Sutures

What is it?

Sutures, commonly called stitches, are sterile surgical threads that are used to repair cuts (lacerations). They also are used to close incisions from surgery. Some wounds (from trauma or from surgery) are closed with metal staples instead of sutures.

What it's used for

Sutures may be used to close surface wounds or deep wounds. To close a deep wound, a doctor may need to sew the two edges together layer by layer, placing and leaving some sutures under the skin surface.

There are two types of sutures that are used for wound repair.

Nonabsorbable sutures are ideal for skin wounds because they are more likely to have a cosmetically appealing result. When these sutures are used in skin wounds, they are removed once the wound has healed. In most areas of skin, it takes about seven days for a bridge of connecting tissue to form between the two edges of the wound. After that, the stitches can be removed safely, and the wound can continue to heal without stitches in place. If the stitches are left in the skin for longer than is needed, they are more likely to leave a permanent scar.

Nonabsorbable sutures also are ideal for internal wounds that need to heal for a prolonged time. Depending upon what the sutures are made of, nonabsorbable sutures either are permanent or deteriorate very slowly. They hold their strength for 300 days or longer. They are made from natural fibers or from synthetic threads such as nylon, polypropylene, polyethylene, or polyester. At the end of a surgery, these long-lasting sutures are used to hold together fibrous internal tissues, since these tissues do not have much blood flow and require a very long time to heal fully. When nonabsorbable sutures are used in deep tissues, they are left in place permanently.

Layers that heal quickly can be repaired with absorbable sutures. These sutures are made from materials that can dissolve gradually inside the body. These sutures are exceptionally strong in the first few days of healing because they are made with multiple fibers, which makes them less likely to break. However, they lose most of their strength by the end of the first two weeks of healing. Absorbable sutures are ideal for repairing muscles, because muscles require strong sutures when they are first healing yet they heal quickly. Absorbable stitches are not removed. The body absorbs them, usually within about 60 days.

Preparation

Before suturing your cut, your doctor will need to know:

How your cut happened: Was the cut made by a piece of glass, wood, or metal that might have broken off inside in the wound? Was the wound contaminated by dirt, manure, or saliva (animal or human)?
When your cut happened: If you have waited several hours before seeking treatment, then your risk of infection is higher than average.
Whether you are allergic to any anesthetics or antibiotics
Your current medications: Are you taking any prescription or nonprescription drugs that could increase bleeding or delay healing?
The approximate date of your last tetanus shot.

These questions will help your doctor to know whether sutures may be an appropriate way to help your wound heal. Some contaminated wounds should not be closed with sutures because this could prevent an infection from draining. Some wounds that have been open for more than six hours also should not be closed with sutures. In these cases, the wound may be cleaned, kept open under a bandage, and allowed to heal slowly from the outer edges inward.

Your doctor will check whether your sense of touch is normal around the cut. The doctor also will feel your pulse, and will check whether you can move your muscles near the cut normally. This will help the doctor know whether any important nerves, blood vessels, or tendons have been cut. Occasionally, it is necessary to check how deep a cut is by inserting a cotton swab or a probing instrument. The doctor will look into the wound to check for small pieces of dirt, glass, metal, or other debris. If necessary, the doctor will order an x-ray that can reveal fragments of glass or metal in the wound.

How it's done

First, the doctor will numb the area around the cut using a needle to inject a local anesthetic. Then, he or she will gently clip away any hairs near the edges of the wound. The doctor will flush the wound with saline (a salt solution) and remove any obvious dirt or dead tissue.

Next, the skin around the wound may be painted with an antibacterial liquid. A sterile cloth or paper drape can be placed around the area of the cut to protect it from bacteria and other contamination while it is repaired.

If necessary, the doctor first will repair the deeper layers of the wound and later, the surface skin. To place stitches, the doctor will use an instrument (a needle holder) to grasp a curved, threaded surgical needle. After passing the needle and thread through the tissue, the doctor will pull the thread tight, tie a knot, and snip the ends of the thread with scissors.

Usually, newly repaired wounds are coated with an antibiotic ointment and covered with a bandage.

If your last tetanus shot is not written in your medical records and you are not sure if you have had a tetanus shot within the last five years, most doctors will recommend a booster shot. If it has been more than 10 years since your last tetanus shot, then you definitely need a booster.

Follow-up

Once you get home, if you have a newly sutured wound on an arm or leg, you should try to keep the injured area elevated above the level of your heart during much of the first day of your recovery. This will make it less likely that the wound will swell, so it can heal more easily. You also should make sure that the bandage stays clean and dry, especially for the first 24 to 48 hours.

For lacerations on most parts of the body, stitches can be removed in about seven days. For lacerations on your face, stitches can be removed earlier (in three to five days). Early removal can help to minimize the scar. For lacerations over a joint, your doctor may recommend leaving stitches in place for as long as 14 days, because it requires a longer time for a wound to heal strongly enough to withstand the repeated pulling and stretching that skin endures when it is near to a joint.

Risks

The skin is a natural barrier that prevents infections. A cut can become infected, even when it is cleaned properly and stitched. Even if a cut appears clean before it is sutured, the doctor may give you antibiotics, especially if your cut is on the hand.

Other problems can arise after wound repair:

You may have a permanent scar. Suture scars fade slowly.
A sutured area of skin may move less easily than the surrounding skin, creating a pulling sensation.
A bulging scar called a keloid may form. Keloids occasionally cause itching or discomfort, and they can cause cosmetic concerns.
Internal tissues occasionally pull apart without healing well, and this can go unnoticed. In the abdomen, poor healing internally can allow the formation of a hernia, a bulge of intestines through layers of a wound that did not seal.