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ADVANCES IN DERMATOLOGIC SURGERY - Editors: Jeffrey S. Dover, MD and Murad Alam, MD
The Forehead Flap for Nasal Reconstruction: How We Do It
A. M. Rotunda, MD1 and R. G. Bennett, MD2
The nose is one of the most challenging anatomic facial areas for the reconstructive surgeon to achieve an optimal, esthetic, and functional result. When large skin areas are missing on the nose and those areas extend to cartilage, the forehead flap provides ample skin, which matches the missing skin in both texture and thickness.
Reconstruction of the nose using distant pedicle flaps has been done for centuries, even before local or general anesthesia existed.1 Initially in the West (meaning Europe) the favored method was the Tagliacozzi flap described around 1600 in Italy. This flap raised a pedicle on the inner arm, which was used to reconstruct the nose. It became known as the Italian flap. In contradistinction, the Indian flap was popularized in the early 19th century by the English, who learned it during their occupation of India. This latter method used the mid-forehead for nasal reconstruction and the donor forehead wound was allowed to heal by second intention. The modern forehead flap is a refinement of the Indian flap and was popularized in the US by Kanzanjian.2
As for any surgical procedure, the patient's medical status should be assessed preoperatively. Most importantly for the forehead flap procedure, the patient's likelihood of bleeding should be determined and a history of excessive bleeding with previous surgical procedures should be noted. If the patient is anticoagulated, some thought needs to be given to how to minimize bleeding during and after the procedure. Usually we have the patient discontinue aspirin 10 days prior to a forehead flap procedure. Coumadin can be continued, but the patient's international normalized ratio (INR) should be within therapeutic range.
The donor area of a forehead flap is the central forehead. If the patient has a "low forehead" (meaning there is a relatively short vertical distance between the anterior hairline and the eyebrows), there is less available donor hairless skin than in a patient with a high balding forehead. If the patient's forehead is very low, a forehead flap may not be the optimal procedure to repair a nasal defect. The physician should discuss with the patient the extent of a forehead flap procedure and the fact that it will require at least two surgical procedures, which will not be completed for at least 4-8 weeks. Some patients may prefer a simpler procedure for wound closure (e.g., skin graft) even though the ultimate cosmetic result may be less than optimal.
Every nasal wound is different and every nose is different. In planning reconstruction of a nose defect, one needs to be cognizant of these two parameters (e.g., Figure 1). If the defect extends from the nose onto the cheek, perhaps the cheek defect is best repaired before planning the forehead flap. If the defect extends full thickness through the ala, a greater flap length from the forehead needs to be obtained than that necessary if a full thickness defect does not exist. Sometimes it may be preferable to consider enlarging a nasal defect to include a whole esthetic unit prior to flap design. Such enlargement will help camouflage the subsequent forehead flap, because one skin type instead of two will cover one esthetic unit.
Making the Template
We cut a Telfa® pad to create precisely the pattern of the wound shape. This Telfa® template is then rotated 180? and placed on the midforehead just inferior to the hairline. The outer perimeter of the template is traced on the forehead skin using gentian violet (Figure 2). In addition we mark, with gentian violet, the lateral vertical borders of the flap pedicle, which extends from the marked template to just above the eyebrows. Generally, the pedicle width is roughly the distance between the medial eyebrows.
Estimating Flap Length
We use a piece of gauze to estimate the pedicle flap length necessary, so that upon rotation, the distal flap end will reach the more distal nasal defect. We place one end of the gauze, which is stretched to the flap length, in the glabella just above the eyebrows and the other end on the midforehead near the hairline at the superior side of the previously marked donor site (Figure 3). While keeping the gauze on the glabella set as a pivot point, we rotate the superior end of the gauze over the forehead 180? to the distal end of the nasal recipient wound. If the stretched gauze length is insufficient for wound closure after rotation, one may need to laterally angulate the superior forehead donor site to provide adequate flap length. If so, the Telfa® template of the wound is used to mark a new donor site, which is then, in turn, checked again using stretched gauze to confirm adequate pedicle flap length.
Cutting the Flap
The flap is cut along the previously marked lines down to the underlying fascia (Figure 4). It is unnecessary to incise all the way to the periosteum. As one extends the pedicle incision inferiorly to just above the eyebrow area, the incision is carried superficially just beneath the dermis at first. Then, using tenotomy scissors, the subcutaneous tissue underneath the superficial incision is carefully separated so as not to transect the supratrochlear arteries. The flap and the donor site wound edges are then undermined, bleeding is stopped using biterminal electrocoagulation, and the flap is rotated 180?.
Suturing the Flap Into the Donor Site
The donor portion of the flap end is thinned, if necessary, to conform to the depth of the recipient wound. If underlying aponeurosis from the superior forehead is present, it is best to trim it off; if left, the aponeurosis will prevent vascularization of the flap from the wound below. This vascularization might be critical for flap survival. The recipient nasal wound edges are undermined and verticalized by trimming excess subcutaneous tissue. The first stitch placed is a buried 4-0 Vicryl® (polyglactic 910) suture from the most proximal portion of the nasal wound to the underside of the flap. This suture anchors the flap in its proper position. A few more buried anchoring sutures may be necessary to further anchor the flap to different nasal contours. The flap wound edges are then apposed to the recipient wound edges using 5-0 Vicryl® and 5-0 Prolene® (polypropylene) sutures. The donor site wound edges are also sutured closed in a vertical direction down the center of the forehead (Figure 5). Care must be taken at this point to ensure that all bleeding vessels are electrocoagulated in the exposed flap pedicle.
Sutured wounds on the nose and forehead are dressed with antibiotic ointment, Telfa®, gauze, and tape. Three additional special aspects of forehead flap dressing include:
The open flap pedicle stays in place for 4-6 weeks after the initial forehead flap (Figure 6). Although some surgeons advocate insetting the pedicle as early as 14 days after the initial procedure, a longer time gives the distal flap end adequate time for full vascularization and allows for aggressive flap shaping should this procedure be necessary at the time of insetting.
Once the insetting site is healed, most forehead flaps can be improved by minor procedures. The most common touch-up procedures we do include flap thinning, and scar line excision with resuturing. For removal of telangiectasias, the vascular laser (e.g., pulsed dye laser) works very well (Figure 8).
Median vs. Paramedian Forehead Flaps
Although the paramedian forehead flap is currently in vogue,3 we prefer the median forehead flap, which is described in this article. In the paramedian forehead flap, the pedicle is cut vertically and superiorly just above the medial side of one eyebrow. In our opinion, the median forehead flap results in a much less noticeable donor site scar on the forehead than that resulting from the paramedian forehead flap. In addition, increased vascular supply is created by the broader median forehead flap base, although the central forehead has a rich blood supply.4
Whole vs. Partial Esthetic Unit
If the recipient wound only involves a portion of a whole aesthetic unit, should the recipient wound be enlarged to include the whole aesthetic unit? Although a replaced whole aesthetic unit generally looks better than a partially replaced aesthetic unit, replacing a whole aesthetic unit may involve more extensive surgery to close the donor site than if a smaller recipient site wound exists. For some patients, because of their age and medical condition, it might be preferable to opt for less surgery.
To Replace or Not to Replace Missing Cartilage
Although some physicians5 advocate replacing the missing nasal cartilage underneath a forehead flap, in general, we find this procedure to be unnecessary. The forehead flap generally provides adequate tissue bulk to round out nasal contours and to recreate a missing ala. However, if contour is an issue after the forehead flap, cartilage can always be added later.
Forehead flaps can create an excellent cosmetic result when used to repair certain nasal wounds. Adherence to principles of patient selection, wound selection, and technique can ensure a successful outcome.
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Last modified: Wednesday, 06-Aug-2014 12:23:34 MDT