Biomechanics of Pharyngeal Deglutitive Function following Total Laryngectomy

Abstract

Objective Postlaryngectomy, pharyngeal weakness, and pharyngoesophageal junction (PEJ) restriction are the candidate mechanisms of dysphagia. The aims were, in laryngectomees, whether (1) hypopharyngeal propulsion is reduced and/or PEJ resistance is increased, (2) dilatation improves dysphagia, and (3) whether symptomatic improvement correlates with reduced PEJ resistance. Design Multidisciplinary cross-sectional study. Setting Tertiary academic hospital. Subjects and Methods Swallow biomechanics were assessed in 30 laryngectomees. Patients were stratified into severe dysphagia (Sydney Swallow Questionnaire >500) and mild/nil dysphagia (Sydney Swallow Questionnaire ≤500). Average hypopharyngeal peak (contractile) pressure (hPP) and hypopharyngeal intrabolus pressure (hIBP) were measured from high-resolution manometry with concurrent videofluoroscopy based on barium swallows (2.5 and 10 mL). In consecutive 5 patients, measurements were repeated after dilatation. Results Dysphagia was reported by 87%, and 57% had severe and 43% had mild/nil dysphagia. hIBP increased with larger bolus volumes (P <.0001), while hPP stayed stable and PEJ diameter plateaued at 9 mm. Laryngectomees had lower hPP (110 ± 14 vs 170 ± 15 mm Hg; P =.0162) and higher hIBP (29 ± 5 vs 6 ± 5 mm Hg; P =.156) than controls. There were no differences in hPP between patient groups. However, hIBP was higher in severe than in mild/nil dysphagia (41 ± 10 vs 13 ± 3 mm Hg; P =.02). Predilation hIBP (R2 = 0.97) and its decrement postdilatation (R2 = 0.98) well predicted symptomatic improvement. Conclusions PEJ resistance correlates better with dysphagia severity than peak pharyngeal pressure and is more sensitive to bolus sizes than PEJ diameter. Both baseline PEJ resistance and its decrement following dilatation are strong predictors of treatment outcome. PEJ resistance is vital to detect, as it is reversible and can predict the response to dilatation regimens.