Chapter 4.22: The Suspension Suture

Pexing suture, ImPli, tacking suture

This is a niche technique designed to fix one or both edges of a defect to a deeper structure. This approach has also been referred to as a pexing suture or tacking suture, and is utilized typically in several situations. First, when repairing a defect that crosses a natural sulcus, it is important to tack down the skin overlying the sulcus so that the natural depression is not blunted, or bridged, by the repair. Second, it is used when working near cosmetic subunit boundaries and free margins, to avoid functional challenges such as ectropion and eclabium, as well as cosmetic distortion of sensitive areas such as the lip and eyebrows. It is also useful in order to fix a flap in place and minimize tension on the distal portion of the flap. Finally, this approach may also be used to prevent nasal valve collapse in the appropriate setting.

Suture choice is dependent in large part on location, though this technique is usually utilized on the face. While some authors have advocated for nonabsorbable clear monofilament suture to provide a lasting suspension effect, in general absorbable suture material is adequate and may mitigate some of the concerns related to leaving a nonabsorbable foreign body in place for an extended period of time. A 4-0 absorbable suture may often be utilized for this approach on the face. While utilizing smaller gauge absorbable suture material is reasonable, it may not provide sufficient tensile strength to adequately and reliably fix the tissue to the periosteum.

1. The wound edge is reflected back using surgical forceps or hooks, and adequate visualization of the underside of the dermis is desirable.

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

3. The first bite is executed by traversing the dermis following the curvature of the needle and allowing the needle to exit closer to the incised wound edge. This will minimize the risk of vascular compromise. Care should be taken to remain in the dermis to minimize the risk of epidermal dimpling. The needle does not, however, exit through the incised wound edge, but rather 1-4 mm distant from the incised edge, or, in select cases, potentially further back from the wound edge.

4. The flap of skin 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 suspension suture. The needle is then blindly inserted through the fat and deeper structures until the bone is reached. A 3-mm bite of the periosteum 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. Hand tying may be utilized as well, which may be useful if the depth of the defect is significant (Figures 4-22A, 4-22B, 4-22C, 4-22D, 4-22E, 4-22F).

This technique is very useful when working around the eyelids and lips, though its use demands familiarity with the underling anatomy so that no sensitive deeper structures are injured or entrapped during the blind placement of the deep anchoring suture. The deep suture should also be placed parallel to the underlying vascular plexus to similarly mitigate this risk.

Placement is based on several considerations, including the degree of tension across the advanced tissue, the presence of a bony prominence, which can be used easily for suspension purposes, and the absence of underlying nerves, which could inadvertently become strangulated by the anchoring suture.

The first half of this suture technique, where the suture material is fixed to the underside of the dermis, may be conceptualized as a single throw of a set-back dermal suture. Depending on the location of the repair and the degree of suspension necessary, a single throw of this technique may be adequate. When reconstructing longer sulci, such as the mental sulcus, a series of spaced suspension sutures can be placed to assure that the natural crease is not bridged by the repair.

Pulling on the suture once it is anchored to the periosteum may help assure the surgeon that the suture is indeed tacked down to an immobile surface.

A central advantage of this technique is that it may permit the use of linear closures in areas where otherwise a flap would have been advisable to minimize free-margin distortion. Thus, for example, closures on the lower forehead or upper malar area may be closed in a linear fashion if the advancing skin (the superior and inferior portions of the repairs, respectively) is effectively tacked down.

A three-point variation of this approach is possible as well, which allows wound-edge approximation and a tacking effect to occur all with one suture placement. This is accomplished by first placing either a buried vertical mattress or set-back dermal suture at the two wound edges and then taking a bite of the underlying periosteum prior to tying the knot. The suture material thus fixes the wound edges together as well as to the underlying anchoring point. This approach, however, may result in suboptimal wound-edge eversion and places additional stress on the suture material, increasing the risk of scar spread. Moreover, it is only appropriate if the anchor target lies in the approximate midpoint of the defect, since it recreates a natural sulcus but does not permit differential pull from one side of the defect; therefore, this approach is of little utility when attempting to avoid cosmetic distortion of sensitive areas.

This technique may also be used as an alternative to cartilage grafting when reconstructing the nose. Loss of alar cartilage may lead to nasal valve collapse, which traditionally was addressed by placing an auricular cartilage graft along the reconstructed alar rim in order to maintain valve patency. A simple and elegant alternative is placing a suture in the ala and fixing it to a point superolaterally in the maxillary periosteum, permitting the nasal valve to remain open and obviating the need for a cartilage graft in many cases.

In select cases, a suspension suture may be used to fix a flap to fascia or other soft tissue structures, rather than periosteum, in order to secure its position and decrease the tension across superficial sutures at the time of final closure.

Since the underside of the dermis is tacked to the periosteum, this technique may result in an area of depression at the site of suspension suture placement. It is therefore important to utilize this approach exclusively in areas with adequate laxity, as poorly placed suspension sutures could theoretically result in an aggravated degree of distortion in cosmetically sensitive areas. Moreover, the presence of only minimal laxity increases the risk of subsequent dehiscence and ischemia.

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 the best location for suspension suture placement. Such areas include the mental crease, the zygomatic arch, malar eminence, and supraorbital and infraorbital ridges. 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.