Background and purpose:With the development of the three-dimensional (3D) science, minimally invasive technology is going into the 3D period. While 3D laparoscope system has been widely accepted by surgeons because of its better visual effect and safer operations compared to traditional laparoscope system, this study aimed to evaluate the feasibility of 3D thoracoscope system in minimally invasive surgery for the treatment of thoracic diseases. Methods: A total of 96 cases of thoracic diseases were accomplished with KARL STORZ 3D thoracoscope during Mar. 2014 to Oct. 2014, including 33 cases of lobectomy, 2 cases of segmentectomy, and 10 cases of wedge resection of pulmonary tumor, 27 cases of mediastinal tumor, 20 cases of esophageal tumor and 4 case of esophageal achalasia. The data of operative time, bleeding volume, postoperative chest tube drainage and hospital time and postoperative complications were counted. Results: All the operations were completed successfully, without conversion to open surgery. All the operations cost 30 to 237 min. The operation of local resection lasted 30 to 120 min, with an average of 52 min, the operation of pulmonary lobectomy lasted 63 to 122 min, with an average of 75 min;the operation of mediastinal tumor resection lasted 35 to 125 min, with an average of 77 min;and the operation of esophageal diseases lasted 57 to 237 min, with an average of 189 min. The bleeding volumes were 2 to 85 mL, 15 to 72 mL, 30 to 186 mL and with the average of 50 mL, 47 mL, 118 mL in pulmonary, mediastinal and esophageal operations respectively. The time of postoperative chest tube drainage of each surgery was 1 to 5 days after pulmonary operations, 1 to 3 days after mediastinal operations, and 2 to 6 days after esophageal operations. The postoperative hospital time of pulmonary operation was 2 to 10 days, with an average of 6.3 days;the time of mediastinal operation was 3 to 6 days, with an average of 4.2 days;and the time of esophageal operation was 4 to 19 days, with an average of 13.3 days. No complications and tumor recurrence or metastasis were observed during the followed 3 months. Conclusion: 3D thoracoscope system not only preserves the minimally invasive advantage of video-assisted thoracoscopic surgery (VATS), it can also provide high-definition and stereoscopic vision and better sense of depth which facilitate the operation more precise and safer, thus operation time becomes shorter. Besides, 3D system possesses the advantage of natural vision similar to open surgery, thus it has an easier and shorter learning curve.

Objective To evaluate the accuracy of selective laser melting of cobalt-chromium(CoCr)clasps with different build angles and support densities.Methods The 3D software constructed a sample clasp(reference object)with an undercut depth of 0.50 mm,which was then imported to a metal 3D printer to form CoCr clasps at different build angles(0°,45°,and 90°)and support densities(0.50,0.70,0.90,and 1.10 mm).A model scanner was used to obtain scans of all clasps(test objects);the test objects were aligned with the reference object and test subjects were aligned with each other through a best-fit alignment method using Geomagic software to obtain root mean square error(RMSE)values for the accuracy of the clasps.The data were statistically analyzed using one-way analysis of variance or non-parametric rank sum test(α=0.05).Results In terms of trueness,the different build angle groups with support density of 0.50 mm were ranked by RMSE values as follows:90°group>0°group>45°group.For the different build angle groups with support densities of 0.70,0.90,and 1.10 mm,the RMSE values ranked as follows:45°group>90°group>0°group.In terms of precision,the different build angle groups with support density of 0.50 mm were ranked by RMSE values as follows:90°group>0°group>45°group.For support density of 0.70 mm,the ranking was 90°group>45°group>0°group,while for support densities of 0.90 and 1.10 mm,the ranking was 45°group>90°group>0°group.Conclusion The accuracy of CoCr clasps varies with the build angle and support density.However,clasps produced at a build angle of 0°and a support density of 0.90 mm exhibit higher accuracy and are recommended for use in clinical and technical laboratories.