Chapter 5.36: The Combined Vertical Mattress-Dermal Suture

Subcutaneous loop suture

This is a combination suture that may be conceptualized as a hybrid between a vertical mattress suture and a dermal suture. It was designed to permit closure of deep defects and simultaneously permit wound eversion with a single suture, obviating the need for bilayered closures.

With all techniques, it is best to use the thinnest suture possible in order to minimize the risk of track marks and foreign-body reactions. Suture choice will depend largely on anatomic location and the goal of suture placement.

Typically, 5-0 monofilament nonabsorbable suture material is appropriate if there is minimal tension, and 4-0 monofilament suture maybe used in areas under moderate tension. In high-tension areas, 3-0 monofilament suture may be utilized as well.

1. The needle is inserted perpendicular to the epidermis, approximately 6 mm distant to the wound edge.

2. With a fluid motion of the wrist, the needle is rotated through the dermis, taking the bite wider at the deep margin than at the surface, and the needle tip exits between the incised wound edges.

3. The needle is then reloaded and inserted through the deep dermis on the contralateral wound edge.

4. The needle is then reloaded again in a backhand fashion and inserted through the deep dermis on the original wound edge.

5. The needle is then reloaded, entering from beneath the dermis on contralateral wound edge, exiting approximately 6 mm from the wound edge.

6. The needle is then reloaded in a backhand fashion and inserted at 90 degrees perpendicular to the epidermis approximately 3 mm from the wound edge on the same side of the incision line as the exit point.

7. The needle is rotated superficially through its arc, exiting on the contralateral side of the wound 3 mm from the incised wound edge.

8. The suture material is then tied off gently, with care being taken to minimize tension across the epidermis and avoid overly constricting the wound edges (Figures 5-36A, 5-36B, 5-36C, 5-36D, 5-36E, 5-36F, 5-36G, 5-36H).

This technique has been described as a simple approach to closure that permits closure of deeper structures (and dead-space obviation) as well as epidermal approximation and eversion. Perhaps its most useful niche is for the closure of very small defects or punch biopsies, where a single nonabsorbable suture may be used for the entire closure.

Like the standard vertical mattress technique, this technique is generally used for its pronounced effect on wound eversion. Therefore, while it is appropriate for most skin closures, it should be avoided when inversion is desired.

As with most transepidermal techniques, it is important to enter the epidermis at 90 degrees, allowing the needle to travel slightly laterally away from the wound edge before fully following the curvature of the needle when utilizing this technique. This will allow for maximal wound eversion and accurate wound-edge approximation.

An advantage of this approach, as with the vertical mattress technique, is that no suture material traverses the incised wound edge and that the suture similarly does not cross the surface of the wound. While this may be less than desirable when attempting to fine-tune epidermal apposition, it is helpful in minimizing the risk of unsightly track marks.

Since the dermal portion of the suture is executed with the same suture as the vertical mattress portion, if suture removal occurs too early there is a risk of dehiscence, since no residual absorbable suture material is left in the wound. Similarly, if sutures are left in place for too long, there is a high chance of leaving residual track marks.

As the dermal portion of the suture is performed, it may be challenging to visualize the deep portion of the wound adequately, making placement of the deeper portion of the suture more challenging.

When removing sutures, a greater degree of force may need to be applied to remove the full length of the suture material, since the single length of suture has performed multiple loops in both the dermis and epidermis. Suture material breakage is therefore a possibility, and care should be taken to apply constant gentle traction.

With any suturing technique, knowledge of the relevant anatomy is critical. When placing this suture it is important to recall that the structures deep to the epidermis may be compromised by the passage of the needle and suture material, or that constriction may take place. That said, the vertical orientation of this approach helps minimize this risk.

This technique may elicit an increased risk of track marks, necrosis, and other complications when compared with techniques that do not entail suture material traversing the scar line, such as buried or subcuticular approaches. Therefore, sutures should be removed as early as possible to minimize these complications, and consideration should be given to adopting other closure techniques in the event that sutures will not be able to be removed in a timely fashion.