Chapter 4.16: The Pulley Buried Dermal Suture

Double buried dermal suture

Wounds under marked tension may be challenging to close even with well-placed buried sutures. The pulley buried dermal suture technique relies on the pulley effect of multiple loops of suture to permit the closure of wounds under even significant tension. In addition, the locking effect of placing a double loop of suture leads the suture material to lock in place after the first throw of the surgical knot, obviating the need for an assistant maintaining the alignment of the wound edges.

Suture choice is dependent in large part on location. Because this technique leaves significant residual suture material both between the incised wound edges and in the superficial dermis from both loops, care should be taken to minimize the liberal use of larger-gauge suture material. On the face, while this approach is only infrequently utilized, a 5-0 absorbable suture is appropriate, and on the distal extremities a 4-0 suture is generally adequate. Using this technique, a 3-0 absorbable suture works well on the back, though when the area is under marked tension a 2-0 suture may be needed as well. Braided suture tends to lock more definitively than monofilament, though monofilament suture allows for easy pull through when taking advantage of the pulley effect.

1. The wound edge is reflected back using surgical forceps or hooks.

2. While reflecting back the dermis, the suture needle is inserted at 90 degrees into the underside of the dermis 2 mm distant from the incised wound edge.

3. The first bite is executed by following the curvature of the needle and allowing the needle to exit in the incised wound edge. The size of this bite is based on the size of the needle, the thickness of the dermis, and the need for and tolerance of eversion. The needle’s zenith with respect to the wound surface should be between the entry and exit points.

4. 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 gently grasped with the forceps.

5. The second bite is executed by inserting the needle into the incised wound edge at the level of the superficial papillary dermis. This bite should be completed by following the curvature of the needle and avoiding catching the undersurface of the epidermis that could result in epidermal dimpling. It then exits approximately 2 mm distal to the wound edge on the undersurface of the dermis. This should mirror the first bite taken on the contralateral side of the wound.

6. Steps (1) through (5) are then repeated, after moving proximally toward the surgeon, with the tail of the suture material resting deep to the loops of suture.

7. The suture material is then tied utilizing an instrument tie (Figures 4-16A, 4-16B, 4-16C, 4-16D, 4-16E, 4-16F, 4-16G, 4-16H, 4-16I, 4-16J).

This technique is useful when there is significant tension across the wound, and therefore a single buried dermal suture may not hold the edges together. As long as undermining has been carried out effectively, utilizing a pulley technique with a thicker gauge suture material should allow for effective closure of all but the tightest wounds.

This technique is also very useful when the surgeon needs the first throw of the knot to securely hold the wound edges together, as this technique is able to effectively lock the suture in position after only a single throw. This obviates the need for an assistant’s constant presence in these instances, and permits precise placement of the suture and knot to allow for precise epidermal approximation.

It is critical to keep the suture material deep to the loops of suture when using this technique, as this is the mechanism by which the suture locks in place after the first throw. As long as the surgeon conceptualizes this approach as placing a standard buried dermal suture followed by a second standard buried dermal suture closer to the surgeon, this technique can be very simple to learn and is easily reproducible.

As always, the choice of suture material is largely based on the individual surgeon’s preference. Braided absorbable suture material has the advantage of locking more reliably than monofilament, though monofilament suture allows for easier pull through and therefore may facilitate the pulley effect of the double loop of suture material.

In areas under extreme tension, a three-loop variation of this approach is possible as well, allowing for an even more dramatic pulley effect. This benefit must be weighed against the added retained suture material that would be associated with the additional loop.

The pulley buried dermal suture, while seemingly a simple approach, can sometimes be difficult to execute properly. Care should be taken to remain at the correct depth when utilizing this technique, as taking overly superficial bites and not following the course of the needle increases the risk of marked wound inversion.

Since pulley sutures leave two loops of suture material in the skin in lieu of one, this may result in an increased risk of foreign-body reaction, suture spitting, or suture abscess formation. Still, since the bulk of retained suture material is in the knots, rather than in the thrown loops of suture, this theoretical risk may not translate into a real-world problem in most cases.

Unlike the pulley set-back dermal suture, the pulley buried dermal suture leaves suture material traversing the incised wound edge, which may similarly increase the theoretical risk of suture spitting or suture abscess formation, especially since the pulley approach may effectively double the volume of nonknot retained suture material when compared to a standard dermal suture.

As with many buried techniques, epidermal dimpling may occur where the arc of the suture reaches its apex at the dermal-epidermal junction; on the face and areas with thin dermis this should be assiduously avoided. Similarly, areas with sebaceous skin, such as the nose, require meticulous avoidance of dimpling which has the potential to persist. In truncal areas or those with thick dermis, however, a small degree of dimpling will resolve with time as the absorbable sutures are gradually resorbed.

The tendency toward wound inversion with this approach means that superficial sutures are needed more frequently with this technique than with many others, since the transepidermal sutures are utilized in order to effect eversion of the wound edges. Since obviating the need for superficial sutures may be desirable both in terms of patient comfort and convenience and ultimate cosmetic and functional outcome, this should be considered before broadly applying this technique.