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Updated: Jun 22, 2026

Preparation of the Rat Vocal Fold for Neuromuscular Analyses
Published on: May 15, 2020
Should all newborns who undergo patent ductus arteriosus ligation be examined for vocal fold mobility?
Marshall E Smith1, Jerald D King, Abdelaziz Elsherif
1University of Utah School of Medicine, Salt Lake City, USA. marshall.smith@hsc.utah.edu
Objectives/Hypothesis:
To determine the incidence of left vocal fold paralysis (LVFP) in premature infants who undergo patent ductus arteriosus (PDA) ligation.
Study Design:
Prospective cohort.
Methods:
The study was carried out in the newborn intensive care unit (NICU) of a tertiary academic medical center. Eighty-six premature newborns who underwent ligation of a PDA were examined postextubation with fiberoptic laryngoscopy to assess vocal fold mobility, regardless of laryngeal symptom status.
Results:
Fourteen infants (16%) had LVFP. All were <28 weeks postmenstrual age (PMA) at birth and <1,250 g at PDA ligation, and were significantly less mature and smaller than infants without LVFP. Infants <28 weeks PMA at birth and <1,250 g at ligation had an incidence of LVFP of 23% and 24%, respectively. Fourteen percent of the infants with LVFP did not have laryngeal symptoms and would have been missed had these been the sole criteria for assessing vocal fold mobility.
Conclusions:
The incidence of LVFP after PDA ligation in the NICU is high, and some cases may be missed if laryngoscopy is performed only when laryngeal symptoms are present. Infants <28 weeks PMA at birth and <1,250 g at ligation are at especially high risk. Vocal fold mobility should be documented by laryngoscopy on all high-risk infants undergoing a PDA ligation in the NICU regardless of laryngeal symptom status, and on all infants with relevant symptoms. The high incidence of this complication warrants greater efforts to prospectively assess vocal fold mobility status in high-risk infants who undergo PDA ligation.
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