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The three major sources of cartilage autografts are the nasal cartilage, the cavum and cymba concha of the ear, and the rib.
A) NASAL SEPTAL CARTILAGE GRAFT
The septal cartilage autograft meets all of the following requirements for an ideal graft to be used in nasal surgery. It is accessible within the surgical field. It provides some variation in thickness and rigidity. It is easy to contour, elicits no host reaction, and is permanent. Its only drawback is lack of availability due to prior surgery or trauma. Large segments of septal cartilage can be removed without adversely affecting the supporting nasal structure as long as an adequate intact dorsal and caudal segment is left in place (Figure 1 A and B).
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| FIGURE I. A and B. Septal cartilage autograft accessed through the external approach. (A) Septal cartilage incision leaving adequate anterior and dorsal supporting segments; (B) removal of a large septal cartilage autograft through external approach. |
Septal cartilage may he accessed endonasally through a hemitransfixion or Killian incision. When an external nasal approach is used for reconstruction, separating the medial crura allows wide exposure of the entire septum. Following cartilage removal, the mucosal lining on either side can be sutured together with a continuous weaving suture or multiple interrupted sutures. This closes the potential dead space and eliminates the need for intranasal packing post-operatively. The inferior portion of septal cartilage adjacent to the nasal spine is relatively thick and strong and provides an excellent supporting graft for use as a columella strut to support or increase tip projection. Just above this inferior portion of cartilage the septum thins out somewhat. It is still firm and a hit more flexible, having the best characteristics for grafts to be utilized within the lobule as a shield or tip replacement graft. Superiorly, the thinner more elastic portions of the septum are a good source for grafts to efface small contour defects (Figure IC). Any smooth, straight segment of the septum can be used as a single or multilayered onlay graft to elevate a depressed nasal dorsum.
B) ALAR CARTILAGE GRAFT The cephalic portion of the lower lateral cartilage, which is commonly removed in nasal tip surgery, can be an excellent source of cartilage autograft to fill in a contour defect in another portion of the nose. In particular, in cases of alar asymmetry, a balance can be accomplished by transecting the cephalic portion of one side and using it to build up the deficient side (see Figure 5 in Section IV.B.).
C) AURICULAR CARTILAGE AUTOGRAFTS
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FIGURE IC. Graft sectioned into three segments which may be used for columella strut (bottom) and onlay grafts to nasal dorsum. |
The ear provides another excellent source of cartilage autografts. The entire cavum and cymba concha can he removed without producing a deformity of the ear. This graft can he harvested from an anterior approach, placing the incision at the depth of the antihelicle fold. The resulting scar is negligible. A bulky ear dressing can he avoided by suturing a bolus pressure dressing into the concha (Figure 2A-C). If one prefers the posterior approach, the graft can be readily obtained through an incision in the postauricular sulcus. Conchal cartilage can be harvested with or without perichondrium. being rather flexible and not as firm as the thicker portions of the septal cartilage. Conchal cartilage has been tubed and used over the nasal dorsum, or as a premaxillary graft to augment a retracted upper lip. When conchal cartilage is used for dorsal augmentation, it is preferable to suture together relatively similar size segments to produce the desired thickness. Conchal cartilage is ideal to recontour small defects along the nasal dorsum or to build up a deficiency of the alar of the nose. It is very useful to correct a vestibular stenosis secondary to absent alar cartilage. It may also he utilized for tip projection. It can be fashioned into a shield, or tip-projecting graft, and is also used as a tip onlay graft. Because of its curvature, it is less desirable than septal cartilage for columella struts. An additional important use of auricular cartilage is as part of a composite graft which includes cartilage perichondrium and both anterior and posterior surfaces of the skin. This is obtained from the outer curve of the ear and utilized most commonly to correct full thickness, alar, nasi, or columella defects. Auricular cartilage has also been used successfully to correct traumatic orbital floor defects.
D) COSTAL CARTILAGE Costal cartilage has been used when large segments of cartilage autografts are needed. It is harvested from the sixth or seventh rib. Although this is an excellent source of cartilage, the operating time is prolonged significantly and adds a moderate amount of morbidity. Costal cartilage, when stored at 4°C for a few days, remains viable. It must be appropriately carved to counteract its tendency to warp, which is a problem when used to correct a depressed nasal dorsum. Costal cartilage has been used to reconstruct malar and mandibular contour defects, as well as various other bony facial defects. Perhaps its most important use today is in providing the framework for total auricular reconstruction of congenital or acquired origin. << previous page next page>>
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