# Impact of skin flap elevation technique on the extent of gustatory sweating after superficial parotidectomy: a comparative study

## TL;DR

This study compares two surgical techniques for parotid gland surgery and finds that one may lead to more subclinical sweating, though not more severe symptoms.

## Contribution

The study introduces new insights into how surgical techniques may influence the extent of subclinical gustatory sweating after parotidectomy.

## Key findings

- Frey syndrome incidence was similar between cold scalpel and monopolar cautery techniques.
- Monopolar cautery showed a trend toward larger areas of subclinical gustatory sweating.
- Differences in extent were observed but not statistically significant.

## Abstract

Frey syndrome is a frequent long-term complication following superficial parotidectomy, with reported prevalence varying widely according to diagnostic methods and follow-up duration. Although most studies focus on the presence of Frey syndrome, limited data are available regarding the influence of surgical technique on the extent or severity of gustatory sweating.

This single-center, prospective observational study included adult patients who underwent superficial parotidectomy for benign parotid gland lesions between March 2021 and March 2023. Frey syndrome was evaluated using the starch–iodine test performed at a median of 12 months postoperatively. Test positivity, clinical symptoms, and the area of starch–iodine test positivity (cm²) were recorded. Patients were grouped according to skin flap elevation technique (cold scalpel vs. monopolar cautery). Tumor size and postoperative outcomes were analyzed, and effect size estimates were calculated to complement statistical significance testing.

Thirty patients were included (median age: 59 years; 70% male). The starch–iodine test was positive in 13 patients (43.3%), whereas clinical Frey syndrome was observed in only 2 patients (6.7%). Test positivity rates did not differ significantly between the cold scalpel and monopolar cautery groups (35.7% vs. 50.0%, p = 0.484). Among patients with a positive test, the monopolar cautery group demonstrated a larger median area of gustatory sweating compared with the cold scalpel group (15.85 vs. 8.00 cm²), although this difference did not reach statistical significance (p = 0.284); a moderate effect size was observed.

While the incidence of Frey syndrome was similar between surgical techniques, monopolar cautery was associated with a trend toward a greater extent of gustatory sweating. Among patients with a positive starch–iodine test, differences were observed in the extent of gustatory sweating according to the skin flap elevation technique; however, these findings should be interpreted descriptively and do not imply a causal effect on disease severity. These findings suggest that the skin flap elevation technique may influence the extent of subclinical gustatory sweating, rather than the clinical incidence or severity of Frey syndrome.