Femoral and Sciatic Nerve Blocks Added to Obturator Nerve Block for Prevention of Obturator Reflex

November 2, 2026 updated by: Tuna Erturk

Comparison of the Efficacy of Femoral and Sciatic Nerve Blocks Added to Obturator Nerve Block in Preventing the Obturator Reflex

This prospective, randomized controlled study aims to evaluate whether adding femoral and sciatic nerve blocks to obturator nerve block improves the prevention of obturator reflex during transurethral resection of bladder tumors under spinal anesthesia.

Ninety patients will be randomly assigned to three groups: obturator nerve block alone, obturator plus femoral nerve blocks, or obturator plus femoral and sciatic nerve blocks. Adductor muscle contractions, surgeon satisfaction, procedure duration, and complications will be evaluated.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet 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

This single-center, prospective, randomized controlled study will include 90 patients aged 18-90 years with American Society of Anesthesiologists (ASA) physical status I-III who are scheduled for transurethral resection of unilateral lateral bladder wall tumors under spinal anesthesia.

Eligible patients will be randomly allocated into three groups of 30 patients each:

Group 1: Obturator nerve block (ONB) alone.

Group 2: Obturator nerve block combined with femoral nerve block (ONB + FNB).

Group 3: Obturator nerve block combined with femoral and sciatic nerve blocks (ONB + FNB + SNB).

The nerve blocks will be performed using ultrasound guidance according to the study protocol.

During surgery, the occurrence and severity of adductor muscle contractions associated with the obturator reflex will be recorded. Contractions will be classified as absent, mild, or severe according to their interference with the surgical procedure. The total number of contractions will also be documented.

Additional assessments will include block procedure duration, surgical duration, surgeon satisfaction using a 0-10 numerical scale, conversion to general anesthesia, bleeding, bladder injury, perforation, blood transfusion, and complications related to the nerve blocks.

The study aims to determine whether adding femoral and sciatic nerve blocks to obturator nerve block improves the prevention of obturator reflex during transurethral bladder tumor resection.

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.
90

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.

Study Locations

  • Turkey (Türkiye)
      • Istanbul, Turkey (Türkiye), 34668
        • Sultan 2. Abdulhamid Han Training and Research Hospital
        • Contact:

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

18 years to 90 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Patients aged 18-90 years.
  • American Society of Anesthesiologists (ASA) physical status I-III.
  • Patients scheduled for transurethral resection of unilateral lateral or inferolateral bladder wall tumors under spinal anesthesia.
  • Patients providing informed consent personally or through a legally authorized representative.
  • No known hypersensitivity to the medications used in the study.
  • No infection or anatomical deformity at the nerve block sites.
  • No antithrombotic treatment and normal coagulation parameters.

Exclusion Criteria:

  • Age younger than 18 or older than 90 years.
  • ASA physical status IV or higher.
  • Absence of informed consent.
  • Hypersensitivity to the study medications or their components.
  • Infection or anatomical deformity at the nerve block sites.
  • Antithrombotic treatment.
  • Abnormal coagulation parameters.

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: Prevention
  • Allocation: Randomized
  • Interventional Model: Parallel 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.
Active Comparator: Obturator Nerve Block (ONB)

Patients will receive an ultrasound-guided obturator nerve block.
Procedure: Obturator Nerve Block

Ultrasound-guided obturator nerve block will be performed.
Experimental: ONB + FNB

Patients will receive ultrasound-guided obturator and femoral nerve blocks.
Procedure: Obturator Nerve Block

Ultrasound-guided obturator nerve block will be performed.

Procedure: Femoral Nerve Block

Ultrasound-guided femoral nerve block will be performed in addition to obturator nerve block.
Experimental: ONB + FNB + SNB

Patients will receive ultrasound-guided obturator, femoral, and sciatic nerve blocks.
Procedure: Obturator Nerve Block

Ultrasound-guided obturator nerve block will be performed.

Procedure: Femoral Nerve Block

Ultrasound-guided femoral nerve block will be performed in addition to obturator nerve block.

Procedure: Sciatic Nerve Block

Ultrasound-guided sciatic nerve block will be performed in addition to obturator and femoral nerve blocks.

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
Number of Participants With at Least One Intraoperative Adductor Muscle Contraction
Time Frame: On the day of surgery, during transurethral tumor resection

Participants experiencing at least one adductor muscle contraction during transurethral bladder tumor resection will be recorded. The number and proportion of affected participants will be compared across the three groups.
On the day of surgery, during transurethral tumor resection

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
Number of Participants With Severe Intraoperative Adductor Muscle Contractions
Time Frame: On the day of surgery, during transurethral tumor resection

Adductor muscle contractions will be classified as severe if they interfere with the surgeon during resection. The number of participants experiencing at least one severe contraction will be recorded and compared across the three groups.
On the day of surgery, during transurethral tumor resection
Surgeon Satisfaction Score
Time Frame: At the end of surgery, on the day of the procedure

Surgeon satisfaction will be assessed using a numerical rating scale from 0 (very poor) to 10 (excellent). Scores will be compared across the three groups.
At the end of surgery, on the day of the procedure
Total Number of Intraoperative Adductor Muscle Contractions
Time Frame: On the day of surgery, during transurethral tumor resection

The total number of adductor muscle contractions occurring during transurethral bladder tumor resection will be recorded for each participant and compared across the three groups.
On the day of surgery, during transurethral tumor resection
Number of Participants With Bladder Wall Injury or Perforation
Time Frame: On the day of surgery, during transurethral tumor resection

The occurrence of bladder wall injury or perforation during transurethral bladder tumor resection will be recorded and compared across the three groups.
On the day of surgery, during transurethral tumor resection
Number of Participants With Inability to Continue Surgery Due to Adductor Muscle Contraction
Time Frame: On the day of surgery, during transurethral tumor resection

Inability to continue surgical resection due to intraoperative adductor muscle contraction will be recorded and compared across the three groups.
On the day of surgery, during transurethral tumor resection

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.
Tuna Erturk

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Tuna Ertürk, MD, University of Health Sciences Sultan 2. Abdulhamid Han Training and Research Hospital

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 (Estimated)

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.
November 2, 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.
February 2, 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.
February 2, 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).
November 2, 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.
November 2, 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.
November 6, 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.
November 6, 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.
November 2, 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.
November 1, 2026

More Information

Terms related to this study

Keywords

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.
  • 20-115

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

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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