Intraoperative computed tomography in otorhinolaryngology

• Published in: Acta oto-laryngologica 2006, Vol.126 (1), p.82-87
• Main Authors: Stieve, M., Schwab, B., Haupt, C., Bisdas, S., Heermann, R., Lenarz, TH
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Cochlear implant; Cochlear Implantation - instrumentation; Cochlear Implantation - methods; computer-assisted surgery; Equipment Design; Humans; Image Processing, Computer-Assisted; Intraoperative Care; intraoperative CT; laser surgery; Medical sciences; Orbital Fractures - diagnostic imaging; Orbital Fractures - surgery; Otorhinolaryngologic Diseases - diagnostic imaging; Otorhinolaryngologic Diseases - surgery; Otorhinolaryngologic Surgical Procedures - instrumentation; Otorhinolaryngologic Surgical Procedures - methods; Otorhinolaryngology. Stomatology; Paranasal Sinuses - diagnostic imaging; Paranasal Sinuses - surgery; Soft Tissue Neoplasms - diagnostic imaging; Soft Tissue Neoplasms - surgery; Tomography, X-Ray Computed - methods
• ISSN: 0001-6489; 1651-2251
• DOI: 10.1080/00016480510040119

Conclusions. Intraoperative CT surgery provides the surgeon with additional information about the altered surgical site in difficult anatomical situations. The skull base and lamina papyracea may be revealed by means of intraoperative CT, which may be beneficial in endonasal sinus surgery involving difficult surgical sites, although individual ethmoid cells cannot be assessed owing to blood artefacts. This provides the surgeon with valuable information that may facilitate the procedure considerably. In soft-tissue surgery it is advisable to apply a contrast agent in order to achieve good soft-tissue contrast, thus allowing the tumour to be adequately distinguished from benign tissue. The intraoperative application of CT is a fairly time-consuming procedure, partly owing to the preparation time (set-up of the appliance; 10-min warming-up phase) and partly due to the length of time required to calculate each image (15 s). Objective. CT is a well-established imaging method for the assessment of osseous and soft-tissue structures in the head and neck region. Saving information and transferring it to the intraoperative site may, however, be problematic. Computer-assisted navigation systems are now able to assist difficult surgical procedures in the field of otolaryngology. To investigate the indications for intraoperative CT, we used it in various surgical procedures in the head and neck region. Material and methods. Intraoperative CT was applied using the Tomoscan M in 46 cases in order to demonstrate the surgical benefit of the following procedures: endonasal surgical procedures on the paranasal sinuses (maxillary and ethmoidal sinusitis, anterior fracture of the sphenoidal sinus); tumour removal by means of laser surgery (carcinomas of the hypopharynx and larynx); and cochlear implantation (to verify the electrode position). After positioning the patient on the CT table, the workstation was set up in the operating theatre. If necessary, the gantry could be moved over the patient's head without repositioning the patient. Results. Intraoperative CT was used to assist in the exposure of the skull base and lamina papyracea in endonasal surgery of the paranasal sinuses. Individual ethmoidal sinuses could not be evaluated owing to blood artefacts. Intraoperative imaging proved particularly helpful in revision surgery for chronic sinusitis in cases with missing anatomical landmarks owing to previous surgeries, where there is an increased risk of inflicting damage t