Absorbable sutures are surgical threads designed to dissolve and be absorbed by the body. These stitches eliminate the need for a follow-up procedure to remove them. Their primary function is to hold wound edges together, providing temporary support while the body’s natural healing processes establish sufficient tissue strength. This makes them suitable for internal closures where manual removal would be impractical.
How Absorbable Sutures Dissolve
The body breaks down absorbable sutures through two main biological processes: hydrolysis and enzymatic degradation. Synthetic absorbable sutures primarily dissolve through hydrolysis. This process involves water molecules within the body’s tissues penetrating the suture material, which then breaks the chemical bonds in its polymer chains. This gradual breakdown reduces the suture’s tensile strength until it is fully absorbed.
Natural absorbable sutures, such as catgut, undergo enzymatic degradation. Enzymes in the body’s tissue fluids attack the suture material, breaking it down into smaller molecules. These smaller components are then absorbed and metabolized by the body. The method and rate of absorption depend on the specific material the suture is made from, ensuring controlled support during the healing period.
The gradual dissolution process allows the wound enough time to heal and regain strength before the suture loses its supportive function. This controlled absorption minimizes complications by ensuring the suture remains effective throughout the initial healing phase. The body eventually clears the degraded material, leaving no foreign object behind.
Common Types and Their Characteristics
Absorbable sutures are broadly categorized into natural and synthetic types, each with distinct properties influencing their use. Natural absorbable sutures like Catgut are derived from the purified collagen of animal intestines, typically from sheep or cattle. Plain catgut sutures absorb within 7 to 10 days, while chromic catgut, treated with chromium salts, can extend absorption time to 10 to 21 days. Catgut is absorbed by enzymatic degradation, which can be less predictable than the breakdown of synthetic materials.
Synthetic absorbable sutures are engineered from various polymers, offering more predictable absorption rates and strength retention. Vicryl, composed of polyglactin 910, is a braided synthetic suture that loses about 50% of its tensile strength within 2 to 3 weeks and is fully absorbed within 56 to 70 days. Polydioxanone (PDS) is a synthetic monofilament suture known for prolonged strength retention, maintaining 50% of its tensile strength for 4 to 6 weeks. Complete absorption occurs between 60 and 90 days, sometimes extending up to 180 days. Monocryl, made from poliglecaprone 25, retains 50-60% of its strength for 7 to 10 days and is fully absorbed between 90 and 120 days. The choice of suture material depends on the specific surgical needs, considering factors like required tensile strength and anticipated healing time.
Why Absorbable Sutures Are Used
Absorbable sutures are widely used in medical procedures due to several practical benefits. A primary advantage is the elimination of suture removal. This is particularly beneficial for internal stitches where removal would be challenging, such as those used in deep muscle layers or internal organs. Not requiring removal also reduces the risk of infection that can occur during a second procedure.
These sutures are frequently chosen for a variety of surgical applications, including general surgery, gynecological procedures, and plastic surgery. They provide temporary support to tissues as they heal, allowing the body to naturally regain strength without the long-term presence of foreign material. For instance, in pediatric surgeries, absorbable sutures are often preferred to avoid the stress of a second procedure for stitch removal in children. Their ability to dissolve also means less trauma to the wound site, promoting healing.