Absorbable sutures, or stitches, are medical tools designed to temporarily hold tissue together after injury or surgery. They keep wound edges approximated, providing the necessary support until the tissue gains enough natural strength. Unlike traditional stitches that require removal, absorbable sutures are intended to naturally break down and disappear over time. When these materials remain visible or palpable longer than expected, it often concerns patients recovering at home.
Understanding the Dissolution Timeline
The process by which these medical devices disappear is not simple melting but a controlled biological event called degradation. Synthetic absorbable sutures, such as those made from polyglycolic acid (PGA) or polyglactin (PGLA), primarily dissolve through a chemical reaction known as hydrolysis. In this process, water molecules present in the body’s tissues gradually penetrate the suture material, slowly breaking down the long polymer chains into smaller, metabolizable fragments.
Natural absorbable sutures, like catgut, degrade differently through enzymatic action, where the body’s enzymes break down the collagen material. Total absorption time is highly varied, ranging from two to three weeks for rapidly dissolving materials to six months or more for long-acting types like polydioxanone (PDS). The wound site environment significantly influences the rate of breakdown; areas with higher blood flow or increased inflammation often experience faster dissolution. Patient-specific factors, including overall health, metabolism, and the presence of infection, can also alter the expected timeline.
Distinguishing Absorbable from Non-Absorbable Sutures
A primary reason for apparent non-dissolution is that the stitches were never meant to dissolve. Non-absorbable sutures, made from materials like silk, nylon, or polypropylene, remain intact indefinitely or until a healthcare provider manually removes them. These are used for external skin closures or for internal areas requiring long-term support, such as in cardiovascular procedures.
Definitive identification requires knowing the material used by the surgeon. Absorbable sutures can be clear or dyed violet, blue, or tan. However, non-absorbable sutures also come in various colors, making color unreliable for positive identification. If you are unsure, consulting your medical records or the surgical team is the only way to confirm the exact material used.
Occasionally, a small segment of an absorbable suture knot may be expelled from the wound, a phenomenon called “spitting a suture.” This occurs when the body treats the suture material as a foreign object and attempts to push it out through the skin surface. This is typically a sign of a localized inflammatory response rather than a major complication. Spitting sutures are often seen weeks or months after the initial procedure and usually resolve once the exposed fragment is removed.
Necessary Actions and When to Contact a Healthcare Provider
If a stitch appears to be lingering past its expected date, maintain good hygiene around the wound site. Gently clean the area as instructed by your surgeon and avoid pulling, picking, or manipulating the visible suture material. Allowing a few more days or weeks for the biological process to complete is often the correct course of action, especially if the wound appears to be healing well.
You must contact a healthcare provider immediately if you observe definitive signs of infection or a serious complication. These “red flags” warrant prompt medical attention:
- Increasing redness or warmth around the stitch site that spreads beyond the immediate wound edges.
- Thick or foul-smelling discharge.
- New or worsening pain, or a noticeable increase in swelling.
- A fever or general feeling of being unwell (malaise).
If the sutures are causing significant irritation, pain, or if a fragment is clearly protruding and cannot be gently wiped away, professional evaluation is necessary. In a clinical setting, a provider can assess whether the stitches are delayed, if they are non-absorbable and need removal, or if an infection is present. If delayed absorption is the only issue, the provider can simply remove the superficial, non-dissolved portion to prevent further irritation or infection.