A surgical stapler is a specialized medical instrument designed to quickly and reliably close large skin incisions or to resect and join internal tissues during complex operations. This device is an indispensable tool in modern surgery, offering a fast and consistent alternative to traditional hand-suturing. The stapler mechanically deploys small, surgical-grade staples to hold tissue edges together, which is beneficial in procedures involving the gastrointestinal tract, lungs, or other organs. Its role is to create a secure closure, known as an anastomosis when joining two hollow structures, that remains sealed while the body heals.
The Core Mechanism of Staple Formation
Tissue Compression and Firing
The mechanical process of surgical stapling involves three distinct, coordinated steps. The first is tissue compression, where the surgeon positions the stapler’s opposing jaws—the cartridge and the anvil—around the tissue. This applies uniform pressure, squeezing the tissue to a specific thickness necessary for proper staple formation and achieving hemostasis. The second step is firing the device, which drives staple pushers forward, advancing the U-shaped staples into the compressed tissue.
Staple Formation
The final step is staple formation, where the legs of the U-shaped staple make contact with the anvil. The anvil features small depressions that force the staples to bend inward, transforming them into a distinct “B” shape. This B-shape secures the tissue while avoiding excessive pressure at the tips, allowing blood to flow through the margin to promote healing. Many internal staplers also feature an integrated blade that simultaneously cuts the tissue between the two staggered rows of staples, allowing for resection and closure in a single action.
Categorizing Surgical Stapler Types
Linear and Circular Staplers
Surgical staplers are engineered in various configurations, tailored to specific anatomical requirements. The linear stapler applies multiple rows of staples in a straight line to close long incisions or create a partition within an organ. They are frequently used in gastrointestinal, thoracic, and bariatric surgeries for both closure and transection. The circular stapler is designed for creating an end-to-end anastomosis, most commonly in the digestive tract. These devices fire two staggered, interlocking rows of staples in a circular pattern to join two hollow structures, such as sections of the bowel.
Skin Staplers
Simpler external devices, known as skin staplers, quickly close the outer layer of a surgical incision. Unlike internal staplers that form B-shapes, skin staplers often form a rectangular shape. This shape approximates and slightly everts the skin edges for easier removal and better cosmetic results. These disposable devices prioritize speed for closing wounds on the scalp, torso, or extremities.
Why Surgeons Choose Staples Over Sutures
Surgeons choose surgical staplers over traditional hand-suturing based on efficiency and patient outcome. One significant advantage is the speed of application, which dramatically reduces the duration of a procedure, especially in lengthy operations. This rapid closure minimizes the time the patient spends under anesthesia, potentially improving overall recovery. Staplers offer a consistency in wound closure difficult to replicate with hand-sewing. The mechanical nature ensures uniform tension across the wound edge, aiding proper tissue alignment and minimizing complications like wound separation.
Furthermore, staplers provide precision in areas that are deep, hard to reach, or accessed through minimally invasive techniques like laparoscopy. The specialized design of laparoscopic staplers allows surgeons to deliver a secure, multi-row closure with controlled accuracy, effective even in high-tension areas. This uniform compression also reduces tissue trauma compared to individual stitches.
Materials Used in Surgical Staples
The material composition of surgical staples is selected to ensure biocompatibility and determine their fate within the body. For internal procedures, the non-absorbable material of choice is typically medical-grade titanium. Titanium is favored because it is strong, lightweight, and highly inert, causing minimal reaction from the immune system. These titanium staples remain permanently after healing and, being non-ferrous, do not significantly interfere with magnetic resonance imaging (MRI) scanners.
Absorbable Staples
A growing number of internal procedures utilize absorbable staples, made from synthetic polymers such as polylactide-polyglycolide copolymers. These polymer-based staples safely dissolve and are fully reabsorbed by the body over weeks or months. Absorbable staples are useful where a permanent foreign object is undesirable. Conversely, staples used for external skin closure are often made of stainless steel, a strong material easily removed once the wound has healed.