Lower Third Nasal Skin Grafting

Abstract

Lower third nasal defects present a special challenge to reconstructive surgeons.. The unique character of the lower third of the nose, with its interwoven concavities, convexities, and varying skin thicknesses, exacerbates the difficult reconstruction of this region. Specific flap algorithms are available for reconstruction of full-subunit alar or full-subunit tip defects (Hill, 1987). The lower third nasal defects or defects larger than 1.5 cm in diameter can be reliably reconstructed and repaired with nasolabial or forehead flaps using either a subunit or defect-only reconstruction (Barton, 1981). These techniques require multiple stages and allow for the replacement of cartilage and lining if missing. Paradoxically, acceptable results are more difficult to achieve with smaller defects, most notably those smaller than 1 cm. Local flaps applied for these defects often result in violation of aesthetic subunits, worsening of the defect by alar notching, and frequent or unpredictable pincushioning. Likewise, the misapplication of skin grafts to large or deep lower third defects often yields a depressed patchwork with unsuitable results. In many cases of lower third nasal reconstruction, particularly those arising from excision of neoplasms by means of Mohs’ micrographic surgery, the defects are shallow and measure less than 1 cm in diameter. These defects rarely encompass greater than 50 percent of aesthetic subunits and are best treated as defect-only reconstructions (Dimitropolous et al., 2005). Such defects can be successfully and reliably treated with well-applied full-thickness skin grafting from the preauricular or more preferential forehead donor site. The evolution of the demonstrated skin grafting techniques started with the recognition of the frustrating paradox in reconstructing small defects of the lower third. Larger defects could be easily and reliably reconstructed with the well-established algorithms (i.e., nasolabial or forehead flap reconstruction). The use of bilobed flaps from the upper third of the nose to recreate defects on the lower third commonly disappoints for two reasons. The inherent design flaw of the bilobed flap violates a second or third aesthetic unit and often completely distorts the alar groove. In addition, the final result is inherently unpredictable because of its tendency to pincushion. There is a common reluctance to advance skin from the nasal sidewall to reconstruct lower third defects, as this destroys the alar groove, an aesthetic subunit that is very difficult to reconstruct.