Keywords
tracheoesophageal voice prosthesis - tracheoesophageal prosthesis maintenance - laryngectomees
- sputum - speech outcomes
Background
Restoring speech communication using a voice prosthesis was a significant medical
advancement for laryngectomees. It enables the laryngectomee to create sound again
immediately after its insertion.[1] A one-way valve (tracheoesophageal prosthesis, TEP) is inserted through a previously-created
tracheoesophageal puncture connecting the trachea and esophagus in those wishing to
speak through tracheoesophageal speech. When the patient occludes the stoma, the exhaled
air is shunted through the TEP into the esophagus, where it induces vibration of the
upper esophageal sphincter.
The main advantage of TEP is that it generates the most intelligible, fluent, natural
sounding voice in contrast to other alaryngeal speech methods.[2] Even though esophageal speech also uses the upper esophageal sphincter as the sound
source, laryngectomees using a TEP rely on pulmonary air for speech production, rather
than the limited air supply available in esophageal speech. This leads to increased
fluency and longer utterance lengths.[3] A disadvantage of tracheoesophageal speech is that it requires continuous care and
maintenance. The patient has to clean and care for the TEP daily, and the prosthesis
needs to be replaced at regular intervals.[4] Those who rely on the speech and language pathologist (SLP) for TEP changes may
have to be seen in the clinic on average every two to three months.[5] Furthermore, patients with stricture or narrowing of the upper esophageal sphincter
region may not be able to achieve good voice.
Tracheoesophageal puncture can be performed at the time of the laryngectomy (primary
puncture) or at a later date (secondary puncture). The advantages of placing primary
TEP are that individuals are not subjected to an additional surgical procedure, and
they can start speech rehabilitation shortly after laryngectomy. However, primary
TEP is associated with an increased risk of fistula formation, leakage at the puncture
site, stomal stenosis, and local infection.[6] Additionally, In those who undergo secondary puncture, the SLP has the advantage
of determining the tracheoesophageal voice quality before the procedure.[6]
[7]
[8] This can assist in determining if the tracheoesophageal voice will be acceptable/functional.
Not every laryngectomee is able to use voice prosthesis.[4] The relative contraindications for voice prosthesis include: poor dexterity, eye
sight, and pulmonary function; impaired mental status; lack of motivation; inability
to manage associated care of stoma and voice prosthesis; voicing difficulties; recurrent
aspiration and dislodging of the TEP; difficulty in occluding the stoma; proximity
of the speech pathologist or otolaryngologist; the lack of support system; and the
potential cost and lack of reimbursement.
The assessments needed before the insertion of the TEP include consideration of the
patient's surgical history and exposure to radio-chemotherapy, the condition of the
upper esophageal sphincter (the presence of pain or dysphagia), and examination of
the stoma (size, regularity and signs of infection) and the TEP (location, free rotation,
patency and fluid leak).[9]
Tracheoesophageal prostheses last only a limited period of time, and require repeated
replacements. They require continuous maintenance by the laryngectomee to achieve
optimal speaking abilities and prevent fluid leakage from the esophagus to the trachea
because of buildup of biofilm by yeast and bacteria.[10] Extending the lifespan of the TEP can reduce the medical expenses associated with
its replacement.
The present manuscript describes the available types of TEPs, the procedures used
to maintain them, the causes for their failure due to fluid leakage from the trachea
to the esophagus, and the methods used for their prevention. Knowledge and understanding
of these issues can assist the otolaryngologist in caring for laryngectomees who use
tracheoesophageal speech.
Types of Voice Prosthesis
Types of Voice Prosthesis
There are two types of voice prosthesis: an indwelling one that is installed and changed
by an SLP or otolaryngologist, and a patient-changed one.[1]
[10] The indwelling prosthesis generally lasts a longer time than the patient-managed
device. An indwelling prosthesis can function well for weeks to months. The patient-managed
voice prosthesis enables a greater degree of independence. It can be changed by the
laryngectomee on a regular basis (every 1 to 2 weeks). The old prosthesis can be cleaned
and reused several times.
Causes of Voice Prosthesis Leak
Causes of Voice Prosthesis Leak
There are two patterns of voice prosthesis leak: leak through the prosthesis and leak around it.[10]
Leakage through the voice prosthesis is predominantly due to situations in which the valve can no longer close tightly.
This may be due the following: colonization of the valve by fungal-bacterial biofilm;
the flap's valve may get stuck in the open position; a piece of food, mucus or hair
(in those with a free flap) stuck on the valve; or the device coming in contact with
the posterior esophageal wall. Inevitably, all prostheses will fail by leaking through,
whether from Candida biofilm colonization or simple mechanical failure.[11]
If there is continuing leakage through the prosthesis from the time it is inserted,
the problem is generally caused by the flap's valve remaining open because of the
negative pressure generated by swallowing.[10] This can be corrected by using a prosthesis that has a greater resistance. The trade-off
is that having such a voice prosthesis may require more effort when speaking. It is
nevertheless important to prevent chronic leakage that can lead to aspiration into
the lungs.
Leakage around the voice prosthesis is less common and is mainly due to TEP tract dilation or the inability to grip the
prosthesis.[12] It has been linked to shorter prosthesis life span. It may occur when the puncture
that houses the prosthesis widens. During insertion of the voice prosthesis, some
dilation of the puncture takes place, but if the tissue is healthy and elastic, it
should shrink back after a short time. The inability to contract back can be associated
with gastroesophageal reflux, poor nutrition, alcoholism, hypothyroidism, improper
puncture placement, incorrectly-fitted prosthesis, TEP tract trauma, local granulation
tissue, recurrent or persistent local or distant cancer, past radiation treatment,
and radiation necrosis.[10]
Leakage around the prosthesis can also occur if the prosthesis is too long for the
user's tract. Whenever this occurs, the voice prosthesis moves back and forth in the
tract (pistoning), thereby dilating it.[12] The tract should be measured, and a prosthesis of more appropriate length should
be inserted. In this circumstance, leakage should resolve within 48 hours. If the
tissue around the prosthesis does not heal around the shaft within this period, a
comprehensive medical evaluation is warranted to determine the cause of the problem.
Another cause of leakage around the prosthesis is the presence of stricture of the
esophagus. The narrowing of the esophagus forces the laryngectomee to swallow harder,
with greater force, so that the food/liquid goes through the stricture. The excess
swallowing pressure pushes the food/liquid around the prosthesis.[12]
Uncontrolled gastroesophageal reflux can limit the voice prosthesis life span. It
is advisable to treat gastroesophageal reflux.[13] Treatment of reflux can allow the esophageal tissue to heal.
Several procedures have been used to treat persistent leakage around the prosthesis.
These include temporary removal of the prosthesis and replacement with a smaller-diameter
catheter to encourage spontaneous shrinkage; using customized prostheses; placing
a purse-string suture around the puncture; injection of gel, collagen or micronized
AlloDerm (LifeCell, Branchburg, NJ, US);[14] cautery with silver nitrate or electrocautery; autologous fat transplantation; inserting
a larger prosthesis to stop the leak; and surgical or non-surgical (removing the prosthesis,
allowing closure to occur) closure of the puncture. Granulation tissue can be removed
by cauterization (electro-, chemo-, laser-).
Increasing the diameter of the prosthesis is generally not recommended. Some, however,
believe that using a larger-diameter prosthesis reduces the speaking pressure (the
larger diameter enables a better airflow), which allows greater tissue healing to
occur while the underlying cause (most often reflux) is treated.[15] The use of a prosthesis with a larger esophageal and/or tracheal flange may be helpful,
as the flange acts as a washer to seal the prosthesis against the walls of the esophagus
and/or trachea, thus preventing leakage.
Patients with a TEP need to be followed by an SLP because of normal changes in the
tracheoesophageal tract. Resizing of the tract may be needed as it can change in length
and diameter with time.[16] The length and diameter of the prosthesis' puncture generally change over time,
as the swelling generated by the creation of the fistula, the surgery and the radiation
gradually decreases. This requires repeated measurements of the length and diameter
of the puncture tract by the SLP, who can select a properly-sized prosthesis.
Cleaning the Voice Prosthesis and Preventing Leakage
Cleaning the Voice Prosthesis and Preventing Leakage
It is very important to keep the voice prosthesis clean to insure its proper function
and durability. When not cleaned properly, the prosthesis can leak, and the ability
to speak can be compromised or weakened. It is recommended that the voice prosthesis
be cleaned at least twice a day (morning and evening), and preferably after eating,
because this is the time when food and mucus can become trapped. Cleaning is especially
helpful after eating sticky foods or whenever one's voice is weak.[17] A prosthesis cleaning brush and flushing bulb are used in the cleaning process.
It is advisable to clean the voice prosthesis' inner lumen at least twice a day and
after each meal. Warm water works better than room temperature water in cleansing
the prosthesis, probably because it dissolves the dry secretions and mucus and perhaps
even flushes away (or even kills) some of the yeast colonies that had formed on the
prosthesis.[17]
Initially the mucus around the prosthesis should be cleaned using tweezers, preferably
with rounded tips. Following that, the manufacturer-provided brush should be inserted
into the prosthesis and twisted back and forth.[18] The brush should be thoroughly washed with warm water after each cleaning. The prosthesis
is then flushed twice with warm (not hot) water using the manufacturer's provided
bulb. The flushing bulb should be introduced into the prosthesis opening while applying
slight pressure to completely seal off the opening. The angle in which one should
place the tip of the bulb varies between individuals. (The SLP can provide instructions
on how to choose the best angle.) Flushing the prosthesis should be performed gently,
because using too much pressure can lead to splashing of water into the trachea. If
flushing with water is problematic, the flush can also be used with air.
The manufacturers of each voice prosthesis brush and flushing bulb provide directions
on how to clean them and when they should be discarded. The brush should be replaced
when its threads become bent or worn out.[16] The prosthesis brush and flushing bulb should be cleaned with hot water, when possible,
and soap, and dried with a towel after every use. One way to keep them clean is to
place them on a clean towel and expose them to sunlight for a few hours, on a daily
basis. This takes advantage of the antibacterial power of the sun's ultraviolet light
to reduce the number of bacteria and fungi.
Placing 2 mL to 3 mL of sterile saline in the trachea at least twice a day (and more
if the air is dry), wearing a heat and moisture exchanger (HME) 24/7 and using a humidifier
can keep the mucus moist and reduce the clogging of the voice prosthesis.
Preventing Yeast and Bacteria Biofilm from Growing on the Voice Prosthesis
Preventing Yeast and Bacteria Biofilm from Growing on the Voice Prosthesis
Overgrowth of yeast and bacteria in the form of a biofilm on the voice prosthesis
is one cause of prosthesis leakage and thus failure. Nevertheless, it takes some time
for yeast and bacteria to grow in a newly installed voice prosthesis and form the
biofilm that prevent its valve from closing completely.[7] Accordingly, failures immediately after voice prosthesis installation are unlikely
due to yeast growth.
The presence of yeast should be established by the person who changes the failing
voice prosthesis. This can be done by observing the typical yeast (Candida) colonies
that prevent the valve from closing and, if possible, by sending a specimen from the
voice prosthesis for fungal culture.[8]
[9] Mycostatin (an antifungal agent) is often used to prevent voice prosthesis failure
due to yeast. It is available with a prescription in the form of a suspension or tablets.
The tablets can be crushed and dissolved in water. There is anecdotal information
that apple cider vinegar, which is known to inhibit Candida growth, can be used to
gargle and be swallowed to prevent yeast growth on the TEP.
Automatically administering antifungal therapy just because one assumes that yeast
is the cause of voice prosthesis failure may be inappropriate without proof. It is
expensive, may lead to the yeast developing resistance to the agent, and may cause
unnecessary side effects.[8] There are, however, exceptions to this rule. These include the administration of
preventive antifungal agents to diabetics, those receiving antibiotics, chemotherapy
or steroids, and those in whom colonization with yeast is evident (coated tongue etc.).
There are several methods that help prevent yeast from growing on the voice prosthesis:[10]
-
Reduce the consumption of sugars in food and drinks, and brush your teeth well after
consuming sugary food and/or drinks.
-
Brush your teeth well after every meal and especially before going to sleep.
-
Clean your dentures daily.
-
Diabetics should control blood sugar levels.
-
Generally avoid antibiotics and corticosteroids, taking only as needed.
-
After using an oral suspension of an antifungal agent, wait for 30 minutes to let
it work and then brush your teeth. This is because some of these suspensions contain
sugar.
-
Dip the voice prosthesis brush in a small amount of mycostatin (nystatin) suspension
or vinegar and brush the inner voice prosthesis before going to sleep. (A homemade
suspension can be made by dissolving a quarter of a mycostatin tablet in 3 mL to 5 mL
of water).[19] This would leave some of the suspension inside the voice prosthesis. The unused
suspension should be discarded. Do not place too much mycostatin or vinegar in the
prosthesis to prevent dripping into the trachea. Speaking a few words after placing
the suspension will push it towards the inner part of the voice prosthesis.
-
Consume probiotics by eating active-culture yogurt.[20]
-
Gently brush the tongue if it is coated with yeast (white plaques).
-
Replace the toothbrush after overcoming a yeast problem to prevent recolonization.
-
Keep the prosthesis brush clean.
The Use of Probiotics Such as Lactobacillus acidophilus to Prevent Yeast Overgrowth
The Use of Probiotics Such as Lactobacillus acidophilus to Prevent Yeast Overgrowth
A probiotic that is often used to prevent yeast overgrowth is a preparation containing
the viable bacteria Lactobacillus acidophilus. However, there is no FDA-approved indication to use L. acidophilus to prevent yeast growth. This means that there were no controlled studies to ensure
its safety and efficacy. L. acidophilus preparations are sold as a nutritional supplement and not as a medication. The recommended
dosage is between 1 and 10 billion bacterial colony-forming units (CFUs).[8] Typically, L. acidophilus tablets contain a dosage somewhere within this recommended amount of bacteria. Dosage
suggestions vary by the tablet's brand, but generally it is advised to take between
one and three tablets daily.[20]
Although generally believed to be safe with few side effects, oral preparations of
L. acidophilus should be avoided in people with intestinal damage, a weakened immune system, or
with overgrowth of intestinal bacteria.[21] In these individuals, this bacterium can cause serious and sometimes life-threatening
complications. This is why individuals should consult their physician whenever this
live bacteria is ingested. It is especially important in those with the aforementioned
conditions.
Conclusions
Restoring speech communication using a voice prosthesis provides the laryngectomee
with the ability to speak using tracheoesophageal voice. The use of TEP requires continuous
maintenance, cleaning and replacement in order to maintain voice quality and prevent
fluid leakage.
