When the body’s tissues are damaged, closing the wound is an important step in the healing process. Proper wound closure helps to reduce the risk of infection by creating a barrier against external contaminants. It also supports the body’s natural repair mechanisms, allowing tissues to mend effectively. Various methods are employed to bring wound edges together, with the choice depending on the wound’s type, size, depth, and location.
Sutures
Sutures are specialized surgical threads used to hold body tissues together after an injury or surgery. They precisely bring wound edges into close approximation, promoting proper healing.
Natural sutures include silk, a strong braided protein, and chromic gut, processed from animal intestines for absorption. While historically important, synthetic alternatives are now more common in medical practice.
Synthetic sutures offer more predictable properties and reduced tissue reaction. Common synthetic materials include nylon, a monofilament polymer that provides smooth passage through tissue and minimal reactivity. Polypropylene is another widely used synthetic monofilament, valued for its inertness and long-term tensile strength, making it suitable for applications requiring permanent support.
Some synthetic sutures, like Vicryl (polyglactin 910), are multifilament, meaning they are braided from multiple strands. This structure often provides excellent knot security and flexibility, although braided sutures can have a higher coefficient of friction, potentially causing more tissue drag. Monofilament sutures, being a single strand, glide more smoothly through tissue but may require more throws to secure a knot.
Surgical needles are integral to the suturing process, designed to carry the thread through tissues with minimal trauma. They come in various shapes, predominantly curved, to allow surgeons to maneuver them in confined spaces. Needles also vary in size and point type, such as tapered for delicate tissues or cutting for tougher skin, each tailored for different tissue depths and types to facilitate precise suture placement.
Other Common Closure Techniques
Beyond traditional sutures, other wound closure methods offer distinct advantages. Surgical staples, medical-grade metal fasteners, are applied with a specialized device. They are often used for longer incisions, like in abdominal surgery or scalp wounds, where speed and efficiency are beneficial.
Staples provide strong closure, especially in areas under tension, and reduce operating time. They are also used internally to join tissues or organs, such as in the digestive tract.
Surgical adhesives, also known as tissue glues, offer a less invasive option for superficial wounds or as an adjunct to sutures. These sterile, liquid formulations, often cyanoacrylate compounds, polymerize upon contact with the skin, forming a strong, flexible bond that holds the wound edges together. Tissue glues are frequently used for small, clean cuts on areas not subjected to high tension, such as facial lacerations.
Surgical adhesives offer quick application and typically do not require removal, as they naturally slough off. This enhances patient comfort, reduces follow-up visits, and provides a protective barrier against bacteria.
Steri-Strips, or adhesive wound closure strips, are another non-invasive option, commonly used for small, clean cuts or to provide additional support after sutures or staples have been removed. These sterile, reinforced adhesive tapes are applied across the wound, gently pulling the edges together. They are particularly useful for minimizing tension on healing wounds, which can contribute to better cosmetic outcomes.
Absorbable Versus Non-Absorbable Materials
Wound closure materials are either absorbable or non-absorbable, determining if they remain long-term or dissolve naturally. The choice depends on the tissue, required healing time, and need for long-term support.
Absorbable materials gradually break down and are safely metabolized by the body, either through hydrolysis (water breakdown) or enzymatic degradation. They are commonly used for internal stitches in deep tissue or organs, where removal would be difficult or unnecessary.
Examples of absorbable sutures include chromic gut, which is a natural material, and synthetic polymers like polyglycolic acid (PGA) or polylactic acid (PLA). The rate of absorption varies depending on the material, typically ranging from a few weeks to several months, ensuring the wound gains sufficient strength before the material disappears. This eliminates the need for a second procedure to remove the material.
Non-absorbable materials remain intact indefinitely or until surgically removed. They are chosen for long-term tissue support, like in cardiovascular repairs, or for external skin closures where easy removal is feasible. Examples include nylon, polypropylene, and surgical staples. External non-absorbable closures are typically removed by a healthcare professional once the wound has healed, offering consistent strength and reliable tissue approximation.
After Wound Closure
After wound closure, the body’s healing process begins. Stages include hemostasis (stopping bleeding), inflammation (clearing debris), proliferation (new tissue formation), and remodeling (strengthening new tissue).
For external non-absorbable closure materials like sutures or staples, removal is typically scheduled once the wound has gained enough tensile strength. The timeline for removal varies depending on the wound’s location and depth, usually ranging from 5 to 14 days, and is performed by a healthcare professional. For instance, facial stitches might be removed within 3-5 days, while those on the scalp could take 7-10 days.
Proper aftercare is important for optimizing healing and preventing complications. Keeping the wound area clean and dry is fundamental to reduce the risk of infection. Patients are often advised to avoid activities that might put tension or strain on the wound, which could lead to reopening or wider scarring.
Monitoring for infection signs like increasing redness, warmth, swelling, pus, or fever requires immediate medical attention. Early detection prevents complications. Scar formation is natural; initial red, raised scars typically flatten and fade over months.