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\begin{document}

\title{Correspondence- Technical Note: Video laryngoscope-guided (GlideScope \selectlanguage{ngerman}®)
injection of botulinum toxin in laryngectomy patients with limited neck
extension\selectlanguage{english}}



\author[1]{Yadsan Devabalan}%
\author[1]{Akshat Malik}%
\author[2]{Peter Clarke}%
\affil[1]{Charing Cross Hospital}%
\affil[2]{Imperial College Healthcare NHS Trust}%


\vspace{-1em}



  
  \date{June 17, 2024}


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\selectlanguage{english}
\begin{abstract}
Functional rehabilitation of post-laryngectomy patients is a challenging
task; this includes achieving optimal speech and swallowing outcomes.
Botox injections are utilised to improve pharyngoesophageal segment
tonicity to improve speech and swallowing outcomes. We propose a novel
and efficacious technique using a portable video-laryngoscope,
GlideScope\selectlanguage{ngerman}®, to directly visualise the injection of botulinum toxin in
total laryngectomy patients with severe radiation-induced changes.%
\end{abstract}\selectlanguage{ngerman}%



\sloppy


Key points:

Botox injections are utilised to improve pharyngoesophageal segment
tonicity to improve speech and swallowing outcomes

Video-laryngoscope guided injection of Botox into the neopharynx is a
easy and safe technique

It is particularly useful for post-radiotherapy patients with limited
neck extension where rigid direct pharyngoscopy is impossible

Introduction:

Functional rehabilitation of post-laryngectomy patients is a challenging
task; this includes achieving optimal speech and swallowing outcomes.
Common problems in these patients relate to either the hypertonicity of
the pharyngoesophageal (PE) segment, PE segment spasm or stricture
formation\textsuperscript{(1)}. Many of these patients would have
received radiotherapy/chemo-radiotherapy as a definitive therapy (before
surgery) or as adjuvant therapy, and radiation induced fibrosis further
worsens the functional outcomes. Inadequate myotomy probably increases
the risk of hypertonicity and spasm.

Pharyngeal constrictor myotomy\textsuperscript{(2)}, pharyngeal plexus
neurectomy and various methods of surgical closure at the time of the
operation\textsuperscript{(1)}can all mitigate the risk of these
complications. Once established, stenosis can be treated by dilatation
with balloon or bougie, or augmenting the neopharynx surgically.
Hypertonicity and spasm, however, can be treated with the use of
Botulinum toxin (Botox) injections, which has been shown to be
efficacious\textsuperscript{(3)}. This chemically denervates the
hypertonic pharyngoesophageal segment by blocking the release of
acetylcholine at the neuromuscular junction. This reduced tone can lead
to permanent improvements in speech in the majority of patients. These
are usually injected under videofluoroscopic control but in patients
with significant fibrosis it can be difficult to get sufficient
injection directly into the muscle fibres and so is undertaken under
direct vision under general anaesthetic, including if an anaesthetic is
required for another procedure such as dilatation or secondary
puncture.\textsuperscript{(4)} Other methods of injecting botulinum
toxin include electromyographic (EMG) guided\textsuperscript{(2)} and
ultrasound-guided. However, rigid endoscopy guided injection of the
Botox remains a helpful approach in some patients with failed prior
transcutaneous injections. This can however prove difficult in
post-radiotherapy patients, particularly those with limited neck
extension.

We propose a novel and efficacious technique using a portable
video-laryngoscope, GlideScope\selectlanguage{ngerman}®, to directly visualise the injection of
botulinum toxin in total laryngectomy patients with severe
radiation-induced changes. This gives a more stable view than that from
a flexible laryngoscope.

Technical Description:

6 patients were treated over the last year using this method. General
anaesthesia was given to these patients and they were ventilated through
an armoured tube inserted through the laryngeal stoma. Patients were
positioned with their neck flexed and head extended, though the
extension was limited in these patients due to post-radiotherapy
fibrosis. A GlideScope was inserted through the oral cavity along the
tongue and the top of the scope was used to lift the base of the tongue
(figure 1). This provided a good view of the neopharynx in all the
cases. Botox was kept ready pre-loaded on a syringe with a 22-gauge
needle. The needle was inserted through the neck and under the direct
vision of the GlideScope, Botox was injected into the PE
segment/posterior pharyngeal wall at the level of the neopharynx down to
the level of the valve (figure 2). It was feasible to inject Botox in
all the patients using this technique and in none of them did we have to
resort to any other technique. All of them had improvements in their
voice outcomes.

Discussion:

GlideScope ® is a video laryngoscope instrument that is primarily used
for oral endotracheal intubation\textsuperscript{(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.\textsuperscript{(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\textsuperscript{(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\textsuperscript{(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.

\textbf{Conclusion:}

We present a novel use for video-laryngoscope to enable ENT surgeons to
safely, easily and efficaciously administer Botulinum toxin injections
in post-laryngectomy patients having a hypertonic/spasmodic PE segment.

1. Bayles SW, Deschler DG. Operative prevention and management of
voice-limiting pharyngoesophageal spasm. Otolaryngol Clin North Am.
2004;37(3):547-58.

2. Chao S-S, Graham SM, Hoffman HT. Management of pharyngoesophageal
spasm with Botox. Otolaryngologic Clinics of North America.
2004;37(3):559-66.

3. Lightbody KA, Wilkie MD, Kinshuck AJ, Gilmartin E, Lewis-Jones H,
Jones TM, et al. Injection of botulinum toxin for the treatment of
post-laryngectomy pharyngoesophageal spasm-related disorders. Ann R Coll
Surg Engl. 2015;97(7):508-12.

4. Krause E, Hempel JM, Gürkov R. Botulinum toxin A prolongs functional
durability of voice prostheses in laryngectomees with pharyngoesophageal
spasm. Am J Otolaryngol. 2009;30(6):371-5.

5. Russell T-M, Hormis A, Trust RNF. Should the Glidescope video
laryngoscope be used first line for all oral intubations or only in
those with a difficult airway? A review of current literature. Journal
of perioperative practice. 2018;28(12):322-33.

6. Zeidan A, Bamadhaj M, Al-Faraidy M, Ali M. Videolaryngoscopy
Intubation in Patients with COVID-19: How to Minimize Risk of
Aerosolization? Anesthesiology. 2020.\selectlanguage{english}
\begin{figure}[H]
\begin{center}
\includegraphics[width=0.70\columnwidth]{figures/botoxfigure1/botoxfigure1}

\end{center}
\end{figure}\selectlanguage{english}
\begin{figure}[H]
\begin{center}
\includegraphics[width=0.70\columnwidth]{figures/botoxfigure2/botoxfigure2}

\end{center}
\end{figure}

\selectlanguage{english}
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\end{document}

