Lymph Nodes
The goal of this exercise is to master the precise dissection and isolation of broncho-vascular structures by removing the lymph nodes.
There are nine lymph nodes located adjacent to each of the eight broncho-vascular structures. Each lymph node requires slightly different instrument positioning to achieve optimal exposure.
Introduction
In open surgery, the most efficient way to perform precise dissection, isolate bronchovascular structures, or remove lymph nodes is by working simultaneously with two instruments, one in each hand: atraumatic forceps and a dissection tool such as scissors or an energy device.
The assistant provides the necessary exposure by retracting the lung using grasping forceps, such as a Duval grasper.
VATS vs. Open
VATS approach should follow the same fundamental principles as open surgery, with some instruments replaced by their thoracoscopic alternatives:
- Curved Suction can effectively replace the role of atraumatic Debakey forceps.
- Foester Grasper serves as a substitute for the Duval-type grasper.
This ensures precision and control while adapting the technique to VATS setting.
Exposure
Achieving optimal exposure is the first step in any dissection and must be continuously optimized as tissues are being divided and the anatomical situation evolves throughout the procedure.
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. The same principles apply as in other exercises, particularly the grasping exercise:
Location. The location of the grasper is crucial to achievening optimal exposure and must be carefully positioned on the lung, respecting all the principles of the grasping exercise
Grasper...
On the flat lung model, the optimal positions for the grasper are often located at the distal ends of the broncho-vascular structures..
Isolation of broncho-vascular structures
Proper understanding of the physical properties of tissues is essential for safely and efficiently isolating broncho-vascular structures during dissection.
Tension
When a linear continuous structure, such as the pulmonary artery, is placed under tension, it becomes taut and relatively rigid, as it cannot stretch along its longitudinal axis.
In contrast, surrounding soft tissues, such as pulmonary parenchyma or fat, can stretch in all directions and remain soft and pliable.
Dissection Plane. Tensioning the structure along its longitudinal axis thus produces a very nice dissection plane and simplifies isolation of the structure from the surrounding tissue
Bi-manual instrumentation
While the general exposure is provided by the assistant using a lung grasper, the surgeon utilizes two instruments to create the tension necessary for tissue division.
Energy devices require an adequate amount of tension on the tissue to effectively separate it. This tension is typically produced by the curved suction or an alternative instrument.
When an energy device is activated on tissue without sufficient tension, it usually only coagulates the tissue without dividing it. This can result in prolonged activation of the device, leading to overheating of the blade, which can be particularly problematic when using harmonic shears.
Curved suction
Due to its slim design and substantial curvature, the curved suction is a highly versatile instrument for manipulating tissues inside the chest.
Suction...
The suction device attaches to tissue via vacuum, while in VATS simulation, friction from the rubbery model achieves the same effect.
An added benefit of suction is its utility in managing bleeding. It can compress the bleeding site, remove blood, and speed up the process of identifying and stopping the bleeding, such as through coagulation.
Pull, not push...
The bell-shaped tip of the suction device can be used to gently pull tissue instead of pushing it, creating an opening rather than bundling the tissues together.
Lymph-node manipulation
Lymph node is a spherical structure that can only be effectively grasped with a grasper when most of its surface is fully exposed.
Attempting to grasp the top of a lymph node while the majority of its surface remains unexposed will not provide a secure grip and is likely to rupture the node.
Ruptured lymph nodes can cause significant bleeding, complicating the dissection process. This bleeding typically subsides only after the lymph node has been completely removed.
En-block resection...
En-bloc resection is the most effective method for lymph node removal, minimizing bleeding by following the avascular plane of surrounding structures.
Starting point
The optimal approach to achieving an en-bloc resection is to follow the surrounding structures, such as the pericardium, vessels, and bronchi.
An ideal starting point is where the distance to the structure is smallest, enabling the dissection to proceed smoothly along that structure.
Pericardium. A location offering the shortest route to the pericardium often serves as an excellent starting point. From there, the pericardium can be followed to identify adjacent structures.
Holes...
Safe dissection avoids deep holes, focusing on wide openings for better exposure and control.
Model-specific tips
Connections. All lymph nodes are connected on each side to tissue located behind the broncho-vascular structure, and this connection must be carefully transected before the lymph node can be removed.
Undersurface. After isolating the surrounding broncho-vascular structures, dissection can proceed beneath the lymph node along the white surface to release it and expose the aforementioned connections.
Final Step.Transecting the pulmonary parenchyma distal to the lymph node is often left as the final step in its removal.