Functional Nasal Grafts for Middle Vault and Alar Collapse
Function of Middle Third of Nose
Dr. Sam Rizk, a NYC rhinoplasty surgeon and specialist states that the middle third of the nasal pyramid is often overlooked during routine preoperative examination and during rhinoplasty operations. The percentage of the nasal bridge which is bone versus cartilage is important in assessing preoperative weaknesses in the nose which can predispose to collapse after a bump reduction of the nasal dorsal septum and upper lateral cartilage. If not addressed with spreader grafts at the time of the initial operation when there is a preexisting weakness in this area of the middle vault, it would result in collapse, sometimes also known as an inverted v deformity (see section on revision rhinoplasty to see pictures of this deformity). The upper lateral cartilages contribute resistance and solidity to the middle vault, both essential for good nasal valve function. The soft tissue cover, of variable thickness, also provides support to the upper lateral cartilages: a thick skin provides more support to these cartilages than does a thin skin.
The Nasal Valve
The nasal valve is a dynamic structure of the nose located between the vestibule and nasal fossa (so called internal nasal valve). The nasal valve is limited laterally by the mobile shape formed by the caudal edge of the upper lateral cartilages and the soft tissues that connect it to the piriform aperture and posteriorly to the head of the inferior turbinate. It is limited inferiorly by the inferior border of the piriform aperture and medially by the septum. The nasal valve is a partial regulator of nasal airflow into the nose. The dilator muscles of the nostrils have an influence on the nasal valve during inspiration and prevent collapse of the valve at high inspiratory flow rates. The valve can be manually opened by the Cottle maneuver, which consists of drawing the cheek laterally away from the midline. If this relieves the nasal obstruction, this is considered a positive Cottle sign. Dr. Sam Rizk will perform this maneuver during the preoperative assessment as well as a maneuver to determine the cartilage versus bone composition of the nose. Results of the Cottle maneuver are considered negative if function is normal or if the nasal obstruction has another cause. Nasal valve function can be evaluated before the surgery. The head is tilted posteriorly and a cotton-tipped applicator used to gently spread the ala from the septum to examine the internal valve for suppleness, integrity, value of the valve angle, and mobility of its lateral border, both at rest and during forced inspiration. The lateral walls are observed for external abnormalities such as aspiration of the lateral walls of the nose with or without alar collapse. As Dr. Sam Rizk states it is important to seek a nose specialist for an excellent functional and cosmetic outcome - a rhinoplasty specialist or surgeon who limits his practice to the nose and facial plastic surgery and who performs many rhinoplasties per week gives the patient the best chance for an excellent outcome. Dr. Sam Rizk is a nose specialist and new york rhinoplasty surgeon who limits his practice to the nose and face and who is double board certified in that area. Dr. Rizk does not perform plastic surgery on the body.
Causes of Middle Vault collapse (evaluating the cause in the preoperative examination)
Middle vault collapse may occur when there is a narrow cartilaginous vault, in contrast with a very wide bony vault or when the nasal bones are convex and there is a slightly inverted v deformity that is a visible demarcation between the nasal bones and the upper lateral cartilages. During inspiration, a tendency of weak cartilages to collapse can be noted. Palpation may show a convexity at the lower border of the nasal bones that can be followed downward on the cartilage vault by a noticeable narrowing. Dr. Sam Rizk who specializes in rhinoplasty (nose job) surgery, emphasizes the importance of evaluating the length of the nasal bones preoperatively and the condition of skin and upper lateral cartilages. After the hump is removed, short nasal bones provide less support to the upper lateral cartilages, primarily when they are weak and concave. The inner surface of the resected nasal bump should be examined to assess the width of the septum. Intraoperatively, Dr. Sam Rizk examines the inside of the nose to assess the airway after removal of the nasal bump and after performing the lateral osteotomies for signs of collapse or weaknesses in the upper lateral cartilage.
The following factors contribute to the weakening of the support of the upper lateral cartilages and increase the potential deformation and collapse called inverted v deformity:
- the avulsion or laceration of the upper lateral cartilages as a result of overaggressive rasping or excessive resection of these cartilages, which would cause a depression of the middle third of the nasal pyramid.
- an osteotomy that is too high, with excessive resection of tissue, especially along a large nose, or when there is a preexisting extensive coetaneous undermining.
The anatomy of the cartilaginous vault must be recreated, specifically the septal/upper lateral cartilage anatomy (the septal T) - that is the anterior septal border must be enlarged and a normal valve angle created.
The mucous roof can be sutured once an extramucosal dissection is done. The cartilaginous graft can be placed over the fixed portion of the nose to create spreading of the upper lateral cartilages and to raise the cutaneous coverage while increasing the functional mobility of the cartilages. Septal cartilage is the best material for dorsal grafts and spreader grafts. The cartilage can also be crushed slightly and positioned superficially on the upper lateral cartilage to reinforce it. Over the dorsum, Dr. Sam Rizk will sometimes use a 2-layered graft composed of an inlay graft wider than the anterior septal border that is inserted between the 2 osteocartilaginous flaps and an onlay graft placed superficially. These 2 grafts are sutured together for stability. The spreader graft consists of cartilage strips that are inserted in submucosal tunnels on either side of the anterior septal border, extending from the junction of the nasal bones and the upper lateral cartilages to the nasal valve area. It is preferable to thin the posterior edges of these grafts and to suture them through the anterior septal border under direct vision.
If septal cartilage is not available as in some revision rhinoplasty cases, then banked rib cartilage is an excellent option, better than ear cartilage. Dr. Rizk states that ear cartilage is better suited as an onlay graft or camouflage graft, rather than a spreader graft. A spreader graft needs to be straighter and stronger than ear cartilage and this is why Dr. Sam Rizk believes septal cartilage or banked rib cartilage is ideal.