When a doctor needs to close a wound, the primary goals are to stop bleeding, prevent harmful bacteria from entering the body, and encourage the best possible healing. Achieving these outcomes requires bringing the edges of the damaged tissue together and holding them securely in place until the body’s natural repair processes take over. Modern medicine offers several highly specialized materials and techniques for wound closure. Each method is selected based on the wound’s specific characteristics and location on the body to optimize recovery.
Surgical Sutures: Material and Types
Traditional stitching, or suturing, relies on highly engineered threads to manually pull and hold tissue layers together. These threads are broadly categorized based on whether the body can naturally break them down over time. Absorbable sutures are designed for internal use or for deep tissue layers, where removing the thread would require a second procedure. These materials lose their tensile strength as they are metabolized by the body, with complete absorption times varying from a few weeks to several months depending on the specific polymer used.
Common absorbable materials include synthetic polymers such as polyglycolic acid and polyglactin 910, which provide predictable rates of strength loss and absorption. Natural absorbable materials like catgut, derived from purified animal intestines, are also available. Synthetic options are often preferred for their more consistent behavior and reduced tissue reaction. Absorbable threads provide temporary support until the wound has regained sufficient strength, eliminating the need for removal.
Non-absorbable sutures are made from materials the body cannot break down, requiring manual removal if placed on the skin surface. These threads are used for long-term tissue support in areas under constant stress, such as the heart or tendons, or for external skin closure. Materials like nylon, polypropylene, and silk are popular non-absorbable choices, valued for their long-lasting strength retention. Silk is known for its excellent handling properties and knot security, while synthetic options like polypropylene elicit less tissue reaction.
Suture threads are also classified by their physical structure as either monofilament or multifilament. Monofilament sutures consist of a single strand, allowing them to pass smoothly through tissue and reducing the potential for bacteria to track along the thread. However, this structure can result in poorer knot security, requiring extra throws to prevent unraveling. Multifilament threads are twisted or braided from multiple small strands, offering superior flexibility and knot security. Braided sutures are often coated to facilitate easier passage through tissue and counteract their rougher surface and higher risk of harboring microorganisms.
Alternative Closure Methods: Staples and Adhesives
Doctors frequently use surgical staples and tissue adhesives for specific wound closure needs. Surgical staples are specialized implants, typically made from metals such as titanium or stainless steel, that are applied with a mechanical stapling device. They are a common alternative for closing long, straight incisions, especially in non-cosmetic areas like the scalp, back, or abdomen. Staples can be placed much faster than sutures, which is a significant advantage in time-sensitive surgical or emergency situations.
The use of metal staples is associated with a low risk of infection and provides a consistent, strong closure. While most staples require manual removal with a specialized instrument after healing, there are newer bioabsorbable staples available. These are composed of polymers like polyglycolic acid and are designed to provide temporary support before being absorbed by the body, eliminating the need for a follow-up removal procedure.
Tissue adhesives offer a non-invasive method of closing superficial wounds. These liquid compounds are usually made from cyanoacrylate derivatives, which polymerize rapidly upon contact with the skin’s moisture. The glue creates a strong, flexible seal over the wound, holding the skin edges together without penetrating the tissue. This method is particularly useful for small, low-tension lacerations and for children, as it avoids the trauma of a needle and the fear associated with suture removal.
Tissue adhesives offer quick application time and the potential for a better cosmetic outcome, as the technique avoids stitch marks. The adhesive layer will slough off as the epidermis exfoliates, usually within five to ten days. However, glues are not suitable for deep or high-tension wounds. They lack the tensile strength required to hold heavily stressed tissue layers.
Determining the Right Closure Technique
The selection of a wound closure method depends on several clinical factors. The location of the injury is a primary consideration. Wounds on the face or areas where appearance is a concern often favor techniques that minimize scarring, such as tissue adhesives or fine, absorbable sutures placed beneath the skin. Conversely, the scalp is a common site for staples due to the need for rapid closure and the high strength required, as it has a thick blood supply and is often covered.
The depth and degree of tension across the wound are also key factors. Deep wounds or those under significant mechanical stress, such as over a joint, require multiple layers of closure. This often involves buried absorbable sutures to alleviate tension on the surface. In high-tension scenarios, traditional sutures or metal staples are necessary to provide the required support for deep layers to heal. Superficial wounds with minimal tension are the best candidates for quick, non-invasive options like surgical glue.
Patient-specific factors, including age, overall health, and potential for infection, also influence the choice. For patients with a high risk of poor wound healing or infection, monofilament sutures or staples may be preferred because they are less likely to harbor bacteria than braided materials. The goal is to choose the method that offers the necessary mechanical support for the expected healing time while achieving the best functional and cosmetic result for that individual.