Forehead Flaps Treatment & Management

Forehead flaps are the mainstay for reconstruction of large cutaneous nose defects. The median forehead flap is mentioned mainly for historical interest, having been replaced by paramedian and midline forehead flaps. These 2 flaps have been refined and modified and provide dependable coverage with good cosmetic results.

The forehead flap uses a vascular pedicle based on the medial brow area, often centered on a unilateral supratrochlear artery. This pedicle provides nutrient supply to the skin paddle of the flap after elevation and during the neovascularization process from the nose into the skin paddle. ^[7]

Traditionally, the pedicle is divided and inset into the donor site after a 3-week interval, although sufficient vascular ingrowth probably occurs by the end of 2 weeks. In high-risk individuals (eg, persons who smoke, patients with diabetes), the flap may be elevated in a manner that creates a thicker flap, with the frontalis muscle intact, and debulked at an intermediate stage after 3 weeks. Final pedicle division occurs as a third stage 3 weeks later. On these rare occasions, the forehead flap is a three-stage procedure rather than a two-stage procedure.

Conversely, the forehead flap can be transferred as a single-stage procedure on select individuals (eg, young persons, patients who do not smoke). Excise the skin of the pedicle, and tunnel the deepithelialized pedicle under intact glabellar skin to fill the nasal defect. This converts the forehead flap into an island flap and allows the reconstruction to be performed in a single stage. The vascular pedicle may be compromised somewhat with this technique; therefore, restrict its use to special circumstances and ideal patients.

A retrospective study by Faris et al indicated that a midline central artery forehead flap can be successfully used in nasal reconstruction, possibly with less transposition of frontal hair to the nose than in supratrochlear-based flaps because of the more inferior pedicle base. The investigators reported that the rate of vascular compromise did not differ statistically between central artery forehead flaps and either glabellar paramedian or classic paramedian flaps. ^[8]

A study by Stigall et al indicated that the use of a paramidline forehead flap employing no Doppler examination to ensure inclusion of the supratrochlear artery can lead to nasal reconstruction outcomes similar to those of a traditional paramedian forehead flap using Doppler identification of the artery. Among the 50 nasal defects repaired in the study, flap survival and complication rates for the paramidline flaps, which extended from the glabellar midline to 1.2 cm lateral to the midline, did not significantly differ from those of the paramedian flaps. ^[9]

Preoperative assessment for nasal reconstruction begins with a determination of patient goals and desires for repair. Some patients may not be particularly concerned with their appearance and want little or no intervention. Others may accept a compromise in aesthetic outcome in return for a less-complicated or single-stage repair. If a patient desires optimal aesthetic appearance with the best chance for function preservation, a staged forehead flap is the best option.

An important part of preoperative counseling includes a review of the prospective resultant scars. This is especially important because a long scar is created on the forehead, where there previously was none. Moreover, in order to accommodate the aesthetic subunits, the nasal scars do not correspond to the existing nasal defect after modification. Although this technique is performed to improve final aesthetics, patients and family are occasionally upset by the increased size of the defect.

Other special considerations include forehead numbness, medialization of the eyebrows, and transposition of potentially hair-bearing skin from the distal aspect of the forehead flap to the nose. Emphasize the significant postoperative care needed for the pedicle and appearance. Analysis of the defect starts with a description of missing tissue and structures. Evaluate missing cartilage or structural support disruptions to determine the need for cartilaginous grafting and function restoration.

Infiltrate local anesthetic with epinephrine throughout the nose and forehead, even with patients under general anesthesia. Carefully outline aesthetic subunits of the nose at the outset of the procedure to help define the defect in terms of aesthetic units.

Excise these units accordingly to place strategically the flap borders (and consequently the final scars) along the borders of these units, thus rendering them less conspicuous. Although the aesthetic units are drawn independent of the existing nasal defect, they are not always completely excised. Some modifications can be used to minimize the amount of skin excised while still preserving the camouflage of scars. The key concept is modifying the defect in terms of shape and borders such that the resultant scars consist of straight lines and sharp corners. They are most inconspicuous when placed along the borders of subunits.

Although strict adherence to a numerical value is unnecessary, some feel that 50% involvement mandates a complete excision of the subunit. This varies, especially when it extends caudally and requires a longer flap. The authors tend to be more aggressive when the additional excision does not mandate a longer forehead flap (ie, when the aesthetic unit of concern is cephalad to the original defect). On the other hand, when a defect only marginally involves the superior border of a nasal tip unit, one is less likely to complete the tip excision because doing so requires extending the forehead flap superiorly and, possibly, into the hairline.

The defect depth is taken down to the perichondrium of the existing nasal skeleton, even if the original defect is more superficial. This allows for less bunching up of the skin paddle, more even scar distribution beneath the flap, and improved topography of the nasal surface.

After involved subunits are excised and the defect shape is modified, cut and mold a malleable foil template (eg, a suture package) to match the new defect as seen in the image below.

This template serves 2 purposes: (1) precisely describing the shape of the defect (especially any irregular and sharp edges) and (2) demonstrating 3-dimensional contours often lost by simple ruler measurements. Account for alar lobule convexity during the initial measurements. Unrecognized convexity results in a flap that is too narrow and a lobule that is flat, without the normal acute alar-facial angle.

The foil template is then transferred to the exact midline of the forehead for markings as seen in the image above. By placing the template (and so the skin paddle of the flap) in the precise midline, the resultant scar is positioned strategically in the center of the forehead and tends to be less conspicuous than paramedian scars.

Plan the vertical position of the template by rotating gauze from the pedicle base, near the medial brow, from the defect site to the upper forehead. This technique assures that the planned flap reaches all defect borders. An ipsilateral flap refers to a pedicle base on the same side as the nasal defect and has the advantage of an effective greater flap length to reach the distal border of the defect. This comes at the expense of a greater arc of rotation, which may comprise the pedicle base.

Alternatively, a contralateral flap has less rotation at the pedicle base but may not reach as far caudally as the ipsilateral flap. Additionally, the contralateral flap tends to cause less visual interference than the ipsilateral flap. Midline defects have no advantage, and the decision is arbitrary.

Elevate the skin paddle of the flap in the subcutaneous plane, superficial to the frontal muscle as seen in the image below. Additional selective thinning is then performed to better match the variable skin thicknesses of different regions of the nose as seen in the image below. If the patient has small vessel disease, such as a smoker, then an intermediate stage is anticipated. In this case, the skin paddle is lifted in the subgaleal plane, with planned thinning as an intermediate stage after 3 weeks. Final pedicle division then occurs at the third stage, another 3 weeks later.

The pedicle portion of the flap is always elevated in a subgaleal plane to the level of the orbital rim. At the inferior border of the pedicle, the dissection continues under the corrugator muscle, allowing the supratrochlear artery to be kept between the orbicularis oculi muscle and corrugator. The periosteum in this region can be incised and incorporated into the pedicle base (as seen in the image below), allowing greater caudal reach and some rigidity to the base for vascular protection.

With the ipsilateral or contralateral flap or the midline versus paramedian flap, center the pedicle base on the medial brow, capturing the supratrochlear artery. The blood flow is not only through the supratrochlear vessel but is also driven by the rich collateral vasculature of that region. The pedicle base must be narrow, no wider than 1.5 cm and usually closer to 1.2 cm. Excessive width in this area compromises the blood flow during the twisting of the pedicle. A narrow pedicle base allows for easier rotation with less kinking and greater reach.

The pedicle base can be extended beyond the supraorbital rim and into the brow as needed for additional flap length without a compromise of flap perfusion. The supratrochlear foramen or notch may be palpated in some individuals and can serve as a reference point. Some authors advocate using a Doppler probe to locate and follow the course of the supratrochlear artery. This practice is used only very rarely because of the dependable anatomy and robust vascular perfusion in this area. After flap elevation, it is rotated to fill the nasal defect and closed in layers with attention to eversion of the skin edges as seen in the image below.

The cephalic border of the nasal defect is under the flap pedicle and is not closed. The forehead donor site is usually closed primarily in a layered fashion, with attention to reapproximating the strong galeal layer. Donor site defects larger than 3.5 cm often cannot be closed primarily and are best allowed to heal by secondary intention rather than with ancillary flaps or skin grafts. The forehead wound undergoes progressive contracture, and the center of the wound fills with granulation tissue, resulting in a final scar that exceeds other techniques. The pedicle is loosely wrapped with antibiotic-impregnated gauze and is changed regularly.

Some surgeons apply a skin graft to the pedicle undersurface to reduce wound weeping.

Pedicle division is performed safely after 3 weeks as seen in the image below. One must aggressively thin the cephalic border of the flap from above to best match surrounding skin thickness; however, exercise caution to avoid extending the level of undermining beyond 50% of the original skin paddle. The vascular supply to the flap is retrograde from the recipient bed, and excessive undermining can jeopardize viability. The original nasal defect wound is freshened, and the superior portion of the skin paddle trimmed to fit the remaining defect. The pedicle base is amputated, thinned, and then inset back into the medial brow region.

On occasion, the base of the pedicle can be entirely excised and the resultant donor site closed primarily. Meticulous attention must be paid to restoring brow symmetry during the pedicle inset because the involved side is usually displaced inferiorly and medially. When unrecognized, the asymmetry (in the future) may be the most distracting feature.

Vigorously debulk the pedicle stump to avoid the common "pincushioning" from a trap-door effect.

Avoid excessive pressure dressings on the nose despite the risk of a small hematoma forming under the skin paddle. (Venous congestion is a greater concern than arterial ischemia, and any extrinsic pressure exacerbates that risk.) A pressure dressing is usually applied to the forehead, although this region is typically quite taut and a hematoma is unlikely.

Observe traditional wound care, including cleaning with dilute hydrogen peroxide and a liberal application of moisturizing ointment. Avoid peroxide on any open wound or skin graft because of the potential for delayed epithelialization and cellular toxicity.

Sun protection is of paramount importance for at least 6 months. Facial scars and flaps are particularly sensitive to pigmentation effects of ultraviolet rays, which can result in permanent discoloration with respect to surrounding skin.

Patients are usually seen the first or second day postoperatively so their dressings can be changed, their wounds can be cleaned (especially intranasally if involved in the repair), and they can be emotionally supported. Once pedicle division is accomplished successfully, long-term follow-up concentrates on tumor surveillance, because these patients are at significant risk for future cutaneous malignancies, which makes early diagnosis essential. Additional ancillary procedures are often performed at follow-up visits (eg, steroid injections to expedite contour improvement or flatten scars, segmental dermabrasion).

Postoperative complications may be classified as either early or late. Vascular compromise is a significant early complication, and the physician must distinguish between arterial or venous events. Arterial ischemia typically manifests as a cool, pale flap that fails to blanch with gentle pressure. On the other hand, venous congestion may be warm to touch and have a darker (even purple) color. The congested flap demonstrates prompt capillary refill and brisk venous bleeding following a pinprick. The distinction is important because respective interventions may be unique.

Venous congestion is more common and may respond to simple measures, such as release of suture lines, medicinal leech therapy, or serial pin pricks. Arterial insufficiency is more problematic, and patient observation may be the only alternative. Conservative debridement and aggressive wound care is the initial measure. Once a clear line of demarcation is identified, elevating and sliding the flap more caudally may be necessary to repair the necrotic segment, especially before wound contracture and alar notching ensue.

Hyperbaric oxygen is a proven modality to enhance marginal tissue viability and is beneficial to congested and ischemic tissues. Achieving a positive outcome mandates prompt recognition and early intervention, (ie, within the first 24 h postoperatively). The extremely high partial pressures generated allow greater oxygen diffusion and penetration of marginal tissues while reducing arterial inflow through vasoconstriction. Hyperbaric oxygen is used preoperatively for patients with known small vessel disease who are in need of complex, total nasal reconstruction. It involves 20 dives preoperatively and 10 more postoperatively.

A hematoma can develop underneath the flap bed and can jeopardize the outcome through compromised viability, delayed vascular ingrowth into the flap, or predisposition to infection. Prompt aspiration of the hematoma and appropriate-spectrum antibiotic therapy are indicated in this situation.

If an area of superficial necrosis or epidermolysis occurs, conservative treatment with observation and gentle debridement is usually prudent. Complete flap loss and death has not been observed and represents an exceedingly rare complication.

A retrospective study by Santos Stahl et al indicated that incidence of partial flap necrosis may be similar for the two- and three-stage techniques for paramedian forehead flap nasal reconstruction. The study involved 87 patients who underwent the two-stage procedure and 100 patients who underwent the three-stage operation, with a follow-up period of at least 6 months. Partial necrosis rates for the procedures were 3.4% (two-stage flap) and 5% (three-stage flap). However, although the relative risk of partial flap necrosis rate did not differ significantly between the two groups, the three-stage flap was used for more complex nasal reconstructions, creating a natural selection bias characteristic of a retrospective review. ^[10]

Some patients may present with epistaxis early after surgery. This is more common following intranasal mucosal flaps used for full-thickness defects. The exposed surface of the pedicle is subject to bleeding, but gentle pressure or focal application of silver nitrate usually resolves the problem.

Late complications are also encountered. Contracture may cause distortion or notching of the nasal ala. This can be a difficult problem to correct secondarily and often requires a 3-layered approach. Pincushioning or excessive thickness of the flap is not uncommon and can be treated with additional thinning or steroid injections. These complications may warrant flap revision or selective thinning. Unfavorable and hypertrophic scars may be minimized with dermabrasion, generally after at least 8 weeks postsurgically. Often, the entire aesthetic subunit also may be dermabraded to assist in blending the flap into surrounding nasal tissue.

Nasal obstruction can occur as an early or late problem and is usually due to a collapse of the sidewall and ala of the nose. Cutaneous defects in this region of the nose are especially susceptible to collapse and functional problems. It is best addressed at the primary stage with aggressive cartilage grafting to serve as a batten of support to this region. The grafting is placed in a nonanatomic area of the nose but is critical to ensure functional results. Secondary grafting for nasal obstruction can be successful.

A retrospective study by Ali et al indicated that in patients who undergo nasal reconstruction with a paramedian forehead flap, the overall 30-day complication risk is not significantly increased by the use of structural grafts. In evaluating different graft types, however, subgroup analysis did reveal that the likelihood of wound-related complications was greater when costochondral grafts were used, the odds ratio being 5.3. ^[11]

A retrospective study by Chen et al of 2175 patients who underwent skin cancer–related facial reconstruction with paramedian forehead flaps found infection to be the most common complication (63 patients; 2.9%), while postoperative bleeding occurred in 30 patients (1.4%), and postsurgical deep venous thrombosis was noted in 10 or fewer individuals (0.5% or below). Patients who had postoperative bleeding, used alcohol, or had a neurologic disorder were at greater risk for immediately returning to the emergency department or for readmission within 48 hours postsurgery, with odds ratios of 13.05, 7.70, and 4.11, respectively. ^[12]

A retrospective study by Choi et al of patients who underwent facial reconstruction with median forehead flaps reported acceptable forehead scarring and no donor-site complications. Although postoperative brow height was slightly elevated and interbrow distance was narrowed, possibly as a result of wound healing–related contracture, brow symmetry did not change. ^[13]

Research found that in patients who undergo forehead flap reconstruction, risk factors for composite surgical site complications in the first 30 days postoperatively include weight loss of greater than 10% in the 6 months prior to surgery, disseminated cancer, dirty/infected wounds (American College of Surgeons class 4 wounds), and an operative time of over 123 minutes. Univariate analysis indicated that low preoperative albumin and hematocrit levels are also risk factors for composite surgical site complications. According to multivariable analysis, the risk of unplanned reoperation in the first 30 postoperative days is increased by higher American Society of Anesthesiologists class and by class 4 wounds. Among the risk factors for surgical site complications, the highest odds ratios (ORs) were for disseminated cancer (OR >13) and class 4 wounds (OR >12). ^[14]

Surgical results with the forehead flap for nasal reconstruction remain very encouraging. Even large and complex defects of the nose are often repaired to a standard of excellent nasal function (nasal airway), acceptable donor site (forehead scar), and an inconspicuous nasal reconstruction. Optimal outcomes depend on a meticulous approach to surgical preparation and technique and to postoperative management. After the decision is made to use a forehead flap, thorough patient education and preparation is critical, especially in regard to the intermediate period in which the pedicle remains intact. Long-term effects should provide good color match, inconspicuous scars, normal nasal contours without excessive bulk, and an acceptable donor scar as seen in the image below.

Future studies in the development of forehead flaps will attempt to further describe the physiologic features of these flaps, especially in terms of neovascularization and healing. Better understanding of these 2 processes may maximize outcomes for many patients.

Patients with small vessel disease, such as those who smoke and those with diabetes, will benefit from improved techniques that preserve pedicle vascular supply or advance neovascularization into the donor flap. Hyperbaric oxygen therapy has proven promising in this area.

The healing process itself can cause complications. Future studies may describe treatments that limit contracture or scarring, improving outcomes and further advancing the art of nasal reconstruction.