Abstract
A thorough working knowledge of suture materials and instruments is essential for successful dermatologic surgery. This chapter reviews suture properties, including physical configurations, capillarity, USP size, elasticity, coefficient of friction, memory, plasticity, pliability, tensile strength and tissue reactivity. The characteristics of the suture materials most commonly employed in cutaneous surgery are also discussed. Detailed advice regarding suture and needle selection for various applications is offered. Nomenclature, appropriate selection and care of various instruments, including curettes, scalpels, needle holders, scissors and forceps, is reviewed. Sample surgical trays are depicted in order to assist those performing cutaneous surgery.
Keywords
sutures, scissors, scalpel, needles, needle holders, forceps, skin hooks, polyglactin, poliglecaprone
- ▪
The characteristics ascribed to a suture include:
- •
physical configurations
- •
capillarity
- •
USP size
- •
elasticity
- •
coefficient of friction
- •
memory
- •
plasticity
- •
pliability
- •
tensile strength
- •
tissue reactivity
- •
- ▪
Sutures used to approximate the dermis and deeper tissue layers are generally absorbable, while cutaneous sutures are usually non-absorbable and require removal
- ▪
The most commonly employed needle in dermatologic surgery is a 3/8 circle that is triangular in shape, with a reverse cutting surface.
- ▪
Needle holders with small smooth jaws accommodate finer needles while those with large serrated jaws are best for larger needles
- ▪
The major types of scissors used in dermatologic surgery are Gradle, tissue, undermining, serrated, suture-cutting, and bandage-cutting
Introduction
As dermatologic surgery continues to expand as a specialty, so does the variety of materials and instruments that are available to facilitate performance of increasingly complex tissue excisions and repairs. A thorough working knowledge of these tools is essential as it allows the physician to optimize the cosmetic and functional outcome of a given procedure. For example, the suture material and surgical instruments needed for a melanoma excision on the back will vary greatly from those required for a blepharoplasty. This chapter will review the wound closure materials and surgical instruments with the greatest value to the dermatologic surgeon. Helpful hints and model surgical tray setups are included to assist in the preparation for surgery in specific anatomic locations.
Discussion
Sutures
Since prehistoric times, humans have been using various materials to sew skin wounds. The first known reference appears in the Edwin Smith Papyrus (c. 1600 BC) . Although the precise suture material was not described, examination of artifacts from that time period suggests it was most likely linen. Hippocrates has been credited with being the first, in 400 BC, to use the term “suture” in reference to sewing human tissue.
Over the centuries, suture materials that have been employed include cotton, leather, flax, insect mandibles, horse hair, and even human hair . Ancient Roman physicians would braid the hair of gladiators tightly in order to close their scalp wounds, thus demonstrating that sutures can produce immediate hemostasis in addition to wound edge approximation.
The ideal suture, were it to exist, would handle easily, hold a secure knot, and have high tensile strength. It would neither cause inflammation nor promote infection, and it would gradually dissolve, thereby obviating the need for suture removal. Unfortunately, the perfect suture material does not exist. However, the ever-widening array of choices available to the dermatologic surgeon and a knowledge of each suture’s individual characteristics increases the likelihood of choosing the best possible materials for each surgical situation.
Suture materials are divided into two categories: (1) absorbable; and (2) non-absorbable. Studies of wound-healing have shown that during the first 1–2 weeks after surgery, the intrinsic tensile strength of the wound is approximately 7–10% of native bursting pressure . At 5 weeks, the intrinsic tensile strength is ~60%; therefore, in general, after 1 month dehiscence is unlikely with normal activity. During this time period, absorbable, buried, dermal sutures are utilized to alleviate tension and maintain wound edge approximation. Transepidermal, non-absorbable sutures are non-tension-bearing, but allow for fine adjustments of the epidermal edges.
The characteristic attributes ascribed to a suture are defined and standardized by the United States Pharmacopeia (USP) as follows:
- •
Two physical configurations exist: monofilament and multifilament. Multifilament suture can be spun, twisted or braided. Braiding serves to increase pliability, strength, knot security and handling , but may abrade or shear tissue. Braiding also potentially increases the risk of infection by allowing bacteria to become entrapped within the suture . Monofilament sutures have a low coefficient of friction and slide easily through tissue (see below) . Their drawback is that they are traditionally more stiff than braided suture and may have decreased knot security, requiring additional throws to ensure that the knot is secure. Until recently, monofilament sutures were used primarily for exterior suturing, and most buried sutures were braided. With the introduction of poliglecaprone 25 (Monocryl ® ), monofilament absorbable suture is now regularly employed for deep sutures.
- •
Capillarity is defined as the ability of a suture to absorb and transfer fluid. Multifilament sutures have greater capillarity than monofilament sutures.
- •
The USP size of a suture is determined by the diameter needed to achieve a given tensile strength and this is expressed in multiples of zeros; the smaller the cross-sectional diameter of the suture, the more zeros. For example, 7–0 polyglactin 910 (Vicryl ® , Polysorb ® ) is a much finer suture than 3–0 polyglactin. The actual diameter of a given USP size varies depending upon the composition of the suture, e.g. a 4–0 surgical gut is a larger-diameter suture than 4–0 polypropylene because polypropylene is innately stronger. In general, the smallest suture that will provide adequate tensile strength for the indicated repair should be utilized.
- •
Elasticity refers to the ability of a suture to regain its original length after being stretched. An elastic suture, such as polybutester, allows for tissue swelling and then maintains tension on the wound edges after the edema has resolved.
- •
The coefficient of friction determines the ease with which a suture will pull through tissue. A suture with a low friction coefficient, such as polypropylene, slides easily through tissue. For this reason, polypropylene is commonly used for the running subcuticular suture (see Ch. 146 ). Knot strength is directly proportional to the friction coefficient of the suture material. The more slippery the suture material, the more likely it is that the resulting knot will unravel. Hence, when suturing with polypropylene, it is prudent to place several additional throws for each knot.
- •
Memory is defined as a suture’s tendency to retain its natural configuration and is determined by the elasticity and plasticity of the suture material. Memory is a useful property for maintaining closure during the postoperative period, and high-memory sutures such as nylon are widely used for surface approximation. Drawbacks of high-memory sutures are that they do not handle very easily and have a relatively low knot strength. As with sutures that have a low coefficient of friction, a few extra throws may help to ensure a secure knot. Suture material with low memory, such as silk, is easy to handle and rarely becomes untied.
- •
Plasticity is the ability of the suture to be molded or retain its new length and form as well as tensile strength after it has been stretched. This is an important characteristic for a suture material that is to be used in situations with tissue edema. Sutures with plasticity, such as polypropylene, will stretch to accommodate edema and not cut into tissue .
- •
Pliability refers to how easily the suture can be bent. Braided suture materials, such as silk, are the most pliable, and they are capable of readily being tied into a knot.
- •
The tensile strength of a suture is determined by measuring the force (in pounds) required to snap it and then dividing that force by the cross-sectional diameter of the suture. In general, synthetic materials are stronger than natural materials. A suture that has been knotted has approximately one-third the tensile strength of the same material unknotted .
- •
Tissue reactivity is the degree of foreign body inflammatory response evoked by a suture when placed into a wound. In general, natural materials (e.g. surgical gut) are degraded by proteolytic enzymes and cause a much greater inflammatory response than do synthetic materials (e.g. polypropylene) which are absorbed via hydrolysis .
Types of Suture Material
Sutures are characterized as absorbable or non-absorbable, based upon their ability to be enzymatically digested or hydrolyzed. Most absorbable sutures lose the majority of their tensile strength long before they are fully absorbed. In general, absorbable sutures are used to close the dermis and deeper subcutaneous layers and are not removed.
Non-absorbable sutures are resistant to hydrolysis and enzymatic degradation. Non-absorbable sutures such as nylon and polypropylene are usually used as surface (or cutaneous) sutures, and they are routinely removed 5–14 days after surgery (earlier on the face and later on the trunk and extremities).
Absorbable Sutures
The most commonly used absorbable sutures are described below and summarized in Table 144.1 .
| COMMONLY USED ABSORBABLE SUTURES | ||||||||
|---|---|---|---|---|---|---|---|---|
| Suture | Configuration | Tensile strength | Ease of handling | Knot security * | Tissue reactivity | Uses | ||
| Surgical gut (plain) | Virtually monofilament | Poor at 7–10 days | Fair | Poor | Moderate | Rarely used today in skin | ||
| Surgical gut (chromic) | Virtually monofilament | Poor at 21–28 days | Poor | Poor | Less than plain | Skin grafts, surface sutures for mucosae | ||
| Surgical gut (fast-absorbing) | Virtually monofilament | 50% at 3–5 days | Fair | Poor | Low | Skin grafts, epidermal closure | ||
| Polyglycolic acid (Dexon ® ) | Braided † | 20% at 21 days | Good | Good | Low | Subcutaneous closure, vessel ligature | ||
| Polyglactin 910 (Vicryl ® , Polysorb ® ) | Braided † | 75% at 14 days 50% at 21 days 25% at 28 days | Good | Good | Low | Subcutaneous closure, vessel ligature | ||
| Polydioxanone (PDS II ® ) | Monofilament | wks | 4/0 and smaller | 3/0 and larger | Poor | Moderate | Low | Subcutaneous closure (high-tension areas) |
| 2 | 60% | 80% | ||||||
| 4 | 40% | 70% | ||||||
| 6 | 35% | 60% | ||||||
| Polyglyconate (Maxon ® ) | Monofilament | 80% at 14 days 60% at 28 days | Fair | Good | Low | Subcutaneous closure (high-tension areas) | ||
| Poliglecaprone 25 (Monocryl ® ) | Monofilament | 50–60% at 7 days 20–30% at 14 days 0% at 21 days | Fair | Moderate | Minimal | Subcutaneous closure (avoid if high tension site) | ||
| Glycomer 631 (Biosyn ® ) | Monofilament | 75% at 14 days 40% at 21 days | Fair | Moderate | Minimal | Subcutaneous closure; similar to poliglecaprone 25 plus an additional week of tensile strength | ||
| Polyglytone 6211 (Caprosyn ® ) | Monofilament | 20% at 10 days | Fair | Moderate | Minimal | Subcutaneous closure; more rapid absorption than poliglecaprone 25 | ||
* Directly proportional to the friction coefficient and indirectly proportional to memory.
Surgical gut
Surgical gut (catgut), one of the first sutures ever mass-produced, is composed of purified collagen fibers derived from bovine or sheep intestine. It is a natural tan fiber that is packaged wet in alcohol and dries quickly when exposed to air. Plain surgical gut is rarely used today because of its poor tensile strength and high tissue reactivity. When used as a buried suture, plain gut loses its tensile strength in 7 to 10 days and is completely digested within 60 to 70 days .
Chromic gut is plain gut that has been processed with chromium salts to increase its resistance to enzymatic degradation and to decrease its tissue reactivity. The tensile strength of chromic gut typically lasts for 10 to 14 days. Chromic gut is still widely used for surface suturing of mucosal surfaces.
Fast-absorbing gut is plain gut that has been heated to begin breakdown of the collagenous material within the suture prior to use. It maintains its tensile strength for 3 to 5 days . Fast-absorbing gut has become popular for suturing skin grafts and for placing surface sutures in wounds that are well approximated by buried sutures. No increase in wound infections has been observed in comparative studies and this suture is convenient for the surgeon and the patient because it does not require removal . However, its relatively high coefficient of friction leads to noticeable tissue drag when suturing skin. This disadvantage can be ameliorated by the addition of a thin layer of petrolatum or mupirocin ointment (referred to as “greasing the gut”).
Polyglycolic acid
Polyglycolic acid (Dexon ® ), introduced in 1970, was the first synthetic absorbable suture and its reduced tissue reactivity and predictable absorption profile represented a vast improvement over surgical gut . It is a braided glycolic acid polymer with easy handling qualities, and it maintains 20% of its tensile strength at 3 weeks. Polyglycolic acid suture is available plain or coated with poloxamer 188. This lubricant coating allows the suture to pass more easily through tissue and makes it more pliable, which facilitates knot tying.
Polyglactin 910
Polyglactin 910 (Vicryl ® , Polysorb ® ), a synthetic, braided copolymer of glycolide and L-lactide, was first introduced in 1974 and supplanted polyglycolic acid as the most popular buried absorbable suture for cutaneous surgery . The water-repelling properties of lactide delay penetration of water, and thus delay the loss of tensile strength. Polyglactin 910 maintains 75% of its tensile strength at 2 weeks and 50% at 3 weeks. Although stronger than polyglycolic acid, polyglactin 910 absorption is generally complete by 90 days, whereas polyglycolic acid is usually still being absorbed at 120 days .
Polyglactin 910 is available either undyed or dyed violet. Although the violet color usually dissipates fairly rapidly, some surgeons avoid the dyed form because occasionally it may be visible when embedded in the skin . Polyglactin 910 has a coating of polyglactin 370 plus calcium stearate which serves as a lubricant, facilitating the passage of the suture through tissue. This suture is immensely popular due to its easy handling characteristics and because it holds knots well and does not tear tissue.
Although polyglactin 910 is traditionally used as an absorbable dermal suture it may be safely used for wound edge approximation as a running cutaneous suture and removed in 5–14 days . This method still requires suture removal, but the use of a single suture for both the dermal and surface wound closure results in a 50% savings in suture cost per reconstruction. It is also an excellent choice for the vermilion lip as it is the authors’ experience that polyglactin 910 maintains excellent approximation, does not irritate the opposing mucosal surfaces, and incites much less inflammation than silk.
Polyglactin 910 is also available in a partially hydrolyzed form (Vicryl Rapide ® ), which is useful as a percutaneous suture that does not need to be removed as it spontaneously dislodges in 7–14 days. Similar to fast-absorbing gut, this suture is indicated for wound edge approximation where only 1–2 weeks of support will be needed and suture removal may be painful or is not convenient.
Polydioxanone
Polydioxanone (PDS II ® ) is a monofilament polymer made from the polyester poly ( p -dioxanone). The primary advantage of polydioxanone over polyglycolic acid or polyglactin 910 is prolonged tensile strength . It maintains ~70% of its tensile strength at 2 weeks and 50% at 4 weeks. Traces of buried polydioxanone are present in 6-month histologic preparations . Polydioxanone is employed in high-tension areas, such as the proximal extremities and trunk. When compared to polyglycolic acid for the closure of skin wounds under tension, polydioxanone was associated with less scar spread and a lower incidence of hypertrophic scar formation .
Similar to polyglycolic acid and polyglactin 910, polydioxanone has minimal tissue reactivity . As a monofilament suture, it retains packaging memory and can be relatively stiff and difficult to tie . However, polydioxanone demonstrates optimal capacity to glide through tissue .
Polyglyconate
Polyglyconate (Maxon ® ), a copolymer of glycolic acid and trimethylene carbonate, is also an absorbable monofilament suture. Its overall properties and indications are similar to polydioxanone. It maintains 80% of its tensile strength at 2 weeks and 60% at 4 weeks , with complete absorption occurring via hydrolysis by ~180 days. Despite this prolonged absorption, there is minimal tissue reactivity. Polyglyconate may be most useful for large surgical procedures on the trunk or extremities that are under substantial tension and require prolonged, suture-based approximation during healing.
Poliglecaprone 25
Poliglecaprone 25 (Monocryl ® ) is an absorbable monofilament suture consisting of a copolymer of glycolide and ε-caprolactone. It exhibits very high initial tensile strength, but this declines rapidly during the early postoperative period with ~50–60% of its tensile strength at 1 week, only 20–30% at 2 weeks (undyed), and essentially 0% at 21 days . This absorption profile limits its use in areas where prolonged dermal support is desired. Complete absorption occurs at ~90 days .
Poliglecaprone 25 offers supple handling and minimal tissue reactivity, which led to a lower incidence of hypertrophic scarring when compared to partially hydrolyzed polyglactin 910 (Vicryl Rapide ® ) for skin approximation in a breast reduction scar model . Furthermore, poliglecaprone 25 demonstrates better knot tying and security than other commonly used absorbable monofilament suture materials . Because poliglecaprone 25 induces less inflammation than polyglactin 910 and glides easily through tissue, for many dermatologic surgeons it has become the absorbable suture of choice for closures in the head and neck region. In a recent randomized study of deep dermal sutures for repair of Mohs defects, a statistically higher rate of suture extrusion occurred with polyglactin 910 (11%) versus poliglecaprone 25 (3%), but there was no difference in ultimate cosmesis .
Its minimal tissue reactivity permits the use of poliglecaprone 25 for epidermal approximation (with removal at 5–14 days), thereby eliminating the need for separate dermal and surface sutures. A randomized, blinded, split-scar study comparing running 5–0 poliglecaprone 25 versus 6–0 polypropylene for facial surface closures found no significant differences in cosmetic outcome at 1 week or 4 months .
Glycomer 631 and polyglytone 6211
Glycomer 631 (Biosyn ® ) and polyglytone 6211 (Caprosyn ® ) are absorbable monofilament sutures with comparable physical characteristics to poliglecaprone 25. Complete absorption of glycomer 631 occurs between 90–110 days, with low tissue reactivity. Polyglytone 6211, introduced in 2002, was designed to offer the most rapid absorption profile within this class of sutures (20% tensile strength at 10 days; complete absorption at 56 days). This property was postulated to underpin the low rate of suture extrusion observed in a recent study .
Non-Absorbable Sutures
The most commonly used non-absorbable sutures are described below and summarized in Table 144.2 .
| COMMONLY USED NON-ABSORBABLE SUTURES | ||||||
|---|---|---|---|---|---|---|
| Suture | Configuration | Tensile strength | Ease of handling | Knot security * | Tissue reactivity | Uses |
| Silk | Braided † | No decrease in 365 days | Gold standard | Good | Moderate | Mucosal surfaces |
| Nylon: | ||||||
| Ethilon ® | Monofilament | Decreases 20% per year | Good to fair | Poor | Low | Epidermal closure |
| Dermalon ® | Monofilament | Good | Good to fair | Poor | ||
| Surgilon ® | Braided † | Good | Good | Fair | ||
| Nurolon ® | Braided † | Good | Good | Fair | ||
| Polypropylene (Prolene ® , Surgilene ® , Surgipro ® ) | Monofilament | Extended | Good to fair | Poor | Minimal | Running subcuticular suture |
| Polyester (Dacron ® , Mersilene ® , Ethibond ® ) | Braided † | Indefinite | Very good | Good (coating decreases) | Minimal | Mucosal surfaces |
| Polybutester (Novafil ® ) | Monofilament | Extended | Good to fair | Poor | Low | Epidermal closure |
Related posts:
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
