Monday, January 3, 2011

Nasal Valve Collapse: Causes, Diagnosis, & External Valve Stenosis

 If you have a functional problem such as Nasal Valve Collapse caused by a previous surgeon (iatrogenic) this may be  due to over re-sectioning of bone &/or cartilage or due to weak or medially displaced lateral crura in the lower lateral cartilage. The Lower lateral cartilage is also referred to as the greater (major) alar cartilage. The Lower cartilage (The crura and lateral components together) have been perceived in different ways by surgeons from its frontal and basal views. The left and right lower cartilage can be viewed together as tripod or the M golden arches of McDonalds Corporation.. Modification of the M arch can in many ways modify the shape of the nasal tip. I believe there can never be enough diagrams so I will include some more illustrations here for better understanding.

Click on pictures for larger view


Causes of Valve Collapse
According to Dr. Gary Bennett, aging weakens the nasal sidewalls and causes the tip of the nose to sag. These changes can obstruct airflow inside the nose. Weak cartilage or cartilage turned inward can also predispose patients to nasal valve obstruction. The primary cause of nasal valve obstruction requiring surgery is previous nasal surgery. Taking down a large bump or decreasing a large tip can weaken support in the rest of the nose. Dividing the cartilage from the septum can cause scarring in the internal valve area that is very difficult to correct. Cosmetically, the nose may look great, but your breathing is still problematic. This can be avoided by choosing a surgeon trained to avoid and correct this deformity.
http://nycfacemd.com/nasal-valve-collapse-and-treatment/

Rhinoplasty, Postrhinoplasty Nasal Obstruction

Author: Thomas Romo III, MD, FACS
Coauthor(s): James M Pearson, MD,Paul Presti, MD, Haresh Yalamanchili, MD

External nasal valve collapse is due to collapse of the nostril margin at the opening of the nose (alar collapse) with moderate-to-deep inspiration through the nose. This phenomenon is usually observed in patients with narrow slitlike nostrils, a projecting nasal tip, and thin alar sidewalls.

This article focuses on only postrhinoplasty-related external valvular collapse. Constantian and Clardy reviewed 160 patients treated for external nasal valve incompetence. Surgical reconstruction was performed with septal cartilage or with composite conchal cartilage-skin grafts. Using rhinomanometry, Constantian and Clardy found that correction of external valvular incompetence increased total nasal airflow during quiet ventilation by more than 2-fold over preoperative values. Thus, the external nasal valve may play a crucial role as the cause of nasal airway obstruction in some patients.

Kern and Wang divide the etiologies of nasal valve dysfunction into mucocutaneous and skeletal/structural disorders. The mucocutaneous component refers to the mucosal swelling (secondary to allergic, vasomotor, or infectious rhinitis) that can significantly decrease the cross-sectional area of the nasal valve and thus reduce nasal airway patency. The skeletal/structural component refers to any abnormalities in the structures that contribute to the nasal valve area. This includes the nasal septum, upper and lower lateral cartilage, fibroareolar lateral tissue, piriform aperture, head of the inferior turbinate, and floor of the nose.
Skeletal deformity
Deformities that affect the external nasal valve
  • Static deformity
    • Tip ptosis
    • Cicatricial stenosis
  • Dynamic deformity
    • Collapsed lower lateral cartilage secondary to excessive excision
    • Nasal muscle deficiency
Physical examination
Identification of patients with nasal valve dysfunction can be difficult. Other more common causes of nasal airway obstruction should always be evaluated and treated as well. The classic maneuver in the evaluation of nasal valve collapse is the standard Cottle maneuver, which is used to assess nasal valve incompetence by judging improvement in nasal breathing with lateral distraction of the ipsilateral cheek. The problem with the standard Cottle maneuver is the results can be nonspecific. A straightforward narrowing of the nasal airway produced by septal deviation or turbinate hypertrophy is improved by the Cottle maneuver. Anterior rhinoscopy is also a poor means of accurately evaluating subtle changes in nasal valve anatomy; the dysfunctional nasal valve can be missed due to distortion from the nasal speculum.

External nasal valve collapse can be diagnosed based on observation of the nostril margin to determine if the alae collapse with moderate-to-deep nasal inspiration. One nostril can be occluded to facilitate this maneuver. Next, a modified Cottle maneuver can be performed with a cerumen curette placed intranasally to support the internal or external nasal valve to determine specifically if improvement in nasal airflow results. Minimal distraction of a collapsed internal valve or stabilization of the external valve during inspiration can dramatically increase airflow on the affected side and confirm the diagnosis. The patient can usually appreciate an immediate improvement in airflow when a flaccid or collapsible valve is supported during inspiration.

More recently, Hilberg et al introduced acoustic rhinometry as a noninvasive and reliable objective method for determining the cross-sectional area of the nasal cavity. Acoustic rhinomanometry is based on the analysis of sound waves reflected from the nasal cavities. Also, analysis can be done before and after topical decongestants are applied, allowing discrimination of mucocutaneous versus structural blockage. Standards for age, race, ethnicity and sex have been recently published.

http://emedicine.medscape.com/article/841574-overview#Classificationofnasalvalvedysfunction

External Valve Stenosis
Author:Alicia R Sanderson, MD

Co-Authors:Craig Cupp, MD, Peter A Weisskopf, MD

Etiology

Nasal valve collapse or obstruction has many potential etiologies. Some of the more frequent causes include the following:
  • Deficiency of the lateral crus of the lower lateral cartilage secondary to previous surgery with overaggressive resection of cartilage
  • Congenital deficiency of cartilage or cephalad rotation of lower lateral cartilage
  • Trauma that leads to loss of tissue
  • Full-thickness surgical resection of the alar with insufficient reconstruction
  • Aggressive narrowing of the nasal tip during rhinoplasty (see the eMedicine article Rhinoplasty, Postrhinoplasty Nasal Obstruction)
  • Caudal septal deflection that narrows the valve and causes increased velocity of airflow with a larger transalar pressure differential
  • Facial nerve palsy that leads to loss of nasal dilators
  • Sequelae of aging that leads to loss of nasal alar stiffness
  • Overprojection of nasal tip that leads to slitlike nares with increased velocity of airflow

Pathophysiology

Any process, condition, or trauma that weakens the lower lateral cartilage or alar walls or that narrows the entrance to the nose can lead to collapse of the external valve. Upon inspiration, the increase in transmural pressure across the nasal ala leads to collapse of the external valve.

Indications
Any airway compromise caused by obstruction of the external nasal valve is an indication of external valve stenosis. The most absolute indication is the symptomatic collapse of the alar upon inspiration.
http://emedicine.medscape.com/article/877600-overview

2 comments:

  1. Hi,

    This is the perfect blog for anyone who wants to know about this topic. You know You definitely put a new spin on a subject that's been written about for years. Great stuff, just great!

    Robert Tomlinson MD

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  2. is it possible to be something else wrong apart from collapsed valve,and if so can it be treated without surgery...if it is a collapsed valve and you need surgery how long doesthe public hospital take to operate,and if you have private insurance is this covered or do they class it has cosmetic surgery

    ReplyDelete