Chapter 4.20: The Double Butterfly Suture

This technique is best used in areas under very significant tension. Wounds under marked tension may be challenging to close even with well-placed buried sutures. The double butterfly suture technique relies on the pulley effect of multiple horizontally oriented diagonal loops of suture to permit the closure of wounds under even significant tension. Since the loops are horizontally oriented, a broader bite of dermis is included with each throw, adding to the theoretical robustness of this closure technique.

As always, suture material choice depends on preference and location. Though this technique is designed for wounds under significant tension on the trunk, it is commonly utilized with a 3-0 suture. While adopting a 2-0 gauge suture material is sometimes useful, especially to avoid bending smaller needles, the knot for this suture is buried in line with the incision and at the base of the dermis and therefore suture material spitting is a risk. Use of an absorbable monofilament (polydioxanone) has been proposed as providing superior outcomes over a braided absorbable suture.

1. This technique ideally requires that the wound edges be incised with a reverse bevel, allowing the epidermis to overhang the dermis in the center of the wound.

2. The wound edge is reflected back using surgical forceps or hooks. Adequate full visualization of the underside of the dermis is very helpful.

3. While reflecting back the dermis, the suture needle is inserted into the undersurface of the dermis approximately 3 mm set-back from the medial edge of the dermis at the base of the bevel. The needle driver is held like a pencil at 90 degrees to the incised wound edge and the needle may be held on the needle driver at an oblique angle to facilitate suture placement.

4. The first bite is executed by placing gentle pressure on the needle so that it moves laterally and upward, forming a horizontal loop that on cross section resembles the wing of a butterfly. The needle then exits the undersurface of the dermis after following its curvature, similarly setback from the incised wound edge.

5. 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.

6. The second bite is executed by inserting the needle into the undersurface of the dermis on the contralateral side distal to the exit point, with a backhand technique if desired and the needle still pointing in the same direction as the first throw, and completing a loop that forms an S when viewed along with the first loop.

7. The needle is then reinserted into the contralateral wound edge in line with its exit point, now heading toward the surgeon, in a mirror image of step (6).

8. Finally, the needle is then reinserted into the contralateral side in a mirror image of the first throw (step 4). Thus, the entry point of the first suture loop and the exit point of the last suture loop are directly across from each other on the undersurface of the dermis.

9. The suture material is then tied utilizing an instrument tie (Figures 4-20A, 4-20B, 4-20C, 4-20D, 4-20E, 4-20F, 4-20G, 4-20H, 4-20I, 4-20J).

This technique is designed for areas under marked tension, though it may be used in any anatomic location. As such, utilizing a sufficiently robust needle may be very helpful in mitigating the risk of needle bending that can be seen when attempting to place the needle in the thick dermis of the back.

It is helpful to conceptualize this technique as forming an S which is then turned into a figure 8. Importantly, the double butterfly technique is not executed by performing two sets of butterfly sutures sequentially.

As with the pulley buried vertical mattress approach, the first bite may be finessed by first reflecting the wound edge back sharply during needle insertion and then returning the edge medially after the apex has been reached. This approach helps lead the needle in the correct course without an exaggerated change in direction with the needle driver, though the needle is oriented parallel to the incised wound edge, as opposed to the perpendicular approach utilized with the buried vertical mattress.

The apex of the needle should be in the papillary dermis; if the needle courses too superficially, dimpling may occur. In particularly high-tension areas, the suture loops may be placed close together in order to mitigate the risk of an accordion effect. The horizontal orientation of the suture loops means that a relatively significant amount of dermis is included within each suture loop. Particularly in areas under marked tension where there is concern regarding the ability of the dermis to withstand tensile forces, this represents an advantage over other double or pulley approaches.

The need to bevel the wound edges means that this technique requires a small degree of preplanning. The bevel may, however, be useful for other techniques as well, as it may help with wound-edge apposition in general, though there is also the theoretical risk of contracture leading to a small separation between the wound edges. If the butterfly suture is utilized without beveling the wound edges, a small amount of dermis may overhang in the incised wound edges, preventing wound-edge apposition. In this event, surgical scissors or a blade may be used to trim back the overhanging dermis to permit the epidermal wound edges to come together unimpeded.

Some authors have raised concerns regarding possible wound-edge necrosis associated with horizontally oriented suture placement. Advocates of this approach report that wound-edge necrosis has not been seen as a complication, and indeed the only time that necrosis seems to be an issue is with superficially placed horizontal mattress sutures, rather than with their buried counterparts. This is likely due to a constrictive effect on the incised wound edge, which is not typically seen with buried sutures.

While the suture loops may be relatively close together, especially under areas of marked tension, the loops themselves should not overlap, as this has the potential to compress the wound edges together leading to central bunching of the wound edges.

Given the marked eversion associated with this technique, patients may be left with a small ridge in the immediate postoperative period. While this is desirable, it is also important to warn patients of this outcome; 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.