The Impact of Malignant Disease on Facial Nerve Function After Parotidectomy

Abstract
Studies of immediate postoperative facial nerve function following parotidectomy focus on benign disease. The purpose of the study was to compare facial nerve function with regard to benign or malignant disease in patients undergoing superficial parotidectomy. Retrospective cohort study of consecutive patients undergoing parotidectomy between 1995 to 2002. House-Brackmann (HB) grade was recorded or assigned at the first postoperative visit. For patients with HB grade of III or greater, final resolution of facial nerve function was recorded. A chi2 analysis for independence was conducted between patients with HB grade of II or less and those with HB grade of III or greater and final pathological finding (benign vs. malignant disease). Mean and median times to resolution were determined for patients with HB grade of III or greater. Times to resolution for benign and malignant disease for those with HB grade of III or greater were compared (Kaplan-Meier method). Sixty-seven patients with benign disease and 52 with malignant disease were included. Ninety-four percent of patients with benign disease had HB grade of II or less at first postoperative visit (mean period, 11.6 d) compared with 76.9% of patients with malignant disease (mean period, 12.4 d). A chi2 analysis found this difference significant (chi2 = 7.36, P =.0067). Time to resolution for HB grade of III or greater was 253.8 days (+/-168.2 d) with median time of 229.5 days for benign disease and 182.4 days (+/-134.6 d) with median time of 138 days for malignant disease. Kaplan-Meier comparison found no significant differences in time to final resolution (P =.83). Three patients in the group with malignant disease had unresolved dysfunction (one patient for >2 y). Patients with benign disease have a greater chance of having HB grade of II or less immediately following surgery; however, whether the disease is benign or malignant, long-term final facial nerve function is the same.