In this exercise, the cartilaginous and bony hump are removed en bloc. Be conservative! Plan to take a small amount of the hump off at first and thereby avoid incising the mucoperichondrium, which provides important support. Later, after the bony-cartilaginous hump has been removed, be prepared to make multiple tine adjustments of both the septum and dorsal margins of the upper lateral cartilages. When lowering the dorsal septum, keep in mind the importance of allowing for the thicker skin over the lower one third of the nose. Also, recognize that inadequate resection at the supratip may result in a polly-beak deformity. (Appendix G)
[Note: The dissector may wish to incise the skin/soft-tissue envelope down the midline either now or subsequent to this chapter. The hump excision may be done first, and then split the skin to examine the result and allow easy exposure for subsequent maneuvers. If the dissector intends to augment the dorsum with a cartilage graft, this may be done first, and then split the skin for easy exposure during the remaining dissection. The skin in the midline can be sutured back together as desired at any time.]
Expose the cartilaginous dorsum with a Converse retractor, and use a no. 15 blade to incise lightly any remaining soft tissue overlying the cartilaginous dorsum. Reflect this tissue laterally on both sides. Next, beginning at the osseocartilaginous junction and proceeding caudally, incise the cartilaginous dorsum at the planned level of initial excision (Figs. I and 2). Try to keep this incision even on both sides, but remember that there will be additional "fine-tuning" modifications after initial hump excision.
Under direct vision, place an osteotome against the bony hump at the osseocartilaginous junction (Fig. 3). Use the incised but attached cartilaginous dorsum to help seat the osteotome at this location. With a gentle, controlled two-tap technique, incise the bony hump with the osteotome (Fig. 4). Take care not to overresect the bony hump, as the osteotome will tend to cut deeper into the bone. Remove the hump with a hemostat or similar instrument, and examine its features (1,2).
When executing hump excision, preserve the underlying nasal mucoperichondrium. The nasal mucoperichondrium provides support to the upper lateral cartilages and helps de-crease the risk of inferomedial collapse of the upper lateral cartilages after hump excision (Fig. 5). [Inferomedial collapse of the upper lateral cartilages and inadequate infracture of the nasal bones can lead to an "inverted V deformity," in which the upper lateral cartilages collapse inferomedially, and the caudal edges of the nasal bones are visible in broad relief, creating an unacceptable appearance.] (3A) (Appendix G)
Figure 1. Beginning at the osseocartilaginous junction and proceeding caudally, incise the cartilaginous dorsum at the planned level of initial excision. This amount of excision is larger than normally performed. Most patients would require smaller dorsal hump excisions.
Figure 2. At this stage, the cartilage remains attached at the osseocartilaginous junction.
Figure 3. Under direct vision, insinuate an osteotome against the bony hump at the osseocartilaginous junction. Use the incised but attached cartilaginous dorsum to help seat the osteotome at this location.
Figure 4. A,B: With a gentle, controlled, two-tap technique, incise the bony hump with the osteotome. Careful examination of the excised hump can help guide additional calibrated excision of remnant cartilage or bone. Assess whether the nasal mucoperichondrium was successfully avoided.
Figure 5. Cross-section at the level of the cartilaginous vault (A). The nasal mucoperichondrium provides support to the up- per lateral cartilages and helps decrease the risk of inferomedial collapse of the upper lateral cartilages after hump excision (B, C). When the nasal mucoperichondrium is violated, inferomedial collapse of the upper lateral cartilages may occur (D, E).
Now make additional fine-tuning modifications to the cartilaginous dorsum as indicated. Examination of the excised hump may guide any additional excision. Trim the anterior (dorsal) margins of the upper lateral cartilages such that they lie on a level with or just be-low that of the trimmed border of the septum. Additional modification of the bony dorsum also may be required.
An ‘open roof" may be created by hump removal. The bony margins should now be smoothed with a rasp by using few but firm strokes (Fig. 6). Any bony fragments should be removed, making sure that all obvious particles are removed from under the skin/softtissue en v elope.
An alternative to the manual rasp is a powered reciprocating rasp or sheathed burr (Figs. 7 and 8) (5). These instruments can be used wherever a manual rasp would be used, but with less soft-tissue trauma. The site to be treated can be directly visualized. The powered instruments are especially useful to smooth the bony margins of the open roof. They also are useful to correct isolated bony irregularities that may be encountered, for example, in secondary rhinoplasty. It appears that a more reproducible result can be obtained with a lower incidence of visible or palpable bony dorsal irregularities. After rasping or burring, bone particles should be irrigated from the surgical site.
Figure 6. Smooth the bony margins with a rasp by using few but firm strokes, cutting only on the down stroke.
Figure 7. The powered reciprocating rasp is an alternative to the manual rasp.
Figure 8. The powered sheathed suction bur is an alternative to the manual rasp.
[Note: This is one approach to hump excision. Another approach is described here. In some cases, the surgeon may wish first to separate the upper lateral cartilages from the dor sal septum. This is accomplished in the submucoperichondrial plane and can be readily ac complished through the hemitransfixion incision or external rhinoplasty approach (Fig. 9). Then rather than excising the entire cartilaginous hump, only a strip of dorsal septum is ex cised. The remainder of the hump excision proceeds as described earlier, the upper lateral cartilages are then shaved down individually so that they are at the same level as the dorsal septum.] This method is good for excision of large dorsal humps where preservation of mu cosal continuity may be otherwise difficult.
PEARLS
• Two-tap technique: Overzealous force on the osteotome may lead to loss of control and undesired under- or overresection of the dorsal hump. A controlled exci sion of the bony dorsum is best achieved with a careful, repeated two-tap technique designed to advance the osteotome only a short distance at a time.
• The surgeon should be sure that the osteotomes are sharp to allow precise bone cuts.
• In cases with large dorsal humps, an extramucosal reduction can be performed by
dissecting mucosa off the undersurface of the middle and upper vaults.
• The beginning surgeon may wish to premark the proposed hump excision on the
nasal skin.
• If the surgeon feels uncomfortable using an osteotome for dorsal-hump removal, a sharp rasp will be effective with less risk of overresection.
• The periosteum must be cleared from the bone prior to rasping to insure effective lowering of the bone.
• Most dorsal humps are primarily cartilaginous. Therefore, the dissector should limit excision of the bony vault.
Figure 9. A—E: Division of the upper lateral cartilages from their attachment to the dorsal septum in the submucoperichondrial plane. Great care should be taken to preserve an intact mucoperichondrium. F: Division of the upper lateral cartilage from the attachment to the dor sal septum, with dissection of a submucoperichondrial flap, may be accomplished from above, as shown here via the external rhinoplasty approach. G: This dissection begins at the anterior septal angle, and then subperichrondrial dissection is performed. Completed di -vision of upper lateral cartilages from septum.
REFERENCES
- Tardy ME. Rhinoplasty: the art and the science. Philadelphia: WB Saunders, 1997.
- Larrabee WF Jr. Open rhinoplasty and the upper third of the nose. Facial Plast ,Sorg Clin North Ant 1993:1: 23-38.
- Johnson CM 1r, "Toriumi DM. Open structure rhinoplasty. Philadelphia: WB Saunders, 1990.
- Toriumi DM. Management of the middle nasal vault. Oper Tech Plast Reconstr Surg 1995;2:16-30.
- Becker DG, Toriumi DM. Gross CW, Tardy ME. Powered instrumentation for dorsal nasal reduction. Facial Plast Sti n g 1997:13:291-297.