Microscopic Parotidectomy: A Prospective Study.

To assess the parameters' setting of the microscope during parotidectomy and the impact of microscopic parotidectomy on facial nerve functional status. A prospective study was conducted on 28 patients in a tertiary care center, who underwent microscopic parotidectomy. Microscope's settings' like magnification, focal length, diameter of the visualized field, and clock position were recorded. Facial nerve functional status was also recorded. All surgeries were performed by right-handed surgeons using Leica F 20 M525 microscope. Clock position of microscope for right parotidectomy ranged between 7 and 10 o clock and for left, it ranged between 7 and 12 o clock. Magnification ranged between 1.3 × and 3.2 ×; magnifications of 1.3 × and 1.8 × were preferred from incision to separation of parotid from sternocleidomastoid muscle, 1.8 × and 2 × for dissection of the facial nerve trunk, and 2 × and 3.2 × for individual branches of the facial nerve. Focal length ranged between 251 and 410 mm and the diameter of the visualized field ranged between 7 and 14.7 cm. Out of 24 cases of benign lesions, 2 (8.3%) developed facial paresis which resolved in 3 months. Two out of four cases of malignancy developed permanent palsy as nerve branches were sacrificed to achieve tumor clearance. Using a microscope for parotidectomy is advantageous for facial nerve dissection, reducing chances of facial paralysis. The microscope was also found to be useful for teaching. The use of appropriate microscopic parameters avoids the glitch of transition from open to microscopic approach.