The goal was to study the incidence and long-term consequences of left vocal cord paralysis (LVCP) after neonatal surgical treatment of patent ductus arteriosus (PDA) in a population-based cohort of adults who were born at gestational ages of =28 weeks or with birth weights of =1000 g in western Norway.
Subjects with a history of neonatal PDA surgery were examined with transnasal flexible laryngoscopy, and those with LVCP were examined with continuous laryngoscopy during maximal treadmill exercise (continuous laryngoscopy exercise testing). All subjects underwent lung function testing, ergospirometry, and pulmonary high-resolution computed tomography. Symptoms were recorded with a questionnaire.
Forty-four (86%) of 51 eligible preterm infants participated in the study, 13 (26%) had a history of PDA surgery and 7 (54%) had LVCP, with the laryngeal appearances varying slightly. As a group, subjects with LVCP had significant airway obstruction, no decreases in aerobic capacity, and no obvious evidence of longstanding aspiration on high-resolution computed tomography scans. The continuous laryngoscopy exercise tests revealed increasing respiratory symptoms in parallel with increasing anteromedial collapse of the left aryepiglottic folds as the exercise load increased. Hoarseness and voice-related symptoms were the most typical complaints. Symptoms were attributed erroneously to other diseases for at least 2 subjects.
LVCP is not uncommon in young adults exposed to PDA surgery as preterm infants. The condition may be overlooked easily, and symptoms may be confused with those of other diseases. Laryngoscopy should be offered on the basis of liberal indications after PDA ligation.