Chapter 4.34: The Stacked Double Purse-String Suture

Like all purse-string approaches, this technique is designed to either shrink the size of a defect or obviate it entirely, depending on the degree of tension and the size of the defect. It is a niche technique, since the purse-string effect tends to lead to a slight puckering in the surrounding skin, a feature that may be acceptable (and will likely resolve with time) on areas such as the forearms and back but is less desirable in cosmetically sensitive locations such as the face. This technique relies on first performing a purse-string closure of the fascia or deeper structures followed by a second purse-string layer through the dermis.

Suture choice is dependent in large part on location, though as always the smallest gauge suture material appropriate for the anatomic location should be utilized. On the back and shoulders, 2-0 or 3-0 suture material is effective, and on the extremities and scalp, a 3-0 or 4-0 absorbable suture material may be used. In the unlikely event this technique is used on the face, a 4-0 or 5-0 absorbable suture is adequate. Since the technique requires easy pull through of suture material, monofilament absorbable suture is generally preferable.

1. Wide and deep undermining is performed around the defect.

2. The wound edge at the far end of the round- or oval-shaped wound, parallel to the incision line, is reflected back.

3. With the tail of the suture material resting between the surgeon and the far end of the wound, the needle is inserted into the deep dermis or superficial fascia on the far edge of the wound with a trajectory running parallel to the incision. The needle, and therefore the suture, should pass through the deep dermis or fascia at a uniform depth. Bite size is dependent on needle size, though in order to minimize the risk of necrosis it may be prudent to restrict the size of each bite. The needle should exit at a point equidistant from the cut edge from where it entered.

4. The needle is then grasped with the surgical pickups and simultaneously released by the hand holding the needle driver. As the needle is freed from the tissue with the pickups, the needle is grasped again by the needle driver in an appropriate position to repeat the preceding step to the left of the previously placed suture.

5. A small amount of suture material is pulled through and the needle is inserted into the deep dermis or superficial fascia to the left of the previously placed suture, and the same movement is repeated.

6. The same technique is repeated moving stepwise around the entire wound until the needle exits close to the original entry point at the far end of the wound.

7. Once the desired number of throws have been placed, the suture material is then pulled taut, leading to a partial closure of the wound, and tied utilizing an instrument tie.

8. Steps (2) through (7) are then repeated, but now in the mid-dermis, closer to the incised wound edge, so that two sets of nested circumferentially oriented sutures are ultimately placed (Figures 4-34A 4-34B, 4-34C, 4-34D, 4-34E, 4-34F, 4-34G, 4-34H, 4-34I).

This technique may be thought of as a hybrid between corset plication and a traditional purse-string closure, and is designed as an efficient method of wound area reduction. In many cases, placing a stacked double purse-string suture can effect complete wound closure and it therefore represents an alternative to a layered repair.

On a pragmatic level, this approach is generally utilized when either a patient is unwilling to undergo a traditional linear closure or when their comorbidities make the additional length of the incision for a linear closure an unrealistic option.

As with linear running dermal techniques, this technique may be used as a modified winch or pulley suture, since the multiple loops help minimize the tension across any one loop and permit closure of wounds under marked tension. Because each throw is not tied off, however, it is important to adequately secure the knot.

As with other running dermal techniques, this approach leaves a fair amount of absorbable suture material in the dermis, and since this technique places two sets of purse-string sutures, it leaves even more suture material in place than the standard purse-string approach. Therefore, foreign-body reactions, suture abscess formation, and infection are possibilities. That said, since each suture line is secured with a single knot, and since most of the bulk of any suture line is in the knots, rather than the lengths of suture material between knots, this technique may be less susceptible to suture abscess or suture spitting than others.

The pucker effect of this closure resolves rapidly in atrophic skin, though it can persist in other areas; patients should realize that some degree of residual puckering toward the center of the wound is to be expected.

Since the entire closure is held by two knots, this approach may be associated with a higher rate of wound dehiscence, as knot failure or failure in the suture material at any point leads to an immediate loss of tension on the closure. Given the concern regarding knot breakage, it may be helpful to attempt to better secure the knot. This may be done by paying particularly close attention to knot tying, tying an extra full knot, adding extra throws, or leaving a longer tail than would traditionally be executed.

This approach provides less wound eversion than vertically oriented approaches such as the set-back dermal or buried vertical mattress sutures. Therefore, consideration should be given to adding additional superficially placed everting sutures, such as the vertical mattress suture, in order to mitigate this problem. Still, since this approach is generally adopted when the surgeon has accepted that the cosmetic outcome may be less than ideal, it may be reasonable to use this approach as a solitary closure.