Grasping Exercise
The goal of the exercise is to grab the lung at the target spots marked around its circumference, starting at No. 1 and progressing to No. 16.
Each target must be grabbed precisely, with the grasper positioned perpendicular to the lung’s edge and aligned with its surface to ensure gentle and accurate manipulation. The right- and left hand-instruments should be used alternately.
Introduction
This exercise focuses on developing two-handed VATS instrumentation skills, teaching the simultaneous use of both hands for effective retraction, exposure, and manipulation of the lung.
Real-Life Relevance
- Gentle handling. Placing a grasper on the lung parenchyma precisely and at an optimal angle of attack is critical to avoid injury. It is particularly important in patients with fragile lungs, such as those with COPD.
- Walking the Lung Edge. Alternating graspers along the lung’s edge is a valuable technique, enabling precise and controlled access to less accessible areas of the lung and mediastinum.
- Retraction. Accurate placement of the grasper on specific lung areas enables efficient retraction.
Optimal retraction simplifies dissection and enhances the functionality of surgical devices, such as endo-cutters, by creating an ideal working space.
Grasping Technique
The properties of the lung remain the same regardless of the surgical approach; therefore, the same principles for manipulation of the lung apply regardless of whether a Duval grasper is used in open surgery or a Foerster grasper in VATS:
- Bite. Grasper bites that are too small can cause the grasper to slip off the lung or injure it by tearing out a piece of tissue.
- Alignment. Proper control of the grasper bite can only be achieved when the grasper is exactly perpendicular to the surface of the lung. Departures from the perpendicular angle result in an inneficient bite with a potential to injure the lung.
Excessive bite...
An excessive bite will immobilize a large portion of the lung, reducing its mobility and potentially complicating the subsequent step.
Grasping the edge...
The safest spot to grasp the lung is at thinner areas, such as the anterior edge. To maintain a perpendicular angle in this scenario, the grasper should be aligned parallel to both lung surfaces.
Two-Handed Operation
In VATS, the angles of the grasper are significantly restricted by the port, limiting direct access to some areas of the lung without violating the manipulation principles outlined above.
To address this problem, the lung must be actively repositioned into an optimal position to ensure valid and effective access from the port.
This is achieved by the instrument holding the lung, which must move the lung into an ideal position for the next instrument to grasp it effectively.
Beginner Struggle...
Beginners often struggle by focusing solely on the instrument intending to grasp the lung, which very often, lacks an adequate angle, making the task impossible.
Therefore, two-handed instrumentation, or the synchronized use of both hands, is essential for successfully completing the grasping exercise.
This approach allows one hand to stabilize or reposition the lung while the other hand effectively grasps or manipulates it. By working in tandem, both instruments can maintain precise control over the lung’s position, ensuring optimal angles for grasping and minimizing the risk of tissue damage.
Bi-Manual Mastery...
Mastering bi-hand coordination not only improves efficiency and accuracy but also builds the foundational skills required for more complex procedures involving delicate lung tissue.
Lung Manipulation
Lungs cannot stretch, which limits their mobility within the chest. When excessive force is applied with a retracting grasper, the lung may either slip from the jaws or have a piece of parenchyma torn away.
Therefore, at each step, it is crucial to locate a sweet spot in the chest where the edge can be optimally positioned for grasping.
Torsion is the enemy...
It is crucial to control both the three-dimensional position of the grasper tip and its rotation to avoid unnecessary torsion, which can distort the lung and create additional challenges.
The bend of a curved instrument can be very useful for achieving a perpendicular attack angle to the edge, but it is always necessary to consider how this bend might affect the next step.
Trial & Error...
When facing a problem, we should avoid using brute force to solve it. Instead, we should identify the root cause, which may stem from earlier steps, and address it directly.
Camera
The camera should closely follow retraction and manipulation movements and utilize the 30° angle rotation to enhance visibility of the right or left side, ensuring optimal perspective.
Zoom Out. A zoomed-out view is generally recommended when the surgeon is manipulating or moving the
lung.
Ensure the endoscope tip remains inside the chest cavity and is not obstructed by the rim of the wound
retractor.
Camera 1st. The surgeon should always operate in an area that allows for the simplest and safest
execution of the task.
If the camera is misaligned, correct the camera position first before continuing,
avoiding work in a suboptimal or inaccessible area of the chest.
Problem Solving Approach...
In case of any problems, it is usually best to open the simulator, perform the task using open surgery, analyze the issue and then find ways to execute it through the limited VATS port access.
Scoring and Feedback
Grasping
The lung should be grasped near or at the marked target, following these criteria:
- Target. The marked (solid black) target must be fully enclosed by the grasper’s ring. If the target is hidden on the lung’s far side, the grasper should be positioned as close to the target as possible.
- Bite. At least half of the grasper’s ring should be on the lung. The bite must not extend beyond the ring; oversized bites will only earn ½ point.
- Perpendicular. The grasper must be perfectly perpendicular to the edge of the lung.
- Parallel. The grasper’s direction must be perfectly aligned with the surface of the lung at the grasping spot.
Camera
- Horizon. The camera horizon must be leveled within a tolerance of ±10°.
- Target. The camera must target the grasper ring, which must lie within the outer target scoring area.
Penalties
The following errors during the grasping process result in penalties:
- Missed Target. A 20% penalty is applied if the target is visible but not fully enclosed by the grasper's ring.
- Illegal grasper. A 10% penalty is applied if an instrument other than a lung grasper is used at any point.
- Twisted lung. A 20% penalty is applied if the lung surface is unnecessarily or excessively twisted.
- Dropped edge. A 50% penalty is applied if the lung edge is dropped between steps.
- Not scorable. The edge and the grasper must be clearly visualized for scoring. If not, the action is not scorable.
- Injury. Any major injury to the lung results in an immediate game over.