Sutures are thread-like medical devices used to hold tissue edges together, promoting healing after injury or surgery. Whether they must be removed or disappear on their own depends entirely on the material used. Healthcare providers select the material based on the wound’s location, tissue tension, and required healing time. All sutures are categorized based on their intended lifespan, leading to two distinct groups with different post-procedure requirements.
Absorbable Versus Non-Absorbable Sutures
Absorbable sutures are designed to break down naturally within the body and do not require manual removal. These materials are primarily used for internal closures, such as repairing organs, muscle tissue, or deep layers of skin, where removal is impractical.
Non-absorbable sutures are made from durable materials that the body cannot metabolize, such as nylon, polypropylene, or silk. They are often used for superficial skin closures or in areas requiring long-term support, like high-tension joints or during certain cardiovascular procedures. Because they remain intact, non-absorbable sutures must be manually removed by a medical professional once the wound has healed sufficiently.
The Dissolution Process of Internal Stitches
Absorbable sutures degrade through specific biological processes. Synthetic absorbable materials, such as polyglycolic acid (PGA) or polylactic acid (PLA), typically break down through hydrolysis. During hydrolysis, water molecules penetrate the suture material, gradually breaking the long polymer chains into smaller, dissolvable fragments.
This process reduces the suture’s tensile strength until it can no longer hold the tissue, and the body eventually absorbs the remnants. Natural absorbable sutures, like catgut, rely instead on enzymatic degradation, where the body’s enzymes attack and metabolize the material. The total dissolution timeframe varies significantly based on the material and location, generally ranging from a few weeks to several months. For instance, certain synthetic types may lose strength within two to three weeks but may not be fully absorbed for 60 to 90 days.
Why Some Stitches Must Be Removed
Non-absorbable sutures are selected because they maintain their strength for extended periods, sometimes for 300 days or more. These materials are resistant to both hydrolysis and enzymatic breakdown, providing necessary support for tissues that heal slowly or are under constant mechanical stress. They are frequently used to close the outermost layer of skin, where they can be easily accessed.
Leaving non-absorbable sutures in the skin for too long can lead to complications, as the body treats the material as a foreign object. Prolonged presence increases the risk of infection by providing a surface for bacteria to accumulate. It also raises the chance of increased scarring, sometimes resulting in noticeable track marks. Therefore, a healthcare provider must remove these sutures, usually between 5 to 10 days after placement, to ensure optimal healing and minimal aesthetic impact.
Recognizing Signs of Wound Complication
Monitoring the wound site for signs of complication is an important part of the healing process. A healthy wound should show gradual improvement, with any initial redness or swelling subsiding over time. Signs that indicate a potential problem require immediate medical attention.
Spreading redness that radiates out from the wound, increasing pain, or a feeling of warmth at the site are common indicators of infection. The presence of thick, chunky, or foul-smelling drainage, especially if it is yellow or green, signals a potential bacterial issue. A fever or general feeling of illness, combined with local wound symptoms, may suggest a systemic infection. Another serious sign is wound separation, known as dehiscence, where the edges of the incision pull apart.