OBJECTIVE To study the benefits of applying digital visible models for endoscopic nasal surgery.METHODS CT data sets of 16 patients were segmented to create digital visible models by using AutoCAD(computer aided design),MOI (Moment of Inspiration) and SketchUp software package.Standard digital available data sets for clinical tasks such as surgical simulation and surgical planning.The digital visible models and the intra-and postoperative corresponding visions were compared. RESULTS The 3D structure model of nasal cavity, sinuses and their adjacent structures for endoscopic nasal surgery were successfully reconstructed.The models allowed the user to interact with the data and manipulate them(in the view of X-ray,looking around inside the model).The model can be observed during operation,provided accurate morphological data for surgery guidance plan.CONCLUSION The method creating digital visible models using AutoCAD,MOI and SketchUp software package is simple and feasible.The digital visible models are suitable for clinical use as well as for education of endoscopic nasal surgery.The benefit of this technology was confirmed by clinicians.

OBJECTIVE To know the principles of the transformations of the spatial directions in the view of the 0~ sinus endoscope and to simulate the space in endoscope using SkechUp software. METHODS The ideal model of the nasal cavity was designed and observed by the 0?rod-lens telescope. The space of the model in the endoscope was simulated using SkechUp.The principles of the transformations of the spatial directions were observed,which consisted of the lateral horizontal line (Lhn,n=0-6),the lateral vertical line (Lvn,n=0-9),the top horizontal line (Thn, n=0-9) and the lateral angle line (LAL).The location of the horizon was observed.RESULTS If the elevation angle (between the endoscope and bottom of nasal cavity) of the endoscope entering the model was unchanged and the distance of the endoscope entering the model was increased gradually,the positions of Lhn,Lvn and Thn in the visual field of the endoscope were replaced by Lh (n+1),Lv (n+1) and Th (n+1) respectively.The positions of Lhn,Lvn and Thn had repeatable characteristics.One horizontal plane in the space can become a horizon in the view and the location of the horizon in the view was invariable.If the distance of the endoscope entering the model was unchanged,the endoscope was moved to produce15?,30?,45?,60?elevation angle gradually,the positions of LAL (15?,30?,45?,60?) had the symmetry and repetition and the position of the horizon in the view was variable.CONCLUSION The directions of Lh and Lv and the locations of the horizon in the view of the 0?endoscope are correlative with the elevation angle of the endoscope,not pertinent to the distance of the endoscope coming into the nasal cavity.The directions of the space in the visual field of the endoscope have the symmetry and repeatable characteristics.Simulating the space in the visual field of the endoscope using SkechUp software provides the bases for the operation.

OBJECTIVE: To classify the external auditory canal cholesteatoma(EACC) by high-resolution temporal bone CT scans and the clinical findings of the patients, and to discuss the clinical and imaging characteristics and the surgical management of the extensive EACC. METHOD: A retrospective study was carried out among 56 patients (58 ears) with EACC and their clinical data were carefully analyzed. We classified EACC as the extensive type and the localized type. The operation strategy depended on the extent of lesion. All cases were followed up for 1 to 6 years after surgery. RESULT: There were 31 patients with localized EACC, 2 with no bone erosion and 29 (31 ears) with bone erosion within external auditory canal, and 25 patients with extensive EACC, 16 with bone erosion of intra temporal bone and 9 with bone erosion of extra temporal bone. Among all the 25 patients with the extensive type, the most common symptoms were otorrhea, otalgia and hearing loss, with 25, 23, 22 cases, respectively. The tympanic membrane (TM) was intact in 23 patients and perforated in two. The mastoid air cells in 23 patients were involved by the lesion, as well as tympanic antrum in eight, tympanic cavity in two, sigmoid sinus bony wall in five, mastoid segment of facial canal in four, and temporomandibular joint in two patients. Twenty patients underwent modified radical mastoidectomy, only one underwent reconstruction of ossicular chain, and four underwent canaloplasty. The average time of ear dry after surgery was 29 days. The postoperative hearing was improved by an average of 15 dB. No recurrence except for one patient was found during the follow-up period. CONCLUSION It was of important clinical significance to classify EACC as the extensive type and the localized type. The extensive EACC was misdiagnosed easily because of the complicated clinical manifestations. The classification was helpful for the diagnosis and the selection of surgery strategy of EACC.
Adolescent ; Adult ; Aged ; Child ; Cholesteatoma ; classification ; diagnosis ; surgery ; Ear Canal ; Female ; Humans ; Male ; Middle Aged ; Otologic Surgical Procedures ; Retrospective Studies ; Young Adult