The Effect of Head Position on the Optik Nerve Sheath Diameter in Patients During Thyroid Surgery

THE EFFECT OF HEAD POSİTİON ON THE OPTİC NERVE SHEATH DİAMETER İN PATİENTS DURİNG THYROİD SURGERY

Study Overview

• Status: Completed
• Conditions: Thyroid Cancer; Thyroid and Parathyroid Surgery; Thyroid Adenoma

Detailed Description

Aim: In thyroidectomy surgery, the patient's head is placed in hyperextension and the patient is placed in a semi-sitting position to facilitate access to the surgical site. This position of the head causes a decrease in venous return or partial obstruction of venous return due to stretching of the neck veins. The aim of our study is to demonstrate the effect of surgical position on intracranial pressure by measuring the optic nerve sheath diameter (OSSD) using ultrasonography in patients undergoing thyroid surgery and to determine its correlation with post-operative headaches.

Material And Method: Our study was conducted prospectively and randomly in patients undergoing elective total thyroidectomy. Patients aged 18-65 with an ASA score of 1-2 and an operation time of less than 4 hours were included in our study. Patients were positioned in the semi-Fowler position with a 30° extension of the head. Bilateral OSSD surgical positioning was applied, and after ensuring haemodynamic stability for 5 minutes and at the end of the operation, measurements were taken twice using ultrasound, and the average was recorded. The Visual Analogue Scale (VAS) was used to assess postoperative pain intensity. Headache was assessed and recorded at 15 minutes, 30 minutes, 1 hour, 24 hours, 3 days, and 7 days postoperatively.

• Study Type: Observational
• Enrollment (Actual): 49

Contacts and Locations

Study Locations

• Turkey (Türkiye)
  • FATİH
    • Istanbul, FATİH, Turkey (Türkiye), 34000
      • Istanbul University Cerrahpasa

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

• Sampling Method: Probability Sample

Study Population

ISTANBUL UNIVERSITY-CERRAHPASA

Description

Inclusion Criteria:

• Patients aged between 18 and 65, with an ASA score between 1 and 2 according to the American Society of Anesthesiologists (ASA) physical status classification system
• whose surgery duration was expected to be less than 4 hours were included in our study.

Exclusion Criteria:

• liver failure
• kidney failure
• intracranial masses
• history of hydrocephalus,
• migraine
• chronic hypoxemia or hypercarbic lung disease
• additional heart disease
• hemodynamic insufficiency
• neurological and psychiatric diseases,
• glaucoma
• patients in whom ocular USG could not provide adequate images
• patients with pathological problems involving the eyelid and its surrounding area
• patients with diseases such as periorbital cellulitis
• patients with preoperative headache complaints
• patients with known diseases that could cause increased intracranial pressure
• patients who refused to participate in the study were excluded from the study.

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
OPTİC NERVE SHEATH DİAMETER	CHANGE İN OPTİC NERVE SHEATH DİAMETER MEASURED BY ULTRASOUND BEFORE AND AFTER POSİTİONİNG DURİNG THYROİDECTOMY	INTRAOPERATİVE PERİOD(FROM İNDUCTİON TO THE END OF SURGERY)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
POSTOPERATİVE HEADACHE SEVERİTY (VISUAL ANALOG SCALE)	THE SEVERİTY OF POSTOPERATİVE HEADACHE WİLL BE ASSESSED USİNG A VİSUAL ANALOG SCALE. THE LOWEST POSSIBLE SCORE ON THE VISUAL ANALOG SCALE WAS 0, AND THE HIGHEST POSSIBLE SCORE WAS 10.	WİTHİN SEVEN DAYS AFTER SURGERY

Collaborators and Investigators

• Sponsor: Istanbul University - Cerrahpasa

Study record dates

Study Major Dates

• Study Start (Actual): April 1, 2025
• Primary Completion (Actual): September 30, 2025
• Study Completion (Actual): November 3, 2025

Study Registration Dates

• First Submitted: December 9, 2025
• First Submitted That Met QC Criteria: December 19, 2025
• First Posted (Actual): December 23, 2025

Study Record Updates

• Last Update Posted (Actual): December 23, 2025
• Last Update Submitted That Met QC Criteria: December 19, 2025
• Last Verified: December 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Endocrine System Diseases; Neoplasms by Site; Neoplasms; Endocrine Gland Neoplasms; Head and Neck Neoplasms; Thyroid Diseases; Thyroid Neoplasms
• Other Study ID Numbers: 1274724

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: THE INDIVIDUAL PARTİCİPANT DATA WİLL NOT BE SHARED BECAUSE OF İNSTİTUTİONAL AND ETHİCAL RESTRİCTİONS

Drug and device information, study documents

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