Sutures, commonly called stitches, are specialized threads used by medical professionals to hold the edges of a wound or incision together, providing the necessary support for the tissue to heal correctly. Their primary function is to stabilize the wound until the body has rebuilt enough internal strength to maintain closure on its own. Whether these threads are supposed to fall out depends entirely on the type of material used. Choosing the right suture material is a deliberate decision based on the wound location, tissue tension, and required healing time.
Understanding Absorbable and Non-Absorbable Sutures
The difference in suture behavior comes down to two major categories: absorbable and non-absorbable materials. Absorbable sutures are constructed from materials designed to be broken down and metabolized by the body over time. They are often used for stitching internal tissues, deep layers of a wound, or for skin closures where removal would be impractical, such as in pediatric patients.
Synthetic absorbable sutures, such as those made from polyglycolic acid or polyglactin, dissolve primarily through hydrolysis. In this chemical reaction, water molecules from the body’s tissues penetrate the suture material, gradually breaking down the polymer chains until the material loses its strength and is absorbed. Natural materials, like catgut derived from animal intestines, dissolve through enzymatic degradation, a less predictable process driven by the body’s local enzyme activity.
Non-absorbable sutures are made from inert materials that the body cannot break down. These threads, including synthetic polymers like nylon and polypropylene, or natural materials like silk and stainless steel wire, must be manually removed by a healthcare provider. They are typically used for external skin closures, where they are easily accessed, or in areas requiring long-term, high-tensile support, such as in cardiovascular or orthopedic surgeries. If placed internally, they remain in the body indefinitely without causing harm.
Expected Timelines for Suture Removal or Dissolution
The expected duration a stitch remains in place depends on both the suture type and the anatomical location of the wound. Non-absorbable sutures used on the skin have removal timelines to ensure adequate healing while minimizing scarring. Wounds on the face, which heal quickly due to a rich blood supply, typically require removal within three to five days for the best cosmetic outcome.
Sutures placed on the scalp or trunk generally remain for seven to ten days, as these areas experience different levels of tension and healing rates. For extremities and areas subjected to high movement or stress, such as joints, the stitches may need to stay in place for ten to fourteen days or longer to prevent the wound from reopening. A healthcare professional determines the precise timing based on the appearance of the healed wound edges.
Absorbable sutures do not have a “removal” date, but their dissolution time varies based on the material’s composition. Fast-absorbing sutures, like plain catgut, may lose strength and disappear within ten to twenty-one days, making them suitable for areas with rapid healing. Slower-absorbing synthetic sutures, such as polydioxanone (PDS), are engineered to maintain tensile strength for weeks and can take up to 180 to 210 days to be fully absorbed, providing prolonged support for deep tissue closure.
Recognizing Abnormal Suture Behavior and When to Call a Doctor
While some external absorbable stitches may visibly fall out as the wound heals, any unexpected or premature loss of non-absorbable sutures should prompt a call to a medical professional. If non-absorbable stitches come out too early, the wound may lack sufficient tensile strength, leading to a separation of the wound edges, a complication known as wound dehiscence. This requires immediate medical assessment.
Patients must monitor the wound site for signs of infection. Indicators include increasing redness, swelling, or warmth that spreads beyond the incision line. The presence of thick, discolored, or foul-smelling drainage (pus) is a strong signal of infection.
Persistent or worsening pain, especially pain not managed by prescribed medication, should be reported. A fever above 100.4°F (38°C) is another systemic sign of infection. For absorbable sutures, the body sometimes attempts to expel the remaining material, often called a “spitting” stitch. This may need minor intervention if it causes irritation or does not resolve naturally.