How Do Skin Staples Work in Animal Surgery From Application to Healing

Skin staples have become a standard wound closure option in veterinary surgery across a wide range of procedures. Their speed of application, consistent wound edge approximation, and low infection risk at the skin surface make them a practical and well-supported alternative to sutures for many external closures. Despite their widespread use, the mechanical process by which a wound stapler achieves and maintains closure, and what happens to the tissue beneath those staples during healing, is not always well understood.

This guide explains how skin staples work from the moment of application through the full healing cycle, covering the mechanics of the device, the biology of staple-supported wound healing, and the clinical considerations that determine when and how a medical stapler should be used in veterinary practice.

 

What Skin Staples Are and What They Are Made From

 

Skin staples used in veterinary surgery are small, pre-formed metal fasteners made from surgical-grade stainless steel. Stainless steel is used because it is biocompatible, corrosion-resistant, inert under physiological conditions, and strong enough to maintain skin edge approximation throughout the healing period without deforming under normal wound tension.

Each staple is formed in a shape that allows the two legs of the staple to penetrate the skin on either side of the wound and be bent inward beneath the surface by the stapler mechanism, creating a secure grip on both wound edges simultaneously. The staple bridge, the horizontal portion spanning the wound, remains above the skin surface and is the visible element after application.

Stainless steel does not degrade in tissue, does not absorb, and does not produce biological reactions under normal conditions. Staples are designed to be removed after wound healing is complete, which for most small animal skin closures is between 10 and 14 days.

 

How a Medical Stapler Works Mechanically

 

The Components of a Disposable Skin Stapler

 

A disposable medical stapler used in veterinary surgery is a single-use device preloaded with a specific number of stainless steel staples held in a cartridge within the device body. The key functional components are the staple cartridge, the advancing mechanism, the forming anvil, and the trigger.

The staple cartridge holds the staples in sequence. The advancing mechanism moves each successive staple into the firing position after each trigger depression. The anvil is the forming surface against which the staple legs are bent into their final shape during firing. The trigger compresses the mechanism, driving the staple through the skin and forming it against the anvil in a single controlled motion.

 

The Firing Sequence

 

When the trigger is depressed, the firing mechanism drives the leading staple downward through the skin on both sides of the wound simultaneously. The two legs of the staple penetrate the skin, pass through the dermis on each side of the wound edge, and contact the anvil surface within the device. The anvil bends the legs inward to form the final staple shape, which locks the staple in the tissue and holds the wound edges in apposition.

The device then automatically advances the next staple into the firing position. Most disposable wound staplers are designed to deliver one staple per trigger depression and advance automatically, allowing consistent spacing with each application cycle. For more on the safe use of disposable skin staplers in veterinary procedures, see How to Use Disposable Skin Stapler Safely in Veterinary Practice.

 

Why Eversion of Wound Edges Matters

 

Before each staple is fired, the wound edges must be slightly everted, meaning turned upward and outward rather than flat or inverted. Eversion is critical because it ensures the dermis on both sides of the wound is in close contact under the staple bridge. When the wound edges are properly everted and the staple is fired, the bridge holds the everted edges together and the wound heals with the dermal layers in apposition.

If the wound edges are flat or inverted when the staple is applied, the bridge presses the epidermal surface down rather than holding the dermal layers in contact, and the wound may heal with surface-level apposition but inadequate deeper layer contact. This can result in slower healing and poorer cosmetic outcomes.

 

How Staples Hold the Wound During Healing

 

Mechanical Load Distribution

 

A skin staple holds the wound by distributing the mechanical load across both wound edges simultaneously. Each staple spans the wound and anchors into the dermis on both sides. Unlike sutures where each individual suture is a single point of tension, a staple distributes its load across the width of the bridge and the two anchor points of the legs. Multiple staples placed along a wound closure line create an overlapping distribution of load that resists the tendency of the wound edges to separate under tissue tension.

In a linear wound under moderate tension, evenly spaced staples provide reliable and consistent edge apposition without the localized stress concentration that can occur at individual suture knots. For high-tension wound areas, sutures may be preferable because individual suture placement can be adjusted to concentrate support exactly where it is needed.

 

Staple Spacing

 

The spacing between staples determines how consistently tension is shared along the wound line. Most disposable wound staplers are designed to fire staples at standardized intervals, typically around 4 to 6 mm apart, which suits most small animal skin closures. The veterinary team must monitor spacing and adjust the positioning of the device between firings if the wound length or tissue density requires modification from the device's default interval.

Too-wide spacing reduces the number of support points and allows the wound edges to separate between staples under tension. Too-narrow spacing creates excess tissue compression between adjacent staples. Clinical judgment on appropriate spacing is guided by animal size, skin thickness, wound location, and wound tension.

 

How Do Skin Staples Work During the Wound Healing Process

 

During the Inflammatory Phase (Days 1 to 5)

 

In the immediate post-operative period, the wound is in the inflammatory phase. Platelets aggregate, clotting occurs, and the immune response initiates at the wound site. The tissue has no native tensile strength during this period and relies entirely on the mechanical closure provided by the staples. The stainless steel staples maintain wound edge apposition throughout this phase, holding the tissue while the biological healing response establishes the early foundation of repair.

 

During the Proliferative Phase (Days 5 to 14)

 

As the proliferative phase progresses, fibroblasts produce collagen and the wound begins to develop its own structural integrity. Epithelialization occurs across the wound surface from the margins inward. Staples continue to support the closure during this phase while the tissue builds strength beneath them. By day 10 to 14 in most small animal patients, sufficient epithelialization has occurred for the staples to be removed without risking wound dehiscence.

The staples do not participate in the biological healing process. They maintain mechanical approximation while the tissue conducts its own repair beneath the staple bridge. The skin does not grow around the staple in the way that suture material can cause epithelial tracking if left too long. However, leaving staples in place significantly beyond the appropriate removal time increases the risk of tissue reaction around the staple entry points and can complicate removal.

 

During the Remodeling Phase (Weeks 2 Onward)

 

By the time staples are removed, the wound has entered the early remodeling phase. Collagen continues to mature and the tissue approaches its final tensile strength over the following weeks. At the point of staple removal, the wound is mechanically competent enough to maintain closure without external support, though full tensile strength continues to develop for weeks to months after removal.

 

 

Staple Removal: How It Works and When It Is Done

 

The Staple Remover Mechanism

 

Staple removal requires a dedicated skin staple remover rather than improvised instruments. The remover has a formed jaw that fits under the bridge of each staple and when closed bends the bridge upward into an M shape, which draws the legs outward from the skin on both sides simultaneously. This motion extracts both legs cleanly from the tissue in a single controlled motion.

Attempting to remove staples with scissors, forceps, or other improvised instruments risks tearing the staple through the skin or failing to extract one leg, leaving metal in the tissue. A proper medical stapler remover makes the process clean, fast, and minimally uncomfortable for the patient.

 

Removal Timing

 

Before removing staples, the wound should be assessed for adequate epithelialization across the full closure line, no signs of active infection, and stable wound edges on palpation. Removal should be deferred if any of these criteria are not met.

 

Clinical Applications of Skin Staplers in Veterinary Surgery

 

orthopedic Procedures

 

Skin closure following orthopedic surgery benefits significantly from stapler speed. orthopedic procedures can involve prolonged anaesthesia, and minimising closure time by using a medical staple gun for skin reduces total anaesthesia exposure. The consistent spacing provided by the wound stapler also reduces variability in closure quality between cases.

 

Large Animal Surgery

 

Equine and bovine skin closure routinely uses staplers because of the thickness of large animal skin and the impracticality of hand-sewn suture closure in field or ambulatory conditions. A wound stapler allows fast and reliable closure of long incisions in large animal patients where the scale of the wound makes suture placement time-intensive.

 

Trauma and Emergency Wound Closure

 

In emergency presentations where rapid wound closure is a priority, a medical staple gun provides faster closure than suturing without requiring the preparation and instrument handling that suture placement demands. For linear traumatic lacerations that are clean and adequately debrided, staples offer a practical and reliable closure option.

 

Routine Surgical Incisions

 

Routine abdominal and thoracic incision skin closures following soft tissue surgery can use staples for the skin layer after internal layers have been closed with appropriate suture materials. The speed of stapler application reduces skin closure time in high-volume practice settings without compromising the quality of the surface closure.

For a comparison of skin staples with sutures and tissue adhesive in wound closure decision-making, see Veterinary Guide to the Best Sutures for Skin Closure After Surgery.

 

How Skin Staples Compare to Sutures and Tissue Adhesive

 

Post-Application Care for Stapled Wounds

 

After staple application, the wound site should be kept clean and monitored daily. Animals should be prevented from licking or scratching the closure using an Elizabethan collar or recovery suit. Light dressings may be appropriate in high-movement areas or for animals likely to interfere with the wound.

Owners should be instructed to monitor for redness, swelling, discharge, or any separation of wound edges between staples, and to contact the clinic promptly if these develop. Staple removal should be scheduled at the appropriate interval based on patient category and wound location.

 

A Reliable Closure Tool in Veterinary Practice

 

Understanding how skin staples work from the mechanical firing sequence through the biological healing phases explains why they are a dependable and efficient closure option for appropriate wound types. Their speed, consistent edge approximation, and compatibility with the external wound environment make them a practical choice in high-volume and high-pressure veterinary surgical settings when applied to the right cases with correct technique.

Gexfix International Corp., in partnership with Assut Europe S.P.A., supplies high-quality disposable skin staplers and dedicated staple removers for veterinary practice, alongside a comprehensive range of wound closure solutions. With over 30 years of manufacturing expertise and ISO 13485-certified production standards, Gexfix supports veterinary practices with the reliable closure tools that consistent surgical outcomes require.

Explore the full range at medicaldevicevet.com.

 

FAQs

 

Q. How do skin staples work to hold a wound closed?

 

A. Each staple drives two legs through the skin on both sides of the wound and bends them inward, locking the wound edges in apposition. Multiple staples placed along the closure line distribute tension evenly, maintaining edge contact while tissue heals beneath the staple bridge.

 

Q. What is a medical staple gun and how does it differ from a surgical stapler?

 

A. A medical staple gun and a surgical stapler refer to the same class of device. In veterinary use, disposable skin staplers are single-use instruments preloaded with stainless steel staples that fire one staple per trigger depression and automatically advance the next staple for consistent spacing.

 

Q. When should a wound stapler be used instead of sutures?

 

A. A wound stapler suits clean, linear, moderate-tension skin closures where speed is a priority, including routine surgical incisions, orthopedic skin closure, and large animal wounds. Sutures are preferred for irregular wounds, high-tension sites requiring individual tension adjustment, and contaminated environments.

 

Q. How long do skin staples stay in after veterinary surgery?

 

A. Most small animal skin closures have staples removed between 10 and 14 days. High-tension areas and large animal closures may require 14 to 21 days. Removal timing should always be confirmed by wound assessment rather than relying on calendar days alone.

 

Q. Does staple removal hurt animals?

 

A. Staple removal with a proper dedicated remover is generally well tolerated. The remover bends the bridge upward to extract both legs simultaneously in a single motion, which is faster and less traumatic than removal with improvised instruments. Anxious patients may benefit from brief sedation or local desensitisation before removal.