Larynx is the second commonest site for cancer in the whole of aerodigestive tract. Commonest malignancy affecting larynx is squamous cell carcinoma. Surgery carries a good prognosis. Conservative laryngeal surgeries are getting common by the day. After total laryngectomy there is a profound alteration in the life style of a patient. The patient is unable to swallow normally, associated with profound changes in the pattern of respiration. Olfaction is also affected.
There are three methods of alaryngeal speech. They are:
1. Oesophageal speech
3. Tracheo oesophageal puncture
Patients after total laryngectomy acquire a certain degree of oesophageal speech. In fact all the other alaryngeal speech modalities are compared with that of oesophageal speech. It is the gold standard for post laryngectomy speech rehabiltation methods.
In this method air is swallowed into the cervical oesophagus. This swallowed air is immediately expelled out causing vibrations of pharyngeal mucosa. These mucosal vibrations along with tongue in the oral cavity cause articulations. This method is very difficult to learn and only 20 % of patients succeed in this endeavour. Patient's with oesophageal speech speak in short bursts, as the bellow effect of the lungs are not utilised in speech generation. The vibrations of muscles and mucosa of cervical oesophagus and hypopharynx are responsible for speech production. Oral cavity plays an important role in generation of oesophageal speech. Air from the oral cavity is swallowed into the cervical oesophagus before speech is generated.
There are two methods by which air can be pumped into the cervical oesophagus. They are:
Injection method: In this method the person builds up enough positive pressure in the oral cavity forcing air into the cervical oesophagus. This is achieved by elevating the tongue against the palate. Air can also be injected into the cervial oesophagus by voluntary swallowing. Lip closure along with elevation of tongue against the palate generates enough positive pressure within the oral cavity to force air into the cervical oesophagus. This method is also known as tongue pumping, glossopharyngeal press and glossopharyngeal closure. This method is effective before speaking Obstruent phonemes like plosives, fricatives and africatives.
Inhalational method: This method uses the negative pressure used in normal breathing to allow air to enter the cervical oesophagus. The air pressure in the cervical oesophagus below the cricopharyngeal sphincter has the same negative pressure as air in the thoracic cavity. Hence during inspiration, this pressure falls below atmorpheric pressure. Laryngectomees often learn to relax the cricopharyngeal sphincter during inspiration thereby allowing air to get into the cervical oesophagus as it enters the lung. This trapped cervical column of air is responsible for speech generation. Patients are encouraged to consume carbonated drinks during the initial phases of rehabilitation. Gases released can be expelled into the cervical oesophagus causing speech generation.
The major advantage of oesophageal speech is that the patients hands are free. The patient does not have to incur cost of a surgical procedure or a speaking device. Nearly 40% of patients fail to acquire oesophageal speech even after prolonged training. This could be due to cricopharyngeal spasm / reflux oesophagitis. Reflux must be aggressively treated. Cricopharyngeal myotomy must be performed in patients with cricopharyngeal spasm. Botulinum toxin injection into the cricopharyngeus muscle can also be attempted.
These are vibrating devices. A vibrating electrical larynx is held in the submandibular region. Muscular contraction and facial tension can be modified to generate rudiments of speech. The initial training phase to use this machine must begin even before the surgical removal of larynx. This helps the patient in easy acclimatization after surgery. There are three types of electro larynges available. They are:
1. Pneumatic - Dutch speech aid, Tokyo artificial speech aid etc.
3. Intra oral type
Among these three types neck type is commonly used. It should be optimally placed over the neck for speech generation. Hypesthesia of neck during early phases of post op period may cause some difficulties in proper placement of this type of artificial larynx. If this device cannot be used intra oral devices can be made use of.
Figure showing TEP
Figure showing electrolarynx
Figure showing intraoral type of artificial larynx
While using intra oral type cup must form a tight seal over the stoma so that air does not escape during exhalation. The oral tip of the tube is positioned in the oral cavity.
The pneumatic artificial larynx uses the patient’s exhaled air to create the fundamental sound. A rubber, plastic, or steel cup is placed over the stoma, creating a seal. A tube is then directed from the cup into the mouth. The exhaled air vibrates a reed or rubber diaphragm within the cup, creating a sound. Speech quality can be varied through a number of mechanisms. Changes in breath pressure can affect pitch and loudness.
The major disadvantage of these electro laryngees is their mechanical quality of speech. There is also a certain degree of stomal noice. With practice a patient can reduce stomal noice by placing fingers over the stoma during phonation. These equipments are expensive and need to be maintained.
Tracheo oesophageal puncture: This procedure for restoration of speech in patient's who have undergone total laryngectomy was first introduced by Blom and Singer in 1979. This procedure should be reserved for patients who have failed to acquire oesophageal speech even after prolonged effort, and are displeased with the voice produced by artificial larynx. The following factors must be borne in mind before performing tracheo oesophageal puncture:
1. The procedure should not compromise oncological clearance
2. Patient should be able to swallow normally without aspiration
3. Voice production should be reliable
4. Procedure should be simple
6. The speech valve must be cheap and freely availabe
7. The valve should be easy to maintain.
This procedure involves creation of a opening between trachea and oesophagus. A one way valve is introduced through this stoma. Through this opening air enters into the oesophagus from the trachea. Tracheoesophageal speech is produced when the force of expired air entering the esophagus from the trachea causes the pharyngoesophageal membranes to vibrate. The apposition of the vibrating membranes produces sound, and the sound is converted into speech through articulation by the mouth and oropharynx. The vibratory segment is located in the lower cervical region in the majority of tracheoesophageal speakers, corresponding to C5 through C7. The cricopharyngeus and the inferior and middle constrictor muscles contribute to the formation of the vibratory segment.
Tracheo oesophageal puncture could be of two types:
1. Primary TEP
2. Secondary TEP
This procedure is performed along with total laryngectomy. After creation of tracheostome, a small opening is created through the posterior wall of trachea to reach the oesophagus. 19 gauge Ryles tube is introduced through this opening to reach the oesophagus. This tube is utilised for feeding the patient during the immediate post operative field. After 6 weeks this Ryles tube is removed and a valve based prosthesis (Blom Singer prosthesis) is introduced through this opening. The main advantage of this procedure is that a second sitting surgery is avoided and the patient will be able to speak within 6 weeks after total laryngectomy.
Only contraindication for this procedure is the patient's inability to maintain the valve due to advancing age.
Image showing Blom singer prosthesis
Is performed 6 weeks after total laryngectomy. These patients must be given adequate time for acquiring oesophageal voice. Electronic larynx option must also be exhausted before proceeding with secondary tracheo oesophageal puncture. The size of the stoma created is also important. The diameter of the stoma should atleast be 2cm. Anything less than this would be considered to be suboptimal.
For tracheo oesophageal puncture to be successful the following factors should be considered:
1. The patient should be motivated
2. The patient should have good manual dexterity to maintain prosthesis
3. Patient should not have cricopharyngeal spasm
4. A trans nasal oesophageal insufflation test must be performed before the procedure. This test will identify those patients who are likely to fail this procedure.
Trans nasal oesophageal insufflation test:
The transnasal esophageal insufflation test is a subjective test that is used to assess the pharyngeal constrictor muscle response to esophageal distention in the laryngectomy patient.
The test is performed using a disposable kit consisting of a 50-cm long catheter and tracheostoma tape housing with a removable adaptor. The catheter is placed through the nostril until the 25-cm mark is reached, which should place the catheter in the cervical esophagus adjacent to the proposed TEP. The catheter and the adaptor are taped into place. The patient is then asked to count from 1 to 15 and to sustain an ‘‘ah’’ for at least 8 seconds without interruption. Multiple trials are performed to allow the patient to produce a reliable sample. The responses obtained are the following:
1. Fluent sustained voice production with minimal effort
2. A breathy hypotonic voice indicating a lack of cricopharyngeal muscle tone
3. Hypertonic voice
4. Spastic voice due to spasm of cricopharyngus muscle
Procedure to tracheo oesophageal puncture will be discussed elsewhere.