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

The Anatomy and Definition of Nasal Valve Collapse and Internal Valve Stenosis

Here is a simple explanation to describe the complexity of  Nasal Valve Collapse, from Drs Litner & Solieman's website: see link below with photo's.

The nasal valve is a term used to describe the narrowest part of the nose internally. This is the area that determines if someone feels normal or obstructed breathing through the nose. When this area is overly narrowed and blocked, we call it nasal valve collapse.  

There really are two types of nasal valve collapse. The collapse of the tip cartilages described above can cause external valve collapse where the blockage is just past the nostril. When most surgeons discuss valve collapse, though, they are talking about internal valve collapse. This occurs when the upper lateral cartilages in the middle of the nose have been too narrowed.  This problem happens when a nasal bump is taken down too much and when the cartilages themselves are shortened or not reattached during a Rhinoplasty. The problem seems to occur more often after a closed Rhinoplasty because most surgeons detach these cartilages without repairing and reattaching them at the end of the procedure. When the natural cartilage supports have been lost, they simply fall inwards and collapse. The result is poor breathing and two visible cosmetic deformities. One is called an ‘inverted V deformity’. That’s because the collapsed area where these cartilages attach to the nasal bones looks like an upside-down letter V. The second problem is that the middle part of the bridge can start to look very pinched.
http://www.rhinoplastyinbeverlyhills.com/rhinoplasty-mistake-8-nasal-valve-collapse

Dr. Craig Murakami explains that an internal nasal valve is considered to have collapsed when the angle of the valve is less than 10[degrees] to 15[degrees]. Its etiology can be congenital, traumatic, or iatrogenic. (1) In the latter case, collapse is often caused by over-resection of the nasal dorsum and upper lateral cartilages during septorhinoplasty. Such an overly aggressive operation can result in concurrent dorsal concavity (saddle-nose deformity) or a narrowing of the middle third of the nose (hourglass deformity).

 http://findarticles.com/p/articles/mi_m0BUM/is_3_83/ai_n6077596/

Important nose anatomy illustration diagrams from Dr. Beckers website. 

http://198.173.122.37/centeranatomy.html

Rhinoplasty, Postrhinoplasty Nasal Obstruction  

Author:Thomas Romo III, MD, FACS 

Coauthor(s): James M Pearson, Haresh Yalamanchili, MD, Paul Presti M.D.

Grymer used acoustic rhinometry to evaluate the internal dimensions of the nasal cavity in 37 patients before reduction rhinoplasty and again 6 months after surgery.³ He demonstrated that rhinoplasty decreases the cross-sectional area of the nasal valve by 25% and the piriform aperture by 13%. Cole et al also used rhinomanometry to reveal that changes of as small as 1 mm to the nasal valve size can dramatically increase nasal resistance

Therefore, the nasal valve, as a regulator of nasal airflow and resistance, has been demonstrated to play a critical role in the function of the nose. Disturbance of the nasal valve area can produce limitations to normal nasal breathing. Multiple schemes can be used to classify the types of nasal valvular dysfunction. One convenient method is to group them according to either internal or external nasal obstruction (see Classification of nasal valve dysfunction). 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 component can be further divided into static and dynamic nasal dysfunction.

In summary, nasal valve dysfunction can be secondary to either mucocutaneous problems or skeletal deformities (affecting either the internal or the external nasal valve), which can be dynamic or static. However, the cause is rarely so straightforward. In most instances, the mucocutaneous and skeletal components and the static and dynamic components contribute in varying degrees to the overall nasal valvular dysfunction.
Skeletal deformity:

Deformities that affect the internal nasal valve area

• Static deformity
  • Inferomedially displaced upper lateral cartilage
  • Narrowing of pyriform aperture
  • Scarring at intercartilaginous junction
  • Turbinate hypertrophy
  • Deviated nasal septum
• Dynamic deformity - Collapsed upper lateral cartilage secondary to disruption of support from the nasal bone, septum, and lower lateral cartilage

Because ventilation involves pressure changes, the nasal airways must be stable both at rest and under the negative pressures created during quiet and forced inspiration. The internal and external nasal valves depend on satisfactory skeletal stability of the upper and lower lateral cartilages, respectively. When either the skeletal or the soft tissue component is congenitally deficient or has been compromised by surgery or trauma, the patient experiences a dynamic collapse of the valve during inspiration, with resultant airway obstruction. Normally, the upper lateral cartilages partially collapse at a ventilatory flow rate of 30 L/min. Thus, even normal nasal valves collapse with vigorous respiratory effort; however, a patient with dynamic nasal valve dysfunction may have a lateral nasal wall that is so weakened that it collapses even during normal nasal breathing.

The internal nasal valve area is the narrowest portion of the nasal passage and thus functions as the primary regulator of airflow and resistance. The cross-sectional area of the nasal valve area is 55-83 mm². As described by the Poiseuille law, airflow through the nose is proportional to the radius of the narrowest portion of the nasal passageway, raised to the fourth power. Thus, changes as small as 1 mm in the size of the nasal valve exponentially affect airflow and resistance through the nasal cavity.

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

Rhinoplasty, Internal Valve Stenosis

Author: David Núñez-Fernández, MD, PhD Co-Authors: Jan Vokurka, MD, PhD, Gloria Fernández-Muñoz, MD

The airflow resistance provided by the airways during breathing is essential for good pulmonary function. The nose is responsible for almost two thirds of this resistance. Most of this resistance occurs in the anterior part of the nose. This region is called the nasal valve, and it acts as a flow-limiter.

External nasal valve collapse can be found in patients without a history of trauma or surgery. These patients commonly have an overprojecting nose with extremely narrow nostrils. Another cause can be an extremely wide columella,

Internal nasal valve collapse can be divided depending on the structure that caused the collapse. In many cases, more than one structure is affected. The most common cause is probably septal deviation.  The second cause is collapse secondary to rhinologic surgery, especially after removal of the nasal roof. Khosh found, in 53 patients, the following causes of nasal valve collapse: previous rhinoplasty (79%), nasal trauma (15%), and congenital anomaly (6%).⁴

Upper lateral cartilage  (ULC)
Thickened cartilage can compromise an adequate aperture. The cartilage can also be twisted, deflected, or associated with excessive return of the caudal border. An absence of cartilage, either congenital or iatrogenic, can produce a flaccid valve that collapses during inspiration.

Lower lateral cartilage  (LLC)
Overresection during rhinoplasty can weaken the cartilage and cause inspiratory collapse. Deformation of the cartilage can be a result of trauma or congenital malformations of the cartilage.

Although uncommon, some patients may have deformities of the pyriform aperture that reduce the space of the nasal valve.

Rhinoplastic procedures are particularly prone to disturbing the nasal valve area. Hump removal affects the nasal valve in several ways. If the hump is particularly large, separation of the ULC can be necessary. Resection of the T-shaped area of the dorsal border of the septum produces a narrower area in the roof. If the mucosa in the valve is not protected during the surgery, which occurred with the use of many older techniques, scarring of the valve can lead to structure formation or stenosis of the valve.

In reduction rhinoplasties, the cross-sectional area of the overall nose is reduced. This increases the resistance to airflow. If the nasal valve is not properly repaired during the surgery, patients may report nasal obstruction after the surgery, even if this was not reported preoperatively. Overresection of the lower lateral cartilage can lead to pinching and inspiratory collapse.

Because it is the narrowest part of the nose, the nasal valve can be affected by minute alterations of the nasal anatomy that would not be important in other areas. 

The angle between the ULC and the nasal septum is 10-15° (normally in Caucasians). Internal nasal valve collapse occurs when, for some reason, this angle is diminished. The result is an increase in nasal resistance to airflow; consequently, the patient reports nasal obstruction. The opposite is known as ballooning. In this case, the nasal valve is excessively open.

The pyriform aperture continues the limit of the valve from the ULC to the floor. The head of the inferior turbinate is immediately posterior to the pyriform aperture and plays an important role in the function of the valve, which is the reason it is also considered part of the internal nasal valvehttp://emedicine.medscape.com/article/877468-overview

Identifying nasal valve dysfunction:

Diagnosis can be difficult if the physician does not visualize the valvular area. Examining the valve without disturbing it with a nasal speculum is important because the speculum usually opens the valve. Sometimes, trimming the vibrissae is necessary to obtain a clearer view of the valve. Another method is to use a 0° endoscope

The Cottle test is useful to evaluate nasal valve stenosis. The cheek of the evaluated side is gently pulled laterally with 1 or 2 fingers, which opens the valve.

NOTE: Cottle test can be nonspecific
The problem with the standard Cottle maneuver is the results can be nonspecific. Dr. Jack D.Sedwick mentions on his website that 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.

A more precise diagnosis can be made based on direct inspection of valvular support during quiet and forced inspiration. Collapse at the internal nasal valve is usually diagnosed based on the identification of medialization of the caudal margin of the upper lateral cartilages due to negative pressure created upon inspiration through the nose. A fine swab or cerumen curette may be used to lateralize the upper lateral cartilage to confirm the presence of internal valvular collapse.

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.⁷ 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://www.providence.org/alaska/medstaff/nasalvalve.htm

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

http://simple-med.blogspot.com/2009_02_01_archive.html

Click on diagrams below for larger view 

Note: Insert Picture, Upper and Lower Lateral Cartilage scrolls interlocking