Sutures, commonly known as stitches, are medical devices designed to hold body tissues together after an injury or surgery until the wound has sufficiently healed. Their fundamental purpose is to secure the edges of a wound, promoting proper alignment and minimizing the risk of infection and scarring. Absorbable sutures are a significant advancement in surgical practice, offering the distinct advantage of dissolving naturally within the body. This unique feature eliminates the need for a follow-up procedure to remove the stitches, simplifying patient care and making them invaluable for internal surgery.
Suturing Before Absorbable Materials
The practice of closing wounds with thread dates back thousands of years, with evidence of suturing found in ancient Egyptian records from as early as 3000 BC. Early surgeons used a variety of natural fibers to approximate tissue, including linen, horsehair, cotton, and silk threads. Roman physician Galen in the second century AD even described using a material called catgut, made from animal intestines, which was an early, though unreliable, attempt at a dissolvable material.
However, these early materials presented significant challenges. Since sterilization was not practiced, the use of animal and plant fibers frequently introduced foreign contaminants, leading to high rates of post-operative infection. Furthermore, non-absorbable sutures required a second, often uncomfortable, procedure for removal once the surface wound was closed. This necessity for an additional intervention compounded the patient’s recovery time.
The Breakthrough: Catgut and the Dawn of Dissolvable Stitches
The true birth of the medically viable dissolvable stitch occurred in the late 19th century, driven by the work of British surgeon Joseph Lister. Although catgut had been known for centuries, it was notoriously inconsistent and often caused severe infection because it was not sterile. The pivotal moment came in the 1860s when Lister began experimenting with antiseptic techniques to address the deadly problem of hospital gangrene.
Lister applied his pioneering antiseptic principle, which involved using carbolic acid, to sterilize the catgut material. By treating the animal-derived collagen with this powerful chemical, he effectively created the first reliably safe, absorbable suture. This innovation, introduced around 1869, allowed the material to be used internally without causing widespread sepsis. The sterilized catgut suture marked the moment a dissolvable stitch became a predictable and practical tool for surgeons.
How Absorbable Sutures Work
Absorbable sutures are engineered to lose their tensile strength and mass in a controlled manner, allowing the body’s natural processes to break them down. The mechanism of dissolution depends on the suture’s base material, primarily falling into two categories. Natural materials, like the historically used catgut, are typically degraded through enzymatic action, where the body’s proteolytic enzymes metabolize the animal protein. This process is highly variable and can sometimes provoke an inflammatory reaction.
Modern synthetic absorbable sutures, however, use a more controlled process known as hydrolysis. In hydrolysis, water molecules within the body’s tissues penetrate the polymer chains of the suture material, chemically breaking the bonds over time. This reaction is predictable, controllable, and generally causes minimal tissue response, making it the preferred method for modern absorbable materials. A requirement for any absorbable suture is tensile strength retention, meaning the material must maintain enough strength to hold the wound securely throughout the initial period of healing before its mass begins to disappear.
The Shift to Synthetic Polymers
Despite Lister’s breakthrough, the natural collagen in catgut still presented issues, including unpredictable absorption rates and the potential for a variable immune response. The major shift towards the modern standard began in the mid-20th century with the development of synthetic absorbable polymers. These materials offered surgeons a level of consistency and control previously unavailable with natural fibers.
The first widely adopted synthetic absorbable suture was based on polyglycolic acid, which emerged in the 1960s and was followed by related materials like polyglactin 910 in the 1970s. These polymers are manufactured to have precise chemical structures that dictate their degradation timeline and strength retention. The synthetic nature of these materials allows for a far more predictable absorption rate and a significantly lower risk of allergic or inflammatory reactions. This consistency and biocompatibility cemented synthetic polymers as the standard for dissolvable sutures in modern surgery.