BACKGROUND The reported incidence of facial weakness immediately after parotid tumor surgery ranges from 14 to 65%. The purpose of this study was to evaluate the incidence of postoperative facial weakness related to parotidectomy with use of preoperative computed tomography (CT), intraoperative facial nerve monitoring, and surgical magnification. Also, we sought to elucidate additional information about risk factors for postoperative facial weakness in parotid tumor surgery, particularly focusing on the tumor subsites. METHODS We retrospectively reviewed 794 cases with parotidectomy for benign and malignant tumors arising from the parotid gland (2009-2016). Patients with pretreatment facial palsy were excluded from the analyses. Tumor subsites were stratified based on their anatomical relations to the facial nerve as superficial, deep, or both. Multivariable logistic regression analyses were conducted to identify risk factors for postoperative facial weakness. RESULTS The overall incidences of temporary and permanent (more than 6 months) facial weakness were 9.2 and 5.2% in our series utilizing preoperative CT, intraoperative facial nerve monitoring, and surgical magnification. Multivariable analysis revealed that old age, malignancy, and recurrent tumors (revision surgery) were common independent risk factors for both temporary and permanent postoperative facial weakness. In addition, tumor subsite (tumors involving superficial and deep lobe) was associated with postoperative facial weakness, but not tumor size. Extent of surgery was strongly correlated with tumor pathology (malignant tumors) and tumor subsite (tumors involving deep lobe). CONCLUSION Aside from risk factors for facial weakness in parotid tumor surgery such as old age, malignant, or recurrent tumors, the location of tumors was found to be related to postoperative facial weakness. This study result may provide background data in a future prospective study and up-to-date information for patient counseling.

中文翻译：

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腮腺肿瘤手术后面部无力的发生率：794例腮腺切除术的肿瘤亚部位分析。

背景技术腮腺肿瘤手术后立即报告的面部无力发生率为14％至65％。这项研究的目的是通过术前计算机断层扫描（CT），术中面神经监测和手术放大倍数评估与腮腺切除术相关的术后面部无力的发生率。另外，我们试图阐明有关腮腺肿瘤手术后面部无力的危险因素的其他信息，尤其是针对肿瘤亚位点的信息。方法我们回顾性分析了794例腮腺切除术治疗因腮腺引起的良性和恶性肿瘤（2009-2016年）。患有分析性面部麻痹的患者被排除在分析之外。根据肿瘤与面部神经的解剖关系将其分为浅层，深层或两者，将其分层。进行多变量logistic回归分析以确定术后面部无力的危险因素。结果在我们的系列术前CT，术中面神经监测和手术放大倍数下，暂时性和永久性（超过6个月）面部无力的总发生率分别为9.2％和5.2％。多变量分析显示，老年，恶性肿瘤和复发性肿瘤（翻修手术）是术后临时性和永久性面部无力的常见独立危险因素。此外，肿瘤亚部位（涉及浅表和深叶的肿瘤）与术后面部无力相关，但与肿瘤大小无关。手术的程度与肿瘤病理（恶性肿瘤）和肿瘤亚部位（涉及深叶的肿瘤）密切相关。结论除了腮腺肿瘤手术中面部无力的危险因素，例如老年，恶性或复发性肿瘤外，还发现肿瘤的位置与术后面部无力有关。该研究结果可为将来的前瞻性研究提供背景数据，并为患者咨询提供最新信息。