Voice and Swallow Outcomes After Office-based Injection Laryngoplasty in Patients With Glottal Insufficiency

Glottic insufficiency (incompetence) is characterized by incomplete closure of the vocal folds when phonating, which causes inappropriate leakage of air through the glottis on attempting to phonate and there is an increased risk of aspiration. A wide range of laryngeal symptoms including dysphonia with or without dysphagia may result .There are varieties of causes of glottic insufficiency (GI); among the most common causes of symptomatic GI are vocal fold paralysis (complete immobility of the vocal fold), vocal fold paresis (weakness or partial immobility of the vocal fold) and presbylaryngis. Other causes of GI are sulcus vocalis, scarring or deformation of the vocal folds .Therefore, different therapy options were proposed for patients with GI based on the size of the glottic gap. Voice therapy is most suitable for patients with minimal glottic gap, regardless the reason.Injection augmentation is reserved for those with small or medium-sized glottic gap .Office-based vocal fold injection was used worldwide in early & late Cases of GI. Office-based vocal fold injection in acute cases such as iatrogenic injury of recurrent laryngeal nerve during surgery has many advantages, these include immediate symptomatic relief, the ability to titrate degree of medialization for optimized outcomes, and monitoring of the airway.Moreover, injection in early cases prevent compensatory mechanisms as ventricular hypertrophy. Recent studies suggest that injection laryngoplasty in early cases reduce the need for permanent laryngeal framework surgery.The ideal material to be used for injection should be biocompatible and inert to decrease the risk of local tissue reaction or fibrosis. Also, the material should be easy to use and have a low cost. Furthermore, it should be durable and resistant to resorption or migration, while it maintains the normal viscoelasticity of the vocal cord after injection.

So, there are 2 types of injection materials: temporary &permanent materials. Long-lasting injection materials(permanent) include autologous fat,calcium hydroxylapatite(CaHA) and taflon. Temporary injection materials include bovine gelatin, collagen-based products, carboxymethylcellulose and hyaluronic acid gel (HA). HA is among the most commonly used substances for injection laryngoplasty.

Actually, office-based vocal fold injection has different techniques such as percutaneous (trans-cricothyroid membrane, trans-thyroid cartilage, and trans-thyrohyoid membrane), per-oral, and trans-nasal endoscopic approaches. Typically, the three approaches are performed with a flexible laryngoscope in place, visualizing the larynx for visualization and to monitor injection effects.