Laryngeal scar stenosis: causes, symptoms, diagnosis, treatment

Cicatricial stenosis of the larynx is one of the frequent complications of non-specific and specific infectious diseases of the larynx (abscesses, phlegmon, gumma, tuberculoids, lupus, etc.), as well as its injuries (wounds, blunt trauma, burns), which lead to cicatricial obstruction of the larynx and the development of chronic respiratory failure syndrome of the larynx.

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What causes cicatricial stenosis of the larynx?

The causes of cicatricial stenosis of the larynx can be divided into three categories:

1. post-traumatic, resulting from an accident, and post-operative (iatrogenic);
2. chronic inflammatory ulcerative-necrotic processes;
3. acute inflammatory processes.

Cicatricial stenosis of the larynx may occur as a result of its trauma and injury, especially when the laryngeal cartilages and their fragments that form its skeleton are damaged and displaced. Secondary perichondritis and chondritis that occur with open wounds of the larynx, or damage to the larynx by caustic liquids often end in necrosis, collapse of the laryngeal walls and its cicatricial stenosis. As clinical practice shows, even timely use of complex treatment, including the most modern antibiotics, does not always prevent post-traumatic complications that lead to cicatricial stenosis of the larynx.

Another no less common cause of cicatricial stenosis of the larynx is surgical interventions on it. Thus, thyrotomy (laryngofissure), performed for cordectomy in case of paralysis of the recurrent nerve or cancer in situ of the vocal fold, or partial laryngectomy, can end with cicatricial stenosis of the larynx, especially if the patient is predisposed to the formation of keloid scars.

Surgical interventions performed as emergency care for asphyxia (tracheotomy, conicotomy, etc.) can lead to severe stenosis of the larynx and trachea, preventing decannulation. According to C. Jackson, 75% of stenosis of the larynx and trachea occur in this way as a result of urgent surgical interventions on the larynx and trachea. Cicatricial stenosis of the larynx can also be caused by damage that occurs during tracheal intubation, if the intubation tube is in the larynx and trachea for more than 24-48 hours. Acute infectious diseases that cause damage to the larynx (diphtheria, measles, scarlet fever, herpangina, etc.) contribute to such stenosis, in which deep bedsores in the larynx with damage to the perichondrium occur especially early. These complications are especially common in children, whose larynx is narrow enough to accommodate an intubation tube for a long time.

Often, a tracheotomy tube, even if the tracheotomy was done lege artis, can cause the formation of bedsores, ulcers, granulations, especially the so-called supracranial spur, which occurs as a result of pressure from the tube on the anterior wall of the trachea, which, approaching the posterior wall of the trachea, causes a narrowing of the lumen of the latter.

In some cases, granulations form in this area, completely blocking the lumen of the trachea above the tracheotomy tube. The occurrence of these granulations is often the cause of insufficient care of the tracheostomy and cannula, which are not replaced in a timely manner and are not cleaned systematically. The use of an extended cannula can provoke ankylosis of the cricoarytenoid joints, and in children - delayed development of the larynx.

Cicatricial stenosis of the larynx may occur as a result of planned surgical interventions on the larynx or the use of chemical or diathermic cauterization. This stenosis is especially common after extirpation of laryngeal papillomas in young children. It has been noted that the use of endolaryngeal laser surgery has a more favorable effect on the postoperative wound process. The use of massive doses of irradiation of the larynx in malignant tumors, causing radiation epitheliitis, is often complicated by the formation of cicatricial stenosis of the larynx. Chronic ulcerative-proliferative processes in the larynx are currently rare and do not so often cause cicatricial stenosis of the larynx. However, if these processes occur, they leave behind deep lesions with massive scarring of the larynx and the occurrence of extensive stenosis. The most significant factor in the occurrence of cicatricial stenosis of the larynx is the gummatous process in the tertiary period of syphilis. Ulcerating gummas after healing leave behind deep scars that form in the vestibule of the larynx or in the subglottic space. Similar changes are caused by both productive and ulcerative-proliferative forms of laryngeal tuberculosis. However, lupus of the larynx leaves behind scars mainly in the epiglottis area, while stenosis of the laryngeal cavity occurs very rarely. The cause of cicatricial stenosis of the larynx is scleroma.

A common cause of cicatricial stenosis of the larynx is banal inflammatory processes accompanied by damage to the submucosal layer and perichondrium.

In rare cases, cicatricial stenosis of the larynx occurs as a complication of laryngeal manifestations of certain infectious diseases (diphtheria, typhus and typhoid fever, influenza, scarlet fever, etc.), which were observed much more often in the pre-antibiotic period.

Pathological anatomy of cicatricial stenosis of the larynx

Usually cicatricial stenosis of the larynx occurs in the narrowest parts of this organ, especially at the level of the vocal folds and in the subglottic space and most often in children. Most often, cicatricial stenosis of the larynx occurs as a consequence of proliferative processes, resulting in the development of connective tissue that is transformed into fibrous tissue, which has a tendency in the process of its development to contraction of fibers and contraction of surrounding anatomical structures. If the alterative process also affects the cartilages of the larynx, then they are deformed and collapse into the lumen of the larynx with the formation of especially strong and massive scars. In milder forms of cicatricial stenosis of the larynx at the level of the vocal folds, they are immobilized, and in cases of damage to the joints of the larynx, their ankylosis occurs, while the respiratory function may remain in a satisfactory state, but voice formation is sharply affected.

After the inflammatory process (ulceration, granulation, specific granulomas) subsides, reparative processes occur at the site of inflammation, caused by the appearance of fibroblasts and the formation of dense scar tissue. The severity of the scar process is directly dependent on the depth of the larynx lesion. Particularly pronounced cicatricial stenosis of the larynx occurs after chondroperichondritis. In some cases, chronic inflammatory processes in the larynx can cause the development of its cicatricial stenosis without prior ulceration. A typical example of this is laryngeal scleroma, the infiltrates of which are localized mainly in the subglottic space. In rare cases, total stenosis of the larynx may occur with the formation of a callous "plug" that completely fills the lumen of the larynx and the initial section of the trachea.

Symptoms of cicatricial stenosis of the larynx

Minor cicatricial formations in the epiglottis or vestibule of the larynx can cause symptoms of cicatricial stenosis of the larynx such as periodic hoarseness, choking, sometimes a feeling of irritation and paresthesia, causing paroxysmal coughing. If there is a limitation of the mobility of the vocal folds with some adduction, then the insufficiency of the respiratory function of the larynx can manifest itself during physical exertion (dyspnea). With significant cicatricial stenosis of the larynx, a state of constant insufficiency of the respiratory function of the larynx occurs, the severity of which is determined by the degree of stenosis and the rate of its development. The slower the stenosis of the larynx develops, the better the patient adapts to the resulting oxygen deficiency, and vice versa. If a tracheotomized patient develops signs of respiratory failure, then in the overwhelming majority of cases this is due to a narrowing of the lumen of the insertion tube by drying secretions. It should be borne in mind that in the presence of compensated cicatricial stenosis of the larynx, the occurrence of acute banal laryngitis can lead to acute stenosis of the larynx with unpredictable consequences.

Endoscopic examination of the larynx usually reveals various aspects of cicatricial stenosis of the larynx; often, mirror laryngoscopy fails to reveal the lumen through which breathing occurs. Along with the impairment of the respiratory function of the larynx, impairment of the phonatory function of varying degrees is often observed - from periodically occurring hoarseness of the voice to the complete inability to pronounce a sound in any key. In these cases, only whispered speech is possible.

Diagnosis of cicatricial stenosis of the larynx

The diagnosis of cicatricial stenosis of the larynx, as such, does not cause difficulties (anamnesis, laryngoscopy - indirect and direct), difficulties may arise only in establishing their causes in the absence of clear anamnestic data. If the same changes as in the larynx are detected in the nasopharynx and pharynx, then it should be assumed that the identified cicatricial phenomena are due to a syphilitic, lupus or scleroma process. In this case, serological diagnostic methods and biopsy are used.

In the presence of cicatricial stenosis of the larynx of any etiology, in all cases, an X-ray examination of the chest organs, X-ray of the larynx, direct laryngo- and tracheoscopy are performed. Under certain indications, the esophagus is also examined to exclude its diseases that can have an adverse effect on the larynx. If the patient has already undergone tracheotomy, then endoscopic examination of the larynx does not cause complications. If laryngoscopy is performed against the background of respiratory failure, then the same room must provide the possibility of performing an emergency tracheotomy, since in decompensated stenosis of the larynx, endoscopic manipulations can cause lightning-fast developing laryngeal obstruction (spasm, edema, wedging of the endoscope tube) and acute asphyxia. In tracheotomized patients, retrograde laryngoscopy can be performed through a tracheostomy using a nasopharyngeal mirror or a fibrolaryngoscope. This method can be used to establish the nature of the stenotic tissue, its extent, the presence of a floating "spur", etc. Cicatricial stenosis of the subglottic space is the most difficult to visualize. In this case, tomographic examination and CT are used.

Differential diagnosis of cicatricial stenosis of the larynx is based on anamnesis data, laryngoscopy, additional research methods, including laboratory ones if there is a suspicion of the presence of specific diseases.

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Treatment of cicatricial stenosis of the larynx

Treatment of cicatricial stenosis of the larynx is one of the most difficult tasks in otolaryngology, which is due to the high tendency of laryngeal tissues to form cicatricial stenosis even with the most gentle reconstructive surgeries. To a certain extent, the formation of cicatricial stenosis of the larynx can be prevented or reduced by corticosteroids, timely relief of local inflammatory-necrotic processes of both vulgar and specific nature, effective treatment of generalized infectious diseases manifested by damage to the larynx. If, as part of emergency care, a conicotomy or upper tracheotomy was performed on a patient, then in the near future it is necessary to perform a lower tracheotomy, ensuring uncomplicated healing of the "intercricothyroid" wound (conicotomy) or upper tracheostomy. In all cases of providing treatment for cicatricial stenosis of the larynx, it is necessary to achieve natural breathing as early as possible, since it not only prevents the formation of scars, but also ensures normal development of the larynx and speech function in children.

Preventive tracheotomy is acceptable for patients with chronic cicatricial stenosis of the larynx and unsatisfactory respiratory function, since sooner or later this surgical intervention will not bypass this patient, but will be performed in a hurry for vital indications. On the other hand, since such stenoses often require planned surgical intervention to restore the lumen of the larynx, the presence of a tracheostomy is an obligatory condition for this intervention.

Adhesions or cicatricial membranes located between the vocal folds are subjected to diathermocoagulation or removal using a surgical laser. In most cases, after this operation, it is necessary to immediately separate the vocal folds using a special dilator, for example, using an Ilyachenko dilator, consisting of a tracheotomy tube and an inflatable balloon fixed to it, inserted into the larynx between the vocal folds for several days.

Laryngeal bougies are solid and hollow. Some of them are used in conjunction with tracheotomy tubes. The simplest type of simple laryngeal bougie, used without a tracheotomy cannula, is a cotton-gauze tampon in the form of a cylinder of the appropriate diameter and length; the tampon is inserted into the narrowed part of the larynx above the tracheostomy. Hollow rubber Schroetter bougies or metal bougies of different diameters are used to expand the larynx without preliminary laryngo-fissure or tracheotomy. Due to their length and shape, these bougies are easy to insert and can remain in the lumen of the larynx from 2 to 60 minutes, with the patients themselves holding them at the entrance to the mouth with their fingers. During laryngostomy, it is recommended to use A.F. Ivanov rubber tees to expand or form the lumen of the larynx, which provide breathing both through the nose and mouth, and through a tube.

Solid bougies connected to a tracheotomy tube (Tost, Bruggemann, etc.) serve only as a dilator, while hollow ones (N.A. Pautov's "smoke tubes"), similar to a stove chimney, or I.Yu. Laskov's composite rubber cannulas, etc., additionally provide breathing through the mouth and nose. In cicatricial stenosis extending to the upper parts of the trachea, extended tracheotomy tubes are used. When blocking the larynx, its anesthesia is mandatory only during the first sessions of this procedure; subsequently, as the patient gets used to the blockage, anesthesia may not be used.

In cases of extensive cicatricial stenosis of the larynx, laryngotomy is performed with subsequent removal of the cicatricial tissue, and the bleeding surfaces are covered with free epidermal flaps fixed in the larynx with appropriate rubber fixators (models). B.S. Krylov (1965) proposed performing laryngeal plastic surgery with a non-free flap of mucous membrane mobilized from the laryngopharynx area, which is fixed with an inflatable rubber balloon, the pressure in which is regulated with a manometer (prevention of flap necrosis from excess pressure).

Treatment of cicatricial stenosis of the larynx is extremely difficult, thankless and lengthy, requiring great patience from both the doctor and the patient. Often, many months, and often years, are required to achieve at least a satisfactory result. And the result to which one should strive is to provide the patient with laryngeal breathing and close the tracheostomy. To do this, it is necessary to have not only filigree endolaryngeal microsurgical surgical technique, but also modern endoscopic means and endoscopic surgical instruments. Surgical treatment should be supplemented with careful postoperative care, means of preventing purulent complications, and after healing of the wound surfaces and epithelialization of the internal surfaces of the larynx - and appropriate phoniatric rehabilitation measures.

What is the prognosis for cicatricial stenosis of the larynx?

Cicatricial stenosis of the larynx has a different prognosis. It depends on the degree of stenosis, the rate of its development, the age of the patient and, of course, on the cause of its occurrence. If cicatricial stenosis of the larynx is caused by a specific infectious process or massive trauma to the larynx, then the prognosis for the restoration of the respiratory function of the larynx is determined by the underlying disease and the effectiveness of its treatment. With regard to the restoration of the respiratory function of the larynx, the most serious prognosis is for total, tubular stenosis and cicatricial stenosis of the larynx caused by extensive chondroperichondiritis of the larynx. Often, with such stenoses, patients are doomed to lifelong tracheostomy. The prognosis in children is complicated by the difficulties of treatment, and if the latter is long enough, by delays in the development of the larynx and speech function.