Evaluation of functional and aesthetic outcomes of free dermal fat graft versus superficial musculoaponeurotic system flap after superficial parotidectomy: randomized clinical trial.

Background: Parotidectomy is the standard procedure for treatment of many parotid lesions; however, it has several drawbacks. Facial asymmetry and Frey's syndrome are the most annoying complications to patients. Insertion of interpositioning grafts into the parotidectomy bed can decrease these complications significantly. Free dermal fat graft (FDFG) and superficial musculoaponeurotic system (SMAS) flap have very promising results. This RCT aimed to compare these two techniques regarding functional and aesthetic outcomes.

Methods: Between February 2016 and October 2021, adult patients undergoing superficial conservative parotidectomy in a single centre for a benign indication were randomized into two equal groups using a closed envelope method. In one group, FDFG was inserted at the parotidectomy bed, whereas, in the other group, SMAS flap was performed. Preoperative, operative, and postoperative data were recorded and analysed. The primary outcome was the development of Frey's syndrome.

Results: Seventy-eight patients were randomized into two equal groups of 39 patients. There was no significant difference between the two groups regarding development of Frey's syndrome. There was no significant statistical difference between study groups regarding demographic data, co-morbidities, parotid pathologies, specimen volumes, total operating time, and postoperative complications. A tendency for over correction was observed in FDFG and under correction in SMAS flap. There was no statistically significant difference between the study groups regarding the patients' aesthetic satisfaction with the majority displaying excellent satisfaction with no poor results.

Conclusion: FDFG and SMAS flap are simple, rapid, and reliable procedures and are effective in improving both functional and aesthetic outcomes post-parotidectomy. They have comparable results; however, selection of either procedure can be determined according to patient and tumour characteristics. Registration number: NCT05452837 (http://www.clinicaltrials.gov).