Linear Stapling and Cutting Devices

The most commonly used linear staplers are the Gastrointestinal Anastomosis Instrument (Covidien, MA) and the Proximate (Ethicon, OH). They have two jaws that connect via a handle. A reloadable stapler cartridge is loaded into one side and the other functions as the base to create the “B” Shape. Once the jaws are closed around the bowel or other tissue, the operator then pushes a sliding mechanism down the handle to deploy the rows of staples on either side of a cutting blade that runs the length of the jaw. This then divides the tissues and staples either side. Once completed, the handle is opened and the tissue is released.

These staplers come in multiple lengths (the most frequently used sizes are 75 or 80 mm for bowel resections or anastomosis). In addition, there are different staple heights that help match the level of compression to the thickness of tissues. The three most common heights are 2.5 mm (white cartridge), 3.8 mm (blue cartridge), and 4.8 mm (green cartridge). Typically, white loads are used for transection of vascular tissue such as mesentery, blue loads are used for small bowel and colon, and green loads are used for thick tissue such as the stomach.

These same staplers come in a laparoscopic version called the Endo GIA (Covidien) or Echelon (Ethicon). They use the same principles but are delivered and fired though a laparoscopic trocar. Some models can be rotated and articulated for better positioning.

Linear Stapling Devices

The two most commonly available types are the Proximate TL stapler (Ethicon) and the Thoracoabdominal (TA) stapler (Covidien). Both of these instruments fire rows of “B” shape staples but do not cut the tissue. Division is accomplished manually, once the stapler has been fired. In abdominal applications, they are typically used to staple across the rectum deep in the pelvis or to close the common enterotomy after creation of a side-to-side anastomosis. They have a pin at the distal end of the stapler that must be engaged prior to firing and typically are on a handle set at a 90-degree angle, enabling better use in the pelvis. Typically, length of the staple lines are 30–90 mm and much like the GIA staplers have different staple heights to match the tissue thickness.

Circular Stapling Devices

Circular staplers are composed of a two-piece system to create an anastomosis (typically end to end) and cut the tissue in the same motion. They are commonly referred to as EEA staplers and come in a variety of sizes: 25, 28, 29, or 31 mm. The system consists of a stapler handle/arm and an anvil. The anvil is secured into one side of the bowel to be anastomosed and secured with a purse-string technique. The handle/arm section is then inserted into the other end and a pin is brought out that connects to the anvil. The two ends are tightened down and the stapler is fired, creating two rows of staples and cutting the tissue on the inside of the staples. The handle/arm and anvil are then removed as once piece. An example of use of this type of stapler would be for a colorectal anastomosis in which the handle/arm would be placed through the anal canal into the rectum and the anvil would be placed in the proximal colon. Typically, these instruments have an indicator to show when the appropriate amount of compression has been achieved on the tissue for creation of the staple line. Once the stapler is removed, the device will have two circular “donuts” of tissue from the anastomosis creation.

Curved Cutting Stapler Devices

The TA style stapler has been traditionally used for resection of bowel in the pelvis, but has the downside of only stapling the tissue. This creates risk when the tissue is manually transected, typically with a long scalpel blade. To better address these issues, the curved cutting stapler was developed. Commonly known as the Contour stapler (Ethicon), this device has a handle on an arm much like the TA stapler. The stapling and cutting blade are housed within a cartridge with a slight curve or bend to it to allow it to better fit in the pelvis. It has a pin at the end of the cartridge to ensure tissue does not get pushed out as the mechanism fires. Then, much like the GIA stapler, it fires multiple rows of staples on either side of a cutting blade.

New Technology

The number of new stapling devices being introduced into the market is constantly increasing. All of these products adhere to the same principles as described above and create a “B” shaped staple. Some of these products have been created to help with low stapling in the pelvis, others are using powered handles or even robotics to ensure consistency in movement of the device. New technology has costs, but also has to potential to improve outcomes and must be constantly evaluated and compared to currently used products.