Utility of a three-dimensional printed pelvic model for lateral pelvic lymph node dissection

Purpose In patients with advanced lower rectal cancer, the complex pelvic anatomy renders lateral pelvic lymph node dissection to be challenging. Therefore, we evaluated the utility of printing a three-dimensional (3D) pelvic model for lateral pelvic lymph node dissection. Methods We included 22 patients who underwent lateral pelvic lymph node dissection for rectal cancer between June 2017 and February 2019. Using CT scans, 3D pelvic images and models were constructed and printed, respectively. Thirty colorectal surgeons subjectively evaluated the utility of 3D pelvic models based on a 5-point Likert scale questionnaire (1 = strongly disagree, 5 = strongly agree). Results The average Likert score for the question "Would a 3D model be useful for understanding pelvic anatomy?" was 4.68. Cases with clinically diagnosed metastatic lymph nodes (4.79 +/- 0.44) scored higher than those without them (4.38 +/- 0.77, p = 0.02). For spatial comprehension of pelvic anatomy, 3D models scored higher (4.83) than 3D images (4.36, p < 0.001). The ease of use of 3D models and images was scored 4.60 and 4.20, respectively (p = 0.015). With experience, the 3D image reconstruction time decreased from 900 to 150 min. Conclusion The 3D pelvic models may be helpful for experienced surgeons to understand the pelvic anatomy in lateral pelvic lymph node dissection.