Role of Methylene Blue in Parotid Surgery

usefulness of the methylene blue staining for identification of facial nerve in parotid gland surgery

The specific surgical morbidity remains significant in parotid gland surgery. In addition to temporary facial weakness and permanent facial nerve injury, postparotidectomy depression and Frey's syndrome (gustatory sweating) are specific for this type of surgery. To reduce the surgical morbidity, several modifications of parotidectomy have been implemented but postsurgical complications remain especially facial nerve injury . To overcome this difficulty, an identification method might be used such as preoperative intravital staining of the gland with methylene blue (MB). Although MB staining is not designed to be used as a sole technique, it can be combined with other techniques such as identification of the anatomic landmarks. MB staining is simple, inexpensive, and not time consuming technique.It is an indirect facial nerve identification technique, because there is no nerve handling,thus decreasing iatrogenic nerve impairment.After injection of the parotid gland with MB dye, fine white nerve fibers can be observed . Tumors in the parotid gland are also easily seen because they are not stained and will be visible in the surgical field.

For MB group, the staining of the glandular tissue will be obtained with 3-4 mL of 1% MB that will be introduced into the gland via the salivary duct several minutes before the surgery.The trans-oral catheterization of the Stensen's duct will be performed and the solution will be injected via intravenous cannula.The glandular tissue will turn dark blue.

Number of cases that don't develop post surgical parotidectomy facial nerve weakness after using preoperative intravital staining of the gland with methylene blue dye.

Twenty cases presented to outpatient clinic in Assiut university hospital with benign or primary malignant parotid gland tumors will be included in the study, clinically evaluated, confirmation of diagnosis will be achieved by CT, MRI, or CT/MRI investigations , ultrasonography and fine-needle aspiration biopsy (FNAB). then Divide the selected cases into two groups randomly; group A for surgeries with MB staining and group B for surgeries without MB staining that serves as control group. type of surgery will be chosen according to CT or MRI data and fine-needle aspiration biopsy (FNAB)then Follow up facial nerve injury manifestations for the included cases for one year for comparison between 2 groups

Inclusion Criteria: All new cases presented with primary benign or malignant parotid tumors. Exclusion Criteria: Cases with secondary tumors of the gland