Recurrent Laryngeal Nerve Monitoring in Pediatric Surgery Using a Modified Dragonfly Electrode

View Video S1 The recurrent laryngeal nerve (RLN) is at risk during pediatric surgery of the neck, mediastinum, and chest. RLN injury for esophageal atresia, tracheoesophageal fistula, tracheobronchomalacia (TBM) established in literature as often courses through operative field. Identifying protecting particularly difficult neonates, aberrant anatomy, reoperative cases.1, 2 Intraoperative monitoring (IONM) standard practice adult thyroid but has not yet been widely adopted surgery.3 An obstacle to routine utilization IONM lack size-appropriate devices patient. Translaryngeal endolaryngeal electrodes may be used small infants, they are associated with significant challenges. obstruct surgical Endolaryngeal place, cause trauma, or dislodge positioning intraoperative bronchoscopy. Endotracheal tubes (ETTs) integrated adhesive most common way monitor RLN. Single channel available ETT 2.0 mm inner diameter (ID) do allow each individually. Thus, if one injured intraoperatively, surgeon alerted by system because contralateral functioning. Double-channel Unfortunately, double-channel (monitor separately) only appropriate children aged 4 years older. We present a modification electrode young term infants. This study was approved institutional review board Boston Children's Hospital. Retrospective chart performed case described below. For all cases monitoring, chemical paralysis must avoided preoperative communication between anesthesia teams vital. appropriately sized selected patient down size 3.0 ID (term infant). As slightly increases outer ETT, need downsized prevent excessive pressure on larynx subglottis. A Neurovision Dragonfly Stick-On (Neurovision Medical Products, Ventura, California) then custom trimmed fit smaller ETT. compatible both Neurovision's Nerveana Nerve Locator Monitor Medtonic Integrity Monitoring (NIM) systems (NIM NIM Vital, Medtronic, Jacksonville, Florida). sensor surgeon, otolaryngologist, anesthesiologist. Depending there two different ways trim sensor. (3.0 3.5), lateral such that center channels remain line tape, resulting significantly narrower (Figure 1). an 4.0 4.5, single cut off, leaving three active (two same color). Regardless how trimmed, voltmeter determine which leads 2). inactive marked placing knot them avoid connecting system. If available, can unravel cords 3). Once determined, wrapped around desired Care taken place proximal cuff (if using cuffed tube) approximate level vocal folds will lie after intubation 4). intubated team concurrent media access control (KARL STORZ SE & Co. KG, Tuttlingen, Germany) blade. horizontal blue lines help mark midpoint should contact true folds. tube secured anesthesia. needles additional (one depending trimmed) (to replace those tied off Dragonfly) placed into anterior neck near cartilage ensure function 5). Two grounding surface stimulator) muscle deltoid trapezius. connected choice baseline amplitude read fold Function ultimately confirmed stimulation individually probe once field open. It important note still modified it set up appropriately, though this manufacturer-approved modification. 4-month-old girl severe TBM brief resolved unexplained events underwent posterior tracheopexy, bilateral bronchopexies, rotation esophagoplasty, partial thymectomy via right thoracotomy. Bilateral RLNs were procedure. stick above 3.5 intraoperatively. Her postoperative flexible fiberoptic laryngoscopy showed normal movements bilaterally. novel technique adapting adhere ETTs infants children. provides immediate feedback location surgery. yields advantages: identification RLN, aid dissection, prognostication post-operative neural lesion site identification. In patients, demonstrates 99% negative predictive value 75% positive signaling loss paralysis.5 Challenges inherent include electrodes: improper placement EMG (too proximal, too distal, rotated) thus poor detection stimulation, providing false response no ability result unexpected injury. move manipulation patient's head even adequate laryngoscopy. addition, accidentally transected, notice when audible visual warning elicited from Conversely, register operating (false positive) provide noisy signal inhibiting accurate monitoring. slip, especially long procedures prolonged exposure airway secretions, dragonfly Please note: publisher responsible content functionality any supporting information supplied authors. Any queries (other than missing content) directed corresponding author article.