Imaging Studies
CT scanning of paranasal sinuses
Axial and coronal views provide good information on the patency of the nasal valve, especially the area under the nasal dorsum (nasal valve area), which is sometimes difficult to visualize. This study is comparatively affordable and can also provide insight into other nasal structures. However, it should not be considered a substitute for a comprehensive physical examination, particularly in the most anterior part of the nose. In the first image below, a normal valvular area can be observed in the axial view. The coronal view (second image) shows a contact area between the right nasal wall and the septum. Both images are from the same patient.
Other Tests
Rhinomanometry
This helps to evaluate the airflow resistance offered by each cavity. It is a useful test, but it does not provide information about the location of the obstruction.
A study by Gagnieur et al suggested that the efficacy of four-phase rhinomanometry may be comparable to that of physical examination in determining whether or not nasal obstruction is caused by internal valve collapse. The investigators found that in patients with internal valve collapse, the size of the inspiratory loop area (the “area defined by the path of the flow/pressure curve in the two phases of inspiration”) was significantly greater than in patients with nasal obstruction resulting from a different cause, with the diagnostic sensitivity and specificity of the loop area being 88.3% and 89.9%, respectively. [10]
Acoustic rhinometry
This method was introduced in the late 1980s. Results provide information about the cross-sectional area of the nose. It can provide information about the position of the obstruction. Results from the anterior portion of the nose are more accurate than results from the posterior, making this test particularly suitable for evaluating the valve. Acoustic rhinometry is important to evaluate the symmetry of the areas because the cross-sectional area varies depending on the size of the nose.
Diagnostic Procedures
The nasal valve is better explored without instruments because tools can open the valve and produce the false impression that the area is normal. A headlight and an endoscope are the only necessary instruments to examine the nasal valve. In many male patients (and some females), the vibrissae are thick, making direct visualization of the area difficult. If this occurs, one option is to trim them until the valve can be visualized.
The Cottle test is a good method to examine the vestibular portion of the nasal valve. It consists of pulling the nasolabial fold upward and laterally and asking the patient if breathing is better (see the image below). An affirmative answer implies that a collapse of the valve is present on that side. A negative answer means the cause of the obstruction is elsewhere in the nose. A false-positive result can occur in patients with collapse of the nasal ala. False-negative results are observed in patients with scars or webs in the valve that prevent it from opening. False-negative results also occur in those with narrowing of the pyriform aperture secondary to congenital malformation or after an excessive narrowing of the nasal base with an osteotomy.
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.
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Rhinoplasty for internal valve stenosis. Normal internal nasal valve anatomy. Notice the relationship between the septum, upper lateral cartilage, pyriform aperture, and inferior turbinate.
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Rhinoplasty for internal valve stenosis. External nasal valve stenosis. The nasal rim is collapsed because of an extremely thick columella.
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Rhinoplasty for internal valve stenosis. Internal nasal valve stenosis. Notice the collapse of the area between the septum and the left upper lateral cartilage. Also notice the decrease of cross-dimensional area due to the deviated anterior septum.
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Rhinoplasty for internal valve stenosis. Septal causes of valvular stenosis, from left to right, are (1) a thickened septum, (2) deflection of the septum, and (3) caudal deviation with an inferior spur.
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Rhinoplasty for internal valve stenosis. Upper lateral cartilage (ULC) causes of valvular stenosis, from left to right, are (1) excessive returning, (2) thickened ULC, (3) twisted ULC, and (4) deflected ULC.
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Rhinoplasty for internal valve stenosis. Mucocutaneous causes of valvular stenosis, from left to right, are (1) synechia, (2) stricture, and (3) edema of mucosa.
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Rhinoplasty for internal valve stenosis. Iatrogenic causes of valvular stenosis. Absence or excessive trimming of the ULC.
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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.
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Spreaders.
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Spreaders.
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Spreaders.
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Spreaders.
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Spreaders.
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Valve collapse.
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Coronal view shows a contact area between the right nasal wall and the septum.
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Normal valvular area in an axial view.
