With running stitches, the first stitch and tie are the same as for a simple interrupted stitch. I generally start at one edge of the wound, although I may start in the center if there is tension. With a linear wound, I stretch the wound (to avoid translational errors) as I begin my first stitch (Figure 3). If there is tension on the wound, I "lock" the stitch after the first throw by pulling both sides of the suture to one side. This holds the first throw tight and helps prevent a loose first knot. I then cut the short end and continue suturing with the long end, making sure that the second stitch is close to the first. Each stitch should run perpendicular to the wound below the surface, leaving the visible portions of suture at a slight angle to the wound (Figure 4). The final 2 stitches, like the first 2, should also be close together. Tie the final knot using a "bite" of suture that is a loop rather than a single loose end (Figure 5). Because suturing done with running stitches relies on a single knot at each end, I make sure that my knots have at least 5 throws each.
STITCHES FOR SPECIAL SETTINGS
Other, less frequently used suturing techniques include:
- Vertical mattress stitch.
- Horizontal mattress stitch.
- Interlocking stitch.
- Subcuticular stitch.
- Buried stitches.
Mattress stitches. The vertical mattress stitch might be described as 2 stitches in 1. It is useful in settings in which you do not want to place a deep stitch because of tension on a wound.
A horizontal mattress stitch is basically 2 stitches side by side. However, in a regular interrupted stitch the suture material crosses above the wound, while in a horizontal mattress stitch, it does not (Figure 6). Use of the mattress stitch helps maintain wound eversion and may decrease suture time by halving the number of knots that need to be tied. Wound inversion may be a problem in skin that has minimal or loose supportive tissue, such as that of the back of the hand (where the horizontal mattress stitch is likely to work well).
A variation of the horizontal mattress stitch is a good choice for the pointed tip of a skin flap. Start on the non-flap area, then run the stitch sideways through the tip of the flap. Finally, finish as you would with a regular horizontal mattress stitch. This technique helps to minimize tissue strangulation in an area with compromised circulation.
Buried stitches. These can be helpful in wounds under tension and when there is potential dead space that needs to be closed. Buried stitches can also improve cosmetic results by minimizing wound tension at the epidermal level and decreasing hematoma formation. However, buried stitches are probably overused. They can increase infection risk, and they can work their way out to the surface weeks after the wound has healed. Newer, antibiotic-impregnated absorbable suture may reduce the risk of infection. Avoid sewing through adipose tissue; this causes strangulation and increases infection risk. When deep stitches are used, make sure the patient is aware of their presence.
Subcuticular stitches. Continuous subcuticular or running dermal sutures are frequently used by surgeons in conjunction with skin closure strips to obviate the need for suture removal. Subcuticular stitches are technically more difficult than other types. The stitches are placed parallel to the skin surface at the dermal-epidermal junction; backtrack slightly with each stitch to ensure correct positioning. Skin closure strips may be used on the surface to improve apposition.
Subcuticular stitches are a good choice for patients who are prone to keloid formation. However, avoid the use of absorbable suture in such patients; it may provoke more tissue reaction than nylon or polypropylene.
If non-absorbable suture is used, make sure that both ends exit the skin, and stitch so that the suture surfaces every 3 cm (this allows it to be easily cut into segments and thus facilitates removal). When absorbable suture is used, the entire closure may remain buried.
Always consider your own safety and comfort when you close lacerations. Use proper lighting and positioning: elevate the bed or examination table until the wound is at about the level of your elbow. Use protective goggles when injecting anesthesia. Avoid grabbing the needle with your hand; use a needle driver and regular-tip forceps to handle the needle instead. You can actually complete the entire repair without ever touching the needle with your hand (Figures 7, 8, and 9).
AFTERCARE, FOLLOW-UP, AND SUTURE REMOVAL
Once the repair is finished, I have the patient put light pressure on the wound with 1 finger for 10 minutes. This minimizes the amount of blood that oozes from the wound (oozing blood can slow healing by separating wound edges). The pressure also minimizes seepage of blood through the needle holes, which can later make suture removal more painful. In addition, a clean outer appearance looks better and may increase patient satisfaction.
After 10 minutes of light pressure, place a sterile dressing, along with a splint to prevent added wound tension when appropriate. Instruct the patient to keep the wound clean and dry (except for antibiotic ointment) for the first 48 hours to allow adequate time for an epithelial layer to form. After that, the patient may shower, and antibiotic ointment is no longer recommended for most wounds.
Wounds are usually checked within 48 hours. In high-risk wounds, a 48-hour check is obligatory.
Suture removal. The appropriate timing of suture removal depends on the location and depth of the wound, wound tension, patient age, and comorbidities. I find the following breakdown of time to suture removal useful (with allowances made for special considerations):
- After 4 to 5 days: facial wounds.
- After 15 days: extremity lacerations, wounds with tension.
- After 10 days: all other wounds.
Consider leaving sutures in for additional time in patients in whom healing may be delayed, such as elderly persons, those with compromised immune systems, and smokers. Leaving stitches in a few extra days prevents wound dehiscence from early removal, and except in facial lacerations—in which a delay in suture removal could cause "cross-track" scarring from the sutures—it has few disadvantages.
Minimizing scarring. Patients frequently ask whether they will have a scar. The appropriate answer is that all lacerations leave some form of scar, but that scarring can be minimized by appropriate sun protection. Initially, this may involve bandages and hats or clothing. Once the wound is healed, counsel patients to use sunscreen daily for at least 6 months and preferably up to a year. Advise patients in whose wounds the tension was initially great enough to hold the edges more than 5 mm apart that with time their scar is likely to widen. Also, warn patients with lacerations from blunt trauma or crush mechanisms that they have a higher risk of noticeable scarring.