Posterior Belly of Digastric Muscle Transposition Flap in Preventing Frey's Syndrome after Superficial Parotidectomy- A Prospective Study.

Introduction: Superficial parotidectomy is an effective management for benign and malignant tumours of the superficial lobe of the parotid gland. Frey's syndrome is one of the most common complications observed after parotidectomy. The objective of our study was to find the incidence of Frey's syndrome 6 months and 1 year postoperatively after doing posterior belly of the digastric flap during superficial parotidectomy. Materials and Methods: This is an observational prospective study done in the Department of General Surgery of the Institute from November 2018 to December 2020. Thirty-eight patients with parotid swellings (both due to benign or malignant causes) were evaluated preoperatively and planned for superficial parotidectomy with a posterior belly of digastric muscle (PBDM) flap to prevent the occurrence of Frey's syndrome. They were followed up in 6 months and 1 year. Minor's test was done in each visit to look for the occurrence of Frey's syndrome. Results: Two patients (5.2%) out of 38 patients developed asymptomatic Frey's syndrome after 6 months postoperatively out of which one patient (2.6%) developed symptomatic Frey's syndrome after 9 months postoperatively with symptoms such as sweating, flushing, and redness over the parotid area during chewing. Discussion: PBDM flap following superficial parotidectomy in a single-stage surgery is an effective and easy method to prevent Frey's syndrome. This procedure is easy to perform and requires no complex dissection. There have not been many studies regarding the use of this flap; hence, this study may be considered as a pilot study.