Chapter 4.38: The Stacked Backing Out Subcuticular Suture Technique

Super loop suture

This is a niche technique that may be conceptualized as a backing out subcuticular approach with the first row of subcuticular sutures placed in the deep dermis, or as a variation of the stacked double purse-string technique. It is useful for wounds under mild to moderate tension, and may be used overlying deeper tension-relieving sutures.

As with any technique, it is best to utilize the thinnest suture possible for any given anatomic location. As this technique is not designed to hold marked tension irrespective of anatomic location, generally a 4-0 or 5-0 suture may be used. This is especially important since a large volume of suture material is left in situ when utilizing this approach. It is best to utilize a monofilament suture material to minimize the coefficient of friction at the time of suture removal, though this technique may also be finessed for use with absorbable suture material.

1. The needle is inserted at the far right corner of the wound, parallel to the incision line, beginning approximately 2-5 mm from the apex. The needle is passed from this point, which is lateral to the incision apex, directly through the epidermis, exiting into the interior of the wound just medial to the apex.

2. With the tail of the suture material resting lateral to the incision apex and outside the wound, the wound edge is gently reflected back and the needle is inserted into the deep dermis or fascia on the far edge of the wound with a trajectory running parallel to the incision line. 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 the deep dermis or fascia at a point equidistant from the cut edge from where it entered.

3. 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 previously mentioned step on the contralateral edge of the incised wound edge.

4. A small amount of suture material is pulled through and the needle is inserted into the deep dermis or fascia on the contralateral side of the incised wound edge after reflecting back the skin, and the same movement is repeated. The needle should enter slightly proximal (relative to the wound apex where the suture line began) to the exit point, thus introducing a small degree of backtracking to the snake-like flow of the suture material. This will help reduce the risk of tissue bunching.

5. The same technique is repeated on the contralateral side of the incision line, and alternating bites are then taken from each side of the incision line, continuing on until the end of the wound is reached. At this point, the needle’s direction is changed to head in the opposite direction, toward the apex where the suture began.

6. Moving in the opposite direction, steps (1) through (5) are then repeated, but now in the superficial dermis, with the suture material snaking an alternating course through the superficial dermis, using a backhand technique if desired.

7. The suture material may either be tied to the free end of suture at the original apex or alternatively it may be tied on the exterior of the wound (Figures 4-38A, 4-38B, 4-38C, 4-38D, 4-38E, 4-38F, 4-38G, 4-38H, 4-38I, 4-38J).

This is a niche technique, as the addition of a second row of subcuticular suture material in the wound may add only modest wound security, since it is a running technique, while it doubles the amount of suture material that will ultimately need to be removed or absorbed.

As with the standard subcuticular technique, body positioning can be very helpful in maintaining an efficient and comfortable technique. Most surgeons are trained to work with the surgical site flat and perpendicular to their body. Since the motions associated with subcuticular suture placement are 90-degrees off from this, it may be useful to stand with the surgeon’s body (shoulder to shoulder) parallel to the incision line. This allows for a flowing motion from right to left without the need to twist the shoulders or wrists.

Since this approach requires the surgeon to perform the second half of the closure moving in the opposite direction, it may be useful to use a backhand technique for many of the suture throws when moving back toward the original wound apex. This may add significantly to the time needed to complete this closure.

A smooth, flowing technique is of paramount importance in executing this technique effectively and efficiently. Some authors have advocated adjusting the angle used to hold the needle in the needle driver from the traditional 90-135 degrees to increase the surgeon’s comfort and minimize the need for physical contortion, though slightly adjusting the surgeon’s body position helps significantly in this regard.

Though it may be conceptualized as a bidirectional, two-depth subcuticular closure, the extra row of sutures in this technique pulls the deep tissues together but also adds only modestly to wound security, as the entire suture line is secured with a single knot. Therefore, it is probably best not used as a solitary closure approach, but rather layered over the top of a deeper suturing technique.

While a central strength of this technique is its entirely intradermal placement, this may also represent one of its greatest drawbacks. This technique results in leaving a very significant quantity of foreign-body material in the dermis and deeper tissues in a continuous fashion. While this may not represent a major problem in areas with a thick dermis such as the back, in other anatomical locations the large quantity of suture that is left in situ may result in concerns regarding infection, foreign-body reaction, and even the potential that the suture material itself could present a physical barrier that would impinge on the ability of the wound to heal appropriately.

The extra row of deep sutures used in this technique raises further concern regarding the possibility of tissue strangulation along the wound margin that could theoretically be associated with tightly placed subcuticular sutures. It, therefore, should be reserved for areas with an outstanding vascular supply, such as the face.

If nonabsorbable suture material is used, removal of long-standing suture entails a theoretical risk that a potential space—albeit a thin and long one—is created on the removal of the suture material. This theoretical risk may be mitigated by utilizing the thinnest possible suture material.