Impact of vocal fold medialization on pharyngeal transit time and incidence of aspiration

Abstract

Objectives: Little objective data exists to support the belief that medialization of a paralyzed vocal fold (VF) decreases the risk of aspiration. On the other hand, an association between increased risk of aspiration pneumonia and a prolonged bolus pharyngeal transit time has been documented. This study assesses the impact of medialization on the incidence of aspiration and duration of pharyngeal transit. Methods: Two groups of patients (1996–2000) with unilateral VF paralysis were identified. One group (n = 12) had isolated VF paralysis due to recurrent laryngeal nerve injury. A second group (n = 7) had multiple cranial neuropathies secondary to skull base surgery or strokes. All patients underwent VF medialization with pre- and postmedialization videofluoroscopic swallow studies. Results: Prior to medialization, aspiration occurred in 33% (4/12) of the patients with isolated VF paralysis, and in 100% of the multiple cranial neuropathy group (overall incidence 58%). Both groups demonstrated prolonged pharyngeal transit (overall mean = 1.3 seconds) compared to controls (mean = 0.84 seconds) ( P < 0.0001). Postmedialization, aspiration in the isolated VF paralysis group decreased to 16% (2/12) and to 57% (4/7) in the multiple cranial neuropathy group (overall incidence 32%). Pharyngeal transit time did not improve after medialization (1.2 seconds) ( P < 0.0001). Conclusions: Aspiration occurs in patients with isolated unilateral VF paralysis or with multiple cranial neuropathies, although the incidence is higher in the second group. VF medialization reduces the incidence of aspiration by 50% but does not eliminate it. Prolonged pharyngeal transit following medialization suggests that the risk of aspiration pneumonia is not eliminated even when aspiration is not identified.