3D printed model of the for cardiothoracic surgery resident education Natalie S. Lui MD1, Winston Trope1, H. Henry Guo MD PhD2, Kyle Gifford2, Prasha Bhandari MPH1, Jalen Benson1, Douglas Z. Liou MD1, Leah M. Backhus MD MPH1, Mark F. Berry MD1, Joseph B. Shrager MD1 Divisions of 1Thoracic Surgery and 2Radiology, Stanford University School of Medicine, Stanford, CA Purpose Results Conclusion remains the gold standard for mediastinal There were 51 resident self assessments and 65 attending assessments completed over A novel, 3D printed model of the mediastinum was an staging, but residents are performing fewer of them with the development of two years. (Residents and attendings could complete more than one assessment). effective tool for teaching cardiothoracic surgery endobronchial ultrasound. We hypothesized that a three-dimensional (3D) General surgery, integrated cardiac residents, and traditional thoracic and cardiac track residents the anatomy and techniques for printed model of the mediastinum would be an effective tool for teaching fellows were included. mediastinoscopy, as measured by resident self assessment and attending assessment. 3D printing is a residents the anatomy and techniques for mediastinoscopy. Residents taught with the 3D model (n=22) were more likely to respond “well” or “very promising technology with many potential applications Methods well” for three of the four self assessment questions. Attendings were more likely to in cardiothoracic surgery resident education. Computed tomography images were segmented using Materialise Mimics respond “very well” to two of the assessment questions. (Figure 4) (Materialise, Leuven, Belgium), and a color model of the mediastinum was Figure 4. Resident self assessments (A) and attending assessments (B) comparing 3D printed using a Stratasys J735 (Stratasys, Eden Prairie, MN). The sternum instruction without and with the 3D model. was printed so it could be detached from the model to increase visibility of A the mediastinal structures, and a pretracheal space was created to fit a video 100 90 p=0.017 mediastinoscope (Figure 1). p=0.004 80 70 p=0.010 A B 60 50 40 30 p=0.738 20 10 Figure 2. Teaching sessions using the 3D model and the 0 How prepared were you for How well did you identify How well could you perform How well could you handle video mediastinoscope. the mediastinoscopy? normal anatomy? an uncomplicated an intraoperative med iastinoscopy? co mplication during

Percentage of responseswell" Percentage or "well" "very med iastinoscopy? innominate artery B Without 3D Model (n=29) With 3D Model (n=22) 50 45 right pulmonary 40 p=0.005 artery Figure 1. The final 3D-printed model of the mediastinum, (A) from the 35 p=0.848 30 p=0.048 anterior right side and (B) from the right side with mediastinoscope inserted. lymph 25 nodes 20 For two years, residents and attendings were asked to provide an online skills 15 assessment after every mediastinoscopy. During the second year, all 10 p=0.680 residents received standardized instruction for mediastinoscopy using the 3D 5 Figure 3. View of the carina in the 3D model using the model, and the model was available in the operating room for review of well"responsesPercentage "very 0 How prepared was the How well did the resident How well could the resident How well could the resident video mediastinoscope. (Figures 2 and 3). resident for the identify normal anatomy? perform an uncomplicated handle an intraoperative med iastinoscopy? med iastinoscopy? co mplication during Funding Resident self assessment and attending assessment scores were compared med iastinoscopy? between the residents taught with and without the 3D model. Western Thoracic Surgical Association 2019 Donald B. Without 3D Model (n=44) With 3D Model (n=21) Doty Educational Award