Chapter 4.30: The Dog-Ear Tacking Suture

This is a niche technique used for reducing the appearance of dog ears, or standing cones, at the ends of elliptical excisions or local flaps. While dog-ear minimization is generally accomplished by excising lesions with fusiform incisions, this often extends the length of the wound significantly, which is undesirable. This technique was designed as an approach to mitigate the raised dog-ear appearance of the standing cone while concomitantly avoiding unnecessarily extending the length of the wound.

Suture choice is dependent in large part on location. Since this technique is designed to bite the deep dermis and the underlying fascia or periosteum, the surgeon may choose to utilize a larger gauge suture than would be used for an equivalently placed buried suture. On the back and extremities, a 2-0, 3-0 or 4-0 absorbable suture material may be used, and on the face and other areas under minimal tension a 4-0 or 5-0 absorbable suture is adequate.

1. The apex of the wound where the incipient dog ear is anticipated is widely undermined. The wound edge at this apex is reflected back using surgical forceps or hooks, and adequate visualization of the underside of the dermis is required.

2. While reflecting back the dermis, the suture needle is inserted at 90 degrees into the underside of the dermis 4-6 mm distant from the apex.

3. The first bite is executed by traversing the dermis following the curvature of the needle and allowing the needle to exit farther from the incised wound edge. Care should be taken to remain in the dermis to minimize the risk of epidermal dimpling. The needle exits approximately 8-mm distant from the incised edge, though this depends on the size of the standing cone that is being smoothed. Keeping the loose end of suture between the surgeon and the patient, the dermis is released.

4. The standing cone may be gently pulled by the suture material so that the location of the first bite directly overlies the planned fixation point. This permits the surgeon to double-check the final position of the suture. The needle is then blindly inserted through the fat and deeper structures until bone is reached. A 3-mm bite of the periosteum or fascia is then taken, and the needle is brought back up through the soft tissues into the open center of the wound.

5. The suture material is then tied utilizing an instrument tie (Figures 4-30A, 4-30B, 4-30C, 4-30D).

This technique works best when the standing cone is fixed to a truly immobile tissue, such as the periosteum. Therefore, this approach is of particular utility on the forehead and other areas over bony prominences. On the trunk and extremities, where no truly fixed underlying anchoring point is present, the standing cone can be fixed to the muscle fascia. Though this does not lead to as dramatic a degree of downward pull as when the dog ear is fixed to the periosteum, it does have a positive impact on the height of the standing cone.

In some locations, such as convexities over the forehead, even defects repaired with a 4:1 ellipse may still display residual standing cones at the apices; therefore, this approach may be used as an adjunct in such cases as well.

This technique can be conceptualized as a suspension suture for the standing cone, where the dog ear is anchored downward to prevent the residual focal elevation that will otherwise be seen in such cases. Since no additional tissue is excised, this technique will occasionally lead to a rippling effect in the areas where it is utilized, though this is generally preferable to the dramatic bump that would otherwise be present when dog ears are left behind.

Some experience is helpful in deciding what degree of residual standing cone appearance is acceptable; wounds on the lower legs, for example, often heal well and residual standing cones may smooth out spontaneously, likely due to the tension over bony prominences; conversely, standing cones over cheeks and other areas with abundant soft tissue often resolve only minimally over time, and therefore leaving significant dog ears in these locations should be assiduously avoided if possible.

In some cases, instead of taking a single bite from the undersurface of the dermis it may be more effective to take two bites, as if a set-back dermal suture were being taken from the imaginary line splitting the standing cone. These two bites are then anchored to a central anchoring point deep to the theoretical midpoint of the standing cone.

This approach, when used in concert with a technique such as the fascial plication suture that leads a round or oval defect to appear more fusiform, may permit closure of wounds with significantly less standing cone removal, leading to shorter—and therefore more cosmetically appealing—scars.

As with any suspension suture, since the underside of the dermis is tacked to periosteum, this technique may result in an area of depression at the site of suture placement.

The anchoring portion of this suture technique carries the risk of damage to an underlying vascular or neural plexus. Familiarity with the underlying bony anatomy is therefore of paramount importance, as it also permits the surgeon to select appropriate locations for dog-ear tacking suture placement.

As suture material is tacked to the periosteum—and traverses muscle and fascia—patients should be warned that they may experience more pain with this approach than would be experienced with a typical bilayered closure.

When tacking to the underlying fascia, since the anchoring point is not entirely immobile, it is possible that the degree of standing cone reduction will be only modest. Therefore, such cases may require a greater degree of standing cone excision than those overlying bony prominences.

The residual focal rippling of the epidermis caused by tissue redundancy will generally resolve with time, though in areas with significant actinic damage and solar elastosis the lack of underlying elasticity may lead to residual textural changes that do not resolve. In these unusual cases, surgical revision may be useful to excise the residual area, as would be done for a dog-ear removal, thus leading to a more acceptable cosmetic outcome.