Evaluation of the effectiveness of platelet-rich fibrin on reducing complications after total thyroidectomy surgeries

To determine the effectiveness of Platelet-Rich Fibrin(PRF) in reducing postoperative complications following total thyroidectomy surgeries

A single-center, randomized, double-blind, parallel-group trial. Participants (N=44) are allocated to either the PRF intervention or saline control group using block randomization with a fixed block size of four generated by Excel.

The trial will be conducted at Amir A'lam Hospital. An unblinded clerk, not involved in treatment/follow-up, will manage the randomization list and inform the independent PRF injection technician of the group assignment. The operating surgeon, outcome assessors, investigators, and patients will be blinded to the group allocation.

Inclusion Criteria: Patients over 18 who are candidates for total thyroidectomy No history of neck surgery Normal preoperative calcium levels Exclusion Criteria: Coagulation disorders Use of therapeutic-dose anticoagulant medications(except for prophylaxis) Known sensitivity to any of the components of PRP and fibrin History of radiotherapy or extensive surgery in the neck region Presence of active infection or advanced malignancy with metastasis

- Intervention Group(Platelet-Rich Fibrin): Injection of Injectable Platelet-Rich Fibrin(i-PRF) during the surgery into the surgical bed prior to suturing, and placement of Concentrated Platelet-Rich Fibrin(C-PRF) in the surgical bed. - Control Group(Standard): Standard surgical procedure without the use of Platelet-Rich Fibrin(using only normal saline injection).

Scar assessment using the Patient and Observer Scar Assessment Scale and the Vancouver Scar Scale, Postoperative drainage volume and duration, hypocalcemia, Patient satisfaction with scar appearance measured by the Visual Analogue Scale, and Duration of hospital stay

We will use block randomization at the individual level. A random sequence will be generated using a computer-generated list of random binary numbers in Microsoft Excel, with a fixed block size of four. In total, 11 blocks of four will be created, each containing 2 participants in the case group(assigned the number 1) and 2 participants in the control group(assigned the number 0). Eligible surgical patients will be assigned to these blocks according to their surgical order upon admission. The allocation sequence will be managed by a secretary who is not involved in the clinical evaluations and is aware of the group assignments. This secretary will be responsible for assigning participants based on the predetermined random list.

To ensure blinding, outcome assessors, researchers, and patients will be kept unaware of group assignments(double-blind). Only the Platelet-Rich Fibrin(PRF) injection technician will be informed about the patient assignments. The PRF injection team will be independent from the surgical team. Consequently, the operating surgeon will have no knowledge of group allocations, preserving blinding integrity for the surgical team and other involved personnel. The PRF injection technician will administer PRF in the case group and inject normal saline using the same method and equipment as the PRF injection as a placebo in the control group. The technician performing the PRF injection cannot be blinded to the grouping due to the nature of the intervention.

‎1. De-identified Individual Participant Data This dataset contains all collected participant-level information from the clinical trial after ‎the removal of all direct personal identifiers. The data to be shared includes:‎ Patient demographics (age, sex).‎ Patient allocation (intervention/treatment group assignment).‎ Primary and secondary outcome measure data.‎ Safety data, including reported adverse events.‎ Data on protocol deviations.‎ ‎2. Clinical Study Report‎ This is a comprehensive summary of the full, formal Clinical Study Report. It will include ‎detailed information on the study design, methodology, participant flow, statistical ‎methods, results for all efficacy and safety outcomes, and a final conclusion. This ‎document will be made publicly available.‎

‎1. De-identified Individual Participant Data • Availability Start Date: This dataset will become available for request after the ‎publication of the primary trial results in a peer-reviewed journal.‎ • Period of Availability: The data will be made accessible indefinitely.‎ ‎2. Clinical Study Report Synopsis‎ • Availability Start Date: This document will be made publicly available ‎concurrently with the publication of the primary results manuscript.‎ • Period of Availability: It will be accessible indefinitely, hosted on the publishing ‎journal's website according to their archiving policy.‎

‎1. De-identified Individual Participant Data Access to the data is open to any qualified researcher who submits a valid request. ‎2. Clinical Study Report Synopsis‎ Based on the publishing journal policies

The shared data may be used for purposes of systematic review, meta-analysis, and independent validation of the original study findings. However, any re-analysis of the data intended for publication as a separate scientific article requires prior written approval from the study authors. Explicit permission is required for any use beyond these specified purposes.

1. De-identified Individual Participant Data By submitting a formal request directly to the study's corresponding author via email. 2. Clinical Study Report Synopsis Directly accessible from the official online platform of the publishing journal.

1. De-identified Individual Participant Data Upon receipt of a formal data request, approval will be sought from the funding body and the institutional research committee. Once all necessary approvals are secured, the de-identified dataset will be prepared and transferred securely to the requester. 2. Clinical Study Report Synopsis No formal request process is required for this document. The Clinical Study Report Synopsis will be made publicly available according to the publishing journal.