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The Set-back Dermal Suture Step-by-Step
The Set-back Dermal Suture Step-by-Step
a. The wound edge is reflected back using surgical forceps or hooks. Adequate
visualization of the underside of the dermis is required. b. While reflecting back the dermis, the suture needle is inserted at 90 degrees into
the underside of the dermis 2 to 6 mm distant from the incised wound edge. c. The first bite is executed by traversing the dermis following the curvature of the
needle and allowing the needle to exit closer to the incised wound edge. Care
should be taken to remain in the dermis to minimize the risk of epidermal dimpling. The needle does not, however, exit through the incised wound edge, but rather 1 to 4 mm distant from the incised edge. The size of this first bite is based on the size of the needle, the thickness of the dermis, and the need for and tolerance of eversion. d. Keeping the loose end of suture between the surgeon and the patient, the dermis on
the side of the first bite is released. The tissue on the opposite edge is then reflected back in a similar fashion as on the first side, assuring complete visualization of the underside of the dermis. e. The second and final bite is executed by inserting the needle into the underside of
the dermis 1 to 6 mm distant from the incised wound edge. Again, this bite should be executed by following the curvature of the needle and avoiding catching the undersurface of the epidermis that could result in epidermal dimpling. It then exits further distal to the wound edge, approximately 2 to 6 mm distant from the wound edge. This should mirror the first bite taken on the contralateral side of the wound. f. The suture material is then tied utilizing an instrument tie.
This technique was compared with the buried vertical mattress suture in a randomized trial and was found to be superior to in terms of eversion and cosmetic outcomes based on both physician and patient assessments.1
One of the chief advantages of this technique is its ease of execution; since the suture follows the arc of the needle on the undersurface of the dermis, there is no need to change planes, affect a heart-shaped suture placement, or guarantee that the suture exit point is precisely at the inside edge of the lower dermis, as may be needed with the buried vertical mattress suture.
Accurate suture placement is predicated on having a sufficiently undermined plane, since the entire suture loop lays on the undersurface of the dermis. Therefore, broad undermining is a prerequisite for utilizing this technique, since the first throw of the needle begins 2 to 6 mm distant from the incised wound edge.
This technique may also be used to minimize dead space when excising a spaceoccupying lesion such as a cyst or lipoma. In this event, taking the first bite set-back even further from the incised wound edge will translate into a larger ridge and will simultaneously minimize the laxity in the central portion of the wound as the dermis is pulled taught so that potential dead space is converted to a hyper-everted wound ridge which will absorb with time.
Patients should be cautioned that they might develop a significant ridge in the immediate postoperative period. Depending on the suture material used and the density of the sutures, this ridge may last from weeks to months. Explaining that the technique is akin to placing a subcutaneous splint may help the patient develop reasonable and realistic expectations and reduce anxiety regarding the immediate postoperative
appearance of the wound.4
A possible complication of hypereversion and an overly broad bite is that the raised ridge may be too large or bulky to be supported by the deep sutures.5 In this event, the wound edges may paradoxically collapse centrally leading to the appearance of a dramatically raised ridge with a central valley approximately 1 week postoperatively. As the sutures absorb over time, this will yield a depressed or inverted scar line. This can generally be avoided by not setting back the sutures more than a few millimeters from the wound edge and by placing a sufficient number of sutures so that the body of the ridge may be easily supported.