The use of 3D printing model as tool for planning endoscopic treatment of benign airway stenosis

Benign tracheal stenosis is a life-threatening condition that needs a prompt treatment when the tracheal lumen is less than 5 mm. In patients unfit for surgery, endoscopic dilation with stent insertion (if indicated) remains the main alternative to restore airway patency and assure ventilation. Endoscopic management of tracheal stenosis may be a cumbersome procedure, that sometimes takes a long time, and may be complicated by stent dislocation especially in cases of complex stenosis, near to vocal folds. In recent years, the 3D printing industry has undergone rapid development, and 3D printing model has been increasingly applied to different medical fields where therapeutic interventions rely on defining complex anatomic structural relationships. Thus, in this review we aimed to evaluate whether the use of 3D printing model as tool for preoperative planning could facilitate the endoscopic treatment of tracheal stenosis and improve outcome. Three papers evaluated this issue: one paper reported a consecutive series of patients while the remaining single case report. All authors concluded that the 3D model aided the understanding of patient's anatomy and the stenosis's characteristic. The possibility of recreating the endoscopic procedure in the 3D model facilitated and shorted the procedural time in live patient. Furthermore, the 3D model was additionally useful to choose the length, diameter and shape of stent and to define the exact distance of the proximal end of stent from the vocal folds after its insertion. Finally, it represented an educational tool for patients and his/her family to understand the procedure, and for residents and fellows to improve endoscopic skills.