Written by György Lichtenberger
Sir Felix Semon has a very special place in history as a result of his research on vocal cord paralysis. Years later, Professor Aurel Rethi, a Hungarian, also contributed to this field of research by undertaking animal experimentation. Their combined investigations have inspired many other scientists to continue this line of research and they have been rewarded with varying degrees of success.
Vocal cord paralysis may be unilateral or bilateral. Unilateral vocal cord paralysis is characterised by dysphonia in some patients, together with aspiration. On the other hand, bilateral vocal cord paralysis has more serious consequences and may be life threatening if the glottic chink between the paralysed vocal cords is less than one millimetre. Accordingly, the data presented in this Semon Lecture will address the management of bilateral vocal cord paralysis only.
Many options have been described for the management of bilateral vocal cord paralysis. Tracheotomy was performed in Egypt in ancient times to save the life of a patient. Surprisingly, this technique is still used in some European countries even today. Subsequently, patients are given a tube with a speaking valve. It would seem that the best alternative option might be a re-innervation technique or implantation of a laryngeal pacemaker thus restoring both breathing and phonation. These methods have not been used in large series of patients and the results that have been reported are somewhat questionable. The management techniques used today can be divided into the following groups :
- Localised resections of the vocal cords
- Retailoring and displacement of the vocal cords
- Displacing of the vocal cords without resection of tissue.
These procedures can be undertaken by translaryngeal, extralaryngeal or by microlaryngoscopic techniques, with or without the use of a laser.
Inspired by my predecessor, Professor Aurel Réthi, who was known during the last century as the father of modern stenosis surgery, experiments were undertaken on laboratory animals to find alternative methods for the management of laryngeal stenosis at the glottic level. As a result of these experiments, new reversible and irreversible methods have been developed based on an endo-extralaryngeal suture technique and a special device to facilitate this has been introduced into clinical practice.
The reversible procedure is indicated if there is a chance of spontaneous recovery. The operation is performed with jet-anaesthesia without tracheostomy.
The irreversible procedure is indicated when there is no chance of recovery. The details of this operation differ from any other technique described as follows :
– The operation is performed with jet-anaesthesia without tracheotomy.
– A microlaryngoscopic laser resection is performed in such a way that the integrity of the mucosal cover medial to the vocalis muscles, arytenoid cartilage and vocal process is preserved so that granuloma and scar formation is prevented.
– Only the anterior two thirds of the arytenoid cartilage is resected submucosally to prevent aspiration.
– The preserved mucosa is reflected laterally to cover the defect created by the submucosal laser resection of the muscles and cartilage.
– Finally, the spared and adapted mucosa is fixed over the defect with endo-extralaryngeal sutures.
One hundred and forty two patients have been managed with the reversible technique over a 25 years period and a success rate of >93% has been achieved. The irreversible technique has been employed on 126 patients over the same period of time and a success rate of >95% has been recorded.
Both these methods of laryngeal rehabilitation are described and illustrated by intraoperative video clips. These techniques have significant advantages when compared to other methods in clinical use. The reversible technique ensures an immediate and stable airway without tracheostomy and without damaging the endolaryngeal structures of the larynx. It does not disadvantage the patient and their chance of spontaneous recovery. The irreversible technique is also performed without a tracheostomy and ensures a stable airway, a wide glottic chink and is without risk of granuloma and scar formation.