RECURRENT laryngeal nerve injury produces an abductor laryngeal paralysis. The vocal cord assumes a median or paramedian position. Accurate diagnosis can be made only by visualizing the vocal cords while the patient is awake. This requires indirect laryngoscopy preoperatively, and, as soon as possible, postoperatively. Many cases are not diagnosed because the vocal cords are examined by direct laryngoscopy at the termination of surgery while the patient is still asleep. Under general anesthesia, the cords assume the cadaveric position, midway between abduction and adduction, and any cord movement is due to the effect of air passing through the glottis.
Diagnosis also cannot be made on the basis of symptoms. Unilateral abductor paralysis may be asymptomatic. Usually there is some voice disturbance but seldom any respiratory problem. Bilateral abductor paralysis causes mild to severe hoarseness and usually severe inspiratory stridor.
Asymptomatic unilateral paralysis does not require treatment. If glottic air leakage
Doyle PJ, Everts EC, Brummett RE. Treatment of Recurrent Laryngeal Nerve Injury. Arch Surg. 1968;96(4):517–520. doi:10.1001/archsurg.1968.01330220033006