Video 4-34. 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.
Wide and deep undermining is performed around the defect.
The wound edge at the far end of the round- or oval-shaped wound, parallel to the incision line, is reflected back.
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.
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.
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.
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.