OBJECTIVE: To evaluate the safety of the circular round window and discus anatomic landmarks of posterior wall of internal auditory canal by investigating the microscopic anatomy of internal auditory canal area of the retrosigmold approach, which can provide the anatomical basis for acoustic neutrinomas surgery. METHOD: Fifteen adult cadaver heads (30 sides) fixed with formalin were used in the study. The retrosigmold approach operations were imitated to dissect the blood vessels and nerves in internal auditory canal area by opening round bony window and removing posterior wall of internal auditory canal. RESULT: Fifteen specimens of 30 sides circular bone window were opened without injury with transverse sinus and sigmoid sinus. The vertical distance between the highest point of bone window margo superior and the lowest point of transverse sinus margo inferior was (4.02 ± 0.32) mm. The vertical distance from the most anterior point of bone window leading edge to the most posterior point of sigmoid sinus trailing edge was (6.31 ± 0.43) mm. The internal auditory canal tubercle located in the anterior superior position of internal auditory canal. The vertical distance from the highest point of internal auditory canal tubercle to the upper margin of internal auditory canal was (2.31 ± 0.32) mm. To expose the whole internal auditory canal, the length and width of the internal auditory canal posterior wall removal was (7.29 ± 0.32) mm, (4.12 ± 0.29) mm. Within this removal range, no case of cochlea, semicircular canal or venous was injured in 30 specimens. CONCLUSION The method of opening round window through retrosigmold approach is simple, practial and convenient. With little variation and easiness of location, the sinternal auditory canal tubercle can be used in the identification of the internal auditory canal. When exposing the whole internal auditory canal, the removal scope of the posterior wall should be paid more attention to, in order to avoid the damage of cochlea, semicircular canal and jugular bulb.
Adult ; Cranial Sinuses ; Ear Canal ; Ear, Inner ; Humans ; Round Window, Ear ; anatomy & histology ; Semicircular Canals ; anatomy & histology ; Temporal Bone

Objective To explore the efficiency of transcervical video-assisted mini-incision thyroidectomy for thyroid tumor. Methods 53 patients with thyroid tumors who underwent the video-assisted mini-incision thyroidectomy from Jan. 2006 to Dec. 2009 in the Department of Thyroid Surgery, Yantai Yuhuangding Hospital,were retrospectively studied. Results All of the patients, except 5 cases converting to open thyroidectomy, underwent the video-assisted mini-incision thyroidectomy successfully. The temporary recurrent laryngeal nerve injury occurred in 1 patients. The subcutaneous fluid accumulation occurred in 3 patients. The skin burns around the incisions occurred in 3 patients. There was no complication of hematoma, hypocalcemia, or superior laryngeal nerve injuries. The follow-up period was from 3 months to 35 months. There was no evidence of recurrence and metastasis by postoperative ultrasonic and CT scan and radioiodine scintigraphy. Conclusions The video-assisted mini-incision thyroidectomy is feasible, safe, and with the advantage of cosmetic results. For thyroid tumor,especially thyroid cancer, longer follow-up is necessary to draw definitive conclusion on recurrence and survival rate.