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Impact of the SMAS on Frey's syndrome after parotid surgery: a prospective, long-term study
Andrea Wille-Bischofberger1, Gunesh P Rajan, Thomas E Linder
1Zürich and Luzern, Switzerland; and Fremantle, Australia From the Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital Zürich; Otolaryngology, Head and Neck Surgery Unit, Ear Sciences Center, Lions Ear and Hearing Institute, University of Western Australia; and Department of Otorhinolaryngology, Head and Neck Surgery, Kantonsspital Luzern.
Background:
Clinical observations indicate that creation of the superficial musculoaponeurotic system (SMAS) flap during parotid surgery decreases postoperative gustatory sweating (Frey's syndrome) and improves cosmesis after surgery.
Methods:
On the basis of their previous study with 23 patients where no SMAS flap was used, the authors performed a prospective, long-term study of 6(1/2) years in 25 patients, using the SMAS flap, and compared these results with the postoperative results of their initial study. Twenty-two patients of the SMAS flap group were available for reassessment of gustatory sweating and symptoms. The Minor starch test was used to document the extent and intensity of postoperative sweating. Satisfaction with postoperative cosmetic results was assessed through a semiquantitative questionnaire as used in the previous study.
Results:
The incidence of symptomatic Frey's syndrome was significantly higher in the no-SMAS flap group after 23 months (43 percent versus 0 percent; p = 0.003). The surface extent of Frey's syndrome after 23 months was significantly reduced in the SMAS flap group (p = 0.006). At final follow-up, the incidence and extent of symptomatic Frey's syndrome showed no significant differences between the two groups (41 percent versus 56 percent; p = 0.42). The rate of satisfactory cosmetic results was significantly higher in the SMAS flap group (96 percent versus 35 percent; p < 0.05).
Conclusions:
Creation of the SMAS flap in parotid surgery for benign lesions delays the onset and reduces the intensity and extent, but does not prevent the occurrence, of Frey's syndrome. It reliably improves the cosmetic results by reducing the retromandibular depression after parotid surgery.
