Dissolvable stitches are designed to be absorbed by the body over time, eliminating the need for removal appointments. However, they sometimes remain visible or take longer to vanish than expected. This article explains how these stitches work and the reasons they might not dissolve on schedule.
How Dissolvable Stitches Work
Dissolvable stitches, also known as absorbable sutures, are crafted from materials the body can naturally break down and absorb. Common synthetic polymers include polyglactin 910 (Vicryl), polyglycolic acid (PGA), and polydioxanone (PDS). Natural absorbable sutures, such as those made from purified collagen (catgut), are also utilized.
The primary method these stitches dissolve is hydrolysis, where water molecules gradually break down the polymer chains of the suture material. Some natural sutures, like catgut, may also involve enzymatic degradation. The rate of dissolution depends on the specific material, with some designed to maintain tensile strength for weeks before dissolving completely over several months. For instance, polyglactin 910 typically loses strength in 2-3 weeks and is fully absorbed in 56-70 days, while polydioxanone can retain strength for 6 weeks and be fully absorbed over 180-240 days.
Reasons for Delayed Dissolution
The type of suture material plays a significant role in how quickly a stitch dissolves. For example, a polydioxanone suture used for deeper tissue layers will remain present for several months, while a polyglycolic acid stitch might be absorbed more rapidly within a few weeks.
The location of the stitch and the tension on the wound can also influence the dissolution rate. Areas of the body that experience more movement or are under constant tension may affect how the suture integrates and breaks down. An individual’s biological healing rate can vary, impacting how their body metabolizes and absorbs the suture material.
Stitches placed superficially on the skin, rather than buried beneath it, are often a common reason for non-dissolution. These external sutures, while sometimes made of absorbable materials, are exposed to air and external elements, which can hinder the dissolution process. They may remain visible and often need to be trimmed or removed by a healthcare professional once the wound has healed.
Inflammation or an infection at the wound site can interfere with the breakdown of absorbable sutures. The body’s immune response to infection can alter the local environment, potentially slowing or disrupting dissolution. Suture extrusion or “spitting” can also occur, where the body perceives the stitch as a foreign object and attempts to expel it. This makes a stitch appear not to dissolve, as a portion emerges from the skin.
What to Do About Non-Dissolving Stitches
If dissolvable stitches appear to be taking longer than expected to vanish, patience is often the initial approach, as some materials are designed for extended absorption periods. Continue to keep the wound area clean and dry, following any post-operative care instructions provided by your healthcare provider. Gentle cleaning can help prevent complications and support the natural healing process.
It is advisable to contact a healthcare professional if you notice signs or experience discomfort related to the stitches. Seek medical attention if there are signs of infection, such as increasing redness, swelling, warmth, pus, or worsening pain around the wound. A fever can also indicate an infection requiring prompt evaluation.
Consult a doctor if the stitches are causing persistent discomfort, itching, or irritation, or if they appear to be interfering with movement or function. Any unusual or concerning changes around the wound site, or if the stitches are clearly not dissolving after a prolonged period significantly beyond the typical expected timeframe for that specific suture type, warrant professional assessment. It is important to avoid attempting to pull out or cut the stitches yourself, as this can introduce infection or cause further injury to the healing wound.