Definition
Description
Stitches, staples, surgical glue, and tapes are four methods used to close wounds. Stitches use specialized needles and thread to “sew” the wound. Staples are thin pieces of metal that are placed with a stapling device through the edges of a wound to close it. Glues and adhesive tapes are materials used to close wounds without puncturing or penetrating the skin around the edges of an incision.
Wounds to the skin, fat, muscle, blood vessels, and other structures in the body may occur accidentally (as in a cut) or purposefully (as in a surgical incision). A number of different methods exist to close a wound; the method selected depends on the type of injury, the type of tissue injured, the location and depth of the injury, and the patient’s general health. Stitches and staples are two commonly used wound closure methods.
Sutures, as stitches are often called, are the way that most wounds are closed. They are the oldest method of wound closure, having been described over two millennia ago by the Indian surgeon Susruta (sixth century B.C.), sometimes called the “father of plastic surgery,” and the Roman physician Claudius Galen (129–200 A.D.), who treated several Roman emperors. These ancient doctors used such natural materials as human hair, hemp, silk, and catgut (a tough thread made from the dried intestines of sheep or horses). Silk and catgut are still used for sutures in the twenty-first century. Synthetic materials were first used for sutures in the 1950s; they are preferred by some surgeons because they are less likely to cause allergic tissue reactions around the edges of the wound. On the other hand, many synthetic suture materials are more difficult to knot securely. Suture materials have various characteristics that determine their use; no single material is ideal for all purposes. The surgeon must often decide whether ease of knot tying is more important than strength or longevity in tissue. The two main components of suture materials are the needle and thread.
MATERIALS. Suture thread is often categorized by how long it retains its strength in tissue. Absorbable stitches lose their strength in a matter of days or weeks and are eventually absorbed by the tissue. This characteristic is useful for the suturing of subcutaneous tissues. Nonabsorbable stitches retain their strength for months to years and may never be absorbed by the tissue. They are generally used for skin and are removed once the wound has sufficiently healed. Suture thread is made of various natural or synthetic components and comes in different diameters for use in different types of tissues. Very fine suture threads are used to close cuts on the face, while threads with a larger diameter are required for subcutaneous tissues.
Suture thread is also categorized by its structure, as either monofilament (one strand or filament) or multifilament, which has a braided structure. Monofilament sutures are less likely to cause infection and can be pulled through tissue with less damage to the skin, but are easily damaged by surgical instruments.
Stainless steel wire is a specialized, nonabsorbable suturing material, used in orthopedic surgery or to close the sternum (breastbone) following heart surgery.
To minimize the risk of infection, all types of suture materials are sterilized before use in a chamber containing ethylene oxide, a gas that kills bacteria, mold, and fungi. A newer technique to further lower the risk of bacterial contamination is to coat the suture material with an antimicrobial substance.
In the United States, the diameter of suturing materials is defined by the United States Pharmacopoeia (USP). The largest diameter is designated as #5, for heavy multifilament sutures used in orthopedic surgery; the smallest is #11-0, extremely fine monofilament sutures used primarily in ophthalmology.
Suture needles may resemble a conventional sewing needle with an eye through which suture material is threaded, or they come with suture thread attached at one end; this connection is said to be swaged (forged). Swaged needles have the advantage of causing less damage to tissue because the swaged end is smaller than the needle body and is less likely to rip tissue than the older type of threaded needle.
Needles may be straight or curved; the most commonly used shape is the semicircle, which permits easier manipulation through tissues by the clinician. Needles vary in length from less than 0.1 in (2 mm) to 2.4 in (60 mm). The point of a needle may be cutting (for tougher tissues such as the skin), rounded (for easily penetrable tissues such as the subcutaneous layers), or blunt (for easily damaged tissues such as the liver).
TECHNIQUE. While various stitching techniques may be used depending on the location of the wound and type of tissue to be sutured, basic suturing technique remains the same. Several instruments are necessary for proper wound closure, including dissecting scissors (for cleaning the wound); suture scissors (for cutting suture thread); a needle holder (for manipulating the needle); and forceps (for manipulating tissue). Wounds resulting from an injury must be cleaned before closure; dead tissue and foreign bodies are removed and the area is cleansed with an antiseptic. Sutures may be interrupted (each stitch is separately placed, tied, and cut) or continuous (one continuous piece of thread composes all the stitches); they may be placed at different angles and depths.
Anastomosis (plural, anastomoses)— The surgical connection of two structures, such as blood vessels or sections of the intestine.
Antiseptic— A substance that inhibits the growth of harmful bacteria and other organisms.
Catgut— A tough natural suture material made from the dried intestines of sheep or horses.
Cyanoacrylate— The chemical name of liquid surgical adhesive.
Ethylene oxide— A colorless gas used to sterilize surgical sutures, bandages, and most other surgical materials or implements.
Monofilament— A single untwisted strand of suture material.
Multifilament— A braided strand of suture material. Multifilament sutures are generally thicker than monofilament and used in such specialties as orthopedic surgery.
Polyglycolic acid (PGA)— A polyester compound used to make bioabsorbable sutures and staples. It is also used in tissue engineering.
Subcutaneous— Under the skin.
Swaged needle— An eyeless surgical needle with the suture material preattached by the manufacturer. Most surgical needles used in the early 2000s are swaged needles.
United States Pharmacopoeia (USP)— An authoritative book, updated annually, that contains lists of medicines, dietary supplements, and surgical supplies; defines their doses or other units of measurement; and sets quality standards for their production and proper use. The USP is used by 130 countries around the world in addition to the United States.
Nonabsorbable stitches should be removed several days to weeks after their placement, depending on their location. For instance, sutures on the face should be removed in approximately 5 days; sutures on the legs and abdomen, in 7 to 10 days; and sutures on the back, in 10 to 14 days. Strips of adhesive tape may be placed over the wound to help support the tissue while it is healing.
Staples are a relatively new method of wound closure, having been introduced in 1908 by a Hungarian surgeon named Humer Hultl. The primary purpose of Hultl’s invention was reliable closure of bowel anastomoses, that is, the joining together of two segments of intestine. Leakage of intestinal contents from anastomoses was a common cause of postoperative mortality in the early twentieth century. The early staplers were large and cumbersome. It was not until the mid-1960s that reliable and easy-to-use surgical staplers were manufactured by the United States Surgical Corporation.
A distinct advantage that modern surgical staples have over sutures is their quick placement—stapling is approximately three to four times faster than suturing. Staples are also associated with a lower risk of infection and tissue reaction than sutures. It is, however, more difficult to correctly align the edges of a wound for stapling, and staples generally cost more than sutures. Common locations of wounds that may be stapled are the arms, legs, abdomen, back, or scalp; wounds on the hands, feet, neck, or face should not be stapled. Additionally, staples are still used to connect cut ends of larger blood vessels or segments of the bowel.
A newer form of stapling uses clips that do not penetrate the skin to close the edges of a wound.
MATERIALS. Most surgical staples used inside the body are made of titanium, a lightweight silvery metal that is less likely to trigger the patient’s immune system or interfere with MRI scanners. Staples used to close skin wounds or incisions are composed of stainless steel and have a crossbar that lies parallel to the skin, two legs that enter each edge of the wound, and tips that hold the staple in place. Staples are placed with the aid of a stapling device that generally holds between 5 and 25 staples. As of 2007, most skin staplers are disposable plastic instruments that contain a single cartridge of staples. Staplers used to place staples inside the body are more commonly made of stainless steel and are not disposable. Forceps are also necessary to help align the edges of the wound together and hold them in place until staples can be placed.
TECHNIQUE. The wound is first cleaned of dead tissue and foreign bodies and washed with an antiseptic. The edges of the wound are aligned and held together with forceps or the clinician’s fingers. The stapling device is held against the wound at the point at which the staple is to be placed. By squeezing the trigger on the stapling device, the staple is automatically placed into the skin; the depth of placement is controlled by how firmly the stapling device is held against the skin. The staples should be removed at approximately the same time as sutures; removal is done with a specialized staple remover.
A newer type of surgical staple is bioabsorbable, meaning that it does not require removal after the wound has healed. These staples are made from polyglycolic acid (PGA), a material that is also used to make absorbable sutures and scaffolds for tissue engineering. Staples made of PGA lose about half their strength within two weeks and are completely absorbed by the body within 4 months.
Tissue glues have been used in surgery on an experimental basis since the mid-1960s; they were formally approved by the U.S. Food and Drug Administration (FDA) for surgical use in 1998. As early as 1964, Eastman Kodak submitted an application to the FDA for the use of cyanoacrylate glues in surgery; the formula was used by Dr. Harry Coover during the Vietnam War to seal chest wounds or other open wounds until the patient could be taken to a military hospital.
In addition to wound closure, surgical glues were approved by the FDA in 2001 as sealants against certain types of bacteria, including staphylococci and pseudomonads.
MATERIALS. Cyanoacrylate glues are familiar to most people in the form of such compounds as Krazy Glue or Superglue, used as household adhesives to bond nonporous materials, including metals. These glues are also used in criminal investigations to develop latent fingerprints on smooth surfaces like glass or plastics. Instructions for the use of cyanoacrylate industrial glues always contain warnings about their capacity to bond with skin; it is this characteristic that led to their use in surgery. The chemical formula of cyanoacrylate approved for medical use is 2-octyl cyanoacrylate; its trade names include Dermabond, Band-Aid Liquid Adhesive Bandage, and Soothe-N-Seal.
Dermabond has several advantages: rapid application, good cosmetic results, strength, and flexibility. It also has several drawbacks: it can only be used to close the uppermost layers of skin, as it causes inflammation to subcutaneous tissues. It cannot be used close to the eyes or mouth, on hairy parts of the body, or to close wounds with jagged or torn edges. The surgeon must use subcutaneous sutures to draw the edges of a deep wound together before applying the surgical glue to the surface of the skin. Last, a small percentage of patients are allergic to cyanoacrylate and develop a skin rash.
TECHNIQUE. Dermabond comes in an applicator that resembles a fountain pen with a thicker barrel. It contains a vial that snaps open inside the barrel when the doctor removes the cap. The adhesive itself is tinted purple and comes out through a porous tip about the size of a pencil eraser when a black button on the side of the barrel is pushed. The doctor or nurse holds the edges of the wound together while applying a layer of Dermabond to the wound with the tip of the applicator. After 15 seconds, the first layer is dry and the doctor can apply the second layer of adhesive. After about 45 seconds to a minute, the closure is complete. It reaches its full strength about three minutes after the second layer has been applied. The patient does not need to cover the Dermabond with a bandage. It is safe to get the closure wet in the course of normal bathing or showering, although patients are usually instructed not to soak the wound.
Dermabond does not have to be removed like staples or nonabsorbable stitches; it wears off the skin in 5-10 days, which is usually enough time for the upper layer of skin to heal.
Over-the-counter (OTC) forms of surgical adhesive have been available since 2004; they come in bottles that contain about 10 applications. As of 2007, these products cost between $5.50 and $7.00 in most parts of the United States.
Surgical tapes have been used for wound closure since the Renaissance period, when the French surgeon Ambroise Pare (1510–1590) made tapes out of strips of sticking plaster for treating facial wounds. This technique allowed the wound edges to be splinted as well as joined together. In modern surgery, adhesive strips can be used to hold the edges of the wound together before suturing or by themselves without sutures.
MATERIALS. The first modern type of adhesive strip used for wound closure was introduced in the early 1960s and is commonly called Steri-Strips. Still used in the early 2000s, Steri-Strips are reinforced strips of a microporous synthetic material backed by an acrylic polymer adhesive that holds the edges of a wound together for 5-7 days. They can be removed at home by the patient after the wound has healed.
A newer type of adhesive strip was known as ClozeX when it was introduced in 2004. Its name was changed to Steri-Strip S Surgical Skin Closure in 2007. The product comes in a range of 11 different sizes to cover a variety of injuries and surgical incision. The original ClozeX was a transparent film with an adhesive backing, designed to hold the edges of a wound together. In 2005, the company introduced a second version with a center pad. According to a report published in 2006, a sample group of both surgeons and patients preferred the new method of wound closure to standard monofilament sutures for speed of application, greater comfort, lower cost, and better cosmetic effect. The limitations of the Steri-Strip S device are similar to those of surgical glues: it cannot be used on hairy portions of the body, infected wounds, wounds that are oozing tissue fluid, or wounds on parts of the body used for repetitive motion (such as knee or finger joints).
TECHNIQUE. Steri-Strips and the newer skin closure device are applied after the patient’s skin has been cleansed with rubbing alcohol or sterile saline solution and dried thoroughly. If the skin closure device is to be used, the surgeon chooses the proper size for the wound and removes a series of liners inside the device, pressing the clear adhesive pad first along one side of the wound and then the other while holding the edges of the wound together. After the adhesive pad is in place, the surgeon applies a series of filament straps that hold the adhesive pad in place. The device is left in place for 7 days. It can then be removed in the doctor’s office or by the patient.
Steri-Strips are commonly used with a liquid adhesive, usually either Mastisol or tincture of benzoin, to help them adhere to the wound longer. After the patient’s skin has been cleansed and dried, the liquid adhesive is applied over the edges of the wound and the entire area where the Steri-Strips will be placed. After the adhesive is partly dry, the strips are placed across the wound (perpendicular to it rather than parallel) without overlapping one another.
BOOKS
Current and Emerging Wound Closure Products and Techniques in Europe and the U.S. Newport Beach, CA: Medtech Insight, 2003.
Lammers, Richard L., and Alexander T. Trott. “Methods of Wound Closure.” In Clinical Procedures in Emergency Medicine. Philadelphia: W. B. Saunders Company, 1998.
O’Leary, J. Patrick, ed. The Physiologic Basis of Surgery, 4th ed. Philadelphia: Lippincott Williams & Wilkins, 2008.
PERIODICALS
Autio, L., and K. K. Olson. “The Four S’s of Wound Management: Staples, Sutures, Steri-Strips, and Sticky Stuff.” Holistic Nursing Practice 16 (January 2002): 80–88.
Barber, F. A., et al. “Sutures and Suture Anchors—Update 2006.” Arthroscopy 22 (October 2006): 1063.
Casper, K. A. “OTC Product: Band-Aid Liquid Bandage.” Journal of the American Pharmacists Association 46 (November-December 2006): 768.
Catena, Fausto, Michele La Donna, Stefano Gagliardi, et al. “Stapled versus Hand-Sewn Anastomoses in Emergency Intestinal Surgery: Results of a Results of a Prospective Randomized Study.” Surgery Today 34 (February 2004): 123–126.
Groce, J. R., et al. “Endoscopic Clip Closure of a Gastric Staple-Line Dehiscence (with Video).” Gastrointestinal Endoscopy 65 (February 2007): 321–322.
Hancock, N. J., and A. W. Samuel. “Use of Dermabond Tissue Adhesive in Hand Surgery.” Journal of Wound Care 16 (November 2007): 441–443.
Kuo, F., D. Lee, and G. S. Rogers. “Prospective, Randomized, Blinded Study of a New Wound Closure Film versus Cutaneous Suture for Surgical Wound Closure.” Dermatologic Surgery 32 (May 2006): 676–681.
OTHER
Doud Galli, Suzanne K. and Minas Constantinides. “Wound Closure Technique.” eMedicine. August 1, 2006 [cited January 3, 2008]. http://www.emedicine.com/ent/topic35.htm.
Lai, Stephen Y. and Daniel G. Becker. “Sutures and Needles.” eMedicine. June 27, 2006 [cited January 4, 2008]. http://www.emedicine.com/ent/topic38.htm.
Terhune, Margaret. “Materials for Wound Closure.” eMedicine. November 19, 2007 [cited January 4, 2008]. http://www.emedicine.com/derm/topic825.htm.
ORGANIZATIONS
United States Pharmacopoeia (USP), 12601 Twinbrook Parkway, Rockville, MD, 20852-1790, (800) 227-8772, http://www.usp.org/.
Stephanie Dionne Sherk
Rebecca Frey, Ph.D.