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Laparoscopic surgical staplers: Theoretical approach, uses, technical and professional comparison

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2017

Staplers

Different tissues have different properties. Different staplers, staples and cartridges are available to adapt to the type of surgical procedure to be performed. Depending on the form of the stapler, they can be linear, curved or circular, either disposable or reusable. The staples are also made of different materials, such as titanium, which causes less immune reaction, stainless steel, or synthetic absorbable materials. Cartridges are classified by colour according to the staple characteristics.

Each stapler model has specific characteristics to adapt to specific situations:

Non-cutting linear staplers
Cutting linear
Cutting curved
Circular stapler

Each type of stapler has its own set of cartridges, where the height of the staple varies. The most important factor in staples is the height of the closed staple, because it must be able to contain the relevant tissue when closed. Each height adapts to the different tissues, such as the mesentery, which requires smaller staples, and vessels or gastrointestinal tissues, which require larger staples. The colour assigned to each staple size may vary depending on the commercial brand.

When choosing the suitable stapler, several characteristics must be kept in mind: firstly, the ability to access the target site through a trocar, articulating or rotating the shaft and correctly positioning the tissue in the jaws, is crucial. It is also important for the stapler to complete the staple line and the cut, avoiding the need for additional movements. As a direct consequence, the absence of immediate staple line leakage and bleeding should be ensured, which reduces the probability of supplementary actions.

Comparison among staplers

There are currently two main global stapler manufacturers. A graphic from a 2014 study clearly shows Covidien and Ethicon jointly held a 69.3 % share of the market.

These are the models of staplers more frequently used in laparoscopic surgery, such as bariatric, colonic or thoracic surgery.

The Echelon Flex ™ GST System provides a better grip on movement and least tissue slippage.
The Echelon Flex ™ Powered ENDOPATH ® Stapler provides battery power and more stability, leading to less potential tissue trauma.
The Endopath ® EMS Endoscopic Multifeed Stapler is intended for single use with 5.3 x 3.7 mm closed staples.
The Endo GIA ™ with Tri-Staple™ Technology makes it possible to operate on a wide range of tissues, due to its ergonomic design, precise articulation and one-hand grasp.

On the basis of the marketing studies, here is a comparison between two of the most frequently used stapler models in the market:

On one hand, the COVIDIEN Endo GIA with Tri-Staple Technology has demonstrated:

Superior staple line strength: Tri-Staple Technology provides superior staple line strength compared to other commercially available products.
It improves intra-luminal leak pressures: the Endo GIA ™ AMT purple reloads with Tri-Staple ™ were superior, with a 90% improvement with respect to other reloads.
Flexibility: it provides a 45 degree angulation in each direction
A superior relative grasping force: the Tri-Staple ™ AVM tan, AMT purple and AXT black reloads have more than twice the clamping force when compared to their respective Endo GIA ™ reloads.

On the other hand, the ETHICON Echelon flex technology has demonstrated:

Better tissue slippage: with 88% less movement at the end effector and less potential trauma to adjacent tissues.
Superior Manoeuvrability: it provides a narrower anvil, a thinner shaft, and greater articulation.
More flexibility: the Advanced Placement Tip is designed to provide an additional 10º of total articulation, providing a 100º span (50º in each direction)
Reliable staple formation: each reload is designed to handle thickness variation.

Video demonstration

To load the device, check that the load size matches the size of the instrument to be used and ensure that the staple retaining cap is present. To insert the reload, slide it against the bottom of the reload jaw until the stapler alignment tab stops in the reload alignment slot of the jaw and snap the reload securely in place. Then remove the staple retaining cap by lifting it straight up and discard. Finally, check the surface of the new reload to ensure that no colored drivers are visible and that the reload lies flat in the jaw channel.

To open and close the jaws, first close the jaws of the instrument by squeezing the handle. To open the jaws, squeeze the handle on the upper part at the back of the stapler.

To fire the device, ensure that the tissue is well positioned with no obstructions. Then fully close the handle several times, as the load is fired. Once completely fired, pull the upper shaft back, which will open the jaws. If using a roticulated stapler, ensure that the tip of the stapler is straight before taking it out through the trocar.

In powered devices, the battery pack must be installed. A click must heard. Any battery orientation is valid. To fire the device, fully press the closing trigger until it clicks and pull the red firing trigger lock back. Finally, pull the exposed trigger to fire.

Expert opinions

Additional aspects of the staplers are examined on the basis of surgeons’ views. In the case of the Covidien Tri-Staple ™, it provides a wider range of thickness coverage. Endo GIA provides articulation at a very narrow angle with a new knife each time. Also, the Endo GIA technology offers a wide range of loads (10 roticulating loads and 10 straight loads), the staple line is also better and roticulation is intuitive and easier to apply. Another advantage noticed is that COVIDIEN staplers and staples are generally more light-handed and more flexible and easier to handle than those from other companies.

The most relevant disadvantages noticed about Covidien staplers were the stamped steel that they are made of, which easily deflects especially on thick tissues. Additionally, they are sometimes harder to push.

On the other hand, ETHICON staplers seem to be better for thick tissues because of the compression key and the manipulation of the tissue before firing. The articulated tip allows more accuracy in small size structures. Also, the Ethicon stapler has a precision machined anvil providing a uniform, consistent staple line every time. Another advantage pointed out is that it is easier to use because it is not necessary to close again with the hand in order to cut.

The main disadvantage noticed was that ETHICON staplers are heavier and are not comfortable to handle.

Conclusions

To summarise, multiple staplers are available on the market. Surgeons must be aware of the different characteristics of each stapler model, each staple size and the tissue targeted in order to choose the most suitable stapler in each situation. Subjective opinions may also influence the decision on the right stapler to use.