Paramedian Forehead Flap for Reconstruction of Nasal Tip Defect

OVERVIEW AND INDICATIONS

The paramedian forehead flap is an interpolated axial flap that is commonly used in reconstruction of defects of the nasal dorsum and tip. Defects often occur from excision of skin cancer, but may also be the result of trauma. The flap is based on a dominant blood supply originating from the supratrochlear artery, and its point of rotation is at the medial canthus. It is a good match for the color, texture, and size of the nasal tip. The donor site typically heals well with acceptable scarring.¹

There are relatively few contraindications for the flap, and even elderly patients with medical comorbidities are acceptable candidates.² However, caution is advised in smokers, diabetics, and patients with atherosclerotic disease due to a higher risk of flap necrosis; surgical delay should be considered in these patients.³ In addition, any anticoagulant medications should be noted preoperatively, though these medications can be safely continued with the exception of clopidogrel, which can lead to excessive bleeding.² Most importantly, patients must be counseled preoperatively and willing to undergo the 2 or more stages of this procedure, in between which they will require dressing changes to a conspicuous pedicle before division and final inset.

ANESTHESIA AND INSTRUMENT LIST

General anesthesia, sedation with local anesthesia, or local anesthesia alone can all be appropriate depending on patient preference and comorbidities. In addition to standard plastic surgery instruments, a Freer elevator and Colorado-tip electrocautery should be included, as well as a Doppler probe to confirm the pedicle.

OPERATIVE TECHNIQUE

First Stage

The patient is placed supine on the operating table. Before injection of any local anesthesia, the flap is marked using a template of the nasal defect (Video) (see Video [online], which details the paramedian forehead flap including advantages and disadvantages). The supratrochlear artery is identified just medial to the eyebrow and traced superiorly with a Doppler probe to mark the pedicle. After injection of 1% lidocaine with epinephrine, the flap is raised from distal to proximal. The dissection plane is superficial to periosteum distally and may contain frontalis muscle to preserve its blood supply, though in our experience it is safe to raise the flap just below subcutaneous fat, and even thin the subcutaneous fat at the distal end in a nonsmoker. Dissection travels deep to the frontalis in the midforehead region and then deep to the periosteum proximally to protect the supratrochlear artery of the flap pedicle. Once the adequate rotation of the flap has been achieved, the distal portion is inset into the nasal defect and secured with sutures. The flap should sit in the defect tension free, without excessive torque on the pedicle or deformation of the nose. The donor site is closed primarily to the extent possible; if the superior portion cannot be closed, it can be left to heal secondarily assuming there is intact periosteum at the wound base. Petrolatum gauze is applied to the raw surface of the flap pedicle, or an absorbable hemostatic dressing can be used if excessive oozing is encountered.

Video 1. Paramedian Forehead Flap. Video from “Paramedian Forehead Flap for Reconstruction of Nasal Tip Defect”.

Download video file ^{(126.6MB, mp4)}

Second Stage

Two to 3 weeks after the first stage of the procedure, the patient returns for pedicle division and debulking of the flap. In a smoker, a full 3 weeks is advised before the division of the pedicle in a two-stage paramedian forehead flap. After ensuring that the distal flap has adequate vascular ingrowth from the recipient site by clamping the pedicle and assessing capillary refill, local anesthesia is injected. The distal pedicle is divided at the superior edge of the nasal defect, such that the distal flap contours well into the defect. The proximal extent of the pedicle at its base is marked as a triangle and incised such that it pulls the ipsilateral brow superiorly into the defect, restoring normal contour and height of the ipsilateral brow. Next, excess fat from the deep portion of the flap is removed; however, excessive debulking into the dermal layer should be avoided, as this can compromise blood flow to the edges of the flap. Sutures are placed and petrolatum-based ointment applied.

Postoperative Care

After the first stage, daily dressing changes with petrolatum gauze are performed for the pedicle, and petrolatum ointment is applied daily to the suture line. If an absorbable hemostatic dressing is used, it is left in place for 1 week. Sutures are removed at 1 week postoperatively, and petrolatum gauze dressing changes to the pedicle continue until the second-stage procedure. After the second stage, the patient returns at 1 week again for suture removal.

Outcomes and Potential Complications

Overall, the esthetic outcome of the forehead flap is excellent and it should be considered the gold standard of nasal reconstruction.² This flap can also be combined with cartilage grafts for full-thickness defects or subtotal nasal reconstruction, which requires 3 or more stages of the procedure.^1,4 Potential complications may include recipient-site hair growth in patients with low hairlines, donor-site scarring, and unintentional brow elevation.² Hematoma or partial flap necrosis may uncommonly occur, but total flap failure is rare as long as precautions are taken in at-risk patients.³ Again, it is imperative that patients understand and are willing to undergo the multi-stage nature of this procedure.