Efficacy of SMAS flap technique to prevent Frey's syndrome and aesthetic outcomes. A retrospective cohort analysis.

[AIM] The aim of this retrospective cohort study was to evaluate the efficacy of Superficial Musculoaponeurotic System (SMAS) flap technique to prevent Frey's Syndrome (FS) and improve aesthetic outcomes following superficial parotidectomy.

[MATERIALS AND METHODS] A total of 140 patients were treated between January 2003 and December 2018 at the Maxillofacial Unit of Magna Graecia University of Catanzaro with Superficial Parotidectomy (SP) for benign tumor and divided in two groups: Group 1 (78 patients) underwent SMAS flap reconstruction of the parotid lodge through a modified facelift incision and Group 2 (62 patients) underwent to SP without the use of SMAS interposition through a Redon type incision.

[RESULTS] Significant statistical difference concerning FS, transient facial nerve injury, facial paralysis, salivary fistula, haematoma and skin deepness were found between Group 1 and Group 2, (0,00% vs 6,45% [p < 0,036], 2,56% vs 16,12% [p = 0,005], 0,00% vs 9,67% [p= 0,006], 1,28% vs 9,67% [p= 0,044], 1,28% vs 19,35% [p = 0,0002]) respectively. No significant statistical differences between the two groups were observed about wound infections (3,84% vs 8,06% [p= 0,466]).

[DISCUSSION] SP represents the gold standard for the surgical treatment of benign tumors of the parotid gland greater than 3,5 cm in size involving superficial portion of the gland, for the low rate of recurrences over time and lower incidence of transient or permanent facial paralysis to which this technique leads. However, SP is not free from other complications such as FS, haematoma, salivary fistula and aesthetic results like facial contour deformity due to surgical site depression and visible scar. A reconstructive technique to reduce the impact of complications after SP is the SMAS flap because its preparation is easy, contextual to the parotidectomy and increases a little the surgical time.

[CONCLUSIONS] This study highlights the advantages of SMAS flap technique in reducing complications following parotid surgery, particularly FS, and in improving the quality of life.

[KEY WORDS] Frey's Syndrome, Minor test, Parotid benign tumor, SMAS flap, Superficial parotidectomy.