Bronchopleural fistula (BPF)
Definition
Bronchial fistula is a pathology of the bronchial tree, characterized by pathological communication of the bronchus with the external environment, pleural cavity, or lumen of internal organs. The clinical picture is determined by the relationship of the bronchus with other anatomical structures. Common signs are dyspnea, cyanosis, and cough with discharge of the contents of drained organs (pus, food masses, bile, etc.). The diagnosis of bronchial fistula is confirmed by X-ray diagnosis (lung X-ray, fistulography, bronchography, CT), endoscopy (bronchoscopy, EGD), pleural puncture with manometry. Tactics for bronchial fistulas can be conservative or surgical.
General information
A bronchial fistula is a fistula causing an abnormal communication of a bronchus with a cavity, organ, or skin surface. Bronchial fistulas are one of the most challenging problems of pulmonology and thoracic surgery, as they are difficult to treat conservatively, support chronic purulent processes, and significantly aggravate the postoperative prognosis. The frequency of bronchial fistula formation is closely related to their etiology. Thus, congenital esophageal-tracheal and esophageal-bronchial communications occur in 0.03% of newborns. Postoperative defects prevail in the structure of acquired bronchial fistulas – they account for 2-30% of complications of lung resection.
Reasons
The formation of congenital bronchial fistulas occurs intrauterine. The occurrence of broncho-esophageal and tracheoesophageal fistulae is caused by incomplete separation of the respiratory and digestive systems at a certain stage of embryogenesis under the influence of various factors affecting the fetus (avitaminosis, intrauterine infections, trauma, radiation, etc.). In most cases of this malformation, there is a fistulous passage between the main bronchus (usually the right bronchus) and the esophagus. The etiology of acquired bronchial fistulas may be different:
- Postoperative defects. The most common postoperative fistulas are caused by bronchial stump failure or its necrosis, pleural empyema, the spread of tumor process along the bronchial wall, and other causes. Statistical data show that postoperative bronchial fistulas are two times more often formed after pneumonectomies performed for lung cancer than after other resection interventions (lobectomy, bilobectomy, etc.).
- Infections of the lungs and bronchi. The second place among the causes of acquired bronchial fistulas is occupied by specific and nonspecific purulent-destructive processes of the lungs: actinomycosis, tuberculosis, lung abscess, and bacterial destruction of the lungs. Spontaneous pneumothorax, cancerous tumor decay, echinococcosis of the lung, perforation into the bronchial tree of esophageal diverticula, cysts, or liver abscesses lead to the formation of a defect in the bronchial wall.
- Traumatic injuries. The third group of factors leading to the formation of bronchial fistulas is associated with closed chest trauma, lung injury, etc.
Classification
In addition to the division into congenital and acquired, bronchial fistulas are subdivided into single (62%) and multiple (38%, including “lattice lung”). Taking into account the etiologic factor, they can have a posttraumatic, postinfection, or postoperative origin. Depending on the level of localization, fistulas of the main, lobar, segmental, subsegmental bronchi, and alveolar fistulas are distinguished. In clinical practice, the greatest value is represented by the anatomical classification, which distinguishes:
External (thoracobronchial) fistulas
- Bronchocutaneous and bronchopleurocutaneous communication opens on the surface of the chest wall as a spongiform (with one opening) or canal-like (with two openings—external and internal) communication.
Internal fistulas
- bronchopulmonary – is a communication of the bronchus with a suppurative cavity in the lung tissue (cavernous tuberculosis, lung abscess, gangrenous focus, etc.).
- bronchopleural – characterized by direct contact of the bronchus with the pleural cavity
- broncho-organ (broncho-esophageal, bronchogastric, broncho-intestinal, etc.) are rare; they are formed in the presence of a pathologic channel connecting the bronchus with the lumen of the esophagus, stomach, intestine, gallbladder.
Symptoms of bronchial fistulas
The criteria that determine the symptomatology of bronchial fistulas are their anatomical features, diameter, the timing of the defect, and the presence or absence of infection. Common symptoms accompanying the development of pathology include signs of intoxication (fever with chills, weakness, tiredness, headache, poor appetite) and respiratory failure (cyanosis, dyspnea, chest pain). In addition, different types of bronchial fistula are characterized by their specific manifestations.
External (bronchocutaneous, bronchopleurocutaneous) fistulae are characterized by a visible defect in the skin of the chest wall, which periodically discharges mucous or mucopurulent discharge and, when coughing and pushing, can release air. Getting water into the fistulous passage provokes a sharp attack of coughing and suffocation. Sometimes, removal of the occlusive dressing causes increased coughing, dyspnea and cyanosis, and voice disturbance up to aphonia.
Bronchial fistulas communicate with the “dry” pleural cavity, manifested by a dry cough or coughing up a small amount of mucous sputum. In bronchopleural fistulas developed against the background of purulent pleurisy, the general condition of patients is aggravated by purulent-resorptive fever, intoxication, and exhaustion. There is a large volume of purulent, stinking sputum when coughing, marked dyspnea, air discharge from the pleural drainage, and subcutaneous emphysema. The clinic of bronchopulmonary fistulas is defined by subfebrile coughing with the discharge of mucopurulent sputum, sweating, and weakness.
The main sign of broncho-organ fistula is the patient’s coughing up the contents of the organ with which the bronchus communicates: food eaten, bile, gastric, or intestinal contents. Congenital tracheal- and broncho-esophageal fistula may be suspected soon after birth based on gagging during feeding, bloating of the stomach, and the development of aspiration pneumonia. The main manifestation of acquired fistulae is a cough associated with fluid and food intake and sometimes choking.
Complications
A prolonged course of bronchial fistulas can lead to pneumonia and chronic empyema of the pleura. Complications in the form of hemoptysis or pulmonary hemorrhage and aspiration pneumonia of the other lung are possible. Systemic consequences are sepsis, massive internal bleeding, and visceral amyloidosis.
Diagnosis
When examining a patient with a presumptive diagnosis of “bronchial fistula,” cyanosis of the skin and mucous membranes, dyspnea, tachycardia, characteristic deformation of the terminal phalanges of the fingers (“drumsticks,” “hourglasses”). Auscultation reveals scattered multi-caliber rales.
Bronchocutaneous fistulas opening on the surface of the chest wall are detected visually. For diagnostic purposes, probing of the fistula with an injection of an aqueous solution of methylene blue may be performed. The occurrence of cough with the release of colored sputum confirms the presence of a bronchial fistula. To obtain information about the extent and configuration of the fistulography with contrast agents. In some cases, diagnostic thoracoscopy is performed through the fistulous opening in the chest wall to clarify the localization, number, and size of fistulous passages.
The bronchoscopic examination is of great diagnostic value in internal fistulas, allowing the assessment of the state of the bronchial tree and radiologic diagnostic methods: review radiography, CT lung, and bronchography. Bronchopleural fistulas can be detected with the help of pleural puncture with manometry—when the bronchial tree communicates with the pleural cavity, negative pressure cannot be created by aspiration of air. In case of suspected bronchoesophageal or bronchogastric fistula, esophagogastroscopy is indicated.
Treatment of bronchial fistulas
In most cases, bronchial fistulas require surgical treatment. However, some bronchial fistulas can be treated conservatively. This pathology should be treated by thoracic surgeons with a full arsenal of management methods for patients with bronchial fistulas. Conservative treatment of bronchial fistulas involves sanitizing purulent cavities, drainage of the pleural cavity, lavage with antiseptic solutions, administration of proteolytic enzymes and antibiotics, removal of foreign bodies, application of active aspiration apparatus, etc. After obliteration of residual cavities, small bronchial fistulas can be closed independently.
There is a positive experience of fistula elimination by chemical cauterization or electrocoagulation of the fistula, which destroys the epithelial lining and stimulates the growth of connective tissue in the canal. In large fistulas, temporary endoscopic closure of the fistula-forming bronchus can be with a special foam filling – this tactic allows performed lavage of the purulent cavity and creates favorable conditions for rapid elimination of bronchial fistula.
Conservative treatment of bronchial fistulas is successful only in 10-12% of cases, so most patients are shown surgical closure of the defect. For surgical elimination of the thoracobronchial fistula, its excision with subsequent suturing and muscle grafting with a leg flap can be performed. In postoperative fistulas, it is shown to perform reamputation of the bronchus stump. Elimination of esophageal-bronchial fistulas requires suturing of defects on the side of the esophagus and bronchus, possibly resection of the altered part of the lung. Bronchopleural fistula closure can be performed by intrapleural thoracoplasty or lung decortication.
All these treatment options are available in more than 530 hospitals worldwide (https://doctor.global/results/diseases/bronchopleural-fistula-bpf). For example, Open chest surgery can be done in 23 clinics across Mexico for an approximate price of $8.2 K (https://doctor.global/results/americas/mexico/all-cities/all-specializations/procedures/open-chest-surgery).
Prognosis and prevention
The outcome and prospects of recovery depend on the cause that led to the formation of bronchial fistula, completeness, adequacy, and timeliness of treatment measures. The most severe prognosis and high lethality (30-70%) is noted in postoperative fistulas complicated by pleural empyema. In bronchial fistula, waiting tactics are inadmissible; it is necessary to start conservative measures as early as possible and surgical intervention after the necessary preparation. Prevention of acquired bronchial fistula consists of compliance with the technique of bronchial stump treatment, timely therapy of purulent and destructive lung diseases, and prevention of chest trauma.
