The vast majority of sutures, staples and endostaples are used to close procedures involving acute surgical wounds. Typically, chronic wounds do not involve use of suture and staple products unless some degree of surgical intervention is employed to remove necrotic tissue or to create a new acute wound bed to aid healing.
Sutures are classified as absorbable or non-absorbable; monofilament, multifilament or braided; and natural or synthetic. Absorbable or non-absorbable describes the suture’s effective life within tissue. Absorbable sutures lose the majority of their tensile strength within 60 days after use. Non-absorbable sutures are resistant to living tissue and do not break down. Monofilament, multifilament and braided describe the structure or configuration of the suture and is based on the number of strands used to manufacture the product. Natural or synthetic refers to the origin of the suture. Natural suture materials include surgical gut, chromic gut, catgut and silk. Catgut is made from the natural collagen fibers found in the intestine of sheep, goats, cattle, hogs and horses. (It was never made from the gut of cats.) It is debatable whether catgut should continue to be used for suturing wounds, since cotton is cheaper and cotton or synthetic threads are less likely to result in an infection. Synthetic suture materials include nylon, polyester, stainless steel, polypropylene, polyglycolic acid (PGA), polyglycolide-co-caprolactone (PGCL), and polydioxanone.
Sutures are made of two component parts, the needle and the suture. These can be found in a wide range of sizes and types, made of a range of materials, and the method of attachment of the suture to the needle can involve a variety of methods. Sutures are divided into braided and monofilament categories. Braided sutures are typically more pliable than monofilament and exhibit better knot security. Monofilament sutures are wirier and may require a more secure knot. Their major advantage is that they cause less tissue drag, a characteristic that is especially important in cardiovascular, ophthalmic and neurological surgery. Over the last few years, some companies have developed devices (such as Abbott Vascular’s Perclose, ProGlide and Prostar suture-mediated devices) that can complete the suturing process and tie the finishing knot quickly.
Stapler devices are an evolution of suture technology. The goal of stapler products is to avoid infection, make it easier to skillfully suture a wound closed, and make the total procedure go faster and more easily. Staples are made of stainless steel and biomaterials and are used to join internal tissues, reconstruct or seal off organs, remove diseased tissue, occlude blood vessels, and close skin incisions. They are primarily used during surgery as internal and/or external closure devices.
Staples are available in an assortment of sizes and features; procedure-specific stapler devices have been developed for use in one specific procedure or for multiple uses.
Internal staplers are used to approximate (or close) internal tissues and organs. The devices may be reusable or disposable. Some disposable staplers may be reloaded several times during the course of a single patient surgical procedure, before being discarded.
The most recent internal staplers are used to perform minimally invasive surgical procedures. These allow the surgeon to endoscopically secure internal wounds instead of having to operate through an open procedure. Staples can be made to dissolve, which obviates the need for removal. Such staples are ideally suited to laparoscopic surgery and are delivered via procedure-specific laparoscopic instruments. However, most staples are still made of stainless steel and when used for internal stapling procedures, whether open or laparoscopic, are not removed after healing. Skin staples are removed after the incision is healed. Probably the major benefit of staples is that they can be applied more rapidly than sutures and can be placed precisely without requiring the skill necessary for sutures. This also means increased safety for the patient, and patients can often be discharged more rapidly if procedures are stapled rather than sutured.
While cosmetically acceptable results are usually obtained, staplers normally are not used in highly visible areas such as the face. Here surgeons will still close by hand to minimize any scarring. In many procedures, sutures have begun to be replaced by cyanoacrylate glues, but the ideal alternative to suturing has not yet been developed; for example, cyanoacrylate glues used for external skin closure are only one-fifth as strong as sutures.
Traditional types of physical wound closure (sutures, staples, clips) continue to represent the lion's share of the wound closure and related products market. However, as shown in the graph, the share of the total market is declining due to the relatively higher growth of advanced wound products like sealants, glues, hemostats and anti-adhesion products.