Single-Stage Versus 2-Stage Facial Reanimation With a Free Functional Muscle Flap: Protocol for a Systematic Review

Facial paralysis is a condition that has several etiologies and is associated with significant physical and psychosocial complications. Classically, 2-stage facial reanimation was used to treat patients with unilateral facial paralysis; however, single-stage facial reanimation has seen an increase in use. Studies comparing both techniques are limited, and to the best of our knowledge, no systematic reviews have compared these techniques.

We aim to perform a systematic review that explores how the outcomes of single-stage facial reanimation with a free functional muscle flap compare against those of 2-stage facial reanimation.

This systematic review protocol has been written according to the PRISMA-P (Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols) and NICE (National Institute for Health and Care Excellence) guidelines. The search strategy will involve 3 stages: electronic databases (MEDLINE, Embase, and Web of Science Core Collection), trial registers (ClinicalTrials.gov), and snowballing. Studies published from 1995 to 2025 will be screened using inclusion and exclusion criteria. Data will be extracted into a standardized spreadsheet, and the risk of bias and quality of evidence will be assessed. Two reviewers will screen, extract, and assess the included studies. Discrepancies will be discussed and rectified with a third reviewer, if needed. A narrative synthesis of the findings will be performed and presented with descriptive and statistical analyses, where possible, using GraphPad Prism (GraphPad Software).

The review formally began in February 2025 and will be performed and reported according to this protocol and the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. A PRISMA flow diagram and checklist have been used to summarize the current search and study selection. A narrative synthesis and tables will be used to summarize the results of the included studies. Where possible, statistical analyses will be presented using graphs and figures. The final systematic review is expected to be published in December 2025.

This systematic review will aim to summarize the outcomes of the single-stage and 2-stage facial reanimation techniques and explore the differences between these surgical techniques, if any. The results will provide updated information for patients and clinicians. Moreover, the review may help identify potential areas for further research and policy development.

PROSPERO CRD42024556255; https://www.crd.york.ac.uk/PROSPERO/view/CRD42024556255.

PRR1-10.2196/64009.