Dissolvable stitches, also called absorbable sutures, are medical threads used to close wounds and surgical incisions without requiring manual removal. They are constructed from materials the body can naturally break down, securely holding the wound together during the initial healing period. This technology prevents the need for a follow-up appointment solely for stitch removal. The choice of material and how quickly it dissolves is carefully matched to the type of tissue being repaired and the required healing time.
Visual Characteristics of Dissolvable Stitches
The initial appearance of dissolvable stitches can vary significantly based on the material used and whether they are synthetic polymers or natural fibers. Many synthetic types, such as those made from polyglactin, are dyed a violet or purple color for high visibility. Undyed sutures are also common, appearing clear, white, or beige, especially when used for more cosmetic closures just beneath the skin’s surface. Natural sutures, like chromic gut, often have a distinct yellow-gold or bronze hue.
Threads are either a smooth, single strand called monofilament, or a braided, multi-strand material known as polyfilament. Monofilament sutures, which resemble fine fishing line, tend to slide through tissue more easily and may cause less tissue reaction. Braided sutures offer greater knot security but have a higher surface area. Regardless of the thread type, the knots are typically tied small and tight to secure the wound edges.
External dissolvable stitches are visible on the skin’s surface, appearing as small loops or continuous running threads. Internal dissolvable sutures are placed in deeper layers of tissue, such as muscle or the fatty layer beneath the skin, and will not be seen. Surgeons use the smallest thread necessary to provide support, minimizing the physical presence of the stitch.
The Process and Timeline of Dissolution
Dissolvable stitches are designed to lose their tensile strength before they are fully absorbed. This process occurs through hydrolysis, where water molecules in the body break down the polymer chains of synthetic materials. Natural materials, like catgut, rely instead on enzymatic degradation for breakdown.
The timeline for dissolution is specific to the material, ranging from a few weeks to several months. For instance, fast-absorbing sutures used on the face or in the mouth may lose all strength within 5 to 7 days and be fully absorbed in about 42 days. Conversely, a material like polydioxanone (PDS) used for deep internal support may retain strength for over 40 days but take six months or more for total absorption.
As the stitches begin to break down, their visual characteristics change. They may lose their vibrant color, becoming dull, transparent, or hazy. You might notice the thread appearing frayed, fuzzy, or shorter at the edges as the material weakens and fragments. Occasionally, the exposed knots on the skin’s surface may dry out, becoming hard and brittle instead of dissolving cleanly.
Identifying Normal Healing Versus Complications
During normal healing, mild itching is common around the suture line as new skin forms and scabs develop. Small, loose fragments of the stitch material may fall away from the wound. The wound edges should appear closely aligned, and any initial redness and swelling should steadily decrease after the first few days.
A common occurrence is a “spitting stitch,” where the body pushes out an internal suture it perceives as a foreign body. This typically looks like a small, red, pimple-like bump forming along the incision line, often with a tiny piece of thread protruding from the center. While alarming, this usually indicates the underlying wound has healed sufficiently to expel the material.
Watch for signs of a possible complication, such as a worsening infection. Persistent or spreading redness, increased warmth, or swelling beyond the initial healing phase require medical evaluation. Signs of severe infection include fever, a foul odor emanating from the wound, or the presence of thick, yellow or green pus-like discharge.