An 80-year-old male was referred to us with squamous cell carcinoma of the left pre-auricular area that was confirmed through incisional biopsy (). The patient was suffering from occasional bleeding, discharge, and repeated ulceration of the lesion. We performed computed tomography of the head and neck region before surgery, which showed no evidence of invasion. We performed wide excision of the tumor with a 0.5 cm lateral margin throughout. We obtained a safe margin of depth without parotid gland injury even though the tumor bed was close to the parotid gland fascia (). However, we could not completely rule out micro-injuries to the parotid gland fascia although we reserved parotid gland fascia. After wide excision, the skin defect was covered with a 5×6 cm full thickness skin graft from the left inguinal area. The usual compression dressing with a tie-over suture was applied to maintain the skin graft.\nOn the fifth postoperative day, we discovered exudate from the base of the skin graft through the slit incision site (). The dressing materials were wet and the discharge from the operative site increased during meals. The amount of discharge was approximately 50 mL, and its amylase level was 200,000 unit/L. Accordingly, we confirmed the exudate was salivary discharge and he was diagnosed with a sialo-cutaneous fistula.\nWe decided to use botulinum toxin type A injection because of concern for graft failure due to increased sialorrhea that was not controlled by conventional compression dressings. Using a tuberculin syringe, we administered a transcutaneous injection of 25 IU of the toxin at a point 0.5 cm above the site of the fistula at the surgical incision line and administered another 25 IU injection 0.5 cm anterior from that point. The injections were performed only for the superficial parotid gland in order to avoid post injection facial nerve paralysis. The discharge draining from the sialo-cutaneous fistula was considerably reduced after the second day of injection. The patient fully recovered within a week without any complications such as graft shearing or failure ().
A 79-year-old woman visited our emergency department with three stab wounds in her right preauricular area (). We found no abnormal finding during the retrograde irrigation test for Stensen duct that was performed in the ampulla. However, facial expressions such as the area around the mouth and blinking of the eyes were unnatural, so the possibility of facial nerve injury could not be ruled out. An emergency exploration was performed under general anesthesia in the operating room. To minimize additional injuries and conduct a more reliable exploration of the injured areas, the wounds were connected to expose all the injured areas. Even though more dead space was created due to this procedure, we definitely found injuries in the parotid glands and an injury at a marginal mandible branch of the facial nerve (). After neurorrhaphy for the facial nerve injury, the wound was sutured, and a closed 100-mL Jackson-Pratt drainage tube was inserted (). The injured parotid gland area was not wide in size and the tissue was soft, so it was not repaired.\nAs postoperative management, oral administration of 10 mg nortriptyline once daily for 3 weeks was started from the day of surgery to prevent secondary complication, such as infection due to persistent salivation. During treatment with nortriptyline, the patient complained of mouth dryness, which showed that the drug had an anticholinergic action. The drainage tube was removed on the 6th day after the surgery, when 5 mL per day or less drainage was collected for 3 days in a row. Due to the possibility of partial wound dehiscence, delayed stitch out was planned, and all sutures were removed on the 10th postoperative day. Complete and unremarkable wound healing was observed, and no complications were reported 7 weeks postoperatively ().