C-MAC D-Blade vs Macintosh for Postoperative Vocal Cord Evaluation

December 11, 2025 updated by: Sami Akbulut, Inonu University

Comparison of the C-MAC D-Blade Videolaryngoscope and the Macintosh Laryngoscope for Postoperative Vocal Cord Assessment After Thyroidectomy

This study compares two different laryngoscopes-the C-MAC D-Blade videolaryngoscope and the Macintosh direct laryngoscope-for evaluating vocal cord mobility after thyroidectomy. Patients undergo standard anesthesia and intubation with one of the two devices. After surgery, vocal cord function is assessed to identify early postoperative vocal cord impairment. The study aims to determine whether videolaryngoscopy provides a more reliable and less traumatic method for postoperative vocal cord evaluation compared with the traditional Macintosh laryngoscope.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

This prospective randomized study evaluates two laryngoscopic techniques used during endotracheal intubation in patients undergoing thyroidectomy. The C-MAC D-Blade videolaryngoscope provides an angulated blade and video-assisted view of the glottis, while the Macintosh laryngoscope represents the traditional direct visualization method. Because postoperative vocal cord impairment is an important early indicator of potential recurrent laryngeal nerve injury after thyroidectomy, accurate assessment immediately after surgery is clinically valuable.

In this study, eligible patients were randomly assigned to intubation using either the C-MAC D-Blade videolaryngoscope or the Macintosh laryngoscope. All procedures were performed under standard anesthesia protocols by experienced anesthesiologists. After extubation and recovery, vocal cord mobility was evaluated using a standardized six-grade scoring system to assess postoperative vocal cord function.

The study compares intubation characteristics, glottic views, optimization maneuvers, hemodynamic responses, and postoperative vocal cord mobility between the two devices. The primary aim is to determine whether videolaryngoscopy offers a more reliable and less traumatic method for postoperative vocal cord evaluation. Secondary objectives include evaluating ease of intubation, maneuver requirements, and perioperative physiological responses. The findings may help guide device selection for airway management in thyroid surgery and improve early detection of recurrent laryngeal nerve dysfunction.

Study Type

Interventional

Enrollment (Actual)

102

Phase

  • 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 Locations

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

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria

  • Age between 20 and 70 years.
  • Height greater than 145 cm.
  • Body mass index (BMI) between 20 and 35 kg/m².
  • American Society of Anesthesiologists (ASA) physical status
  • Scheduled for elective thyroid surgery under general anesthesia.

Exclusion Criteria

  • Prior neck surgery or radiotherapy
  • Large thyroid mass causing severe anatomical distortion.
  • Mouth opening less than 4 cm.
  • Short neck less than 6 cm in length.
  • Limited head and neck mobility
  • Unexpected difficult intubation.
  • Known history of recurrent laryngeal nerve injury
  • Presence of any neurological disorder.

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: Diagnostic
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: C-MAC D-Blade Videolaryngoscope
Patients in this group were intubated using the C-MAC D-Blade videolaryngoscope to facilitate glottic visualization and to perform postoperative vocal cord mobility assessment.
Device: Videolaryngoscope (C-MAC D-Blade)
The C-MAC D-Blade videolaryngoscope was used to perform endotracheal intubation and to obtain a video-assisted view of the glottis. Its angulated blade design allows indirect visualization, providing improved glottic exposure during intubation and postoperative vocal cord mobility assessment
Active Comparator: Macintosh Laryngoscope
Patients in this group were intubated with the traditional Macintosh direct laryngoscope, which was also used for postoperative assessment of vocal cord mobility.
Device: Direct Laryngoscope (Macintosh)
The Macintosh direct laryngoscope was used for endotracheal intubation with conventional direct visualization of the glottis. This standard laryngoscopic technique was also used for postoperative assessment of vocal cord mobility.
Other Names:
  • Direct Laryngoscope
  • Macintosh Blade

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Postoperative Vocal Cord Mobility Score
Time Frame: Within 30 minutes after extubation
Vocal cord mobility will be assessed using a standardized six-grade scoring system (I-VI) to detect postoperative vocal cord impairment after thyroidectomy.
Within 30 minutes after extubation

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Glottic View (Cormack-Lehane Grade)
Time Frame: During intubation procedure
The view of the glottis during intubation will be assessed using the Cormack-Lehane grading system.
During intubation procedure
Need for Optimization Maneuvers
Time Frame: During intubation procedure
Whether external laryngeal maneuvers or additional attempts were required to facilitate intubation.
During intubation procedure

Collaborators and Investigators

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

Sponsor

Inonu University

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)

January 23, 2023

Primary Completion (Actual)

May 26, 2023

Study Completion (Actual)

May 26, 2023

Study Registration Dates

First Submitted

December 1, 2025

First Submitted That Met QC Criteria

December 10, 2025

First Posted (Estimated)

December 11, 2025

Study Record Updates

Last Update Posted (Actual)

December 12, 2025

Last Update Submitted That Met QC Criteria

December 11, 2025

Last Verified

December 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 2022/115

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Individual participant data will not be shared because the dataset contains identifiable clinical information and the study was not designed with external data distribution in mind

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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