Once the suture is satisfactorily placed, it must be secured with a knot. The instrument tie is the most commonly used method of securing sutures in cutaneous surgery. The square knot, or surgeon 's knot, is traditionally preferred. The knot should be tightened sufficiently to approximate the wound edges without constricting the tissue and impeding blood flow.
When tying suture knots, properly squaring successive throws is important. That is, each tie must be laid down perfectly parallel to the previous tie by reversing the loops in each successive throw. When tying rope, this is accomplished using the memory aide "left over right and twist, and then right over left and twist. " With instrument ties, this is accomplished by alternating sides as the suture is twisted around the needle driver. This procedure is important in preventing the creation of a granny knot, which tends to slip and is inherently weaker than a proper square knot. The first throw in the knotting sequence is often looped or twisted twice, producing the surgeon 's knot. When the desired number of throws is completed, the suture material is cut (if interrupted sutures are used) or the next suture may be placed (if running sutures are used). An absolute minimum of three throws are needed for knot security, but some sutures require more throws to remain tied. When in doubt, five throws will hold almost all sutures securely.
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Many varieties of cutaneous suture materials and needles are available. In modern sutures, the suture is swagged (attached) to the needle. Cutting and reverse-cutting needles are most commonly used for skin surgery, although tapered "plastics " needles are also used. Both cutting and reverse-cutting needles have a triangular body. A cutting needle has the point of the triangle on the inner curve of the needle, which is directed toward the wound edge. A reverse-cutting needle has the point of the triangle on the outer curve of the needle, which is directed away from the wound edge and reduces the risk of the suture pulling through the tissue.
A number of various types of sutures are available. They may be monofilaments (Prolene or Ethilon) or multifilamentous (silk). Tensile strength is defined as the amount of weight required to break a suture divided by its cross-sectional area. The designation of suture strength is the number of zeros. The higher the number of zeros (1-0 to 10-0), the smaller the size and the lower the strength of the suture. Memory is the inherent ability of a material to return to its former shape after being manipulated and is usually related to its stiffness. A suture with a high level of memory is more difficult to handle and more susceptible to becoming untied than a suture with low memory. An absorbable suture is one that will lose most of its tensile strength within 60 days after implantation. Nonabsorbable sutures do not lose tensile strength within 60 days and usually need to be removed.
- Instruments for skin suture placement are found in Appendix G and can be ordered through local surgical supply houses.
- Suture materials can be ordered from Ethicon, Somerville, NJ. Web site: http://ecatalog.ethicon.com/EC_ECATALOG/ethicon/default.asp.
- Closure of wounds
- Anchoring tubes and devices to the skin
- None specifically; see specific suture technique chapters.
To prepare the suture for tying, pull it through the skin until a tail of about 2 cm remains. Although there are multiple techniques for an instrument-tying suture, one simple, easy-to-remember method is shown next.
- Pearl: A shorter suture tail (about 2 cm) is much easier to work with and better conserves suture than a long tail.
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Be careful not to allow the running end of the suture to accidentally touch nonsterile areas and become contaminated. A simple way to avoid this and keep good control of the needle is to grasp the needle between the thumb and forefinger of the nondominant hand and gently wrap (so as not to pull the tail through the wound) the excess suture around the three middle fingers during the tying procedure.
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Start the tie by placing the needle driver parallel to and directly over the incision also described as "place the needle driver " in the valley. ' " This will be the position to begin each throw of the knot. The dominant hand is holding the needle driver, and the nondominant hand is grasping the running suture that has the needle on the end of it.
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Without displacing the dominant hand or the needle driver, wrap the running end of the suture twice over the top of and around the needle driver.
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Grab the tail of the suture with the jaws of the needle drivers.
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Pull the dominant hand and needle driver toward the nondominant side, while simultaneously pulling the nondominant hand and running suture toward the dominant side to place the first throw of the surgeon 's knot. This will result in the provider 's forearms being crossed, and this position will be maintained until the next throw is placed.
- PITFALL: Do not let go of or reposition the hands, suture, or needle driver until the tie is completed. This method relies on the progressive placement of the hands in each step to correctly tie the knot.
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Now place the needle driver back, parallel to, and directly over the incision in exactly the same position as in Step 2. Wrap the running end of the suture once over the top of and around the needle driver.
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Grab the tail of the suture with the jaws of the needle drivers. Pull the dominant hand and needle driver back toward the dominant side while simultaneously pulling the nondominant hand and running suture toward the nondominant side to place the second throw of the knot. Note that the provider 's arms should now be uncrossed.
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Steps 2 through 5 are then repeated, with only single wraps for each pass, until the desired number of throws is placed. Cut the suture with suture scissors with approximately 0.5-cm ends.
- Pearl: When in doubt about the number of throws to use, remember that five throws will work for most sutures.
Step 9 View Original Step 9 View Original
- Strangulation of skin edges because of excessive tension
This technique is the same for patients of all ages.
Instruct the patient not to pick at, break, or cut the stitches. Have the patient cover the wound with a nonocclusive dressing for 2 to 3 days. A simple adhesive bandage (Band-Aid) will suffice for many small lacerations. Have the patient make an appointment made so the provider can remove any nonabsorbable sutures.
Coding Information and Supply Sources
See the specific suture technique chapters for coding information.
Adams B, Anwar J, Wrone DA, et al. Techniques for cutaneous sutured closures: variants and indications.
Semin Cutan Med Surg.
2003;22(4):306 " 316. [View Abstract]
Fundamentals of Cutaneous Surgery
. St. Louis: CV Mosby; 1988:384 " 394. 3
Guyuron B, Vaughan C. A comparison of absorbable and nonabsorbable suture materials for skin repair.
Plast Reconstr Surg.
1992;89:234. [View Abstract]
Hollander JE, Singer AJ. Laceration management.
Ann Emerg Med
. 1999;34:356. [View Abstract]
Ivy JJ, Unger JB, Hurt J, et al. The effect of number of throws on knot security with nonidentical sliding knots.
Am J Obstet Gynecol
. 2004;191(5):1618 " 1620. [View Abstract]
Lammers RL, Trott AT. Methods of wound closure. In: Roberts JR, Hedges JR, eds.
Clinical Procedures in Emergency Medicine.
3rd ed. Philadelphia: WB Saunders; 1998:560 " 598. 7
Lober CW, Fenske NA. Suture materials for closing the skin and subcutaneous tissues.
Aesthetic Plast Surg
. 1986;10:245. [View Abstract]
. Philadelphia: WB Saunders; 1990:1 " 68. 9
Moy RL. Suturing techniques. In: Usatine RP, Moy RL, Tobnick EL, eds.
Skin Surgery: A Practical Guide.
St. Louis: Mosby; 1998:88 " 100. 10
Moy RL, Lee A, Zalka A. Commonly used suturing techniques in skin surgery.
Am Fam Physician
. 1991;44:1625 " 1634. [View Abstract]
Moy RL, Waldman B, Hein DW. A review of sutures and suturing technique.
J Dermatol Surg Oncol.
1992;18:785. [View Abstract]
Odland PB, Murakami CS. Simple suturing techniques and knot tying. In: Wheeland RG, ed.
. Philadelphia: WB Saunders; 1994:178 " 188. 13
Stegman SJ, Tromovitch TA, Glogau RG.
Basics of Dermatologic Surgery
. Chicago: Year Book; 1984:41 " 42. 14
Atlas of Cutaneous Surgery
. Boston: Little, Brown; 1987:26 " 28. 15
Basic Soft-Tissue Surgery
. Kansas City: American Academy of Family Physicians; 1998: 34 " 38. 16
2008 MAG Mutual Healthcare Solutions, Inc. 's
Physicians ' Fee and Coding Guide. Duluth, Georgia. MAG Mutual Healthcare Solutions, Inc.