Partial superficial parotidectomy for pleomorphic adenoma of the parotid gland: Early post-operative outcomes.

INTRODUCTION: There has been historical controversy regarding the extent of resection in the management of pleomorphic adenomas. This study aims to evaluate the extent of surgery and short-term postoperative outcomes of partial superficial parotidectomy (PSP) for the management of pleomorphic adenomas at a tertiary, high-volume center. METHODS: A retrospective chart review of patients who underwent PSP was performed. Variables included demographics, pre-operative facial nerve function, operative techniques, postoperative complications/facial nerve function, and recurrence. RESULTS: 151 adults who underwent PSP for pleomorphic adenoma from January 1st, 2000 to December 31st, 2022 were identified. Median age was 55 (IQR 40-66) years with females representing 74 % of the cohort. Median tumor size at presentation was 1.8 (IQR 1.3-2.3) cm. Baseline facial nerve function was excellent for most patients (House-Brackmann I, 99 %). Most patients underwent a superficial inferior parotidectomy (88 %). Modified Blair incision (70 %) was the most common incision. Intraoperatively, the facial nerve was identified in 149 (99 %) patients. The main trunk was identified in 126 (85 %) patients. No patient had tumor spillage. Only two patients required parotid bed reconstruction. The most common complication was ear numbness (60 %). Postoperatively, 114 patients were House-Brackmann grade I at both preoperative and postoperative assessment, 8 went from grade I to II, and 1 went from grade VI to II (Bell's palsy that resolved to grade II following surgery). Median follow-up was 1(IQR 1-5) month. CONCLUSION: PSP is efficacious in the management of pleomorphic adenomas with preservation of facial nerve function, and minimal post-operative complications. Future study is needed to assess long term recurrence risk.

Non-Nutritive Sweetened Beverages Impair Therapeutic Benefits of Metformin in Prediabetic Diet-Induced Obese Mice.

Metformin, a frontline therapy for type 2 diabetes and related metabolic diseases, results in variable outcomes. This study aimed to investigate whether sweetened beverages (caloric or non-caloric) affect the therapeutic benefits of metformin on glucose, food intake, and weight loss in diet-induced obesity. Mice were given a high-fat diet and sweetened water for 8 weeks to induce obesity and glucose intolerance. Then, mice were randomized to receive metformin in either water, high-fructose corn syrup (HFCS), or the non-nutritive sweetener saccharin for 6 weeks. After 6 weeks of metformin treatment, all groups had improved glucose tolerance compared to pretreatment. However, saccharin resulted in worse glucose tolerance and weight gain outcomes than the water or HFCS groups and correlated with lower plasma growth differentiation factor 15 levels. In conclusion, reducing non-nutritive sweetener consumption during metformin therapy is recommended to avoid impairing the therapeutic effects of metformin on body weight and glucose homeostasis.