A suture is a medical device used to hold body tissues together after an injury or surgical incision, facilitating the natural healing process. The visual appearance of a wound closure varies significantly depending on the material used, the specific pattern of stitching, and the stage of healing. Understanding these characteristics helps patients monitor their recovery and recognize what is normal.
Materials Used to Close Wounds
The materials used for wound closure fall into several categories, each with distinct physical characteristics. Sutures, the traditional “stitches,” are broadly classified by what happens to them over time. Absorbable sutures are designed to break down naturally within the body and are often used for internal layers or in children’s skin closures to avoid a second procedure for removal. These threads frequently appear clear or are dyed violet to improve visibility during placement, and their temporary nature means they will not be visible at the skin surface long-term.
Non-absorbable sutures, conversely, are made of synthetic materials like nylon or polypropylene, or natural materials like silk, and retain their strength for an extended period, requiring manual removal when used on the skin. These threads are often brightly colored, such as blue or black, making them easier to see against the skin for removal, or silver if they are metallic.
Suture threads also differ in physical form: monofilament sutures consist of a single, smooth strand, which glides easily through tissue, while multifilament (braided) sutures are made of multiple twisted or woven strands, offering better knot security.
Beyond threads, other materials are used for skin approximation. Surgical staples appear as small, metallic, rectangular U-shapes arranged in a precise line along the incision. Adhesive strips, commonly seen as thin, white or tan tapes, are placed perpendicular to the wound, pulling the edges together without penetrating the skin.
Visual Patterns of Suture Placement
The pattern in which the suture material is placed determines the final visual appearance on the skin. The interrupted suture pattern involves placing and tying each stitch individually, resulting in a series of distinct knots and stitch points along the wound like a dotted line. If left in too long, this pattern can sometimes leave small, visible marks that resemble a ladder or “cross-hatching” on the healed scar.
The continuous, or running, suture pattern uses a single thread that weaves along the entire length of the incision, finished with a knot only at the start and the end. This technique is faster to apply and results in a smooth, continuous line, sometimes appearing as a zig-zag or spiral pattern, which distributes tension more evenly.
If the continuous suture is placed just beneath the skin’s surface, it is known as a subcuticular suture. Subcuticular sutures are designed to be largely invisible on the surface, with the thread running horizontally within the dermal layer of the skin. This technique typically leaves only a clean, approximated line on the skin with the knot either buried beneath the surface or exiting slightly at one or both ends. This method is preferred for cosmetic results, as it avoids the visible stitch marks associated with sutures that pass through the outermost skin layer.
Appearance of a Healing Suture Site
During the initial inflammatory phase, which lasts a few days, the wound site will show mild, expected signs of the body’s natural response. It is normal to observe slight redness (erythema) and a small amount of swelling (edema) around the incision line. A small amount of thin, clear, or pale yellow drainage is also considered healthy as the body begins the repair process.
A wound that is healing properly should show gradual improvement, with redness and swelling decreasing over the first week. The skin edges should remain tightly joined, and the formation of a scab or crust is a normal protective layer. Pain and warmth should also steadily diminish, signaling that the body is successfully creating new tissue.
Certain visual changes can indicate infection and require medical attention. Signs of concern include redness that spreads rapidly from the incision, especially if it forms red streaks, or swelling and warmth that worsen after the initial few days. Thick, opaque drainage, often described as pus (yellow, green, or foul-smelling), is a strong indicator of infection. The final appearance is the scar, which initially appears raised, firm, and red or purple. Over several months to a year, the mature scar will flatten, soften, and fade to a pale color closer to the surrounding skin.