We report a case of a salivary duct cyst that was diagnosed definitively by histopathological examination after surgery performed for a cyst of the parotid gland. A 27-year-old male patient presented to us with a one-week history of swelling and tenderness in the lower part of the left ear. On physical examination, we found an easily movable mass near the lower part of the left ear. An ultrasound and MRI examination of the neck revealed a subdermal cystic lesion in front of the parotid gland overlying the left masseter muscle. The cytologic examination findings were classified as Class II, malignancy was not admitted. We scheduled an operation for diagnosis and complete removal of the cyst. An S-shaped incision was made in front of the left ear. A subdermal cystic lesion was observed in front of the parotid gland overlying the left masseter muscle. The cyst wall was adherent, with particularly strong adhesion to the hypodermis, and because the cyst wall burst during detachment, it was removed to the extent possible. Histopathological examination revealed the diagnosis of a salivary duct cyst. After the patient had been commenced on solid food 2 days after the operation, an increase in clear fluid from the drain was observed, which was suspected to be caused by leakage of saliva. Pressure was applied with gauze to the wound site and going without food, the symptoms reduced gradually, with complete recovery achieved within 2 months. Diagnosis of salivary duct cyst before surgery is difficult, and care must be taken during the operation to avoid- salivary leakage and facial nerve paralysis. When the wall is adherent, especially if it is strongly adherent to the hypodermis, the cyst should be resected with extra care.

　Bow hunter's syndrome is characterized by temporary vertebrobasilar insufficiency caused by compression of the vertebral artery associated with neck rotations. A 50-year-old woman visited our department with the complaint of having trouble walking because of rotatory vertigo; examination revealed unidirectional nystagmus. She was suspected as having vestibular neuronitis and admitted for treatment. While hypoplasia of the vertebral artery and normal variations of the circle of Willis were confirmed at admission, they were not considered as being linked to the woman's symptoms, and she was discharged. Although examination revealed unilateral canal paresis and the patient was diagnosed as having vestibular neuronitis, 6 weeks after discharge, the patient visited our hospital again with the complaint of episodes of transitory loss of consciousness accompanying neck rotation, which confirmed the diagnosis of bow hunter's syndrome. The woman was provided with lifestyle guidance alone and was followed up. Until now, 2 years after the first onset of her symptoms, she has not experienced any further episodes of unconsciousness, despite the persistence of unilateral canal paresis. The condition that was initially regarded as vestibular neuronitis was finally diagnosed to be a vestibular disorder caused by Bow hunter's syndrome.

　Video-assisted endoscopy systems are highly useful for accurate otorhinolaryngological diagnosis and treatment. However, these are still not widely used at outpatient clinics, because of their high cost and the complexities of setting up these systems.

　Recently, a unique small digital interchangeable lens camera (Olympus Air A01) was launched for general consumers, which costs only about one-hundredth of a medical camera. It looks like a small cylinder and does not have an LCD or usual control dials and switches. Instead, it can be connected wirelessly to a smartphone/tablet PC that acts as both remote control and display.

　I assembled an Olympus Air A01 camera, tablet PC (12.9-inch iPad Pro, Apple), rigid endoscope and battery-powered LED light source (11301 D3, Karl Storz) into a compact wireless video system, which has proved useful for high-resolution live stream video viewing during examination and treatment. Furthermore, we can also record still images and videos at even higher resolutions.

　Microdebrider system and navigation system was introduced into endoscopic sinus surgery, and the accuracy and safety of operation improved by leaps and bounds. Adaptation of endoscopic surgery has expanded to a skull base disease. But if used inappropriately, useful instrument becomes a dangerous instrument. The surgeon needs surgical procedure learning, anatomical understanding, and surgical training and have to understand the characteristics of the surgical instrument and use it safely. In the future, along with the development of surgical instruments, it is also important to create environments such as maneuver training and education system. This time, I outlined the development of surgical instruments that developed and examined future prospects.

　Coblation radiofrequency has been recentry described in tonsillectomy and adenoidectomy. The instrument has suction, saline irrigation, and bipolar coagulation, and cutting capabilities all at the tip of a single instrument, allowing tissue resection and hemostasis to be achieved with a clear field of view. We have performed three cases of coblation-assisted endoscopic sinus surgery. The first case is resection of juvenile nasopharyngeal angiofibroma (JNA) tumor. The second case is resection of inverted papilloma. The third case is segmental resection of fibrous dysplasia. Coblation allowed for a controlled debulking of the tumors with less blood loss and without the need for multiple instruments. Coblation may be an effective instrument for endoscopic resection of sinus tumors.

　A 45-year-old female with severe Graves orbitopathy was treated with Orbital decompression. Half a year after the operation, she developed left Maxillary sinusitis. Medication lead to improvement, but we decided to perform endonasal endoscopic sinus surgery. It is because the ostium of the maxillary sinus is closed and there was a possibility of recurrence. Orbital decompression exposed the lamina papyracea and orbital floor, so the risk of injury to the orbit was very high. She was treated with endonasal endoscopic sinus surgery supported by Navigation system. Navigation system was very useful to prevent complications.