Here, we present a protocol to navigate the bronchial maze in a structured manner, splitting the bronchoscopy into a stepwise approach-the four landmarks approach.
Flexible bronchoscopy is a technically difficult procedure and has been identified as the most important procedure that should be integrated into a simulation-based training program for pulmonologists. However, more specific guidelines that govern bronchoscopy training are needed to meet this demand. To ensure patients a competent examination, we propose a systematic, stepwise approach, splitting the procedure into four "landmarks" to support novice endoscopists navigating the bronchial maze. The procedure can be evaluated based on three established outcome measures to ensure a thorough and effective inspection of the bronchial tree: diagnostic completeness, structured progress, and procedure time.
The stepwise approach relying on the four landmarks is used at all simulation centers in Denmark and is being implemented in the Netherlands. To provide instant feedback to novice bronchoscopists when training and to relieve time constraints from consultants, we suggest that future studies should implement artificial intelligence as a feedback and certification tool when training new bronchoscopists.
Lung cancer is the leading cause of cancer mortality1. Flexible bronchoscopy is essential to navigate through the bronchial tree and identify the correct segments for the diagnosis and staging of lung cancer and allocation to the correct treatment for the patient2. Lower yields of diagnostic biopsy material, higher complication rates, and increased patient discomfort are seen in the early part of a trainee's learning curve3,4,5. To ensure independent/unsupervised practice on patients, satisfactory educational levels must be met. A training modality to ensure basic competence is simulation-based mastery learning, where the trainee practices until proficiency criteria are met6. Several tools have been developed to assess bronchoscopy performance7,8, and the following performance measures have been established: (1) diagnostic completeness (DC)-proportion of visualized segments9; (2) structured progress (SP)-number of segments visited in the correct progression order10; and (3) procedure time (PT)-time from passing through the vocal cords to the end of the procedure9.
Novice bronchoscopists can be confused by the maze, looking like similar bronchi, and several fail to complete a course in simulation-based bronchoscopy11, even though it has been identified as the most important technical procedure to learn in pulmonary medicine12. Therefore, through this protocol, we propose a stepwise, structured progression through the bronchial tree (Figure 1), relying on four landmarks as a guide. We suggest that novice operators should be taught according to this approach to ensure visualization of all the bronchial segments in a structured way, in the shortest amount of time, with correct handling of the scope.
Following Danish law, an educational study without the participation of patients does not require ethical approval.
1. Handling of the scope
2. Structured progress: angle of the scope and the four landmarks
3. Systematic bronchoscopy: the four landmarks approach
The four landmarks approach has been taught at CAMES since 2011, where the simulation-based bronchoscopy course is concluded by passing a finalizing test13. From 2015-2017, 77 participants entered the course, of which only 33 (43%) completed it11. The low completion rate was due to several factors: time constraints, the course not being mandatory, maternity leave, and no protected time to train. Of those who completed the course, 14 (42%) found the most important factor for completing the course to be: "A systematic simulation-based course is valuable" (Table 2).
Figure 1: The bronchial tree with the four landmarks. To help the operator navigate the bronchial tree, the path can be split into four landmarks: Landmark 1, the trachea; landmark 2, the right upper lobe; landmark 3, the right middle and lower lobe; and landmark 4, the left upper lobe, lingula, and left lower lobe. Please click here to view a larger version of this figure.
Figure 2: Landmark 1. Trachea with the carina. The scope should be held at a 0° angle. Please click here to view a larger version of this figure.
Figure 3: Landmark 2. Right upper lobe-the Mercedes star. The scope should be held at a 90° angle clockwise for vizualising the upper lobe. Please click here to view a larger version of this figure.
Figure 4: Landmark 3. Right middle and lower lobe. The scope should be held at a 0° angle clockwise for visualizing the middle lobe, and at a 0° angle for vizualising the lower lobe. Please click here to view a larger version of this figure.
Figure 5: Landmark 4. Left lung with left upper lobe including the lingula, and the left lower lobe. The scope should be held at a 90°, 45°, and 0° angle counter-clockwise for vizualising the upper lobe, lingula, and lower lobe respectively. Please click here to view a larger version of this figure.
Figure 6: The lungs with their segments seen laterally. Top: The left lung seen laterally with landmark 4, consisting of the upper lobe, lingula (left), and the lower lobe (right). Botton: The right lung seen laterally with landmark 1, consisting of the upper lobe (right upper corner), and landmark 2, consisting of the middle lobe (right lower corner) and the lower lobe (left). Please click here to view a larger version of this figure.
Landmarks | Angle of the bronchoscope |
Landmark 1, Trachea with Carina. | 0° angle. |
Landmark 2, Right Upper Lobe – The Mercedes Benz Sign. | 90° angle to the right. |
Landmark 3, Right middle and lower lobe. | 45° angle to the right for middle lobe and with a fully extended tip for segment 6. |
0° angle for segments 7, 8, 9 and 10. | |
Landmark 4, Left lung with left upper lobe including lingula, and left lower lobe. | 90° angle to the left for left upper lobe and lingula. |
45°angle to the left with a fully extended tip for segment 6. | |
0° angle for segments 8, 9 and 10. |
Table 1: Correspondence between the four landmarks and the angle of the bronchoscope. After accessing each lobe, defer from the designated angle to inspect the lung segments.
Most important factors | Responses (percent) |
Clinically relevant course | 17 (57%) |
High Value of a systematic simulation-based course | 14 (47%) |
Certification was needed | 3 (10%) |
Table 2: Most important factors for completion of a simulation-based course in flexible bronchoscopy. Values are presented as number (percentage). The total is greater than 100%, as some participants mentioned more than one factor. Respondents = 30.
We propose a systematic and complete inspection of the bronchial segments, splitting the bronchoscopy into four landmarks to help guide novice bronchoscopists through the bronchial maze. As more specific guidelines that govern bronchoscopy training are needed14, we propose that our systematic and stepwise approach should be evaluated using three basic outcome measures: DC, SP, and PT.
DC and PT are established outcome measures and the first used when evaluating bronchoscopy performance9. The naming of bronchial segments follows a structured sequence to match the intended progression during bronchoscopy15. However, other assessment studies have yet to evaluate the level of systematic progression, even though a systematic approach is important when performing endoscopic pulmonary procedures16. The SP score can differentiate bronchoscopy performance between novices and experts and even the performance level within the expert group10. When comparing a systematic approach to a targeted endobronchial ultrasound-guided biopsy (EBUS-TBNA), the former resulted in a higher diagnostic yield for the staging of lung cancer17. Therefore, we suggest adding SP as an outcome measure for future assessment studies and making it a focus when training novice bronchoscopists to ensure no segments are missed.
There are several other important aspects to consider when performing a bronchoscopy, such as biopsy technique, wall collisions, patient communication, sedation, etc., but these aspects do not fall within the scope of this manuscript. Our study demonstrates a basic concept that we believe should be taught as a first step in bronchoscopy education. Additionally, novice operators desire more feedback, and the lack of feedback has been identified as a key reason for not completing a bronchoscopy course11. The four landmarks are meant as a support to novice trainees, but autogenerated feedback could be desirable as a replacement for senior supervised feedback. Autogenerated assessment of scope handling has already been developed for bronchoscopy18,19, and should as well be developed for segment inspection. Feedback through electromagnetic navigation bronchoscopy enhances the amount of visualized lobes but is not able to guide and ensure that the operator visualizes all segments20. We hope that, with its rapid development and usefulness , future studies can try to develop AI that can help guide novice bronchoscopists through all the bronchial segments and provide them with instant feedback to optimize and certify their performance through bronchial identification systems.
Our approach to learning bronchoscopy has several strengths. It follows current evidence using a mastery learning approach in a simulation-based setting21, based on a four-step model22. It has been taught this way at CAMES since 201123, and it has been implemented at the other three simulation centers in Denmark. Furthermore, it is currently being implemented in the Netherlands. With this article and video, we hope to expand and generalize the initial part of learning flexible bronchoscopy based on the most current evidence.
Flexible bronchoscopy should be taught in a simulation-based setting, where the trainee is taught the basic concepts of a systematic and thorough bronchoscopy with correct handling of the bronchoscope. By splitting the procedure up into a stepwise approach consisting of four landmarks, we propose a guideline for learning bronchoscopy in a simulation-based setting.
The authors have nothing to disclose.
The authors have no acknowledgments.
Evis Exera II | Olympus | Not provided | Endoscopy Tower |
BF-Q180 Bronchoscope | Olympus | Not provided | Flexible Bronchoscope |
CLA Broncho Boy | CLA | Not provided | Bronchial Tree Phantom |