INDICATIONS/CONTRAINDICATIONS
Tracheal dilation is indicated for relief of symptoms related to stenosis or obstruction caused by both benign and neoplastic conditions. Postintubation tracheal stenosis is the most common benign etiology requiring tracheal dilation. Other causes include neoplasms, trauma, inflammatory processes, and infection (Table 34.1). Secondary involvement of the trachea by a neoplasm is far more common than primary tracheal tumors.
Rigid bronchoscopy and tracheal dilation are indicated for the urgent relief of tracheal stenosis. Severe tracheal stenosis that is symptomatic is an emergency. A small amount of mucus or blood can completely obliterate the airway without warning and precipitate anoxia.
There are no absolute contraindications to tracheal dilation. Once the indication is established, the practitioner must select the appropriate method to most effectively deal with the airway narrowing. Tracheal dilation is often a prelude to a more definitive surgical procedure such as tracheal resection. Tracheal dilation on its own may not be effective or durable and familiarity with other techniques such as tracheal resection, T-tube insertion, or tracheal stenting is necessary.
PREOPERATIVE PLANNING
The patient often presents with a delay in diagnosis, and may have been treated as having “adult-onset asthma.” Important adjuncts for preoperative care of a patient with tracheal obstruction include airway humidification, oxygen, heliox, and mild sedation provided in an intensive care unit.
When the patient has any element of distress or there is concern about the security of the airway, advanced imaging of the airway by computed tomography (CT) is deferred. In a less severe presentation, CT scanning is useful for planning further interventions.
Assembly of a team proficient in airway dilation and management is paramount. Emergent airway dilation requires general anesthesia, and the anesthesiologist must be familiar with appropriate anesthetic technique. Tracheal dilation must be performed in an operating room suite with capability for flexible and rigid bronchoscopy as well as equipment and materials necessary for establishing a surgical airway if tracheal dilation is not possible or fails.
TABLE 34.1 Diagnoses Associated with Tracheal Stenosis or Obstruction
SURGERY
Anesthesia
General anesthesia is induced by either an inhalation or intravenous technique, and neuromuscular blockade is avoided until it is determined that the airway can be secured. If dilation and intubation beyond the stenosis do not appear straightforward, a temporary solution is jet ventilation through a rigid bronchoscope or endotracheal tube positioned proximal to the lesion, as long as there is a patent lumen. In most instances, slow and patient induction with an inhalational anesthetic delivered through a mask or laryngeal mask airway is sufficient. A flexible bronchoscope delivers 1% lidocaine topically to the vocal folds and mucosa of the subglottis, if bronchoscopy is performed without paralysis.
Positioning
Patients are positioned supine. A blanket or pillow may be placed beneath the occiput to improve alignment of the oral, pharyngeal, and laryngeal axis.
Technique
Rigid bronchoscopy is the standard technique for dilation of a benign stenosis in an adult. A complete set of equipment and materials for rigid bronchoscopy is mandatory (Table 34.2 and Fig. 34.1). A Jackson rigid bronchoscope is preferable as it has a gently rounded tip as opposed to the sharper spade-like tip of the Storz bronchoscope (Fig. 34.2). A blunt tip permits safe passage of the bronchoscope through a stenosis or tumor. A 7- or 8-mm Jackson rigid bronchoscope is used to examine the glottis and intubate the trachea, taking care to not travel into the stenosis. A suction device clears secretions that may have accumulated at the stricture. A rigid telescope, introduced through the rigid bronchoscope, enhances examination of the stenosis.
