Tracheal Diseases

B. Anatomic relationships:
· Anterior - thyroid isthmus, innominate artery, aortic arch
· Posterior - esophagus
· Lateral - azygous, pleura, recurrent laryngeal nerves
· Inferior - anterior and posterior subcarinal lymph nodes

C. Arterial supply:
· Three branches of the inferior thyroid artery on either side of the upper trachea
· Subclavian, supreme intercostal, internal thoracic, innominate, superior and middle bronchial arteries all contribute to varying degrees
· Lateral longitudinal vessel anastomoses feed transverse vessels, which penetrate between cartilage rings to supply submucosa
· Mobilize only 1-2 cm circumferentially to avoid ischemic necrosis
· Mobilize anteriorly and posteriorly to avoid significant vessels

B. Tracheoesophageal fistula
· Tracheal lesion easily closed, esophageal portion more difficult
· Rarely has associated stenosis

C. Congenital stenosis
· Webs and diaphragms most often occur at subcricoid level
· Three types of stenosis: generalized hypoplasia, funnel-like narrowing, and segmental stenosis
· Main bronchi most often normal with generalized hypoplasia, vary in size with funnel-like narrowing, and commonly have anomalies with segmental stenosis
· Associated with a wide range of anomalies throughout the body
· About 50% of pulmonary sling cases are associated with lower tracheal stenosis

D. Diagnosis of congenital stenosis
· Suspicion in infants with inspiratory and expiratory stridor or more severe respiratory distress
· Wheezing, retraction, poor feeding, failure to thrive may also be present

E. Management
· Operations in infants are high risk, as postoperative edema may obstruct small airways and mechanical ventilation may disrupt anastomoses
· A conservative approach is wise, as less than 1/3 of the trachea in a child can be resected
· Webs can be dilated or excised endoscopically
· Stenoses should not be dilated, as this can create longitudinal tears, resulting in recurrent scarring and stricture
· Tracheostomy for palliation is a suitable alternative to allow growth for surgical repair

B. Squamous cell carcinoma
· Most common tracheal neoplasm
· Well localized exophytic or ulcerated lesion
· Multiple lesions or a superficially infiltrating variety also occur
· 1/3 of patients will present with mediastinal or pulmonary metastasis
· Spread is usually to regional tracheal lymph nodes and then directly into mediastinal structures

C. Adenoid cystic carcinoma (cylindroma)
· Grows slowly and displaces mediastinal structures rather than invading
· Submucosal and perineural spread may occur for quite long distances
· Best chance at cure is complete resection at first operation

D. Clinical Features
· Dyspnea on exertion
· Wheezing
· Stridor
· Excessive secretions
· Hemoptysis
· Pneumonia
· Cough

E. Secondary tracheal neoplasms
· Thyroid cancers are the most common indication for tracheal operations for secondary malignancy
· Laryngeal carcinoma involves the upper trachea by direct extension
· Bronchogenic carcinoma more commonly involves the carina or bronchial origin on the right
· Tracheoesophageal fistula can result from radiation therapy for or from invasion by esophageal cancer
· Other tumor include carcinoid, head and neck, breast, and lymphoma

B. Blunt injuries
· Closed trauma may lacerate or sever the trachea
· A severed trachea should be re-approximated if possible
· The distal trachea should be intubated for security
· A tracheostomy tube should be inserted in the distal severed end for complex injuries and repair undertaken later
· A vertical split at carina is usually diagnosed by a pneumothorax that fails to resolve with closed suction
· Bronchoscopy, thoracotomy, and occasionally cardiopulmonary bypass are required to repair this lesion
· Traumatic TEF should be promptly repaired, as inflammation makes repair difficult when the diagnosis is delayed
· Always establish the function of the recurrent laryngeal nerves and larynx prior to surgery, if possible

A. Laryngeal level
· Sealing cuffs may irritate vocal cords, causing granulomas and fusion of the posterior commissure
· Mucosal erosion at the cricoid can cause subglottic stenosis
· Most lesions are reversible with time

B. Stomal level
· Principle factors include a stoma that is too large, loss of tissue from infection (rare), and pressure erosion from rigid connecting systems (most common)
· Avoid injuring the first cartilaginous ring during original tracheostomy to prevent subglottic stenosis
· Avoid low placement of the tracheostomy to prevent innominate artery erosion and supracarinal stenosis

C. Sealing cuff level
· Most common cause is direct pressure necrosis by high-pressure cuff
· This has essentially disappeared with use of low-pressure, high-volume cuffs
· Children may develop granuloma on anterior tracheal wall when ventilated without a cuff

D. Tracheomalacia
· Usually occurs in segment of trachea between stoma and the cuff
· Secretions pool here and inflammation leads to cartilage thinning

E. Tracheoesophageal fistula
· Manifested by sudden appearance of secretions in tracheobronchial tree
· Pneumonitis, pneumonia, abscess, and gastric dilitation may develop
· Methylene blue in tube feedings will appear promptly in the trachea

F. Trachoinnominate fistula
· Manifested by sudden exsanguinating hemorrhage into the tracheobronchial tree
· Emergent tamponade with high-pressure cuff or digital pressure is necessary

A. Upper half of trachea
· Collar incision with partial upper sternal split, if necessary, is used for benign and malignant lesions of the upper trachea
· Almost all stenoses above the carina can be reached through this approach as well
· Dissect anteriorly from the cricoid cartilage to the carina, staying close to the trachea
· The recurrent laryngeal nerves must be identified
· Divide the trachea and intubate distally
· About 4.5 cm can be removed without additional mobilization
· Laryngeal release is preferred, if needed, taking care to avoid injury to the superior laryngeal nerves
· Hilar release is more hazardous and is contraindicated in patients with poor pulmonary function
· Once the sutures have been placed, the distal tube is removed and the endotracheal tube is readvanced past the anastomosis
· All sutures are tied and the anastomosis tested under water for leakage

B. Lower half of trachea
· Posterolateral thoracotomy in 4th interspace provides optimal exposure and should be performed on the side contralateral to the aortic arch (usually right)
· About 4.5 to 5 cm can be resected without extreme maneuvers
· Release technique include hilar dissection, loosening of the carina, and cervical flexion
· Laryngeal release does not provide any additional mobilization
· A pleural or pericardial flap is constructed to protect the anastomosis