Recurrent Laryngeal Nerve Monitoring During Pediatric Aerodigestive Tract and Cardiac Surgery

Purpose The purpose of this study is to compare the rate of recurrent laryngeal nerve (RLN) injury in pediatric patients undergoing aerodigestive and cardiac surgeries with intraoperative laryngeal nerve monitoring (IOLNM) versus standard surgery without IOLNM. The study also aims to evaluate whether continuous electromyography monitoring reduces clinically detectable postoperative nerve dysfunction in children undergoing RLN-risk surgery.

Hypothesis The investigators hypothesize that patients who undergo surgery with IOLNM will have a lower rate of RLN injury, less severe nerve injury when injury occurs, and a shorter duration of neuropraxia/vocal cord paresis compared with patients who undergo standard surgery without monitoring.

Justification Vocal cord paralysis is a recognized complication of pediatric thyroid, airway, esophageal, and cardiac surgery because the RLN is vulnerable along its course through the neck and chest. RLN injury can lead to dysphonia, dysphagia, aspiration, and respiratory insufficiency, making prevention clinically important. Existing evidence suggests IOLNM may reduce RLN injury, especially in pediatric surgery where some procedures have reported injury rates as high as 40%; however, the current literature is limited by a lack of prospective randomized studies and lack of direct prospective comparison against standard surgical care. The recent availability of pediatric-compatible monitoring electrodes also makes this question feasible to study in infants and young children.

Research Method/Procedures This is a single-centre, randomized, double-blinded, controlled clinical trial conducted at Stollery Children's Hospital. Eligible participants are patients under 18 years of age undergoing RLN-risk surgery involving the trachea, esophagus, thyroid, mediastinum, ductus arteriosus, or aortic arch, with specified inclusion and exclusion criteria. Participants, study investigators, clinicians performing follow-up flexible laryngoscopy, and video raters are blinded to allocation; surgeons and personnel directly involved in intraoperative care cannot be blinded.

For participants randomized to the intervention arm, IOLNM is used during a single surgery. Surgery otherwise proceeds according to standard of care. Within four weeks of their surgery, participants are seen in follow-up by Dr. Isaac or another pediatric otolaryngologist. At that visit, they complete the PedsQL, PVRQOL, Pediatric VHI, and dysphagia questionnaires, and undergo video-recorded flexible fiberoptic laryngoscopy. The recorded laryngoscopy is anonymized and reviewed by a blinded independent expert. For patients with RLN injury, further clinical follow-up and repeat laryngoscopy every three months for at least one year or until recovery occur as part of standard care.

Safety monitoring is performed during surgery, the postoperative hospital stay, and follow-up visits. Adverse events related to IOLNM include, but are not limited to, laryngeal trauma, airway bleeding, or inflammation, and are reported to the study coordinator, principal investigator, and local HREB in accordance with institutional and Health Canada standards.

• Impact on voice in UVFI patients [Time frame: The questionnaire will be given within four weeks of the UVFI diagnosis.]
• Severity of dysphonia in UVFI patients [Time frame: Voice assessment will be completed within four weeks of UVFI diagnosis]
• Swallowing outcomes in UVFI patients [Time frame: Swallowing assessments will be completed within four weeks of UVFI diagnosis and as recommended by SLP/ENT]
• Swallowing symptom burden in UVFI patients [Time frame: Questionnaires will be given within four weeks of UVFI diagnosis]
• Rate of spontaneous resolution of UVFI [Time frame: These outcomes will be measured by flexible laryngoscopy at 3 month and 6 month intervals after the time of UVFI diagnosis]