This technique is designed as an efficient method of wound area reduction. In many cases, placing a purse-string suture can effect complete wound closure, and it therefore represents an alternative to a layered repair of a fusiform incision. That said, a recent randomized controlled trial demonstrated that purse-string closures do not result in appreciably improved scarring over secondary intention healing.
It has been suggested that some defects on the back and extremities, particularly in elderly patients with loose skin, are better closed with a purse-string approach than with a traditional linear closure, since linear closures often heal with a residual scar and require a significantly longer excision line, while the puckering that may be present immediately postoperatively with purse-string closures is likely to resolve with time. That said, in the right hands linear closures on the trunk and extremities often heal with subtle scarring, even when wounds are closed under tension.
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.
A monofilament suture is generally used to permit easy pull through as well as straightforward suture removal.
The purse-string technique may also be used to effect hemostasis in the case of an oozing wound. For wounds in highly vascular areas, such as the scalp, a purse-string suture may be performed distant from the wound edge; small vessels will be captured within the ring of the purse-string suture and compressed when the suture material is tightened, leading to improved hemostasis. A double ring of purse-string sutures may be used as well to take even better advantage of this hemostatic effect.
Tying a purse-string closure under significant tension may be challenging, as suture material tends to slip after the first knot throw. Utilizing hemostats to secure the suture ends in position during suture lockdown may help mitigate this problem.