The general term used to describe a surgical suture is simply “suture,” though many people commonly refer to them as “stitches.” This medical device is designed to hold body tissues together after an injury or a surgical procedure. The term “suture” is derived from the Latin word sutura, meaning “a sewing together,” which accurately reflects its function in modern medicine. The choice of material and technique represents a careful balance between promoting healing and minimizing the body’s natural reaction to a foreign object.
Defining the Suture
A suture is a medical assembly used to approximate wound edges, bringing them close together to facilitate natural healing. Its primary function is to provide temporary mechanical support, ensuring the tissue remains stable until its own biological repair mechanisms have established sufficient strength. This mechanical support helps the wound heal by primary intention, leading to a neater scar and a reduced risk of infection.
The basic structure of a surgical suture consists of two main components: the needle and the thread or filament. The needle is engineered to be sharp enough to pass cleanly through tissue while minimizing trauma, and it is firmly attached to the thread material. The thread itself is the part that remains in the wound, holding the tissue edges in alignment to close the incision or tear. The selection of the needle’s shape and size is determined by the specific tissue being closed, such as a tapered needle for soft internal organs or a cutting needle for tougher tissue like skin.
The application of a suture, technically called suturing, is the precise action of stitching the wound shut. By holding the tissues together under controlled tension, the suture allows the body’s cells to bridge the gap and rebuild the damaged structure. Surgeons select a specific suture size and technique based on the tissue’s location and the amount of tension it will endure during the initial healing period.
Suture Material Types and Properties
Suture materials are broadly categorized based on what happens to them within the body, dividing them into absorbable and non-absorbable types. Absorbable sutures are designed to lose their tensile strength and be safely broken down by the body over time, eliminating the need for a follow-up removal procedure. These materials are typically used for internal closures, such as deep tissue layers or in organs where temporary support is needed.
The body degrades absorbable materials through enzymatic digestion (natural materials like catgut) or hydrolysis (synthetic polymers). Synthetic absorbable materials, such as polydioxanone (PDS) or polyglactin 910, are common because their absorption rate is more predictable. The time it takes for these sutures to completely dissolve varies widely, ranging from a few weeks for fast-absorbing types to several months for products like PDS.
Non-absorbable sutures are made from materials the body cannot break down, meaning they remain permanently or must be manually removed. Common examples include synthetic polymers like nylon, polypropylene, and polyester, as well as natural materials like silk. These sutures are often used in areas where long-term strength is required, such as in heart surgery, or for external skin closures where they can be easily taken out once the surface has healed.
Suture threads are further classified by their physical structure as either monofilament or multifilament. Monofilament sutures consist of a single strand, passing through tissue smoothly and less likely to harbor bacteria. However, they can be more difficult to handle and have poorer knot security. Multifilament sutures are braided or twisted from multiple small strands, offering greater flexibility and excellent knot security, although this braided structure can potentially increase the risk of infection.
Post-Surgical Care and Removal
Once a wound is closed with sutures, post-surgical care focuses on protecting the site and monitoring for complications as the tissue heals. For external wounds closed with non-absorbable sutures, a follow-up appointment is necessary for removal, which generally occurs between seven and fourteen days after the procedure. The timing is determined by the specific location on the body, as areas with higher movement or tension, like joints, may require a slightly longer duration of support.
The removal process involves a healthcare provider assessing the wound, cleaning the area, and using sterile instruments to cut and gently pull out the stitches. To provide continued support and minimize scarring after removal, adhesive strips, often called Steri-Strips, are frequently applied across the incision line. Patients are advised to avoid activities that place excessive tension on the wound for several weeks to prevent the healing incision from separating.
Patients with internal sutures do not need to worry about removal because the material is designed to be gradually broken down and absorbed. However, all patients must watch the wound carefully for signs of infection, including:
- Increasing pain
- Spreading redness
- Unusual warmth
- Swelling
- Any discharge resembling pus
Maintaining a clean, dry wound environment, often with protective ointment and a non-stick dressing, is an important part of the care routine.