Long-Term Results of a Pedicled and Innervated Sternocleidomastoid Muscle Flap to Immediately Reconstruct Superficial Parotidectomy Defects.

Abstract

Importance: Conventional reconstruction techniques for superficial parotidectomy have been criticized for their ability to provide long-term volumetric correction and to prevent Frey's syndrome. Objective: To demonstrate the long-term effectiveness of a pedicled and innervated sternocleidomastoid muscle flap (PISCMMF) to reconstruct superficial parotidectomy defects. Design, Setting, and Participants: This is a retrospective cohort study of patients treated by a single surgeon in a tertiary care center from July 2012 to March 2018. Seventeen of a possible 34 eligible adults having undergone reconstruction with a PISCMMF for benign parotid disease with at least 1 year of follow-up were included through convenience sampling. Patients with revision parotid surgery, malignant parotid tumors, neck dissections, or prior spinal accessory nerve dysfunction were excluded. Intervention: A PISCMMF was used to immediately reconstruct superficial parotidectomy defects. Main Outcomes and Measures: Participants underwent three-dimensional facial imaging, starch-iodine testing for Frey's syndrome, and completed a validated satisfaction questionnaire. The surface area of the positive starch-iodine tests was calculated. An average model was generated from participant images, allowing the calculation of surface millimeter differences comparing the operative with nonoperative sides. Results: Seventeen patients [7 male (41.2%), mean age 50.82 ± 12.37 years] underwent a PISCMMF to reconstruct excision (mean specimen weight = 21.45 ± 12.22 g) of benign lesions [9 pleomorphic adenomas (52.9%), 5 Warthin's tumors (29.4%), 2 cysts (11.8%), 1 chronic parotitis (5.9%)], with a mean follow-up time of 35.41 ± 12.30 months. Rates of objective and subjective Frey's syndrome were 29.4% and 11.8%, respectively. The average surface area affected was 2.32 cm2 [standard deviation (SD) = 1.95 cm2] compared with the average surface area of 16.35 cm2 (SD = 9.20 cm2) of the excised specimens. Facial symmetry analysis revealed an average millimeter difference of -1.57 ± 2.55 mm that was not significant at a threshold of 2 mm [t(16) = 0.69, p = 0.50]. No participants had postoperative shoulder or neck dysfunction. Overall satisfaction was 95.4%. Age (β = -0.51, p = 0.02) and case number (β = 0.44, p = 0.04) were significant predictors of smaller millimeter difference (R2 = 0.48, F(2,14) = 6.41, p = 0.01). The specimen mass (β = -0.05, p = 0.35) did not predict millimeter difference (R2 = 0.11, F(1,8) = 0.10, p = 0.35). Conclusions and Relevance: A PISCMMF immediately reconstructing parotidectomy defects successfully restores facial symmetry, prevents clinically significant Frey's syndrome, and results in high patient satisfaction in the long term without significant morbidity.