The laryngeal mask airway: A new technique for fiberoptic guided vocal cord biopsy

Study Objective: To describe a new technique for vocal cord biopsy involving placement of a laryngeal mask airway (LMA) during general anesthesia and fiberoptic guided biopsy. To report our early experience with this technique. Design: Descriptive study. Setting: Teaching hospital. Patients: 10 patients undergoing vocal cord biopsy for minor laryngeal pathology and with no evidence of infraglottic airway obstruction. Interventions: Patients were premedicated 1 hour preoperatively with pethidine 1 mg/kg and atropine 0.01 mg/kg. Following preoxygenation, anesthesia was induced with propofol 2.5 mg/kg and fentanyl 1 mg/kg. Once airway control was established with a facemask, vecuronium 0.1 mg was given and anesthesia established with oxygen (O-2) and nitrous oxide mixture and isoflurane 1% to 2%. Gentle direct laryngoscopy was then performed to inspect the pharyngeal structures and the LMA was then inserted in the standard manner by highly experienced LMA users. A fiberoptic scope was passed via a self-sealing mount down the shaft of the LMA to the level of the vocal cords. The vocal cords were then sprayed with local anesthetic and the biopsy taken. Measurements and Main Results: The age and weight range were 29 to 57 years and 65 to 85 kg, respectively. All patients were smokers or recent ex-smokers. LMA insertion was readily achieved in all patients, and an excellent view of the vocal cord was obtained. There were no problems with ventilation or obtaining tissue samples, and O-2 saturation remained greater than 95% throughout the perioperative period. Tissue samples were adequate in all patients. Hypertension and other adverse cardiac events did not occur during the procedure, which lasted 10 to 20 minutes. There were no problems during emergence from anesthesia, and all patients were discharged home on the same day. Conclusions: The technique has potential advantages over suspension microlaryngoscopy in that it is relatively noninvasive, it allows good airway control with adequate views of the vocal cords, and it facilitates a smooth recovery.