**2.1. Voice rehabilitation after laryngectomy**

The function of the upper esophageal sphincter is to prevent breathed air from entering into the esophagus and to stop reflux of esophageal content into the pharynx to prevent airway aspiration, and the function of lower esophageal sphincter is to prevent gastroesophageal reflux.

The function of the esophagus is very simple: to actively transport solids and liquids from the pharynx to the stomach. It has no digestive, absorptive, metabolic, or endocrine functions, but in some people, esophagus takes another very important function [2]. These people are laryngectomized persons. Namely, after total laryngectomy, the lower respiratory tract is permanently separated from the upper respiratory tract. The breathing function begins and ends in the permanent tracheostoma, and the upper respiratory tract loses its function [3]. In such anatomical condition, the esophagus has a key function in two of three primary approaches to speech rehabilitation of laryngectomized patients: esophageal and tracheoesophageal speech therapy method. The upper part of the esophagus gets the function as some kind of air activator, and the pharyngoesophageal segment gets the function of the voice generator, thus

The standard options of laryngeal carcinoma treatment are surgery, radiotherapy, chemotherapy, or a combination of these modalities. When a conservation surgery is not indicated due to the tumor stage and localization, or due to patient's general medical condition, then total laryngectomy is considered. This surgical procedure implies a surgical removal of the entire larynx, from the hyoid bone to the second tracheal ring, and the lymph nodes on the ipsilateral or bilateral side. After removal of the larynx, the circular defect in the anterior wall of the pharynx is reconstructed and sutured to the base of the tongue. Inferiorly, resected distal part of trachea is brought forward and sutured to the skin edges forming permanent tracheostoma. Postoperative care after total laryngectomy includes nasogastric tube feedings and maintenance of tracheostoma. If the tracheostoma is satisfactory in size and shape, it is preferable not to use laryngectomy tube in the tracheostoma. Alaryngeal speech training may begin as early as 3 weeks after operation. Postlaryngectomy aphonia is one of the most devastating outcomes of total laryngectomy, and effective voice is critical to the successful prevention of psychological, social and economic consequences of totally laryngectomized individuals [4]. After total laryngectomy, there is a defect of hypopharynx that needs to be reconstructed. The base of tongue then makes anastomosis with neopharynx. Sometimes there is a retraction of the base of tongue, changed tonus of the pharyngoesophageal segment, an extension of a part of pharynx and esophageal stenosis, which can cause dysphagia in 10–58% of cases [5]. Reconstruction of the upper esophageal segment and the hypopharynx is essential for the swallowing function and alaryngeal phonation. In addition, radiotherapy and postoperative infection increases the risk of occurrence of scarring and stenosis of the oropharyngeal segment, causing dysphagia and odynophagia. Postoperative radiotherapy causes other problems such as reduced sense of taste, xerostomia, muscle fibrosis and tooth loss, which increases dysphagic disorders. Therefore, laryngectomees often need to modify their way of nutrition [6].

allowing the function of the voice resonators.

**2. Total laryngectomy**

68 Esophageal Cancer and Beyond

Total laryngectomy leaves a number of significant and permanent anatomic and physiologicalfunctional changes. One of them is the impossibility of loud laryngeal speech. Laryngectomy is the removal of vocal cords which are the vibrating source of sound, and it causes changes in the anatomic structures of the resonator, whereas tracheotomy prevents the use of the lungs as a physiological source of energy for the phonation. Patient is temporarily socially deprived which diminishes the quality of life and brings with it the limitations in other life spheres. Postoperatively, achieved by rehabilitation, a future alaryngeal voice will be created in the area where esophagus transitions into hypopharynx, under the influence of the airflow that causes the mucosa vibration [5]. This area is called neoglottis or pseudoglottis, and it is a pharyngoesophageal segment, anatomical structure in the area of the upper aerodigestive tract [7].

Rehabilitation of voice after removal of larynx has been known for more than 150 years [8]. The first well-known description of the possible way of producing alaryngeal voice was given by Czermak in 1859. He established an alaryngeal voice by redirecting the airflow from the endotracheal tube through a tube into the mouth of the laryngectomized patient [9]. After Billroth performed his first laryngectomy in 1873, his assistant, Gussenbauer, equipped the patient with a pneumatic device which had the function of a speech machine [8, 10, 11]. In the mid-nineteenth century, rehabilitation was discovered by establishing an esophageal voice. At the same time, various mechanical devices were used to transmit vibrations and thus allowed loud speech [12, 13]. In the mid-twentieth century, the first tracheoesophageal fistula was made, which allowed the air stream to reach the upper part of the esophagus and the pharynx [14]. A few years later, a voice prothesis was developed according to the principle of a one-way permeable valve that allows the airflow from the trachea into the esophagus and prevents the passage of food and fluid from the esophagus into the trachea.

Back a few decades, the world trend is the earliest possible rehabilitation of voice and speech after laryngectomy. The beginning and type of rehabilitation depend on the health, psychosocial and socioeconomic status of the patient [15].

Patients have three methods of substitute voice and speech:

