Park: Reconstruction of Nasal Defects. Than 1.5 Centimeters in Diameter

Transcription

1 The Laryngoscope Lippincott Williams & Wilkins, Inc., Philadelphia 2000 The American Laryngological, Rhinological and Otological Society, Inc. Reconstruction of Nasal Defects Larger Than 1.5 Centimeters in Diameter Stephen S. Park, MD Objective: To review the repair of larger nasal defects (>1.5 cm in diameter) and the vascular supply to the forehead flap. Study Design: Retrospective chart review ( ) and cadaver analysis of forehead flap vasculature. Methods: Chart review was made of patients with cutaneous nasal defects greater than 1.5 cm in diameter. An intravascular silicone cast was used to detail the arterial supply to forehead flaps focusing on contribution from the supratrochlear and angular vessels. Results: In 127 patients with nasal defects, 76 defects were greater than 1.5 cm in diameter and were repaired with a midline forehead flap (44 [58%]), paramedian forehead flap (3 [4%]), single-stage midline forehead flap (8 [11%]), interpolated melolabial flap (5 [7%]), local nasal flap (7 [9%]), or skin graft (9 [12%]). All original defects were modified to some degree with an aggressive application of the nasal esthetic subunit principle. Forty-three patients (57%) had cartilage grafts, 18 (24%) had a fullthickness defect requiring repair of the internal lining, and 11 (14%) had some degree of complication, although no patient had full-thickness necrosis of a flap or required a second flap. Analysis of the vascular pedicle to the midline and paramedian forehead flaps demonstrated significant contributions from the angular artery. Skin paddles from a midline and paramedian forehead flap had similar vascular arcades. Conclusions: Nasal reconstruction has reached a standard of consistent esthetic results with restoration of nasal function. The midline forehead flap is dependable and robust and leaves a donor site scar consistent with the principle of esthetic units. Key Words: Nasal reconstruction, forehead flap, tissue engineering. Laryngoscope, 110: , 2000 Presented as a Candidate s Thesis to the American Laryngological, Rhinological and Otological Society, Inc. From the Department of Otolaryngology Head and Neck Surgery, University of Virginia Medical Center, Charlottesville, Virginia. Editor s Note: This Manuscript was accepted for publication April 17, Send Correspondence to Stephen S. Park, MD, Department of Otolaryngology, University of Virginia, P.O. Box , Charlottesville, VA , U.S.A. INTRODUCTION Nasal reconstruction is rich in its ancient history and evolution through contemporary concepts to a level where the bar of expectation includes the restoration of function as well as excellent cosmetic appearance. Significant landmarks include the appreciation of a multilayered defect with the need to repair deficits of internal lining and structural framework, the versatility of the forehead flap and its modifications, and the adaptation of the esthetic subunit principle. The nose is perceived as a series of topographic esthetic subunits that are defined by subtle changes in contour and natural creases. Scars that lie at the border of two units are often inconspicuous to the casual observer as the block images are assimilated. The principle is used liberally in nasal reconstruction with the strategic placement of scars through defect modification. There is benefit to an aggressive approach to esthetic subunits rather than using the 50% cut-off point some authors have advocated. 1 The forehead flap is often described as a paramedian flap centered on the supratrochlear artery with the assumption that the paramedian design improves viability. 2,3 Modifications have been applied to the precise midline forehead flap that capture the virtues of both the historical, wide-based median forehead flap and the more contemporary unilateral paramedian flap. Its dependability and robust vasculature afford aggressive thinning and a narrow pedicle. Moreover, in some circumstances, the pedicle may be de-epithelialized and converted to a singlestage island forehead flap. Stressing the repair of internal lining deficits is a relatively new concept and can be performed in a number of ways. A thin physiological flap carrying its own vascularity is ideal for full-thickness defects and can usually be harvested from within the nose. It is important to be familiar with a variety of flaps because, on occasion, only a single option may be available. Re-establishing a framework in nasal reconstruction is of paramount importance for maintaining both form and function. Structural grafts are used liberally and often in nonanatomical locations to prevent sidewall collapse and alar retraction and maintain nasal projection away from the facial plane. The current gold standard is an autogenous cartilage graft, typically harvested from the septum 1241

2 or auricle. In subtotal and total nasal reconstruction, adequate supplies of autogenous cartilage may be difficult to acquire; this has led to alternative sites including rib and split calvarial bone, but with associated rises in comorbidity. 4 Trials with irradiated homograft rib have had some clinical success, 5 7 yet other authors question the longevity of such materials. 8 Tremendous industrial resources are invested in alloplastic materials in hope that they might become the new implant of choice for structural grafting; however, no single material has yet surfaced with wide acceptance for safety, host compatibility, and longevity. 9,10 The predicament of insufficient grafting material during nasal reconstruction remains. This study reviews the repair of nasal defects greater than l.5 cm in diameter and of varying depths. These principles of nasal reconstruction are followed, and the outcomes reviewed. MATERIALS AND METHODS Chart Review A retrospective chart review was performed on all patients seen with nasal defects from 1994 to 1999 and in whom at least a 3-month follow-up was available. Data collected included demographics, etiology of defect, location of defect (including percent of each esthetic subunit), method of repair (including resurfacing flap, structural support, and internal lining), surgical outcomes, and ancillary procedures. All preoperative data were obtained from a computer-based patient profile record that was initiated at the time of the original patient encounter. Photographic documentation of all patients was available and reviewed. Vascular Analysis of Forehead Flap Fresh cadaver heads were used for the study of the arterial basis of the paramedian forehead flap and midline forehead flap. Forehead flaps were elevated by the methods used clinically and described above. The paramedian and midline flaps were elevated independently on separate heads. A radio-opaque silicone rubber cast (Microphil, Flow Tech, Carver, MA) was used to fix and study the respective arterial systems. The internal carotid artery was cannulated to perfuse the supratrochlear artery and the facial artery for the angular vessel. Soft tissues were dissected in the medial canthal areas to demonstrate the degree of collateral flow from the angular artery to the forehead flap. Forehead flaps were amputated and soft tissues dissolved off, to demonstrate the vascular arcade within the skin paddle. Highlights of Surgical Techniques Forehead flap. The nasal esthetic subunits are drawn directly on the nose at the onset of surgery. Great attention is given to preserving sharp corners at the junction of subunits. Then the defect is modified to complete the esthetic subunit so that the resultant scars lie along the borders of these subunits. This invariably involves enlarging the existing defect. This subunit principle is aggressively followed with rapid excision of normal nasal skin to control the placement of subsequent scars. Even defects that are marginally involved are modified in accordance with the subunit principle, especially when the defect enlargement is cephalad in cases in which the length of the forehead flap remains unchanged. Subunits of minimal involvement (e.g., 10%) are usually handled more conservatively by incorporating the defect into the adjacent unit. An exception to the esthetic subunit principle is a midline vertical scar of the upper two thirds of the nose; although this bisects the dorsal subunit, the casual observer also sees the face and nose as two halves and a vertical 1242 line between them can remain inconspicuous. A template is made of the defect using a suture packet again, taking care to cut straight borders and crisp corners that is then transferred to the exact midline of the forehead for tracing. The vertical position of this template is determined by measuring from the medical aspect of the brow, recognizing that the length-limiting point is not always the most inferior aspect of the wound but may be the proximal contralateral corner. Doppler study of the supratrochlear artery is not performed. With the template positioned in the midline, the pedicle is designed to be based on the medial brow, capturing the supratrochlear artery as well as collaterals from the angular artery. Elevation of the forehead flap begins in the subcutaneous plane rather than the subgaleal plane as the skin paddle is dissected directly off the frontalis muscle and galea. Then selective thinning is performed to match the native nasal skin thickness. For patients with extremely thick skin or significant small-vessel risk factors, the skin paddle can be elevated in the subgaleal plane with a planned intermediate stage for debulking. The pedicle of the forehead flap is elevated in the subgaleal plane and runs obliquely toward the medial brow. Often, the periosteum at the base of the pedicle is incorporated with the flap to provide more length and rigidity to this region. The pedicle can easily extend below the level of the brow to provide addition flap length. Pedicle division takes place after a 3-week interval, at which time the proximal portion of the flap is aggressively debulked to allow the skin paddle to match the thin native skin of the upper nose. A representative case (case 1) is described in Case Reports. Single-stage midline forehead flap. The single-stage forehead flap is based on a subcutaneous pedicle that is tunneled beneath the intact glabellar skin and delivered into the nasal defect, thus obviating the need for a second-stage pedicle division. Defect modification and flap design are similar to the conventional two-stage flap. Once the skin paddle for the midline forehead flap has been elevated, the plane of dissection is dropped to the subgaleal layer. Skin from the glabella is then carefully lifted to create the subcutaneous pedicle. The tunnel is continued beneath the glabellar skin into the nasal defect. Wider undermining is performed to avoid compression on the buried pedicle. In addition, the procerus muscle is partially resected to minimize excessive bulk in this region. A contralateral pedicle tends to work better with less asymmetric fullness in the canthal areas. Portions of this procerus muscle can be transferred back up to the glabellar area to fill in the depression that ensues after transfer of the subcutaneous pedicle. Melolabial flap. The initial preparation of nasal subunits and templates is similar to that for the midline forehead flap. The flap is designed around a pivot point located along the nasal facial groove. Skin incisions at the proximal pedicle are narrowed substantially to allow easy rotation of the flap and facilitating the second-stage division and closure of this donor site. The subcutaneous portion of the pedicle, however, remains wide and captures perforators off the angular artery. Pedicle division is performed after a 3-week interval. The stump of the pedicle is usually excised and donor site closed primarily, thus leaving a single scar along the nasofacial junction. This is performed at the expense of creating subtle facial asymmetry along the melolabial folds. As an alternative, the pedicle can be returned to the midface, although this will create two vertical scars, one being in the cheek facial unit. Full-thickness skin graft. When repairing larger defects with a skin graft, an exception is made to the principle of esthetic units. Usually these defects are of the upper two thirds of the nose, in areas where the native skin is significantly thinner than the nasal tip or ala. The defect shape is modified to create square edges from a typically circular defect. Edges of the defect are gently beveled toward the center to smooth the transition from

3 native skin to skin graft. This is in distinction to the manner in which wound margins are modified during local flap reconstruction, when they are beveled away to maximize skin eversion. On occasion, repair can be delayed for several weeks to allow granulation tissue to accumulate within the depth of the wound, thus improving the final contour to this region. The preferred donor site is the supraclavicular area, because it has minimal morbidity from harvesting and a good color match. Often, there are other simultaneous facial flaps that create standing cutaneous deformities requiring direct excision. These standing cones can serve as an excellent donor for skin grafts to the nose. Smaller nasal defects can be grafted with skin from the melolabial fold or preauricular area. Structural support. Defects of the lateral and inferior nose are often reinforced with autogenous cartilage grafts to prevent sidewall collapse, as well as cephalic soft tissue retraction. Existing cartilage and normal nasal anatomy have little to do with the need for structural grafting; defects of the alar lobule and sidewall that are moderately deep must be reinforced, despite not resecting any native cartilage. The alar lobule and tip are usually reinforced with conchal cartilage, and the middle one third and sidewall are repaired with septal cartilage. The grafts are placed in a nonanatomical location, because normal nasal anatomy does not have cartilage in these areas. The intention of these grafts is to reinforce the native fibroareolar tissues, and they are secured with a through-and-through suture to the internal nasal lining. A flaring suture is often placed from the caudal/lateral border of the upper lateral cartilage to either the dorsal septum or contralateral upper lateral cartilage. 11 Internal lining. Deficits of the internal lining require meticulous repair. Very small punctate defects can be closed primarily without difficulty. An independent flap is required to repair larger full-thickness nasal defects; if left unrepaired, the area will heal secondarily, but not before significant wound contracture, alar distortion, and nasal obstruction. There are a number of different flaps available for reconstituting the internal lining, and one must be facile with many of them. The ipsilateral septal mucosal flap can be based on the septal branch from the superior labial artery, and the entire septal mucosa can be elevated and mobilized. This flap is rotated laterally to provide internal lining to that side of the nose, although it can be performed bilaterally. A representative case (case 2) is described in Case Reports. The bipedicled bucket-handle intranasal flap is an excellent means of repairing lining deficits along the caudal margin. Wide undermining is necessary superiorly as well as medially onto the septum and laterally toward the turbinate. A relaxing incision is created far intranasally to facilitate caudal mobilization of this mucosal flap. Once the mucosa is mobilized inferiorly, there should be no tension or retraction in the cephalic direction. Often, any tendency of the flap to pull superiorly continues after reconstruction and ultimately creates small degrees of alar notching. The hinged composite septal flap is an excellent means of providing simultaneous internal lining and structural support to the middle third of the nose. The septum is based dorsally and hinged as a composite flap of cartilage and contralateral septal mucosa to repair internal lining defects. The ipsilateral septal mucosa can be replaced, although it often breaks down and leaves a septal perforation. Folding the distal tip of the resurfacing flap can repair caudal defects of the internal lining. This must be planned on the outset and designed accordingly, extending the distal border of the flap superiorly. The alar border tends to be unnaturally thick but can be revised in the future. The inferior turbinate flap is a source of intranasal lining and can be used when the septum has been significantly violated. 12 The entire inferior turbinate is delivered extranasally, and the inferior conchal bone removed. The mucosal flap is based anteriorly and used for caudal lining repair. The epithelial turn-in flap uses external nasal skin to be turned over and faced intranasally. It is flipped 180 and has been shown to be a dependable alternative for reconstituting internal lining. 13 The flap is elevated from a superior to an inferior direction and based on a subcutaneous pedicle inferiorly. The skin paddle can be thinned aggressively, but an adequate subcutaneous pedicle must be preserved. CASE REPORTS Case 1 A 62-year-old man had a basal cell carcinoma excised and was referred for reconstruction (Fig. 1A F). The defect involved 50% of the right sidewall and 75% of the dorsal esthetic subunit (Fig. 1B). A small portion of the defect extended onto the cheek. The nasal esthetic subunits were completed with attention to straight lines and sharp, crisp corners at the junction of subunits. A cartilaginous batten graft from the septum was placed along the sidewall to reinforce the internal nasal valve (Fig. 1C). The cheek aspect was addressed by advancing the lateral border of the defect medially to create a line that corresponded to the cheek/nose esthetic border. The nose was resurfaced with a contralateral midline forehead flap transferred as a two-stage, interpolated flap. A template was fashioned to fit the defect and transferred to the exact midline of the forehead (Fig. 1D). A contralateral midline forehead flap was transferred to resurface the nasal defect (Fig. 1E). One year after surgery he continued to do well without nasal obstruction. Resultant scars were deliberately placed along the junction of esthetic units, including the donor site scar in the exact midline of the forehead, and remained inconspicuous (Fig. 1F). Case 2 A 74-year-old woman had an excision of a recurrent basal cell carcinoma of the nose resulting in a large full-thickness defect (Fig. 2A D). A majority of her septum, including the septal arterial branch to the septal mucosa, remained intact. The residual septum was rocked out of her nasal cavity, after excision of a small wedge of cartilage above the anterior nasal spine, to provide support to the dorsum of the nose. Bilateral septal mucosal flaps were elevated off the septum and based on an anterior/inferior pedicle containing the septal artery (Fig. 2B). These mucosal flaps provided internal lining to the lower two thirds of the nose. Cartilaginous grafts and a midline forehead flap completed the reconstruction (Fig. 2C). Two years after repair she developed some cicatricial stenosis of the vestibules but had a sufficient airway and declined further revision (Fig. 2D). RESULTS Chart Review From 1994 to 1999 there were 127 patients who had cutaneous defects of the nose; of these patients, 76 (60%) had a defect greater than 1.5 cm in diameter. Sex was equally distributed (40 male and 36 female patients), with an average age of 62 years (age range, 36 to 84 y). All but one patient had defects secondary to cutaneous malignancies, the single traumatic patient being a police officer who had a nasal amputation. Nasal resurfacing was by one of the following methods: interpolated midline forehead flap (44 [58%]), full-thickness skin graft (9 [12%]), single-stage island midline forehead flap (8 [11%]), local nasal flap (7 1243

4 Fig. 1. A. A 62-year-old man with a nasal defect after Mohs surgery. B. Nasal esthetic subunits are defined and demonstrate involvement of the sidewall and dorsum with minute involvement of the cheek unit. C. Complete excision of involved esthetic subunits, and a small advancement of the right lateral cheek medially to align with the nasal facial border are evident. A small cartilaginous batten can been seen to the right sidewall for structural reinforcement. Note the crisp angles and apices of the esthetic units. D. The defect template is transferred to the precise midline of the forehead for flap elevation. E. The midline forehead flap is transposed to the nose, based on a left unilateral vascular pedicle. F. One-year postoperative full-face view; resultant scars are less conspicuous because of their strategic placement along esthetic subunit borders. [9%]), melolabial flap (5 [7%]), and paramedian forehead flap (3 [4%]). Defects involving each esthetic subunit were represented within the group, and no single unit had a significantly greater incidence over others. All patients with defects greater than 1.5 cm in diameter had more than one esthetic unit involved, although not all had more than one unit entirely excised The eight patients who had repair with the singlestage midline forehead flap had defects of the dorsal and/or sidewall subunits; no lower nasal defects were repaired with this single-stage flap. The nine patients who had resurfacing with a full-thickness skin graft had superficial defects that did not violate the underlying nasal musculature and were limited to the upper two thirds of the nose.

5 Fig. 2. A. A 74-year-old woman with a large, full-thickness nasal defect after Mohs surgery. B. Bilateral septal mucosa flaps are elevated and rotated to reconstitute internal lining. The residual posterior cartilaginous septum is rocked outward to provide dorsal support. C. Extensive cartilaginous grafting provides a new framework to the nose. D. Two-year postoperative oblique view demonstrating long-term nasal support and patency. Four of the melolabial flaps were for defects primarily of the alar lobule; one was for a columellar defect. Patients with a paramedian forehead flap had an anatomical finding that precluded a midline forehead flap, two with old central scars and one with a suspect cutaneous lesion. Forty-three patients (57%) had defects of sufficient depth to require a cartilage graft. Thirty-two conchal cartilage grafts and 14 septal cartilage grafts were used. Three patients had more than one cartilage donor site. Nine patients had a flaring suture placed to the caudal/lateral border of the upper lateral cartilage to widen the internal nasal valve. Three patients had nasal tip grafts placed to improve tip definition. Eighteen patients (24%) had defects of the internal lining that were repaired through a variety of methods: ipsilateral septal mucosal flap (5 [28%]), bipedicle buckethandle flap (5 [28%]), hinged septal-composite flap (3 [17%]), epithelial turn-in flap (2 [11%], primary closure (2 [11%]), inferior turbinate flap (1 [5%]), folded cutaneous flap (1 [5%]), and labial mucosal flap (1 [5%]). Complications were encountered in 18 patients (24%). No patients had necrosis of their resurfacing flap, although six patients (8%), all having conventional interpolated midline forehead flaps, had a distal epidermolysis of less than 5% of the flap. These wounds were managed conservatively with local wound care and healed uneventfully. Three of these individuals had some systemic small vessel disease, smoking (2), and diabetes (1). Two of the remaining three were healthy but had old, transverse scars in their forehead. The third patient had no obvious risk factors. Twenty of the 76 patients (26%) reported an active use of tobacco. Aside from the two who had epidermolysis of the distal flap, no other significant complication was associated with tobacco use. Two individuals (3%) admitted to some degree of new-onset nasal obstruction after surgery but declined revision to improve it. One obstruction was attributable to cicatricial stenosis of the vestibule, and the other, to collapse of the sidewall. Three patients had some loss of the internal lining flap, and this represented 17% of patients with internal lining deficits. Although only small portions of the flaps died, all patients had some external consequence from it. A septal mucosal flap, bucket-handle flap, and inferior turbinate flap represented these three patients. Other complications included a hematoma (2 [3%]), bacitracin reaction (2 [3%]), cartilage graft resorption (1 (1%)], wound separation (1 [1%]), congestion (1 [1%], infection (1 [1%], and hypertrophic scarring (1 [1%]). Both hematomas occurred in the glabellar area and resolved without surgical intervention. The cartilage graft resorption was identified through palpation of the alar lobule where a conchal cartilage graft had been positioned 6 months earlier. No detectable alar retraction or collapse occurred. The wound separation was a result of excessive tension on the wound, and it was revised on the first postoperative day. One patient demonstrated significant flap congestion, was treated with urgent postoperative hyperbaric oxygen (HBO) therapy, and recovered without tissue loss. Two patients received scheduled perioperative HBO therapy because of significant tissue injury to that vicinity from previous radiation therapy and the anticipation of multiple local and regional flaps. Both individuals had full-thickness nasal defects after recurrent basal cell carcinomas that were once treated with irradiation. The protocol involved 20 preoperative dives to 2.0 atm and 10 postoperative dives. Fifteen patients (20%) had some additional procedure performed: Kenalog injection (7 [9%], dermabrasion (3 [4%]), osteotomy (3 [4%]), and additional debulking (2 [3%]). Cadaver Study Cannulation of the internal carotid artery demonstrated direct perfusion of the ipsilateral supratrochlear vessel and a rich vascular supply to the paramedian forehead flap. This supratrochlear artery also provided good arterial perfusion to the midline forehead flap, although the main trunk of the supratrochlear vessel was captured only in the base of the pedicle. Perfusion of the angular 1245

6 artery via the facial artery illustrated a dense network of collateral vessels in the medial canthal and glabellar areas. Perfusion of the angular artery alone was able to demonstrate a robust arcade of vessels within the midline forehead flap (Fig. 3). DISCUSSION Nasal defects come from a variety of causes, and it is no surprise that a majority of these patients have a cutaneous malignancy of the nose treated by Mohs micrographic surgery. The size and location of the defect do not necessarily reflect the demographics of nasal lesions, but more a referral pattern from the dermatological surgeons at this institution. The fact that 76 of 127 patients (60%) with nasal defects had lesions greater than 1.5 cm in diameter reflects the comfort level of the Mohs surgeons. Often, the smaller lesions that are referred by the dermatological surgeon are associated with a discrete challenge in location or depth. Only one patient had a forehead flap that was not related to a cutaneous malignancy; he had a nasal amputation from a fall and required a full-thickness repair. Resurfacing of Larger Cutaneous Defects While a majority of patients have a two-stage interpolated flap for larger nasal resurfacing, there are occasions Fig. 3. The rich collateral circulation along the glabellar and medial brow areas after perfusion of the right-side facial artery alone. The supratrochlear artery was not injected when simpler methods can be adapted with good results. Furthermore, there are individuals for whom a fullthickness skin graft represents the ideal method of repair with respect to optimal esthetic outcome. This is particularly true for the fair-skinned individual with a superficial defect involving the upper third of the nose. In this area the native skin is especially thin, and an excellent color and contour match can be expected. In patients who are very poor surgical candidates the defect may be best repaired with a singlestage procedure, be it a skin graft or larger local flap. There was one patient in our group who had a significant cutaneous defect of the ala and sidewall but had advanced Alzheimer s disease and was a permanent resident in a nursing facility. The full-thickness skin graft provided the simplest and quickest method of repairing her defect without jeopardizing further nasal complications. Identifying surgical candidates who are at exceptional risk is not determined solely by age. The oldest patient in our group was 84 years old with a significant full-thickness nasal defect that was repaired with septal mucosal flaps, septal and conchal cartilage grafts, and a midline forehead flap. Naturally, patients from this age group struggle more during the postoperative period, especially while there is significant swelling. Once over this period, however, their levels of social confidence and self-image return. In general, patients with more advanced age but otherwise in good health remain excellent candidates for a nasal reconstruction that provides normal nasal physiology and esthetic outcomes that restore a positive self-image. Midline Forehead Flap By far the most common method of nasal resurfacing was with the midline forehead flap. This flap serves as a workhorse for larger cutaneous defects because it fulfills many of the criteria for the ideal flap. There is excellent match in color and skin texture and sufficient skin to resurface the entire nose without the need for preoperative tissue expansion. The donor site morbidity is acceptable, including when one allows any residual defect to heal by second intention. The distinction between the paramedian and midline forehead flap requires clarification. The original median forehead flap is based on both supratrochlear vessels and, occasionally, includes a supraorbital artery to maximize flap viability. As this Indian flap became popular in the West, early flap designs by Kazanjian 14 and Converse 15 used this original technique with a wide pedicle base. Later, it was shown that this forehead flap can be raised off only a single supratrochlear artery and that the pedicle can be safely narrowed to 1.5 cm without jeopardizing viability It has been thought that such a narrow pedicle would require the entire flap to be centered immediately over the supratrochlear vessel to ensure perfusion. The precise midline forehead flap harvests the skin paddle from the exact center of the forehead but is based on a narrow unilateral pedicle from the medial brow area. This design captures many of the virtues of both types of forehead flaps. The perfusion at the pedicle base is not solely dependent on the supratrochlear artery but has a robust collateral inflow from the angular artery. The cadaver study illustrates the vascular network in this region and the contribution from the

7 angular artery to the midline forehead flap. This clinical review is consistent with the anatomical study and demonstrates excellent dependability for flap viability. The pedicle can be narrow and extend below the level of the brow to facilitate flap rotation with less vascular kinking. Aggressive thinning of the skin paddle to the immediate subdermal plexus can be safely accomplished without jeopardizing the viable limits of the midline forehead flap. A common problem with earlier forehead flaps was the excessive bulk when the frontalis muscle and galeal were included in the transfer. While flap viability is maintained with the midline forehead flap, unique advantages can be realized. The oblique pedicle allows a slightly longer reach compared with the paramedian flap. The resultant scar from the midline forehead flap is in the exact center and consistent with the principle of esthetic units; the casual observer tends not to notice a vertical scar that divides the face into two halves. It should be noted, however, that the donor site scar from a paramedian forehead flap tends not to be particularly objectionable. The single-stage island forehead flap was first described by Converse and Wood-Smith 20 in 1963 for resurfacing larger defects of the nasal dorsum. They were of the opinion that the island flap would provide greater mobility because the skin portion of the flap pedicle would hinder rotation of the flap and create more kinking of the artery. They described tunneling the flap under the nasal skin but encountered more problems of venous congestion and fullness to the glabellar area. Our experience with eight singlestage forehead flaps did not reveal similar problems of impaired venous outflow. The technique is slightly different in that the subcutaneous pedicle is based on the medial brow area and wide undermining of glabellar skin is performed. In addition, the procerus muscle is excised to create more room for the tunneled pedicle. This single-stage flap is used for dorsal and sidewall defects and not extended to the nasal tip or ala. There is some fullness in the glabellar area that tends to regress over time. One patient (13%) requested a revision to this area with pedicle debulking. The pedicle is based on the contralateral side to avoid creating asymmetry along the medial canthal areas. Melolabial Flap We have not had as much experience with the melolabial flap, although other authors have demonstrated excellent versatility with it. 21 It has been used more often for alar defects that are smaller and limited to the lower third of the nose. The advantage of keeping the pedicle away from the eyes can be significant for people who are entirely dependent on glasses. There is less tissue availability because of the difficulty in closing the donor site. One can replace the pedicle back to the cheek to maintain midface symmetry, but with the disadvantage of creating an additional scar running obliquely against the relaxed skin tension lines of that area. We are more likely to amputate the pedicle base and close the donor site primarily. Framework Preservation of nasal function may be the single most significant milestone in major nasal reconstruction and has been realized through the liberal use of structural grafts and sutures. Cartilage grafts in nasal reconstruction serve three primary roles: 1) to provide rigidity to the sidewall and avoid lateral collapse during inspiration, 2) to resist cephalic retraction of the alar margin, and 3) to establish nasal contour and projection. The dimension of the cutaneous defect is not a direct indicator for the need of cartilage grafting. Many smaller defects (even less than 1.5 cm in diameter) may be of sufficient depth and in the supra alar area that will easily lead to sidewall collapse and nasal obstruction. Many smaller but deeper defects in this region are repaired with a local rotation flap over a thin cartilaginous batten graft. Sutures can be used to reshape existing cartilages, and their versatility is widely demonstrated in rhinoplasty techniques. Sutures can also be used to influence the position of the upper lateral cartilages and the corresponding internal nasal valve. 11 The flaring suture is a very quick and noninvasive means of augmenting nasal physiology and is often employed in nasal reconstruction to this area. The subtle outward flaring action of the upper lateral cartilages created by this suture can have a significant impact on the cross-sectional area. 22 More often, this suture is placed in conjunction with cartilaginous batten grafts to the nasal sidewall to provide additional support along the nasal valve. These flaring sutures are used even in patients without pre-existing narrowing of the internal nasal valve as a prophylactic measure to guard against future collapse from sidewall destabilization. The combination of liberal cartilage grafts and the flaring suture has resulted in a low incidence of nasal obstruction (3%). Patients with an excellent esthetic result but new-onset nasal obstruction often are unhappy and frustrated. Although some cartilage grafts are placed unnecessarily (i.e., collapse would not have occurred without it), the added time and morbidity are not substantial. Later correction of this problem by slipping a cartilaginous graft into the flail sidewall is not always easily achieved and often less successful. Cicatricial contracture along the vestibule is difficult to guard against and mandates meticulous repair of all linings and strong structural support to the rim. Secondary repair of this type of narrowing is more challenging. Autogenous cartilage remains the gold standard for reconstituting the nasal framework. Conchal cartilage has been used most often during these cases as a framework to the nasal sidewall and base. Its natural curvature lends itself well to recreating an alar lobule. These grafts are always placed more caudally than what is intuitive to preserve a natural alar/columellar relation during soft tissue contraction. The nasal septum is usually used for supporting the middle third of the nose and can be placed as a free graft or a hinged composite graft from the dorsum. In addition, the septum can be used for tip-enhancing grafts and various struts. Larger nasal defects and revision work often have inadequate supplies of septum and conchal cartilage. As one reaches for alternatives, the donor site morbidity rises as the quality of material declines. Alloplastic materials may be associated with problems when placed in such superficial areas as within the nose. The search for an alternative framework material continues. 1247

8 Tissue-engineered cartilage is a potential source of grafting material that might fulfill many criteria of the ideal clinical implant, including excellent host compatibility, viability, dependability, longevity, and minimal donor morbidity. It is a relatively new field of study with the concept of growing whole functional tissue from individual cells under guidance of biomechanical engineering. In terms of cartilage, it uses a biodegradable template as a scaffold for individual chondrocytes and engineers the growth of mature cartilage in predetermined three-dimensional shapes. The benefits of such a material in nasal reconstruction are substantial. Previous work with tissue engineering has been with bovine chondrocytes grown in athymic mice. 23,24 We have successfully demonstrated the ability to grow tissue-engineered cartilage from auricular chondrocytes in an immunocompetent host 25,26 (Fig. 4). There are a few issues that must be resolved before human application, such as long-term durability in terms of shape, definition, and viability. Because the precise three-dimensional morphology is not always reproduced, it may be applied first as a block of cartilage initially grown at a temporary site (e.g., the abdomen), followed by explantation, final carving and adjustments, and reimplantation into the definitive site. The vascular network found within this cartilage is unique to tissue-engineered cartilage and may affect the degree to which this material is insulated from the host and its ability to be transplanted as predictably as normal cartilage grafts. Further investigation will allow us to better understand the mechanism of tissue-engineered cartilage. It may prove to be an implant of tremendous clinical utility if one could harvest a small piece of cartilage from a punch biopsy of the auricle or nasal septum and amplify the number of cells in vitro. These cells may then be seeded on a biodegradable template preshaped into any complex shape and implanted into the definitive site. In addition to major nasal reconstruction, there are other potential uses for such a cartilaginous graft in the head and neck (e.g., laryngotracheal reconstruction, vocal cord medialization, microtia, and septal perforation repair). Internal Lining Roughly a quarter of the patients referred to us have had full-thickness nasal defects. The fact that eight different Fig. 4. A block of cartilage grown through tissue-engineered mechanisms in the general configuration of an auricle techniques were used for repairing internal lining speaks to the need for being facile at more than one method. Many surgeons have a personal preference, but it is not uncommon for a particular flap to be unavailable, creating the need to resort to one s second or third choice. Flap selection may be influenced by the size of the defect, other unrelated lesions, and ischemic factors. The septal mucosal flap was first described by Millard 17 and represents our most common flap utilized for internal lining repair. It is thin, physiological, and consistent with the dictum of replacing like tissue with like tissue. The entire nasal septal mucosa can be based on the septal branch off the superior labial artery and is of sufficient integrity to reconstruct the internal lining of the entire lower two thirds of the nose. One is often left with a septal perforation, which must be accepted as a probable association with this flap. The bipedicle bucket-handle mucosal flap was also used often and is the flap of choice for smaller mucosal defects of the alar lobule. The septal artery does not dependably supply this portion of the internal lining and the lateral pedicle must be maintained. The secondary donor site defect location is far intranasal, usually beneath the nasal bones, and can be allowed to heal by second intention. We have not found the need for placing skin grafts in that area. The composite septal hinged flap is an excellent means of providing both intranasal lining and cartilaginous framework to the middle third of the nose. The cartilage is typically straight and can also assist with dorsal support to that area. It does not have sufficient reach to allow structural framework to the alar lobule. The ipsilateral septal mucosa can be used for alar lining or can be replaced to fill the resultant septal perforation. Often, this area breaks down and perforation recurs. The epithelial turn-in flap has the advantage of not disrupting the residual internal lining. It is particularly useful when one anticipates discarding some of the external nasal skin during completion of the esthetic unit. Rather than discarding this skin, it can be used as part of the internal reconstruction. The epithelial turn-in flap does not appear to cause problems with desquamation or excessive bulk but is limited by the amount of dorsal nasal skin that remains. 13 The inferior turbinate mucosal flap is relatively new but appears to provide a significant amount of mucosa without much donor site morbidity. 12 Other methods of repairing internal lining defects, such as a second cutaneous flap or microvascular flap, have not been used and remain lower in the selection algorithm because of the bulk and functional problems associated with them. Complications Although full-thickness necrosis has not occurred in any of the forehead flaps, epidermolysis of the distal border was found in six patients (8%) and represents the most common complication. These are all managed conservatively with diligent wound care and recover without major sequelae. Allowing a portion of the wound margin to heal by second intention may result in a slightly wider or depressed scar. This can be more problematic, as these scars typically occur at the distal margin of the flap, corresponding to native skin that is thicker, and can leave more textural discrepancies. Three of the patients (50%)

9 with epidermolysis have had some small vessel risk factors: tobacco use (in 2 patients) and diabetes (in 1). Two of the remaining three patients have an old cutaneous scar in the forehead from blunt trauma many years ago. Although the flap is designed around it, one can assume that some of the subdermal vascular plexus of the flap may have been injured and the cutaneous axial pattern flow disrupted. Scars that appear superficial and well healed may, nonetheless, represent a significant compromise to the vascularity of the distal skin. In retrospect, it may have been prudent to elevate this flap in the subgaleal layer and incorporate an intermediate stage for debulking. Of the 20 patients with a history of active tobacco use, 18 (90%) had their forehead flap elevated and debulked in the usual manner without compromise, and the nasal reconstruction completed in two stages. This suggests that the intermediate stage that has been advocated for all smokers may be excessive. Three of the 17 patients with internal lining deficits had partial flap loss. While the flaps are thought to be relatively robust, they remain very delicate, and meticulous handling and wound closure remain vital. Incomplete elevation and mobilization often leave some degree of tension that may compromise suture lines. Osteotomies were performed on three patients with a pre-existing nasal deviation. Patients with previous nasal fractures and a twisted nose have resultant scars that follow the irregular contours of the underlying framework. Often, the nasal reconstruction for these individuals appears far more conspicuous than their counterparts with a normally aligned nasal dorsum. The distortion of the esthetic subunits that is found with a twisted nose compromises the final esthetic outcome. Realigning the bony pyramid during nasal reconstruction is easily performed and can significantly enhance the result in terms of making the flap inconspicuous. Hyperbaric oxygen has been used in three patients and has the potential of providing a significant impact. A flap that has either venous congestion or arterial ischemia may be greatly enhanced with a course of HBO therapy. On occasion, flaps may contain areas of both congestion and ischemia and are amenable to HBO. The mechanisms of action come from the tremendous increase in dissolved oxygen, improved diffusion, and amplification of the ischemic gradient. These variables not only maintain marginal tissue while neovascularization progresses, but also enhance the rate of vascular ingrowth. Congestion is relieved by arterial vasoconstriction that occurs as a result of the elevated tissue oxygen levels and appears to work significantly better in conjunction with medicinal leeches. 27 The greatest application for HBO may be its prophylactic use in high-risk individuals, especially those with a history of radiation therapy. Hypovascularity, hypoxia, and hypocellularity characterize irradiated tissue. Preoperative and postoperative courses of HBO can improve the vascular density and flap viability. 28 CONCLUSION Reconstruction of larger nasal defects has made tremendous advancements and raised the standard of expectation to that of an inconspicuous nose maintaining normal physiological function. The days of a blob on the nose are past. Significant concepts include the aggressive application of esthetic subunits, the versatility and dependability of the midline forehead flap, meticulous replacement of internal lining defects, and liberal cartilage grafting in nonanatomical locations. BIBLIOGRAPHY 1. Menick FJ. Reconstruction of the nose. In: Baker SR, Swanson NA, eds. Local Flaps in Facial Reconstruction. St. Louis: Mosby, 1995: Quatela VC, Sherris DA, Rounds MF. Esthetic refinements in forehead flap nasal reconstruction. Arch Otolaryngol Head Neck Surg 1995;121(10): Burget GC, Menick FJ. The paramedian forehead flap. In: Burget GC, Menick FJ, eds. Aesthetic Reconstruction of the Nose. St. Louis: Mosby, 1994: Frodel JL, Marentette LJ, Quatela VC, Weinstein GS. Calvarial bone graft harvest. Arch Otolaryngol Head Neck Surg 1993;119: Dingman RO, Grabb WC. Costal cartilage homografts preserved by irradiation. Plast Reconstr Surg 1961;28: Schuller DE, Bardach J, Krause CJ. Irradiated homologous costal cartilage for facial contour restoration. Arch Otolaryngol 1977;103(1): Murakami CS, Cook TA, Guida RA. Nasal reconstruction with articulated irradiated rib cartilage. Arch Otolaryngol Head Neck Surg 1991;117(3): Welling DB, Maves MD, Schuller DE, Bardach J. Irradiated homologous cartilage grafts: long-term results. Arch Otolaryngol Head Neck Surg 1988;114(3): Romo T, Sclafani AP, Sabini P. Reconstruction of the major saddle nose deformity using composite allo-implants. Facial Plast Surg 1998;14(2): Ahn MS, Monhian N, Maas CS, et al. Total nasal reconstruction with alloplastic and autogenous grafts. Facial Plast Surg 1998;14(2): Park SS. The flaring suture to augment the repair of the dysfunction nasal valve. Plast Reconstr Surg 1998;101(4): Murakami CS, Kriet D, Ierokomos AP. Nasal reconstruction using the inferior turbinate mucosal flap. Arch Facial Plast Surg 1999;1: Park SS, Cook TA, Wang TD. The epithelial turn-in flap in nasal reconstruction. Arch Otolaryngol Head Neck Surg 1995;121: Kazanjian VH. The repair of nasal defects with the median forehead flap: primary closure of the forehead wound. Surg Gynecol Obstet 1946;83: Converse JM. New forehead flap for nasal reconstruction. Proc R Soc Med 1942;35: Millard DR Jr. Total reconstructive rhinoplasty and a missing link. Plast Reconstr Surg 1966;37(3): Millard DR Jr. Hemirhinoplasty. Plast Reconstr Surg 1967; 40(5): Millard DR Jr. Reconstructive rhinoplasty for the lower half of the nose. Plast Reconstr Surg 1974;53(2): Millard DR Jr. Reconstructive rhinoplasty for the lower twothirds of the nose. Plast Reconstr Surg 1976;57(6): Converse JM, Wood-Smith D. Experiences with the forehead island flap. Clin Plast Surg 1963;31: Younger RA. The versatile melolabial flap. Otolaryngol Head Neck Surg 1992;107: Schlosser RJ, Park SS. Surgery for the dysfunctional nasal valve. Arch Facial Plast Surg 1999;1: Vacanti CA, Langer R, Schloo B, Vancanti JP. Synthetic polymers seeded with chondrocytes provide a template for new cartilage formation. Plast Reconstr Surg 1991;88: Kim WS, Vacanti JP, Cima L, et al. Cartilage engineered in predetermined shapes employing cell transplantation on synthetic biodegradable polymers. Plast Reconstr Surg 1994;94: