Intraoperative recurrent laryngeal nerve monitoring during video-assisted throracoscopic surgery for patent ductus arteriosus.

Objective: To develop a technique to identify and localize the recurrent laryngeal nerve (RLN) during video-assisted thoracoscopic surgery (VATS) for patent ductus arteriosus.
Design: Prospective clinical study.
Setting: Children's hospital.
Participants: Sixty infants and children scheduled for elective closure of patent ductus arteriosus.
Interventions: With parental informed consent, 60 infants and children undergoing elective VATS for patent ductus arteriosus were studied. A thin, pencil-point, Teflon-coated, stimulating probe allowed direct stimulation (<2 mA, 100-msec pulse width) of the left RLN inside the thorax. A commercially available 4-channel neurologic monitor recorded compound evoked electromyograms (EMGs) from the left RLN and right RLN (as control) by needle electrodes placed percutaneously in the neck. Hoarseness, stridor, feeding difficulties, and voice changes were assessed postoperatively.
Measurements and Main Results: Left RLN EMGs were easily obtained in 59 of the 60 patients. The surgeon correctly identified the RLN visually once in the first 7 patients; this ability subsequently improved. EMG localization of the location or course of the RLN altered dissection, clip size, or clip position in 37 of 59 patients.
Conclusion: Intraoperative EMG to identify location and route of the RLN was easy to perform, was effective in identifying RLN position, and appeared to facilitate dissection and clipping of the ductus.