The Core Difference: Dissolvable vs. Non-Dissolvable
When a healthcare provider closes a wound, they will choose one of two main types of sutures: absorbable or non-absorbable. The choice depends on the wound's characteristics, location, and the required healing time. Understanding these fundamental differences is key to knowing what to expect during your recovery.
How Dissolvable Stitches Work
Dissolvable sutures, also known as absorbable sutures, are crafted from materials that the body's natural processes can break down and reabsorb over time. They are most often used for internal incisions or deep wounds where physical removal would be difficult or unnecessary. The mechanism of dissolution varies by material:
- Natural absorbable sutures: Historically, these were made from natural fibers like treated animal intestines (catgut). The body uses enzymes to digest these protein-based materials. Concerns over tissue reaction have led to a decline in their use, particularly for external wounds.
- Synthetic absorbable sutures: Modern dissolvable stitches are more commonly made from synthetic polymers, such as polyglactin (Vicryl) or polydioxanone (PDS). These materials degrade through a process called hydrolysis, where water in the body breaks down the chemical bonds in the stitch material. This process is more predictable and generally causes less tissue inflammation than natural sutures.
How long they take to dissolve varies significantly based on the material, stitch thickness, and wound location. For instance, some sutures dissolve in just a couple of weeks, while others can take months.
How Non-Dissolvable Stitches Work
Non-dissolvable sutures are made from durable materials that resist the body's breakdown processes. These materials, such as nylon, polypropylene (Prolene), or silk, are designed for long-term wound support. Since the body cannot absorb them, they must be removed manually by a medical professional after the wound has healed sufficiently.
Non-dissolvable stitches are typically used for:
- Closing external skin wounds or incisions.
- Repairing tissues that heal slowly or require prolonged support, such as tendons or ligaments.
- Procedures where permanent tissue approximation is necessary, such as certain cardiovascular surgeries.
Because they are chemically inert and provide reliable, long-term support, non-dissolvable sutures offer superior tensile strength for more demanding applications.
Deciding Factors for Suture Choice
Several factors influence a doctor's decision when choosing between dissolvable and non-dissolvable sutures. This tailored approach ensures optimal healing and patient outcomes.
- Wound Location and Depth: Internal wounds or deeper layers of an incision are almost always closed with dissolvable sutures to prevent a second procedure for removal. For external, superficial skin wounds, non-dissolvable stitches are common, especially in areas with significant tension.
- Healing Rate: Tissues that heal quickly, like those in the mouth, may use rapidly absorbing sutures, while slow-healing tissues like fascia or tendons require materials with longer absorption times or non-dissolvable options for lasting support.
- Cosmetic Outcome: In cosmetically sensitive areas like the face, surgeons might use a combination of absorbable sutures buried under the skin to minimize scarring, with fine, non-dissolvable stitches on the surface for precise alignment. Some studies also suggest non-dissolvable sutures may cause less inflammation and potentially better scarring on skin surfaces, though recent research shows comparable results in many cases.
- Patient Age and Condition: In children, where removing sutures can be a stressful procedure, absorbable stitches are often preferred for facial cuts. The patient's overall health and potential for infection are also considered, as some materials may carry a higher risk.
A Detailed Comparison of Suture Types
| Feature | Dissolvable (Absorbable) Stitches | Non-Dissolvable (Non-Absorbable) Stitches |
|---|---|---|
| Mechanism | Digested by enzymes or broken down by hydrolysis. | Resists breakdown by the body indefinitely. |
| Removal | No removal required; absorbed by the body. | Manual removal by a medical professional is necessary. |
| Common Use | Internal procedures, deep wounds, oral surgery. | External skin closures, tendons, ligaments, heart surgery. |
| Primary Benefit | Eliminates need for follow-up removal appointment, reducing patient discomfort and inconvenience. | Provides maximum, long-term tensile strength and support. |
| Considerations | Can sometimes cause inflammation or irritation on the skin's surface; absorption rate varies. | Requires a return visit for removal; can cause stitch marks on the skin. |
Materials Used for Surgical Sutures
Common Absorbable Materials
- Polyglycolic Acid (PGA): A synthetic braided suture often used for repairing hand or facial lacerations, absorbing in 8–10 weeks.
- Polydioxanone (PDS): A synthetic monofilament that provides longer-term support, taking several weeks to months to dissolve. Used for deep soft tissue repair.
- Poliglecaprone (MONOCRYL): A synthetic monofilament suture most commonly used for subcuticular closures in cosmetic surgery.
- Chromic Catgut: A natural, animal-derived material treated to prolong its absorption time. Less common today due to potential for inflammatory reaction.
Common Non-Absorbable Materials
- Nylon: A synthetic monofilament known for its strength and low tissue reaction, making it ideal for skin closure.
- Polypropylene (Prolene): A synthetic monofilament often used in cardiovascular and plastic surgery due to its strength and inert nature.
- Silk: A natural braided suture prized for its easy handling and knot security, though it degrades over time and can cause a tissue reaction.
- Stainless Steel: The strongest option, typically used for orthopedic or sternal closures.
Essential Care for Your Stitches
Regardless of the type of stitch, proper care is crucial for preventing infection and ensuring optimal healing. Your healthcare provider will give specific instructions, but general guidelines include:
- Keep the wound clean and dry: Avoid soaking the wound in baths or swimming pools, especially in the first 48 hours. Gently pat the area dry after showering.
- Follow dressing instructions: Keep any dressings in place for the time recommended by your doctor. Change them if they become wet or dirty.
- Avoid straining the area: Refrain from strenuous activities or movements that could pull on the wound and cause it to reopen.
- Don't pick at stitches: Picking or scratching at the wound or stitches can introduce bacteria and interfere with the healing process.
- Monitor for infection: Watch for signs of infection, such as increasing redness, swelling, warmth, worsening pain, or pus.
What Happens If Stitches Don't Dissolve?
While uncommon, some dissolvable stitches, or parts of them, may not fully dissolve or fall out as expected. This can happen for several reasons, including individual healing variations or a foreign body reaction to the material. If this occurs, or if your stitches cause irritation after the wound has healed, you should contact your doctor. They can determine if the remaining suture material needs to be removed. You should never attempt to remove them yourself.
Conclusion: What to Expect from Your Stitches
The question of whether stitches are dissolvable or not depends entirely on the surgical requirements and the type of material used. Dissolvable sutures are convenient for internal wounds and certain cosmetic procedures, as they are absorbed naturally. Non-dissolvable sutures provide long-term strength and are removed manually once healing is complete. Both are effective for promoting proper wound closure. Always follow your medical team's specific instructions for the best outcome and be patient with the healing process.
For more detailed information on different surgical suture materials, consult authoritative resources like the National Institutes of Health (NIH) or WebMD.
