Whether they are caused by surgery or injury, wounds generally must be closed for proper healing. Wound closure is typically done with sutures (stitches) using thread or staples, depending on the type and location of a wound. The term "stitches" refers to sutures, and is the surgical procedure or process of bringing the skin and tissue together with a material that will keep a wound closed. For traditional sutures, doctors use a thread or strand of material, but surgical staples can also be used in certain cases.
Suture Types
Sutures can be either absorbable or non-absorbable. Absorbable sutures are intended to be broken down by the body over time and eventually dissolve completely. Some materials used to make absorbable sutures are derived from animal products that have been specially processed. Other absorbable sutures are made from synthetic polymer materials such as polylactic acid (Vicryl), polyglycolic acid (Dexon), polyglyconate (Maxon) and polydioxanone (PDS).
Permanent, non-absorbable sutures are sometimes preferred because they are resistant to body chemicals that might otherwise dissolve them too early in the healing process. Non-absorbable sutures are useful for maintaining long-term tissue wound closure (apposition) and healing. Non-absorbable sutures can be made from nylon, polypropylene (prolene), or silk.
Stitching Methods
- Continuous stitch: This is quick to perform using the same suture line without cutting, which helps distribute the tension along the length of the stitched wound.
- Simple interrupted stitching: The same suture line can be used more than once to make separate stitches that allow for more precise closure of the tissue, especially that of skin and fascia.
- Mattress stitches: These can be placed either vertically or horizontally. Mattress stitches go deeper into the skin layers and allow for excellent closure of incision edges while minimizing tension.
- Sub-cuticular stitch: Using an absorbable suture, the stitch is made at the dermal-epidermal junction to allow for better closure so that postoperative suture removal is unnecessary. This stitch is a convenient technique to close skin incisions.
Medical Staples
Staple types are classified according to their material or shape. Medical staples are most commonly made from titanium or stainless steel. However they can also be made from other materials like iron, chromium, nickel or plastic. Medical staples may be straight, curved or circular.
Staples are usually used as an alternative to suturing with thread-like materials to close skin incisions, in areas that are hard to stitch, or during procedures that must be performed quickly. Circular staples are used to make end-to-end surgical closures or connections, as in a bowel resection to help reattach the separated bowel parts.
Uses
Absorbable sutures:
- Gut sutures: Used to close tissue that requires minimal support and heals rapidly, such as that of the oral cavity mucosal layer, or procedures of superficial blood vessels
- Vicryl sutures: Best for the lower layers of skin, and approximating muscle or fatty tissue
- Maxon and monocryl sutures: Used for sub-cuticular stitches and soft tissue approximation
- PDS: Used for stitches of muscle and fascia tissue
Non-absorbable sutures:
- Prolene sutures: Used in tissue of fascia, muscle or blood vessels
- Nylon sutures: Used for closure of skin, surgical incisions or drainage tubes
- Silk sutures: Typically used to tie off blood vessels or bowel segments
Advantages of Stitches vs. Staples
The cosmetic benefits between suturing with thread-like materials or medical staples is equivalent. The choice of suturing material and technique depends on the type or location of the wound and the physician who performs the procedure. Generally, staples tend to allow for rapid skin closure with minimal wound inflammation, and are easier to remove than stitches.
There may be some advantage to using traditional thread-like sutures over staples due to the ease of application and removal. Medical staples must be removed with a special staple remover tool. Most thread-like sutures are removed by cutting the suture next to the knot, then pulling the knot out gently until the suture is completely removed. Typically, using staples to close skin incisions works best with two health care professionals, where one aligns the skin edges with a forceps while the other applies the staples. Stitches made with thread-like materials can usually be applied or removed by one health care professional.
Precautions
Regardless of the wound closure technique being used, the following precautions must be considered to avoid wound breakdown, and to achieve a well-healed incision with minimal scarring:
- Ensure skin incision is located along the intrinsic tension lines for minimal scarring
- Maintain good blood supply to the wound
- Avoid over-tightening the stitches to reduce the tension and prevent any wound breakdown or unwanted scars
- Eversion (alignment) of skin edges for best healing with minimal scarring
- Usage of Steri-Strips, Band-Aids, and skin adhesive materials to strengthen incision during and after suture removal
Recovery After Wound Closure
As soon as the wound has healed enough to withstand the expected stress or pressure on that area, the stitches or staples should be removed. If stitches are left in place beyond that period, they will most likely leave an unwanted scar. Approximate guidelines are as follows:
- Facial stitches typically remain in place for three to five days
- Extremities stitches are typically left in place for about ten days
- Joint stitches are left in place for ten to fourteen days
- Back stitches should remain in place for fourteen days
- Abdominal stitches should usually be left in place for seven days
