Compared with total parotidectomy and complete superficial parotidectomy for the removal of a parotid pleomorphic adenoma, partial superficial parotidectomy with dissection and preservation of the facial nerve—defined as the excision of a tumor with a 2-cm margin of normal parotid parenchyma except at the point where the tumor abuts the facial nerve—is associated with a lower incidence of transient facial nerve dysfunction, facial contour disfigurement, and subsequent Frey's syndrome. The partial procedure is not associated with any increase in recurrence, and it requires less operating time. The author hypothesized that the use of this procedure to remove a benign pleomorphic adenoma might result in even less morbidity (transient or permanent facial nerve dysfunction, facial contour disfigurement, Frey's syndrome, and hypoesthesia) without increasing the risk of recurrence if only a 1-cm margin of normal parotid parenchyma was removed and if the posterior branches of the great auricular nerve were preserved. To test this hypothesis, the author conducted a retrospective study of 30 patients—15 who had undergone the standard partial procedure (2-cm margin with great auricular nerve sacrifice) and 15 who had undergone the modified version (1-cm margin with great auricular nerve preservation). After a mean follow-up of 10 years, there were no significant differences between the two groups in terms of facial nerve dysfunction, facial contour disfigurement, Frey's syndrome, and recurrence. Moreover, preservation of the posterior branches of the great auricular nerve did not prevent alterations in sensitivity (i.e., hypoesthesia) in 7 of the 15 patients (46.7%). Although a 1-cm area of normal parotid parenchyma around a benign pleomorphic adenoma was a safe margin, it was no better than a 2-cm margin in terms of morbidity and recurrence. Preservation of the posterior branches of the great auricular nerve will result in an objective reduction in hypoesthesia in approximately half of patients, but because it does not ensure freedom from sensitivity alterations in all cases, patients should be advised of the risk of postoperative numbness in the earlobe and the infraauricular area.
Minimally Invasive Surgery for Parotid Pleomorphic Adenoma
