Sutures, commonly known as stitches, are medical devices used to hold body tissues together after an injury or surgical procedure. They close wounds, providing support and aiding the natural healing process. Stitches help approximate wound edges, which can reduce bleeding, lower the risk of infection, and minimize scarring.
Understanding Different Stitch Materials
Not all stitches are designed to disappear on their own; understanding their composition is important for proper wound care. Surgical stitches fall into two categories: absorbable and non-absorbable. Absorbable stitches are crafted from materials the body naturally breaks down and absorbs over time. These materials can be natural, such as catgut, or synthetic polymers like polyglactin 910 (Vicryl) and polydioxanone (PDS).
Non-absorbable stitches are made from materials the body cannot metabolize, including synthetic fibers such as nylon, polypropylene (Prolene), and natural silk. Since these materials do not dissolve, non-absorbable stitches must be manually removed by a healthcare professional once the wound has healed. The choice between absorbable and non-absorbable materials depends on the wound’s location, depth, and the required duration of tissue support.
The Process of Dissolution
The dissolution of absorbable stitches is a gradual process within the body, eliminating the need for manual removal. Synthetic absorbable sutures typically break down through hydrolysis, a chemical reaction where water molecules interact with the suture material. Natural absorbable sutures, such as catgut, are broken down by enzymatic degradation, where the body’s enzymes target and fragment the material. This process aligns with the wound’s healing rate, ensuring the wound remains closed for the necessary period.
The timeframe for complete dissolution varies widely, influenced by the stitch material, size, and wound location. Some fast-absorbing gut sutures may dissolve within 5 to 7 days, while synthetic materials like polyglycolic acid can take 2 to 3 weeks. Polyglactin 910 sutures typically lose strength over a few weeks, with complete absorption occurring between 56 and 70 days. Polydioxanone sutures provide extended wound support and can take several months, sometimes up to 230 days, for full absorption.
Common Reasons for Stitches Not Dissolving
When stitches do not seem to dissolve as expected, several factors could be at play. One common reason is that the stitches might actually be non-absorbable, designed to be removed by a medical professional. This can be a source of confusion for individuals expecting their stitches to disappear naturally.
External exposure is another factor; if a portion of an absorbable stitch remains outside the skin, it may dry out and fail to dissolve properly. Localized infection at the wound site can also interfere with the normal dissolution process, as infections introduce inflammation and alter the biological environment. Stitches placed too tightly or under excessive tension can also take longer to dissolve, as increased tension impedes blood flow necessary for the body’s natural breakdown mechanisms. Individual variations in metabolism and immune response can also affect how quickly the body processes and absorbs the suture material. Sometimes, only part of the stitch may dissolve, leaving a visible remnant.
When to Seek Medical Advice
If you are concerned about your stitches, or if they do not seem to be dissolving as expected, consult a healthcare professional. Seek medical attention if you notice signs of infection around the stitch site, such as increased pain, redness, swelling, warmth, pus, or any unusual discharge from the wound.
Other concerning symptoms include fever or if the wound edges appear to be pulling apart. Stitches causing discomfort or irritation, or remaining visible long after their expected dissolution timeframe, also indicate a need for medical review. A healthcare professional can assess the type of stitches used, evaluate the wound’s healing progress, and determine if any intervention is necessary.