Regional Clinical Hospital for War Veterans,

Kemerovo, Russia

 

 

INTRODUCTION

In the group of professional risk the incidence of chronic laryngitis achieves 34 %, but among the whole pathology of ear, nose and throat – 8.4-10 %. Chronic laryngitis is the persistent trophic and structural changes in larynx tissues with disorders in innervation, perfusion and secretion. This disease significantly decreases the quality of life of patients, with influence on not only medical aspects, but social ones. The highest incidence is noted in the most employable persons, with mean age of 45. One should note that the male and female ratio is 2:1. The percent of men prevails in the population of patients with chronic laryngitis [1]. The main factors of development of chronic laryngitis in miners are smoking, malnutrition and improper nutrition, contact with coal rock dust, changes in gas composition of the air (decreased oxygen, increased CO₂, presence of methane, carbon oxide, sulphurated hydrogen, sour gas, nitrogen oxides, explosive gases etc.), manual labour, significant draughts in mines, neuropsychic overload [2]. As result of non-balanced nutrition the foodborne diseases appear, such as gastrointestinal ones, for example, gastroesophageal reflux disease. Many research works of domestic and foreign investigators show that gastroesophageal reflux disease (GERD) is one of the most common gastrointestinal diseases in the modern society, with close connection with diseases of throat and larynx [3].

The problem of treatment of chronic laryngitis takes a special part in otorhinolaryngology, because of improper efficiency of anti-relapsing measures and absence of the uniform opinion about the pathogenesis of this disease.

Kemerovo region is the location with the high concentration of rough manufacturing and processing plants. According to the economic potential it is the largest territorial production complex of Russian Federation. The region excavates 57 % of the Russian coal, produces 12 % of mill products and steel, 55 % of ferrum alloys, 69 % of rails, 100 % of tramrails, 20 % of coke. Therefore, Kemerovo region is characterized with acute ecological problems. Among the cities of Kemerovo region, Novokuznetsk takes the first place for gross emissions from stationary sources (22.8 % of the total amount of emissions). Out of 2,734,075 residents of the region (the data for January, 1, 2014) more than a half participates in harmful production, resulting in the high level of respiratory diseases in the population of Kuzbass, including chronic laryngitis. Therefore, the actuality is related to timely and accurate diagnostics of laryngeal chronic pathology, because in 60 % of patients the chronic inflammatory processes (laryngitis) present the background for development of laryngeal tumors [4].

Kuzbass is the leading coal producing region of Russia. It produces 57 % of coal in the country. There are 120 coal producing enterprises in Kuzbass at the present time (63 mines, 57 open mines, 42 coal conversion enterprises). Their production capacity is 245 million tons per year for coal extraction and 166 million tons for conversion. The total staff amount is 109,000 persons. The monthly average labour capacity in the coal industry of the region increased two times for the last 15 years and achieved 209 tons per a person per a month.

Coal miners are more exposed to respiratory diseases associated with coal dust aspiration. Long term influence of increased dust levels results in development of severe occupational respiratory diseases - dust bronchitis and chronic laryngitis.

One can observe the tendency to decreasing incidence of laryngeal cancer in Kemerovo region during the last 10 years (average annual rate of growth was 1.76 %), the lowest indices were found in 2009-2010. In 2009 the proportion was 5.3 ± 0.2 %. Generally, in Kemerovo region the dynamics of the incidence of laryngeal malignant neoplasms is similar to the rates in Russian Federation, but the rates of malignant laryngeal neoplasms are higher. The laryngeal cancer-associated mortality decreased during the last 10 years (average annual rate of growth -1.86 %). The dynamics of morbidity and mortality in patients with malignant laryngeal tumors corresponds to the rates in Russian Federation for the period of 10 years [5].

According to the statistics during the last 3 years in Kemerovo region 421 patients with laryngeal cancer were found, among them, 72 % with stages III and IV. The gathered international experience of laryngeal microsurgery allowed qualitative increasing early diagnostics of laryngeal cancer, solving the problem of voice rehabilitation in surgical treatment of tumor-like formations and benign tumors, as well as improving diagnostics and surgical treatment of laryngeal diseases with maximal sparing for tissues in all age groups. However, the questions are opened for discussion: from which parts one should take biopsy samples, what is sufficient volume of removed tissues? Solution of these problems usually depends on intuition and experience of treating physician, frequency of negative histological responses because of incorrectly chosen parts of altered mucosa, expressed throat reflex in some patients and unfavorable anatomic structure of the larynx. The frequency of process and appearance of laryngeal structures are not constant reliable criteria for establishing correct diagnosis.

Some authors the method of autofluorescent endoscopy, which has high sensitivity for identification of laryngeal changes compared to classical endoscopy. Physical principle of the method is based on agitation of own fluorescence (autofluorescence) of mucosa by the means of light from blue zone of the optical spectrum (375-440 nm). With this aim the special sources of light are used, such as xenon lamp or semiconductive laser. The high affinity of endogenous and exogenous luminous colors to tumor tissue became the basis for development of this method of differential diagnostics of laryngeal diseases, which require secondary fluorescence or tissue fluorescence, after introduction of photosensitizers into the patient’s body which increase quantum yield of luminescence during interaction with some chemical substrates. It is considered that registration of increased level of fluorescence in definite region of examined organ allows reliable diagnosing malignant tumor [6]. Unfortunately, the method is expensive and it requires special equipment. However, its value and inaccessibility for most otorhinolaryngologic departments of Russia should not be a barrier to the improvement of traditional surgical treatment methods for chronic laryngitis.

Objective – to define the tactics of effective surgical treatment of chronic laryngitis in miners.

                                         

MATERIALS AND METHODS

The study included 249 miners with chronic laryngitis which received surgery with maximal saving of intact tissues. All patients were divided into 2 groups, without statistical differences in age and gender (p = 0.445, p = 0.574). The process of distribution of the patients into the groups was performed using computer randomized codes (simple randomization). The study was opened, cohort, prospective, prolonged, randomized, and controlled. The type of randomization was simple (even, odd). The selection of the patients was realized according to the inclusion and exclusion criteria.

The inclusion criteria: 249 admitted miners with chronic laryngitis, age of 31-50, with performed surgical treatment.

The exclusion criteria: 76 patients without indications for surgical treatment. This group received conservative treatment.

All patients gave the consent for participation in the study. The examination of ear, throat and nose was performed on admission to the departments, as well as videolaryngoscopy (with Olympus fibroendoscop and rigid optics Karl Storz 70⁰), and, if indicated, MSCT and MRI of the larynx and stroboscopy. All patients with chronic laryngitis, who received endolaryngeal surgery, were divided into 2 subgroups. The first subgroup included 167 patients (67.1 ± 3.1 %) who received endolaryngeal surgery under local anesthesia during indirect laryngoscopy. The altered parts of laryngeal mucosa were removed using the laryngeal corneoscleral punch like “Kordes”. In the second subgroup of 82 (32.9 ± 3.1 %) patients endolaryngeal intervention was performed under anesthesia during direct microlaryngoscopy (with the surgical microscope by Karl Zeiss and O. Kleinsasser instruments for laryngeal surgery by Karl Stolz). For all patients with unsmooth borders of a lesion the coloring of altered parts of laryngeal mucosa using the special device developed by us was performed. This device includes a syringe and a conductor with a connector like “Luer”. The principle of the method is based on the accumulation of dye with specific cell substrates. Non-altered non-squamous epithelium is colored, which after 2-3 sec becomes black, dark brown or green-brown color. Leukoplakia regions are not colored. This imaging method allowed to receive more objective information about state of the larynx and degree of development of a pathologic process.

 

RESULTS

The estimation of the treatment results was carried out on the basis of repetitive examination of 249 patients in annual examination during 3 years and was performed on the basis of clinical and endoscopic data. Besides evaluation of patients’ complaints and the data of indirect laryngoscopy the questionnaire, assessment of pain syndrome intensity according to visual analog scale and videolaryngoscopy were carried out. During statistical preparation of the data for each sample the hypothesis of normal distribution was tested. The statistical preparation of the materials was realized with STATISTICA 6.1, SPSS 11.0, INSTAT 2.0. The relative level of significance (p) was calculated. The critical level of significance was 0.05. Chi-square test (χ²) was used for testing statistical hypotheses about differences in absolute and relative frequencies, proportions and relationships in two independent samples. Chi-square test is 4.05 (number of degrees of freedom df = 1, p = 0.05). The confidence intervals (CI) were constructed for confidence coefficient p = 98 %. The paired intergroup comparison of the values was performed with Mann-Whitney U-test (U = 0).

In the first group of the miners (surgery under local anesthesia, n = 167) the recovering was in 107 (63.3 % ± 1.3 %) miners, incomplete removal of a neoplasm – in 34 (21.3 ± 5.9 %), malignization – in 6 (3.5 ± 0.7 %). In the second group (surgery under endotracheal anesthesia, n = 82) the recovery was in 67 patients (81.7 ± 0.7 %); 15 patients (22.5 ± 5.1 %) had positive clinical effect of treatment (reducing or absent complaints of voice changes, throat tickling, feeling of lump in throat). There were no cases of process malignization.                                                       

 

CONCLUSION

1.                 The number of patients with chronic laryngitic is great in Kuzbass, especially among miners. It is 6.7 % of all patients in otorhinolaryngological departments.

2.                 The full recovery is achievable in 63.3 % ± 1.3 % of the patients after surgery under local anesthesia with use of laryngeal corneoscleral punch like “Kordes”.

3.                 The use of the offered method of surgical treatment of chronic laryngitis allows significant increasing the rates of recovery and achieving full recovery in 81.7 ± 0.7 % of patients, and decreasing percent of patients with further development of malignant process in the larynx.