Resected specimen size: A reliable predictor of severe Frey syndrome after parotidectomy

Frey syndrome is a common complication after parotidectomy. This study aimed to investigate the potential predictors for developing severe Frey syndrome after parotidectomy and to identify patients who may benefit from additional preventive maneuvers.

A total of 485 patients received parotidectomy because of parotid tumors at the Otolaryngology Department of the National Cheng Kung University Hospital, from July 2009 to November 2015. Only 115 of 485 patients were included in this study and to fill in a questionnaire to determine the occurrence and severity of Frey syndrome.

A total of 115 parotidectomies were identified. 84 (73%, 84/115) patients were aware of the discomfort and were thus considered symptomatic. 39 (34%, 39/115) patients considered the symptoms apparently affected their quality of life. MSI tests showed that 56 (49%, 56/115) patients had a positive MSI test. By combining the results from symptom questionnaire and MSI test, 23 patients (20%, 23/115) had a severe form of Frey syndrome. Among all clinicopathological variables, the resected specimen size was the only significant predictor of the severe Frey syndrome group (P = 0.04). Disease pathology, tumor size, and adjuvant radiotherapy did not correlate with the severe Frey syndrome. Using receiver operating curve analysis, the best cutoff value of the resected specimen size (in largest dimension) for predicting severe Frey syndrome was 40 mm(sensitivity: 71.7%, specificity: 42.0%; area under the curve = 0.6483). The odds ratio of severe Frey syndrome with every 10 mm increase in the largest diameter of resected specimen was 1.30 (95% confidence interval, 1.01-1.68; P = 0.04).

Resected specimen size is the only significant predictor of developing severe Frey syndrome after parotidectomy. Preventive interventions may have to be considered in high-risk patients whose resected specimen size (in largest dimension) is greater than 40 mm.