信恩美醫診所部落格

The caudal septum is considered the most important anatomic structure in providing nasal base support. Stabilizing the nasal base is a critical step in correction of the short nose. It can provide a good long-term outcome with preservation of the nasal tip projection. However, in Asian patients, the qualities of the caudal nasal septum are occasionally unsuitable. For instance, it may be very thin or weak, or it may be curved or distorted. Under these circumstances, achieving a stable support is difficult. Additionally, the amount of donor septal or conchal cartilages is occasionally limited and makes the buildup of a stable nasal base even more difficult. Therefore, when an extension graft is fixated to the caudal septum for lengthening the nose, the summation force (including the generated reaction force, the postoperative scar contraction force, and gravity) may shift the cartilage grafts to either side of the caudal septum and subsequently lead to the collapse and deviation of the nasal tip or nose elongation failure (Figure 2). In some situations, patients may even develop a one-side check-valve nasal obstruction because of the distorted dorsal-caudal nasal septum (Figure 2). When the short-nosed Asian patient presents with a weak or deviated caudal septum, the placement of spreader grafts or extended spreader grafts alone or in conjunction with a floating-type columella strut⁸ may create similar problems.

Figure 2.  When the caudal septum is very pliable, deviated, or overresected, it may collapse and result in loss of tip projection or subsequent failure of the nose elongation. The inset illustration shows the potential one-side check-valve nasal obstruction developed as a result of a distorted dorsal-caudal nasal septum. Reprinted with permission.

To overcome problems resulting from caudal septal instability, the caudal septum can be replaced in situ with batten grafts or septal replacement.⁹ However, batten grafts are usually difficult and may not easily allow complete elimination of the residual inherent tensile forces or cartilage memory of the deviated caudal septum, which may result in distortion later. Septal replacement is designed to remove the caudal septum and then replace it either after external remodeling with batten grafts or replace it completely with an alternative material, such as autogenous or banked rib cartilage grafts.^10-16 However, many patients may be reluctant to undergo rib cartilage grafting surgery because of its invasiveness, rigidity, and potential warping problems. The caudal septal advancement technique therefore has several advantages. First, the caudal septum can be externally reinforced with batten grafts. Second, the caudal septum is not just replaced, but also advanced as a fixed-type columella strut graft, so the stability of the nasal base can be predictably achieved. Last, the strut cartilage graft is saved. Therefore, caudal septal advancement is strongly indicated in a patient with a more pliable, flimsy, or deviated caudal septum or with marginal shortage of cartilage graft supply.

The difference between Dini and Ferreira’s report⁵ and the present study is the sequence of the procedures. Dini and Ferreira externally fixated the spreader graft to the L-shaped caudal component first and then reintroduced the caudal septum, with its inferior aspect fixated to the nasal spine. The disadvantage with that sequence is the difficulty of properly angling the spreader graft to the cephalic dorsal septum. Therefore, in the present investigation, the sequence of the procedures was modified by advancing the caudal septum with fixation to the nasal spine first. Spreader grafts were then used to bridge the gap between the caudal septum and the cephalic dorsal septum in the proper angle.

The fixation of caudal septum to the nasal spine must be addressed because an unstable suture may allow the caudal septum to slip out of the midline, resulting in caudal nasal deviation (or the “click” when the patient smiles). Therefore, the fixation of the caudal septal base must be secured with two 5-0 polydioxanone sutures. With increased experience, the author now prefers to suture through two predrilled holes at the nasal spine for stable fixation.

To date, the literature contains no reports addressing difficult short nose correction by this integrated approach—that is, by combining caudal septal advancement with external septoplasty. These results show that when patients with short noses present with a weak or deviated caudal septum that is unable to sustain the reaction force induced by nose lengthening, the integrated approach is an appropriate and acceptable alternative to traditional techniques.

As a side note, for augmentation materials, the author prefers to use Gore-Tex rather than silicone implants because Gore-Tex is more biocompatible with the human body, and the long-term risks of capsular contracture and calcification-induced deformation are reduced.¹⁷