Fiducial Photography Distance Determination For Obtaining The Proper Amplified Endoscopic Imaging Of Parathyroid Gland By Image1HD System

Objective To determine a proper fiducial photography distance setting for obtaining the ideal amplified endoscopic imaging of parathyroid gland by high definition endoscopy system.Methods30patients were operated with MTVAT mode (modified Miccoli’s Approach) for treatment of thyroid carcinoma from April.2013to March.2014. In the operation, high definition imaging was established by Image1Endoscopy System (Karl Storz Co.) to observe parathyroid gland and related fine anatomy.5fiducial photography distances (1.0/1.5/2.0/2.5/3.0cm) were separately tested in operations. Maximally amplified parathyroid gland images of each setting were obtained by the "approaching-amplifying photographic method", and then the size of the real parathyroid glands as well as their screen images were measured and recorded to calculate the magnification times. A proper fiducial photography distance setting was determined postoperatively by comparison of the magnification times, as well as clarity, stability of the imaging and surgical maneuverability.Results①30parathyroid glands were successfully observed and measured.(2)At the longest fiducial photography distance (3.0cm), the parathyroid gland could be stably magnified by14.39±3.02(long trail)/13.31±3.05(wide trail) times, but their contour and color not clear.③It the intermediate distance (2.5cm), the parathyroid gland could be magnified by16.56±3.09(long trail)/15.42±4.30(wide trail)times with the graphics stable, and the color and contour became clear, but the vascular pedicle and the tiny vessels under the capsule still blurred.④At the shortest distance (1.0cm), the parathyroid gland could be magnified by27.58±7.52(long trail)/26.20±8.02(wide trail) times, not only the color and contour, but also the vascular pedicle and the tiny vessels under the capsule of the gland became further clearer, unfortunately the graphics was shimmy and unstable.Conclusion①2.5cm can be a proper fiducial photography distance for searching, identifying and preserving parathyroid gland in MIVAT, while1.0cm can be a special fiducial photography distance for further confirming parathyroid gland when necessary.②Current high definition endoscopy system can be applied to identifying the parathyroid gland if fiducial photography distance were properly set and "approaching-amplifying photographic method" were used. Along with the magnification of the imaging, the features of the parathyroid gland may become clearer, including its yellow-brown color and oval contour, as well as the detail structures such as the tiny vessels under the capsule and the vascular pedicle.