Multi-material three dimensional printed models for simulation of bronchoscopy

Abstract

Background: Bronchoscopy involves exploration of a three-dimensional (3D) bronchial tree environment using just two-dimensional (2D) images, visual cues and haptic feedback. Sound knowledge and understanding of tracheobronchial anatomy as well as ample training experience is mandatory for technical mastery. Although simulated modalities facilitate safe training for inexperienced operators, current commercial training models are expensive or deficient in anatomical accuracy, clinical fidelity and patient representation. The advent of Three-dimensional (3D) printing technology may resolve the current limitations with commercial simulators. The purpose of this report is to develop and test the novel multi-material three-dimensional (3D) printed airway models for bronchoscopy simulation.

Methods: Using material jetting 3D printing and polymer amalgamation, human airway models were created from anonymized human thoracic computed tomography images from three patients: one normal, a second with a tumour obstructing the right main bronchus and third with a goitre causing external tracheal compression. We validated their efficacy as airway trainers by expert bronchoscopists. Recruited study participants performed bronchoscopy on the 3D printed airway models and then completed a standardized evaluation questionnaire.

Results: The models are flexible, life size, anatomically accurate and patient specific. Five expert respiratory physicians participated in validation of the airway models. All the participants agreed that the models were suitable for training bronchoscopic anatomy and access. Participants suggested further refinement of colour and texture of the internal surface of the airways. Most respondents felt that the models are suitable simulators for tracheal pathology, have a learning value and recommend it to others for use in training.

Conclusion: Using material jetting 3D printing to create patient-specific anatomical models is a promising modality of simulation training. Our results support further evaluation of the printed airway model as a bronchoscopic trainer, and suggest that pathological airways may be simulated using this technique.

Keywords: 3D printing; airway pathology; bronchial tree; bronchoscopy; multi-material; simulation.

Conflict of interest statement

All authors declare no conflict of interests.

Figures

Fig. 1

3D virtual model after reconstruction of the normal airways

Fig. 2

Standard airway trainer, comprising detachable lower airway model attached to upper airway structures. Surrounding this are a series of 3D printed models derived from CT scans as described in the Methods section

Fig. 3

Three 3D printed models are shown: a Normal tracheobronchial anatomy to the extent of the third order of bronchi (segmental bronchi), b pathologic specimen, with occluding tumour (arrow), and c pathologic specimen, with displacement of the trachea by a retrosternal goitre

Fig. 4

Bronchoscopic validation questionnaire responses in segmented bar chart

Fig. 5

Upper row: bronchoscopic view of carina showing left mainstem bronchus orifice (LMB) and right mainstem bronchus orifice (RMB), as seen from a standard airway trainer, b 3D printed normal of normal anatomy and c 3D printed model of right mainstem bronchus tumour (*). Middle row: bronchoscopic view of right mainstem bronchus, as seen from d standard airway trainer and e 3D printed model of normal anatomy, showing right middle lobe orifice (RML), right lower lobe orifice (RLL) and superior basal segment orifice (B6). The tumour model is not shown because the model was truncated after the first order of bronchi. Lower row: Bronchoscopic view of left inferior lobar bronchus, as seen from f standard airway trainer and g 3D printed normal of normal anatomy showing superior basal segment orifice (B6), medial basal segment orifice (B7), anterior basal segment orifice (B8), lateral basal segment orifice (B9) and posterior basal segment orifice (B10)