Draft:External nasal valve collapse
{{AFC submission|d|ai|u=Sarmccord|ns=118|decliner=Jlwoodwa|declinets=20250426071603|ts=20250425131523}}
{{Short description|Functional nasal obstruction due to collapse of the nostril's lateral wall during inspiration}}
{{Draft topics|medicine-and-health}}
{{AfC topic|other}}
{{Infobox medical condition
| name = External nasal valve collapse
| synonyms = External nasal valve insufficiency, lateral wall collapse
| field = Otolaryngology, Facial plastic and reconstructive surgery
| symptoms = Nasal obstruction, inspiratory collapse of nostrils, impaired breathing during exercise, snoring
| complications = Chronic mouth breathing, sleep disturbance, reduced quality of life, aesthetic deformity
| causes = Iatrogenic (e.g., post-rhinoplasty), trauma, congenital hypoplasia, age-related weakening
| risks = Previous nasal surgery, septal deviation, thin skin envelope, weak cartilage
| treatment = Structural grafts, nasal implants, revision rhinoplasty
| frequency = Common and underdiagnosed
}}
External nasal valve collapse is a structural disorder involving insufficient support of the lateral nasal wall, resulting in narrowing or collapse of the nasal airway during inspiration. This dysfunction affects the most anterior part of the nasal passage and is a frequently underdiagnosed contributor to chronic nasal obstruction.
Anatomy
The external nasal valve includes the alar rim, lower lateral cartilage, nasal sill, and surrounding soft tissue. It is bordered medially by the columella and laterally by the lateral crus of the lower lateral cartilage. Unlike the internal nasal valve, which depends on fixed bony and cartilaginous angles, the external valve relies more heavily on the integrity of soft tissue and cartilage to maintain patency.
Etiology
The condition may be congenital or acquired. Congenital hypoplasia of the lower lateral cartilage may predispose individuals to early collapse. Acquired causes include iatrogenic weakening following rhinoplasty, particularly over-resection of the lateral crus, as well as blunt nasal trauma, age-related cartilage atrophy, and structural changes resulting from chronic inflammation or previous surgery involving the nasal ala.
Pathophysiology
Collapse occurs when the nasal sidewall lacks sufficient structural resistance to inspiratory negative pressure. In static collapse, obstruction is present at rest, while dynamic collapse is more prominent during deep inspiration. This condition is often seen in combination with other structural abnormalities such as internal nasal valve narrowing or septal deviation, which together exacerbate airflow limitation.
Clinical presentation
Patients typically report persistent nasal blockage that does not improve with medical therapy. Other symptoms may include visible nostril collapse during inspiration, habitual mouth breathing, impaired sleep, decreased exercise tolerance, and reduced sense of smell.
Diagnosis
Diagnosis is primarily clinical, based on physical examination during normal and forced inspiration. The modified Cottle maneuver—lateral traction on the cheek that improves airflow—can support a diagnosis of valve dysfunction. Nasal endoscopy is used to evaluate internal anatomy, while acoustic rhinometry and rhinomanometry provide objective measures of nasal resistance. Computed tomography (CT) may be indicated in patients with prior surgery or complex anatomy.
Management
Surgical intervention is the mainstay of treatment for symptomatic external valve collapse. Several techniques are used to restore lateral wall stability. Alar batten grafts placed along or above the lateral crus reinforce the sidewall and improve its resistance to collapse. Lateral crural strut grafts are inserted beneath the lateral crus to reposition and stabilize weakened cartilage. Alar rim grafts support the margin of the nostril and help maintain its shape and caliber.
In some cases, suture-based suspension techniques are employed to provide temporary or adjunctive support to the lateral nasal wall. Bioabsorbable implants made of polylactic acid may be inserted under local anesthesia and offer a minimally invasive option for selected patients.
= Revision rhinoplasty =
When external valve collapse results from a prior rhinoplasty, revision surgery is often required. This may involve restoring cartilage support, correcting previous over-resection, and addressing aesthetic concerns. Outcomes are improved when functional restoration is integrated with aesthetic planning.