arms: Arms 1, 2

Other: Preoperative low-residue diet

A low-residue diet (less than 10 g dietary fibre per day) for the three days before surgery, with standardised food lists and a patient information sheet. This is a dietary measure, not a laxative; no mechanical bowel preparation is used.

Cross-reference to arms: Arms 2, 4
Experimental: Arm 3 - Deep NMB (no diet)
Deep neuromuscular blockade (post-tetanic count 1-2, continuous infusion) with no dietary restriction. No mechanical bowel preparation.
Drug: Deep Neuromuscular Blockade (NMB)

Rocuronium by continuous infusion to maintain profound relaxation (no train-of-four twitches; post-tetanic count 1-2) until the end of the field measurement and surgery; reversed with sugammadex and confirmation of full recovery (train-of-four ratio ≥ 0.9) before extubation.

Cross-reference to arms: Arms 3, 4
Experimental: Arm 4 - Bundle (diet + deep NMB)
Three-day low-residue diet AND deep neuromuscular blockade - the combination of interest. No mechanical bowel preparation.
Other: Preoperative low-residue diet

A low-residue diet (less than 10 g dietary fibre per day) for the three days before surgery, with standardised food lists and a patient information sheet. This is a dietary measure, not a laxative; no mechanical bowel preparation is used.

Cross-reference to arms: Arms 2, 4

Drug: Deep Neuromuscular Blockade (NMB)

Rocuronium by continuous infusion to maintain profound relaxation (no train-of-four twitches; post-tetanic count 1-2) until the end of the field measurement and surgery; reversed with sugammadex and confirmation of full recovery (train-of-four ratio ≥ 0.9) before extubation.

Cross-reference to arms: Arms 3, 4
Active Comparator: Arm 1 - Control (no diet + standard neuromuscular blockade NMB)
Usual care: standard (moderate) neuromuscular blockade (train-of-four 1-2, intermittent bolus) and no dietary restriction. No mechanical bowel preparation.
Drug: Standard (moderate) neuromuscular blockade

Rocuronium by intermittent bolus to maintain a train-of-four count of 1-2 (usual care); reversed with sugammadex and confirmation of full recovery (train-of-four ratio ≥ 0.9) before extubation.

Cross-reference to arms: Arms 1, 2

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Lowest CO₂ insufflation pressure at which the surgical field is adequate (blinded Transvaginal Natural Orifice Endoluminal Surgery - Objectiveisual Index: vNOTES-OVI ≥ 1)
Time Frame: Intra-operative (single measurement window)
During a standardized intra-operative window, insufflation pressure is lowered from 12 mmHg to 6 mmHg in 1 mmHg steps, with a 60-second equilibration at each step; at each step a 3-second de-identified video clip is scored by 2-3 blinded assessors with the vNOTES-OVI (0/1/2). The consensus (median) score yields, per participant, the lowest pressure at which the field is adequate (OVI ≥ 1). Lower pressure indicates a better field.
Intra-operative (single measurement window)

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Continuous surgical-field score (vNOTES-OVI)
Time Frame: Intra-operative
Blinded vNOTES-OVI (0/1/2) at each insufflation-pressure step, analysed as a threshold-free ordinal/continuous measure.
Intra-operative
Lowest pressure at the strict threshold (vNOTES-OVI = 2)
Time Frame: Intra-operative
Lowest insufflation pressure at which the field is perfectly exposed (OVI = 2), blinded scoring.
Intra-operative
Requirement for a third working instrument
Time Frame: Intra-operative
Whether an instrument beyond the camera and the two standard working instruments - introduced through the platform's existing channel, not a new abdominal port - was required solely to expose the field or displace bowel (yes/no per case).
Intra-operative
Postoperative nausea and vomiting - complete response
Time Frame: 0-24 hours postoperative
Proportion of participants with no nausea AND no vomiting AND no rescue antiemetic during the first 24 hours.
0-24 hours postoperative
Nausea severity
Time Frame: 0-24 hours postoperative
Worst nausea severity on a 4-point verbal scale (none/mild/moderate/severe), assessed by a blinded assessor at 0-2, 2-6, and 6-24 hours.
0-24 hours postoperative
Vomiting episodes
Time Frame: 0-24 hours postoperative
Number of vomiting/retching episodes during the first 24 hours.
0-24 hours postoperative
Operative time
Time Frame: Through surgery completion
Skin-to-skin operating time.
Through surgery completion
Estimated blood loss
Time Frame: Through surgery completion
Estimated intra-operative blood loss (mL).
Through surgery completion
Conversion to another approach
Time Frame: Intra-operative
Conversion to conventional laparoscopy or laparotomy (yes/no).
Intra-operative
Intra-operative and early postoperative complications
Time Frame: hrough 24 hours postoperative
Complications recorded as counts by group.
hrough 24 hours postoperative

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Fatih Sultan Mehmet Training and Research Hospital

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
Dr. Lutfi Kirdar Kartal Training and Research Hospital
Kocaeli City Hospital
Kutahya City Hospital

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
July 1, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
July 25, 2027

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
September 1, 2027

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
July 22, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 22, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
July 28, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
July 30, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 29, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
July 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • ATADEK 2026/12, 2026-12/513

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

IPD Plan Description

Sharing IPD is curretly under restriction without health ministry's official permisson.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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