Lexington Medical designs and manufactures AEON™, an endoscopic surgical stapling system for minimally invasive surgery. This guide explains how a surgical stapler works, why components like the handle, I-beam, cartridge, anvil, knife, and staple reload matter, and how AEON™ is engineered to support consistent staple formation across tissue types.
What happens between trigger and tissue — and why every component matters for patient outcomes.
Introduction
A surgical stapler does something remarkable in a matter of seconds: it simultaneously cuts and seals tissue with a precision that directly affects hemostasis, leak prevention, and patient outcomes. Yet for most surgeons, the mechanics behind that moment — what actually happens between pulling the trigger and the staples entering tissue — remain largely invisible.
This article breaks down the anatomy of a linear cutting stapler component by component, explains the engineering decisions that determine performance in the OR, and shows why not all surgical staplers are built equally.
Most surgeons are familiar with surgical staplers and utilize them on a regular basis. They allow for quick, reliable, and safe division and sealing of a variety of tissues and organs, and they are an indispensable tool in minimally invasive surgery. While they are ubiquitous in the operating room and straightforward to use, they are actually one of the most technologically advanced devices used by surgeons, with a tremendous amount of engineering expertise involved in their design and production. They need to be able to handle tissues from blood vessels at less than 1 mm to stomach and bronchus at up to 5 mm thick. Manufacturing tolerances for the cartridges and anvils are measured in microns.
All surgeons are familiar with the fact that staple height varies, and that different tissues and organs require different staples based on their thickness. Some surgeons may have a deeper understanding of the mechanics and engineering behind these critical devices, but many surgeons don’t think much about what happens between pulling the trigger and when the staples are fired into the tissue. Like driving a car, you want your stapler to do its job without having to think about how it’s doing it.
For purposes of simplicity, this blog will focus on the most commonly used stapler, the linear cutting stapler. This is used in thoracic surgery for transecting lung and bronchus; in intestinal surgery for dividing and anastomosing small and large bowel; in bariatric and gastric surgery for dividing the stomach and small bowel and fashioning anastomoses, in gynecology for dividing the vaginal cuff, and in hepato-pancreatic-biliary surgery to divide liver and pancreas. It is also used in all these disciplines as well as urology and gynecology to divide major, named vessels and mesentery.
The Basic Anatomy of a Surgical Stapler
The basic anatomy of the surgical stapler, from proximal to distal, includes:
- Handle
- I-beam and knife (inside the shaft)
- Cartridge
- Anvil
The Handle: Closing, Firing, and Articulation
Let’s start at the handle. The handle has a trigger which serves two purposes: to close the jaws of the stapler, and to fire it. Closing the jaws should give tactile feedback to the surgeon so that they can assess the tissue thickness and make changes to the cartridge if it feels “too thick” or “too thin”. Once the jaws are closed and the decision is made to fire, it is helpful to keep the jaws clamped to compress the tissue and allow for as uniform a tissue thickness as possible. The handle also allows for articulation with a separate lever. Many staplers have a ratcheted gear with preset angles of articulation. The Lexington Medical AEON™ stapler has a smooth, non-ratcheted articulation system that allows for infinite articulation angles.
The I-Beam: The Heart of the Surgical Stapler
Firing the stapler requires pushing a pin or button to switch the trigger from a simple lever which closes the jaws, to a cam, a screw, or a rack-and-pinion type gear which converts the trigger squeeze to linear force pushing the I-beam along the shaft. The I-beam assembly is really the heart of the system: it pushes a “sled” or “wedge” which in turn pushes the staple drivers to fire the staples; it contains a knife which cuts the tissue; it locks the jaws together, so the staple line remains precise.
The I-beam needs to be rigid in the proximal-to-distal axis to provide the force to fire the staples, but the stapler needs to be flexible side-to-side to allow for articulation. The “I” shape (like an I-beam used in construction) allows it to fit into a groove on the cartridge and anvil to lock the two together. The top part of the I-beam is generally visible on the stapler cartridge which allows the surgeon to see how far it has progressed.
The Staple Cartridge: Drivers, the Wedge, and Staple Formation
Inside the staple cartridge sits the titanium staples in a “U” shape, sitting atop staple drivers. Most staplers have 6 rows of overlapping staples, and cut in between, leaving 3 rows on either side of the cut. The I-beam as it moves along the cartridge length pushes a wedge which in turn causes the staples to be pushed out of the cartridge to drive the staples through the tissue and into the anvil to form a “B” shape.
The staple drivers are generally a different color than the cartridge and can be seen at the top of the cartridge after firing so that a cartridge won’t accidentally be reused. There is also a lockout that gets engaged after firing to prevent refiring of a cartridge.
The wedge also provides a gap between the staples and the blade, so that the staples are fired before any tissue is cut. This wedge is a small but vital component of the stapler. This is why quality control is so important, and at Lexington Medical each device goes through multiple proprietary, including AI-based, QC steps.
Speaking of cutting tissue, the AEON™ stapler provides a new, clean and sharp blade with every reload, allowing for precise and predictable tissue division. Some stapler manufacturers have reloads which only include staples, and the blade is reused for each firing, which can result in a dull or damaged blade and subsequent “ragged” cuts.
The Anvil: Staple Formation and Tissue Sealing
The staples get pushed into an anvil which forms the staples into a “B” shape, sealing the tissue. The anvil seems like a simple structure, but, like the wedge, it is more complex than it looks. It must be rigid enough to tolerate the firing pressure of the staples without bending. The firing force can be hundreds of newtons.
Why the AEON Surgical Stapler Performs Differently
The ergonomics of a surgical stapler and its performance in tissue are not related to one factor, but a combination of all the above components, in addition to proper surgical judgment. At Lexington Medical, we believe our AEON™ staplers are superior and have data to prove this. Why is this the case? For a multitude of reasons:
- We obsess over the design and performance of our AEON™ stapler. Other manufacturers have not significantly changed their stapler technology in over a decade. We continuously improve our staplers based on surgeon feedback, benchtop studies, and medical literature to make the most consistent, reliable, and ergonomic stapler to provide the best outcomes for patients. Lexington has many dozens of patented technologies incorporated into its staplers.
- While some manufacturers have thousands or tens of thousands of products in their portfolios, Lexington Medical designs and manufactures one class of product: surgical staplers. The staplers are designed and manufactured in one facility in Bedford, MA, USA, and much of the manufacturing and production equipment was also designed by our engineers. This singular focus allows for extremely efficient quality control and enables us to modify the process or the stapler itself easily.
- Benchtop studies have shown that the Lexington Medical AEON™ stapler has superior performance to other manufacturers’ products in terms of proper staple formation in varying tissue thickness (see graph below).
Proper B-formation rate by tissue thickness
Testing performed with ex vivo porcine gastric tissue. Thickness measured at 8 g/mm² compression. Data on file (MC-021020).
- Clinical studies have also demonstrated superiority of the AEON™ stapler:
- A study comparing the AEON™ stapler to other staplers showed a decreased rate of fistula formation and a shorter length of stay with the AEON™ stapler (Sheen et al., 2023) [4].
Add source citation here (author, journal, year). Confirm POPF figure with Leon before external use.
POPF: postoperative pancreatic fistula, CCI, comprehensive complication index (Sheen et al., 2023)[4].
As a surgeon, you want the best possible outcomes for your patients without exception, and a state of the art, best in class surgical stapler can go a long way to achieve this.
What Surgeons Should Look for in a Better Surgical Stapler
When evaluating surgical staplers, surgeons may consider staple formation consistency, staple-line hemostasis, tissue compression, articulation control, knife sharpness, reload selection, ease of use, clinical evidence, and manufacturing quality control.
AEON™ was designed around these performance factors, including smooth articulation, a new blade with every reload, proprietary quality-control processes, and published clinical evidence evaluating hemostasis and intra-operative and post-operative outcomes and complications.
Key Takeaways
- A surgical stapler is one of the most mechanically complex devices in the OR — manufacturing tolerances on cartridges and anvils are measured in microns.
- The I-beam is the heart of the linear cutting stapler: it fires the staples, carries the blade, and locks the jaws — all in a single controlled motion.
- Staple formation pressure matters critically — too much causes tissue necrosis; too little causes leaks and bleeding.
- The wedge and anvil design are small components with outsized impact on staple formation quality and consistency across tissue types.
- The AEON™ surgical stapler is the only stapler on the market continuously iterated based on direct surgeon feedback, benchtop data, and peer-reviewed clinical evidence — with published studies demonstrating superior hemostasis and reduced complications vs. leading competitors.
Frequently Asked Questions
A surgical stapler simultaneously cuts and seals tissue using a series of titanium staples arranged in rows. When fired, an I-beam advances along the cartridge, pushing staple drivers upward, forming staples into a “B” shape against the anvil, while a blade cuts between the staple rows.
The linear cutting stapler is the most commonly used surgical stapler. It is used in thoracic surgery, bariatric surgery, intestinal surgery, gynecology, and hepato-pancreatic-biliary surgery to divide and seal tissue or create anastomoses.
The I-beam is the central mechanical component of a surgical stapler. It converts trigger force into linear motion, advances the sled that fires the staples, carries the cutting blade, and locks the cartridge and anvil together to keep the staple line precise.
Staple height determines how tightly tissue is compressed after firing. Too much compression can cause tissue necrosis and leaks; too little can result in inadequate sealing and bleeding.
Cartridge selection should match tissue thickness, which varies by anatomy and procedure.
We obsess over the design and performance of our AEON™ stapler. Other manufacturers have not significantly changed their stapler technology in over a decade.
We continuously improve our staplers based on surgeon feedback, benchtop studies, and medical literature to make the most consistent, reliable, and ergonomic stapler to provide the best outcomes for patients.
Lexington Medical, Inc. has many dozens of patented technologies incorporated into its staplers.
Staples begin in a “U” shape within the cartridge. When fired, the staple drivers push them upward and into the anvil, which has precisely shaped wells that bend the staple legs inward to form a closed “B” shape — sealing the tissue on both sides of the cut.
Surgeons evaluating surgical staplers may consider staple formation consistency, staple-line hemostasis, tissue compression, articulation control, knife sharpness, reload options, ease of use, clinical evidence, and manufacturing quality control.
References
[1] Hogan, G., et al., Comparative Analysis of Hemostasis and Staple-Line Integrity between Medtronic Tri-Staple™ with Preloaded Buttress Material and the AEON™ Stapler in Bariatric Surgery. JSLS, 2024. 28(2). https://doi.org/10.4293/JSLS.2023.00058
[2] Raftopoulos, Y., et al., Prospective Randomized Comparison of Linear Endostaplers During Laparoscopic Sleeve Gastrectomy. Obes Surg, 2022. 32(10): p. 3472–3480. https://doi.org/10.1007/s11695-022-06240-4
[3] Redmann, J.G., et al., Improving Hemostasis in Sleeve Gastrectomy With Alternative Stapler. JSLS, 2020. 24(4). https://doi.org/10.4293/jsls.2020.00073
[4] Sheen, A.J., et al., Preliminary experience in laparoscopic distal pancreatectomy using the AEON™ endovascular stapler. Front Oncol, 2023. 13: p. 1146646. https://doi.org/10.3389/fonc.2023.1146646
