Discussion:
GlideScope ® is a video laryngoscope instrument that is primarily used for oral endotracheal intubation(5). It provides optimal glottic views and it is this benefit that can be directly translated into our patients to provide a good view of the neopharynx. The main benefit with this is that it allows for an optimal view without the need for substantial neck extension (figure 2), which is very difficult to achieve in patients with extensive post-radiotherapy fibrosis.
Usually, video fluoroscopy-guided Botox injections are performed. However, in some patients injections are required under general anaesthetic, which has the advantage of excellent visual control and minimal risk to blood vessels or surrounding muscles.(4) Usually a view of the neopharynx is then achieved with a rigid pharyngoscope, but in those with short necks or cervical spine pathologies, it is difficult to extend the neck to allow a good view and provide access. Video fluoroscopy may not be available in a resource-limited setting and requires a radiographer and the Speech and Language therapist to be present. There is the added risk of radiation exposure, particularly if these patients require repeat procedures.
Rigid instruments such as pharyngoscopes and oesophagoscopes(4) are used to directly visualise and inject the Botox. However, it is challenging to use rigid instruments in patients with limited neck extension, these further carry a risk of perforation to the surrounding tissue, something that does not exist with the GlideScope. Furthermore, video-laryngoscopy carries a significantly lower risk of aerosol-generation and transmission compared to direct laryngoscopies(6), an issue that is topical in the COVID-19 pandemic.
The GlideScope ® can also provide direct vision of the neopharynx where this is impossible with a rigid instrument to enable accurate placement of dilation balloons or to ensure the safe passing of bougies and has been used by the authors for this purpose.