Vessels & Bronchi
The goal of this exercise is to master the technique of safely passing the endo-cutter's anvil behind the broncho-vascular structure in a consistent and reliable manner.
Every possible scenario, with all types of endo-cutters and configurations (including articulation), should be practiced and thoroughly mastered.
Introduction
The flat lung model consists of eight broncho-vascular structures grouped into three distinct lobes, resembling human anatomy and providing the standard order of division. Following a clockwise direction, the structures represent:
- Upper Lobe. Bronchus, artery and vein.
- Middle Lobe. Bronchus and vein.
- Lower Lobe. Vein, artery and bronchus.
Before starting with this exercise, all lymph nodes must be removed from the model, following the instructions in the lymph node exercise.
Planning
Similar to the endo-cutter exercise, execution of this exercise needs to be planned carefully which can be distilled into answering the following key questions:
- Ports. Which ports will be used for the retracting grasper and the endo-cutter? In a 2-port or uniportal approach, the vertical order of the instruments must also be considered.
- Rotation. How should the stapler be rotated to properly orient the anvil toward the structure while keeping the handle in a comfortable position for manipulation?
- Articulation. Is articulation necessary? If so, how much articulation is required for optimal execution?
Vertical order...
The endo-cutter is typically inserted beneath all other instruments.
Open...
Often, the easiest way to answer all of these questions is to study the situation with an open simulator.
Exposure
Achieving optimal exposure is crucial to successfully completing this exercises.
Exposure is achieved using the lung grasper by positioning it on an appropriate spot on the lung and gently pulling or pushing it in the desired direction. Same principles apply as in other exercises, particularly the lymph node exercise:
- Tension. The broncho-vascular structure should be under slight tension to provide support to the anvil when it is being passed behind it.
The Angle
The anvil must enter behind the structure on one side and exit on the opposite side. Therefore, both the entrance and exit points need to be properly exposed to ensure unobstructed passage.
- Narrow A narrow angle is a common cause of poor exposure.
- Wide A wider angle typically provides a more comfortable exposure.
This angle is not fixed but can be adjusted by retracting the lung into a different position, which often requires repositioning the retracting grasper on the lung.
By widening the angle on one side of the broncho-vascular structure, the angle on the opposite side necessarily becomes narrower. A 90° angle is often ideal for achieving the optimal balance between exposing the entrance and exit points.
Verifying the angle...
The angle and the passage should always be verified using a slightly curved dissector before introducing the endo-cutter.
Insertion technique
The endo-cutter must be introduced into the chest cavity safely to prevent disturbing other instruments or causing harm. Although the insertion is generally more complex than in the endo-cutter exercise, the same fundamental rules still apply.
It may seem obvious to direct the anvil straight to the broncho-vascular structure, but a more effective approach is to push it past the structure to the paravertebral space and then retract to guide the tip behind the structure. This method offers significant advantages:
- Balance & Relaxation. Inserting the endo-cutter deep enough allows the shaft’s weight to counterbalance the handle, reducing hand strain. This provides a more relaxed grip and a stable, stress-free starting point. Conversely, directing the anvil straight to the structure can create tension, making the task more difficult.
- Response. When the camera is centered on the broncho-vascular structure, directing the anvil straight to the structure often limits visibility to just the anvil's tip. By pushing the device beyond the structure, the entire anvil, including the articulation point, becomes visible. This improved view enhances understanding of how the device responds to hand movements, increasing control and precision.
Articulation
To guide the anvil behind the structure, a curved trajectory is required. This means the angle at which the anvil enters behind the structure differs from the angle at which it exits, which is why some endo-cutters are designed with a curved tip.
By combining articulation with rotation of the stapler, it is possible to control the anvil's direction and effectively manage a curved trajectory, even without a curved tip.
Upward-Pointing Tip. In nearly every situation, the endo-cutter should be articulated to achieve an upward-pointing tip.
Curved tip...
An endo-cutter with a curved tip requires less articulation, and excessive articulation may often lead to additional challenges.
Curved Trajectory
To achieve a curved trajectory of the anvil, an articulated endo-cutter must be rotated while being passed behind the structure. This requires a well-coordinated movement along the longitudinal axis, applying minimal force, and sufficient rotation to smoothly guide it along the curved trajectory.
This movement should be practiced repeatedly, with true mastery achieved when the anvil can be passed smoothly behind the structure without interruptions multiple times in a row.
Adjusting the Angle
Successfully exiting on the opposite side often represents the more challenging part of passing the anvil behind the structure. This difficulty is typically caused by inadequate exposure of the exit point, often due to an overly wide entrance angle that consequently narrows the exit angle.
It is often beneficial for the surgeon operating the stapler to also control retraction, allowing them to adjust the angle dynamically while passing the anvil behind the structure.