The endoscopic forehead procedure involves the placement of four incisions in the scalp (Fig. 43.3). The first two incisions are located approximately 2.0 cm on either side of the midline, 1.0-2.0 cm posterior to the hairline. For patients with excessively long foreheads (more than 8 cm), these paramedian incisions are placed directly at the hairline. It is important to keep the forehead incisions as anterior as possible. Otherwise, visualization and dissection in the glabellar region will be compromised. The next set of incisions is located in the temple region, bilaterally, 2.0 cm posterior to the hairline. The incisions should be directed parallel to the hair follicles to prevent unnecessary alopecia, postoperatively. Each incision should measure 1.5 cm in length.
Prior to surgical dissection, local anesthesia using 50 ml of 0.5% lidocaine with 1:200,000 epinehphrine is diffusely distributed in both a subcutaneous and a subperiosteal fashion. Early administration of the anesthetic will provide maximal hemostasis required during endoscopic visualization.
To better understand the operative procedure, the forehead is divided into four zones (Fig. 43.4). Zones 2 and 3 can be safely dissected in a "blind" fashion without the use of the endoscope. Owing to the vital neurovascular structures located in zones 1 and 4, dissection in these zones requires the use of the endoscope at all times.
The endoscopic procedure begins through the incision in the temporal area, designated zone 1. A 1 cm incision is made through the skin and subcutaneous tissue, deep to the superficial temporal fascia. Dissection continues inferiorly, remaining above the intermediate temporal fascia. The initial dissection can be performed blindly in a circumferential fashion for approximately 1-2 cm. With the tissues elevated, a silastic port protector is inserted and the remainder of the dissection is performed under endoscopic control.
An elevator is used to dissect to the temporal line of fusion superiorly. The elevator is then used to score and elevate the periosteum 1.0 cm medial to the tem-
The paramedian incisions are then made as previously described and are carried down through the periosteum. Dissection in zones 2 and 3 can be performed with a blind sweeping technique, as long as the dissection remains in a subperiosteal plane. The endoscope is inserted during dissection in zone 4. In general, zone 4 begins about 3 cm cephalad to the superior orbital rims. Endoscopically assisted dissection should always be performed in zone 4. The initial dissection proceeds toward the lateral aspect of the superior orbital rim. Further dissection laterally toward the temporal line of fusion will allow connection of zones 1 and 4. The dissection then proceeds in a medial direction along the superior orbital rim. Cautious dissection in this area is mandatory given that the authors have noted considerable variation in the supraorbital nerve anatomy.
Occasionally, an accessory branch of the supraorbital nerve can be identified as far as 3.0 cm superior and lateral to the supraorbital nerve proper. Every effort should be made to preserve any accessory nerve branch. After identification of the supraorbital nerve, dissection continues medially, exposing the origins of the corrugator muscles. The supratrochlear nerve travels in the substance of the corrugator muscles, so careful elevation of the corrugators is required. Typically, three fascicles of the supratrochlear nerve are identified and preserved. Prior to resection of the cor-rugator muscle, the periosteum of the superior orbital rim is released with a curved elevator. The periosteum should be released from the zygomaticofrontal suture line laterally moving medially toward the glabella. In patients with heavy tissues, especially men, the periosteum is released by cutting it with endoscopic scissors. With the periosteum cut medially, the supra-
trochlear nerve and corrugator muscles are clearly delineated.
The corrugator muscle is extensively resected from its point of origin to just beyond the supraorbital nerve. We prefer to resect approximately 80% of the corrugator muscle to assure that glabellar frown lines are eliminated. Once the corrugator has been removed, the depressor supercilii muscle can occasionally be identified. Resection of the depressor superci-lii muscle is indicated if medial brow ptosis is present. An endoscopic scissor then is used to divide the periosteum deep to the procerus muscle. The procerus muscle is resected after being thoroughly exposed. Resection of the procerus muscle should proceed down to the level of the nasoglabellar angle. Occasionally, bleeding will occur during procerus resection. Given the superficial location of the dissection, care must be taken when using cautery in this area. Overzealous cauterization in this location can lead to disastrous consequences (i.e., burning of the skin). When the muscle resection is complete, the area is packed with epinephrine-soaked pledgets. Attention is then directed back to the temporal region where the endoscopic midface lift is started at this point.
Completion of the endoscopic forehead procedure with drain placement, incision closure, and elevation and fixation of the brow proceeds after completion of the endoscopic midface suspension. Briefly, two suction drains are placed through separate stab incisions in the scalp, adjacent to the paramedian access ports. An endoscopic biter is used to direct the tips of the drains to the level of the glabella and the anterior forehead. Each drain is secured with a heavy drain stitch. The paramedian incisions are closed in two layers. A blunt traction hook is then used to elevate the scalp and to position the brow. When proper brow position is obtained, a small stab incision is made in the scalp, with a no. 11 scalpel. A 1.1 mm drill bit with a 4 mm stop is inserted through the stab incision and a unicortical hole is drilled in the calvarium. A 1.5 mm titanium post (Synthes, Paoli, PA, USA) is then placed in the drill hole. In most cases, two para-median posts (one on each side) are sufficient to maintain the proper brow position. Proper location of the posts will have a significant impact on brow position. Under most circumstances, post placement corresponds to a superomedial axis from the lateral brow. This will provide maximal elevation of the lateral brow. More central post placement is chosen for patients requiring greater elevation of the central and medial brow. Excessive elevation and asymmetric elevation of the brows should be avoided at all costs. The surprised and inquisitive appearances, respectively, that result are poorly tolerated and cosmeti-cally unacceptable.
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