It is understandable to feel concern when dissolvable stitches remain visible or palpable long after you expected them to disappear. These specialized surgical threads, also known as absorbable sutures, are designed to eliminate the need for a follow-up removal procedure by gradually being broken down and absorbed by the body. Slow dissolution is frequently a result of the complex biological and material science at play, and understanding the mechanics of how these materials vanish can clarify why your personal healing timeline might differ from general expectations.
The Science of Absorbable Sutures
Absorbable sutures are constructed from natural or synthetic polymers specifically engineered to lose strength and mass over a predictable timeframe. While older materials like catgut are derived from purified collagen, most modern absorbable stitches are synthetic, made from polymers such as polyglycolic acid (PGA), polylactic acid (PLA), or polyglactin 910 (PGLA). The true mechanism of their dissolution is a chemical process called hydrolysis, which is the breakdown of a compound due to a reaction with water.
In the body, water molecules attack the polymer chains of the suture material, slowly cleaving them into smaller, water-soluble fragments. These fragments are then metabolized and eliminated by the body, similar to other biological waste products. The rate of this hydrolysis is precisely controlled by the material’s chemical structure and density, allowing surgeons to select a suture that provides the necessary wound support for the exact duration of a tissue’s initial healing phase. This process means the stitches are systematically dismantled by a specific chemical reaction within your tissue.
Normal Dissolution Timelines and Variability Factors
The time it takes for an absorbable suture to completely disappear can range widely, from as little as ten days to as long as six months. This broad window exists because the dissolution timeline is highly dependent on the type of material used and its placement in the body. For example, a fast-absorbing suture may be fully absorbed in two to three weeks, while a long-lasting material like polydioxanone (PDS) may retain strength for several weeks and take up to 180 days to be completely absorbed.
Several factors contribute to this variability, making a generalized timeline difficult to apply to an individual. Thicker sutures (a higher gauge) take longer to dissolve than finer ones because there is more material to break down. The location of the stitch is also a major influence; sutures placed in highly vascularized areas, such as the face or mouth, tend to dissolve faster due to increased metabolic activity. Stitches placed internally or in deep tissue layers may also take longer to fully disappear than those on the skin surface, and individual patient factors, including metabolic rate, can subtly influence the speed of the absorption process.
When Slow Dissolving Stitches Signal a Problem
While slow dissolution can be normal, specific signs indicate a complication requiring medical attention. The primary concern is a surgical site infection, signaled by increasing pain, spreading redness, warmth around the wound, and the presence of purulent discharge (often yellow or green). A foul smell emanating from the wound site, or a fever, must be evaluated immediately.
Another common issue is a foreign body reaction, often described as “suture spitting,” where the body actively tries to reject the stitch material by pushing it out before it has fully dissolved. Symptoms often include a localized, small, red, or slightly swollen bump, with a tiny loop or knot of suture material visibly poking through the skin surface. Although not always an infection, this process causes localized inflammation and can become a pathway for bacteria to enter the wound.
Necessary Intervention and Safe Removal
If a lingering suture is causing discomfort, shows signs of a foreign body reaction, or remains long past the expected timeline, professional intervention is necessary. Contact the surgeon who placed the stitches or your primary care physician for an assessment. They can determine if the stitch is simply a slow-dissolving type or if a complication, such as a localized reaction, is occurring.
For exposed or “spitting” sutures, a healthcare provider can usually perform a simple, in-office procedure involving sterile scissors and tweezers to snip and gently extract the exposed portion, immediately resolving localized irritation. You must avoid attempting to pull, cut, or remove the stitches yourself at home. Self-removal can introduce bacteria, increase the risk of infection, cause the wound to reopen, or damage the underlying healing tissue, leading to worse scarring.