Alison Perry – The Physiological Basis of Alaryngeal Speech

Written by Alison Perry

Modern attempts at surgical-prosthetic voice restoration after total laryngectomy began with Eric Blom and Mark Singer (the Blom-Singer procedure) in Indianapolis, USA, in the early 1980s.

However, early success rates were low. We examined the premise that the main reason for failure to develop speech following total laryngectomy is due to anatomical/physiological factors not, as previously thought, due to psychological/social or teaching/learning variables.

During a total laryngectomy, once the larynx is removed, the pharynx is surgically closed and a pharyngo-oesophageal (P-E) segment is constructed by suturing the inferior constrictor and crico-pharyngeus muscles to the upper circular fibres of the oesophagus. This becomes the vibrator for alaryngeal speech – the site where ‘pseudo voice’ occurs.

The experimental hypothesis was that a continuum of tonicity in the P-E segment exists, ranging from hypotonicity (where the PE segment is too flaccid to vibrate and produce sound), through tonicity (where good speech results) to hypertonicity and then spasm (where degrees of excess tone in the PE segment prevent vibration – i.e., voice – from occurring).

A data collection protocol was developed with simultaneous acoustic and aerodynamic measures being taken. Sixty eight laryngectomised people (13 female, 55 male) each underwent insertion of an X-ray guided trans-nasal catheter into their upper oesophagus, which was then connected to an air cylinder. Under videofluoroscopy, controlled air was slowly directed into the upper oesophagus, the opening pressure of the P-E segment during phonation was measured, and voice (if any) was recorded for post hoc analysis.

This instrumental assessment enabled the P-E segment of all patients to be categorised on a continuum of opening pressure/tonicity. From this, the development of a proactive and principled model (including optimal surgical technique) for voice rehabilitation resulted in a success rate of 95% for voice restoration after total laryngectomy at Charing Cross Hospital in 1995.