Identification and management of tracheobronchial injuries due to blunt or penetrating trauma

INTRODUCTION — Tracheobronchial injury (TBI) is an uncommon but potentially life-threatening injury, and few data are available to help guide management [1,2].

TBI can result from penetrating or blunt traumatic mechanisms but may also occur following iatrogenic injury. Some TBIs may be immediately fatal due to asphyxiation from airway obstruction or tension pneumothorax. More subtle injuries can lead to delayed airway stenoses.

A high index of suspicion for these injuries and prompt diagnosis and management are essential for optimizing outcomes in these patients.

The initial management of blunt or penetrating chest and chest wall injury, as well as penetrating and blunt neck injury, is reviewed separately.

●(See "Initial evaluation and management of blunt thoracic trauma in adults" and "Initial evaluation and management of chest wall trauma in adults" and "Initial evaluation and management of penetrating thoracic trauma in adults".)

●(See "Penetrating neck injuries: Initial evaluation and management" and "Surgical exploration for severe neck trauma" and "Blunt cerebrovascular injury: Mechanisms, screening, and diagnostic evaluation".)

INCIDENCE — The true incidence of tracheobronchial injury (TBI) due to blunt or penetrating trauma is unknown since most victims do not survive. Based in part on autopsy series, the estimated overall incidence of TBI, including those who died at the scene, is about 2 to 3 percent [3,4].

Although most often thought of as occurring in the trauma setting, it is important to remember that while rare, iatrogenic TBI can result from airway instrumentation (intubation, rigid bronchoscopy, tracheostomy) or intraoperatively. Intraoperative TBI occurs most frequently during esophageal surgery for middle and proximal esophageal tumors, with the incidence of TBI occurring during transhiatal esophagectomy ranging from 0.4 to 1.6 percent [5,6]. Following routine endotracheal intubation, the incidence of TBI is low, approximately 0.005 percent for single-lumen intubation and 0.05 percent for double-lumen intubation [7]. However, the incidence can be as high as 15 percent following emergency intubation [8]. Finally, the incidence of TBI following percutaneous tracheostomy placement is approximately 0.2 percent [9]. (See "Complications of the endotracheal tube following initial placement: Prevention and management in adult intensive care unit patients", section on 'Laryngeal injury'.)

MECHANISM AND LOCATION OF INJURY — Tracheobronchial injuries (TBIs) are defined as those that occur between the cricoid cartilage and right and left mainstem tracheal bifurcation (figure 1).

The trachea is generally protected from injury by its location relative to the sternum, rib cage, and vertebral column, as well as its relative elasticity and cartilaginous support. However, penetrating injuries and powerful blunt forces can result in significant TBI.

Penetrating — Penetrating injuries generally have a higher incidence of TBI compared with blunt trauma [10,11]. Penetrating TBI may be seen in up to 6 percent of patients with penetrating neck wounds, whereas 1 to 2 percent of penetrating chest injuries have an associated TBI [12]. Perhaps because most traumatic blunt TBIs occur in patients with multiple severe injuries, patients with penetrating TBI tend to have better survival. In a single institution over a 15 year period involving 104 TBIs, overall mortality was 23 percent; mortality for penetrating injury was 16 percent while mortality for blunt injury was 36 percent [10].

Gunshot wounds tend to be a more common cause of penetrating TBI than stab wounds [12]. Although gunshot wounds may affect either the cervical or intrathoracic trachea, injuries to the cervical trachea are more common, likely because deeper intrathoracic injuries may also cause fatal injuries to the heart or great vessels [13]. Stab wounds almost always involve the cervical trachea due to the location of the intrathoracic trachea deep in the chest.

Blunt — Although exact statistics are difficult to obtain, the incidence of TBI following blunt trauma in patients who are brought to the emergency department is approximately 0.5 to 2 percent [12]. In contrast to penetrating injuries, blunt TBIs predominantly involve the intrathoracic trachea. In a review of 183 blunt tracheobronchial injuries reported between 1970 and 1990 (figure 2), the following distribution was noted [14]:

●Among transverse ruptures (74 percent), 4 percent were located in the cervical and 12 percent in the intrathoracic trachea, 25 percent in the right main bronchus, 17 percent in the left main bronchus, and 16 percent in lobar bronchi.

●Among the vertical tears (18 percent), 6.5 percent were in the cervical trachea, 10 percent in the thoracic trachea, and 1.5 percent in main bronchi.

●The remaining injuries (8 percent) were complex, involving the trachea and right or both main bronchi.

Cervical trachea — The cervical trachea is at risk for injury following hyperextension injuries, or by the application of direct force. Examples include weightlifting accidents, strangulation from wires while riding snowmobiles, and seat belt injuries. These mechanisms often occur together, such as when neck hyperextension following sudden deceleration of a vehicle is immediately followed by forward impact of the neck against the steering wheel or dashboard.

The cricoid and thyroid cartilages are the structures most commonly injured following these types of injuries. In the most severe injuries, the point of actual rupture and separation of the cervical airway is most commonly between the cricoid cartilage and trachea. It is important to note that the age of the patient plays an important role in the severity of injury to the cervical trachea. In children, the larynx may suffer serious injury without actual fracture of the relatively flexible cartilages. In older adults, the more calcified cartilages are much more susceptible to fracture. Blunt trauma rarely produces clean tears but rather produces complex injuries, such as airway separation with concurrent fracture of the cricoid cartilage.

Intrathoracic — Injury to the intrathoracic trachea generally results from high-energy trauma, but TBI can also occur from a direct blow, which may be low energy [15,16]. The location of injury to the tracheobronchial tree has been consistent over several series [14,16]. Most blunt injuries occur on the right side, which may be related to the heavier right lung and shorter right mainstem bronchus. In a review of 265 patients with blunt TBI, the site of bronchial rupture was within 2 cm proximal to the carina in 76 percent of patients [16].

Blunt trauma to the anterior thorax during motor vehicle accidents produces a variety of injuries that may involve the thoracic trachea, carina, and main bronchi. After a crush injury, airway pressure may suddenly increase against a closed glottis, potentially leading to rupture when the pressure exceeds the elasticity of the airway.

Injuries following sudden deceleration tend to result in shearing forces applied to the carina, which is the point of maximal airway fixation in the chest [15,16]. For this reason, blunt injuries to the thoracic trachea are most common in the lower trachea and vary widely from complete transection to a partial horizontal tear. Vertical splitting of the trachea from the carina upward may also occur. Injury to the lower trachea may be accompanied by partial or complete shearing of one or both main bronchi. In addition, lobar or segmental bronchi may also be lacerated by crush injuries. These injuries are usually accompanied by deep parenchymal lung lacerations. (See "Pulmonary contusion in adults".)

CLINICAL FEATURES

Symptoms and signs — Symptoms and signs of tracheobronchial injury (TBI) are listed and are reviewed in the sections below (see "Initial evaluation and management of blunt thoracic trauma in adults", section on 'Tracheobronchial injury' and "Initial evaluation and management of penetrating thoracic trauma in adults", section on 'Tracheobronchial injury'):

●Airway obstruction (dyspnea, stridor, overt respiratory failure)

●Subcutaneous emphysema

●Mediastinal emphysema (a mediastinal "crunch" on physical examination, synchronous with heartbeat [Hamman's sign] (movie 1))

●Hoarseness or aphonia

●Hemoptysis

●Air bubbling from a penetrating wound

●Persistent pneumothorax and air leak after thoracostomy tube placement

●Signs of associated injury (eg, spinal injury, blunt cerebrovascular injury)

The most common presenting signs in patients with TBI are subcutaneous emphysema (35 to 85 percent) and pneumothorax (20 to 50 percent) (image 1) [12].

For penetrating cervical injuries, air escaping from a penetrating neck wound is essentially pathognomonic for a TBI. Cessation of the air leak from the cervical wound following intubation confirms the diagnosis.

The sine qua non of intrathoracic TBI is a significant air leak following tube thoracostomy. There may be partial resolution of a pneumothorax, but more commonly the pneumothorax fails to resolve and a continued massive air leak is present. On the other hand, it is important to keep in mind that the main bronchus can be torn without pneumothorax becoming apparent, especially if there is preexisting pleural obliteration.

Imaging findings — Signs of TBI on imaging studies include the following [15,16]:

●Marked air in local soft tissue (ie, subcutaneous emphysema, pneumomediastinum)

●Localized tracheal disruption and mediastinal emphysema seen on computed tomographic scan (image 2)

●Hyoid bone elevated above the third cervical vertebrae

●Persistent pneumothorax with a dependent lung (ie, "fallen lung sign") (image 3)

●Air in the wall of the trachea or mainstem bronchus

●Abnormal endotracheal tube (ETT) location, or distended ETT cuff due to protrusion from the trachea

AIRWAY MANAGEMENT — With appropriate management, most patients with tracheobronchial injury (TBI) can be managed successfully without the need for complex procedures to secure the airway; however, a diagnosis of TBI may not be made prior to the need for intubation.

For patients who are hemodynamically unstable or in respiratory distress and who have TBI, the common practice of rapid sequence intubation can prove disastrous. Attempting to place an oral endotracheal tube in a patient with airway distortion from cricoid or superior tracheal injury can result in airway transection and/or creation of a false passage for the endotracheal tube [17]. The resulting loss of the airway will be compounded if neuromuscular blockade has been administered. Thus, it is imperative to maintain a high index of suspicion for TBI in severe cervical and chest trauma, especially in patients with the signs suspicious for TBI. Maintaining spontaneous breathing until a safe airway has been established is critical.

The American Society of Anesthesiologists (ASA) has an airway disruption algorithm that emphasizes maintaining spontaneous breathing, if possible, until a safe airway can be established [18]. Detailed information on airway management is provided in the following topics:

●(See "Airway management in the adult with direct airway trauma for emergency medicine and critical care".)

●(See "Anesthesia for thoracic trauma in adults", section on 'Traumatic airway injury or obstruction'.)

●(See "Anesthesia for adult trauma patients", section on 'Airway management'.)

●(See "Anesthesia for adults with acute spinal cord injury", section on 'Airway management'.)

Airway disruption — Managing the airway in patients with TBI requires thorough preparation and consideration of several possible difficulties. In most cases of TBI, endobronchial intubation over a flexible bronchoscope is the preferred method of airway management. This will allow identification of the location and severity of the injury as well as provide capability to suction blood and mucous to improve the view. In addition, fiberoptic intubation does not require neck extension for direct laryngoscopy and can be performed while maintaining cervical spine stabilization. Finally, bronchoscopic guidance can allow the cuff of the endotracheal tube to be positioned beyond the level of the injury prior to inflation. In cases where the injury is located at the level of the carina or main bronchus, intubating with a bronchoscope aids the clinician in guiding the endotracheal tube into the uninjured main bronchus to initiate single-lung ventilation, but caution must be exercised when placing these bulky rigid tubes past an already injured airway.

While liberal use of bronchoscopy helps lower the incidence of missed injury, defines injury when present, and helps secure the airway, more complex interventions may be required. As an example, distal airway visualization may be extremely difficult in cases of severe injury due to bleeding and associated airway collapse. In addition, trauma patients who are rapidly deteriorating hemodynamically, or whose mental status will not allow cooperation with this approach, represent challenging situations. In such cases, performing rigid bronchoscopy in the operating room as the patient receives an inhalation anesthetic while maintaining spontaneous ventilation offers several advantages. These include better suctioning of blood and debris to improve visualization and bridging of an airway defect to enable adequate ventilation. However, rigid bronchoscopy requires extension of the neck, which will be contraindicated in cases of known cervical spine injury, or in cases in which injury to the cervical spine is suspected but not yet proven.

Complete airway transection — In cases of significant cervical injury, particularly with air emanating from the wound, attempts at oral intubation or blind intubation through the wound will likely prove futile. Cricothyroidotomy is rarely useful in these situations as the injury may be distal to the insertion site of the tube.

When severe laryngeal injury has occurred and the airway cannot be accessed transorally, one of two approaches is used to secure the airway.

●For penetrating trauma in which the larynx or proximal trachea has been completely transected, the airway must be grasped through the cervical wound and the endotracheal tube inserted directly into the intact distal airway.

●For severe laryngeal injuries, surgeons must be prepared to perform an emergency tracheostomy using local anesthesia. In this case, the tracheostomy tube should be placed through the already injured portion, if at all possible, to preserve the length of trachea available when repair is undertaken. (See 'Surgical repair' below.)

APPROACH TO MANAGEMENT — Following establishment of a secure airway, a thorough assessment of associated injuries should be performed as some of these may require more urgent management, prior to definitive management of tracheobronchial injury (TBI).

Evaluation and treatment of coexisting injuries — Due to the proximity of the trachea to numerous cervical and thoracic structures, tracheobronchial injury is often associated with significant concomitant injuries that are frequently the main determinants of survival. Coexisting injuries include:

●Vocal cord injury, which is often bilateral  

●Injury to the esophagus, which may be transected (see "Overview of esophageal injury due to blunt or penetrating trauma in adults", section on 'Esophagoscopy and esophagography')

●Vertebral body fractures and spinal cord injury (see "Cervical spinal column injuries in adults: Evaluation and initial management" and "Acute traumatic spinal cord injury")

●Injury to the carotid arteries, jugular veins, and intrathoracic great vessels (see "Blunt cerebrovascular injury: Mechanisms, screening, and diagnostic evaluation", section on 'Indications for imaging' and "Clinical features and diagnosis of blunt thoracic aortic injury", section on 'Approach to imaging')

●Pulmonary contusion (see "Pulmonary contusion in adults")

●Chest wall injury including fractures of the first rib, clavicle, or sternum (see "Initial evaluation and management of rib fractures")

Acute injuries — The need for repair of acute TBI is generally based on ongoing risk for airway obstruction, massive air leak, or mediastinitis [19]. Although there are certain circumstances in which it is reasonable to allow spontaneous healing of airway injuries, especially in patients with other significant injuries, prompt repair is preferable to avoid airway stenosis in the future. For cervical tracheal injuries, laryngeal and vocal cord injuries need to be thoroughly evaluated and addressed in conjunction with definitive TBI repair. (See 'Surgical repair' below.)

Selective nonoperative management — While most patients with TBI are best served by surgical intervention, a select group of patients may be appropriately managed nonoperatively [20]. While there is evidence for nonoperative management of posterior tracheal injury, typically iatrogenic injury, it is important to note that data are scant regarding nonoperative management for anterior tracheal injuries, which are much more common in the trauma setting.

Successful outcomes of nonoperative management have been best described in the setting of iatrogenic TBI following intubation or tracheostomy placement that results in laceration of the posterior tracheal wall [21]. A morphological classification of the degree of injury to the posterior tracheal wall has been proposed (table 1) [22]. Depending upon the depth of the tracheal wall involvement, lesions were staged as follows:

●Level I – Mucosal or submucosal tracheal involvement without mediastinal emphysema and without esophageal injury

●Level II – Tracheal lesion up to the muscular wall with subcutaneous or mediastinal emphysema without esophageal injury or mediastinitis

•Level IIIA – Complete laceration of the tracheal wall with esophageal or mediastinal soft-tissue hernia without esophageal injury or mediastinitis

•Level IIIB – Any laceration of the tracheal wall with esophageal injury or mediastinitis

Injury levels 1 and 2, and some level 3A injuries, with no or minimal mediastinal and subcutaneous air, may generally be safely managed nonoperatively, provided the criteria described below are met. (See "Complications of the endotracheal tube following initial placement: Prevention and management in adult intensive care unit patients", section on 'Laryngeal injury'.)

Posterior TBI may be managed nonoperatively provided there is:

●Minimal subcutaneous and/or mediastinal emphysema without expansion

●Absence of signs of mediastinitis

●Ability to evacuate an associated pneumothorax with a chest tube without a large, persistent air leak

●Ability to maintain ventilation

●Absence of a concomitant esophageal injury

●Ability to inflate the endotracheal tube (ETT) cuff distal to the injury and maintain adequate ventilation with minimal positive end-expiratory pressure (PEEP) in cases where ongoing intubation is necessary

For patients who will be managed nonoperatively, broad-spectrum antibiotic coverage is advised for up to one week, especially if mediastinal air is present. Finally, it is important to perform surveillance bronchoscopies to assess for development of granulation tissue and/or development of stenosis.

Tracheal stenting — The successful use of tracheal stents in the management of TBI has been reported, but the data are limited to case reports and anecdotal experience. Most reports describe the use of stents for the management of iatrogenic posterior tracheal wall injuries [23]. Either silicone Y-stents for distal injuries or fully covered expandable stents for mid-tracheal injuries have been used. In this setting, stents are removed in 4 to 12 weeks in most cases if healing of the defect is observed. In the author's practice, covered expandable stents were used successfully to manage two patients with small gunshot wounds to the anterior mid-tracheal wall. In both cases, the injuries were associated with large air leaks and there were no associated injuries to the esophagus or great vessels.

For patients who are nonoperative candidates, have other significant injuries, or have tracheal injuries that are difficult to access surgically, the use of a stent may be reasonable provided the air leak can be controlled. If necessary, in most cases, an endotracheal tube can easily be placed through a stent. However, there are no data available on long-term outcomes, and the use of stents is not recommended for the management of patients with TBI who are good candidates for surgery.

SURGICAL REPAIR — Principles involved in operative repair of tracheobronchial injury (TBI) include obtaining adequate exposure, preserving adequate airway length for reconstruction with conservative debridement, preserving the laterally based tracheal blood supply, buttressing the repair, and possibly creating a tracheostomy, particularly in multiply injured patients.

Cervical airway injury — Injuries to the cervical trachea are generally best approached through a collar incision (figure 3). A collar incision can be extended inferiorly to a partial or full sternotomy, if additional tracheal exposure is required. In addition, the incision can be extended along the border of the sternocleidomastoid muscle for exposure of the carotid sheath or to access to the cervical esophagus. (See "Surgical exploration for severe neck trauma", section on 'Neck exposure'.)

Small tears or lacerations that generally occur after penetrating knife wounds can be closed with limited debridement and direct approximation with interrupted 4-0 absorbable sutures (eg, polygalactin [Vicryl], polydioxanone [PDS]) sutures. For larger and more complex lesions when direct reapproximation is not an option, resection of the injured portion of the trachea with anastomosis is preferred to simply covering the defect with a local muscle flap. A tension-free anastomosis can generally be accomplished following resection of up to six tracheal rings.

The basic principles of airway repair include the following:

●The trachea may be safely mobilized anteriorly to the level of the carina, but circumferential dissection around the trachea should be limited to the injured segment to avoid injuring the laterally based tracheal blood supply. Excessive lateral dissection increases the risk of devascularizing the remainder of the trachea and jeopardizing healing of the anastomosis.

●The repair is best accomplished with interrupted 4-0 absorbable sutures with knots tied on the outside of the trachea to minimize subsequent granulation formation. For anastomoses performed near the brachiocephalic artery, it is important to interpose an ipsilateral strap muscle flap between the repair and the artery to minimize the risk for fistula formation. (See 'Complications' below.)

●For complete transection, which most often occurs just below the cricoid cartilage, approximation of the separated portions of the trachea can usually be accomplished following minimal debridement. Although the degree of separation will often seem quite large, there is usually only minimal loss of tracheal length, so tension on the anastomosis is fairly minimal. It is extremely important to remember that significant injury may have occurred to one or both of the recurrent laryngeal nerves. For this reason, a postoperative tracheostomy is often required. If at all possible, the tracheostomy should be placed distal to the repair.

●For concomitant esophageal injury, tracheal separation allows good access to the esophagus. Repairing the esophagus should occur first, followed by placement of a pedicled strap muscle flap over the repair and repairing the tracheal injury last. If the trachea has not been completely separated, it is best to resect the injured portion of the trachea first, and then to establish cross-field ventilation through the distal trachea to allow repair of the esophagus and muscle flap placement, followed by performance of the tracheal anastomosis. (See "Overview of esophageal injury due to blunt or penetrating trauma in adults".)

Intrathoracic airway injury — For injury to the intrathoracic trachea or mainstem bronchi, bronchoscopic identification of the location of the injury is necessary to guide the operative approach. Prior to repair of distal tracheal or mainstem bronchus injuries, an assessment must be made of the associated damage to pulmonary parenchyma and its vascular supply. If severe, concomitant lung resection should be considered. However, given the morbidity associated with a trauma pneumonectomy, every attempt to preserve functional pulmonary tissue should be made. (See "Pulmonary contusion in adults".)

A transthoracic approach (ie, thoracotomy) provides the best exposure for intrathoracic injuries.

●Injuries to the lower trachea, carina, or right mainstem bronchus are best approached via a right thoracotomy through the 4^th intercostal space.

●Injuries isolated to the left mainstem bronchus are best approached through a left thoracotomy, also through the 4^th intercostal space.

With a transthoracic approach, additional length may be obtained to reduce anastomotic tension by incising the pulmonary ligament as well as releasing the pericardium around the pulmonary veins.

A transsternal approach (median sternotomy) can be used for patients with injury to the lower trachea and carina and concomitant spinal injury that precludes positioning for a thoracotomy. With a transsternal approach, the anterior pericardium is opened between the aorta and superior vena cava (SVC), which are retracted. Opening the posterior pericardium will then expose the trachea.

The principles of repair described for repair of injuries to the cervical trachea also apply to repair of intrathoracic airway injuries. (See 'Cervical airway injury' above.)

Intrathoracic repairs should always be buttressed with vascularized tissue. Two excellent options include elevation of a pericardial fat pad or the use of intercostal muscle harvested at the time of thoracotomy. It is important not to wrap the tissue buttress circumferentially around the repair.

Finally, the repair should be inspected by bronchoscopy prior to leaving the operating room. If the patient is not able to be extubated immediately following the repair, it is important to ensure that the cuff of the endotracheal tube is not positioned adjacent the repair.

COMPLICATIONS — Complications following repair of tracheal injuries can be grave. Avoiding excessive anastomotic tension, preserving adequate tracheal blood supply, and buttressing intrathoracic repairs are critical in avoiding serious complications such as dehiscence and major postoperative hemorrhage. A high index of suspicion, as well as prompt diagnosis and management of these complications when they occur, is essential to minimize mortality.

Anastomotic separation — Anastomotic separation most often presents within the first week postoperatively. Signs and symptoms include coughing new blood-streaked sputum, stridor, dyspnea, and subcutaneous air. Flexible bronchoscopy, ideally performed in the operating room, is required to examine the anastomosis.

Once a diagnosis of separation of a cervical anastomosis is confirmed, the incision should be opened and the wound explored. The area of separation should be debrided and bridged with either a small tracheostomy tube or T-tube. If the brachiocephalic artery is nearby or is visible, a pedicled strap muscle flap should be interposed to prevent fistula formation. (See 'Arterial fistula' below.)

Anastomotic separation that occurs in an intrathoracic location may initially be able to be spanned with an endotracheal tube placed with bronchoscopic guidance. Ultimately, the area of separation should be covered with a silicone stent.

Arterial fistula — Fistula formation between the brachiocephalic artery and the anastomosis presents as sudden, massive hemorrhage. The first step is emergency intubation to secure the airway and attempt to tamponade the bleeding with the cuff of the endotracheal tube. The patient must then be brought directly to the operating room for a median sternotomy. Arterial repair should not be attempted; rather, the brachiocephalic artery is divided with a vascular stapler. The anastomotic airway defect may be repaired if the area of separation is small. If larger, it will need to be bridged with a tracheostomy tube. It is imperative to place a vascularized pedicled flap between the trachea and the artery. If a strap muscle flap is not sufficient, then a pectoralis muscle flap should be used. (See "Overview of flaps for soft tissue reconstruction".)

Missed injury — Approximately 50 to 70 percent of tracheobronchial injuries (TBIs) are not recognized within 24 hours, as many patients with TBI are able to maintain effective ventilation and may require treatment of more life-threatening injuries. In one review, the median time to diagnosis was nine days [16]. For other patients, the diagnosis is not made likely due to the subtleness of the injury and lack of significant symptoms [11,16]. Over the course of approximately one month, the development of granulation tissue at the site of injury leads to fibrosis and ultimately stenosis [12]. Symptoms of airway obstruction often progress precipitously in these patients. Depending upon the level of obstruction, patients with missed injuries may present with dyspnea, stridor, or recurrent pneumonias. Imaging studies may reveal a significant amount of atelectatic lung.

For late injuries identified on bronchoscopy, an initial dilation is generally required to improve symptoms or allow drainage of infected secretions. However, this is unlikely to provide a lasting solution. Definitive treatment is surgical repair, which should be delayed until four to six months after the initial injury to allow the inflammatory reaction to subside and scar tissue to mature. It is important to ensure the patient is no longer requiring mechanical ventilation and is not likely to need additional major surgery in the near future for further management of injuries. Although consideration of concomitant lung resection must be made in case of chronically infected and bronchiectatic lung, the surgeon should not assume that healthy, chronically atelectatic lung cannot regain function. As in the acute TBI repair, it is important to buttress the repair when managing late stenosis, which often requires bronchial sleeve resection, with a pedicled tissue flap. Surgical repair in these instances has been shown to achieve excellent results and recovery of lung function [24]. (See 'Surgical repair' above.)

SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Penetrating neck injury" and "Society guideline links: Thoracic trauma".)

SUMMARY AND RECOMMENDATIONS

●Tracheobronchial injury – Tracheobronchial injury (TBI), which is injury that occurs between the cricoid cartilage and right and left mainstem tracheal bifurcation, is an uncommon but potentially life-threatening injury. (See 'Introduction' above and 'Incidence' above.)

●Mechanism of injury – TBI can be due to penetrating or blunt traumatic mechanisms or from iatrogenic injury. Traumatic TBI is more commonly related to penetrating mechanisms, which occur primarily in the cervical region. While most blunt injuries occur near the carina, direct forces to the neck can cause injury to the cricoid and thyroid cartilages. (See 'Mechanism and location of injury' above.)

●Associated injuries – Most traumatic TBIs occur in patients with multiple severe injuries. Coexisting injuries can include vocal cord injury, which is often bilateral; injury to the esophagus, which may be transected; pulmonary contusion; chest wall injury; spine/spinal cord injury; and fractures of the first rib, clavicle, or sternum. (See 'Evaluation and treatment of coexisting injuries' above.)

●Clinical features – TBI may be suspected based upon symptoms, associated injury, or findings on radiography (air in the tissues, elevated hyoid bone, pneumothorax with dependent lung, abnormal endotracheal tube position), but definitive diagnosis is made based upon seeing the injury during clinical examination on initial evaluation or during surgical exploration, or during bronchoscopy. It is important to remember that classic signs of TBI can be absent. The liberal use of bronchoscopy should help lower the incidence of missed injury and help define injury when present. (See 'Clinical features' above.)

●Diagnosis – The preferred method of airway management for most cases of TBI is endobronchial intubation over a flexible bronchoscope, which also aids in identification of the location and severity of the injury; however, more complex interventions to secure an airway may be needed, such as rigid bronchoscopy or a surgical airway (eg, direct intubation into transected airway through an open wound, tracheostomy through the injured area). (See 'Airway management' above.)

●Management – Once a secure airway is established, other life-threatening injuries can be treated, prior to definitive repair of TBI. Possible associated injuries should be evaluated since some of these may require simultaneous management; in particular, ENT surgery consultation is advised to determine the extent of injury to the larynx and, in particular, to assess the function of the vocal cords. (See 'Approach to management' above.)

•Repair of acute TBI is generally based on ongoing risk for airway obstruction, massive air leak, or mediastinitis. Prompt repair is generally preferred to avoid the development of airway stenosis in the future. (See 'Acute injuries' above.)

•A select group of patients may be appropriately managed nonoperatively, which is best described for iatrogenic laceration of the posterior tracheal wall following intubation or tracheostomy placement (nontrauma patients). Criteria to be considered for nonoperative management are listed above. For patients who will be managed nonoperatively, broad-spectrum antibiotics are given for one week and surveillance bronchoscopy is performed to monitor for development of granulation tissue and/or stenosis. (See 'Selective nonoperative management' above.)

•For late injuries identified on bronchoscopy, definitive surgical correction after initial dilation should be delayed four to six months after the initial injury to allow the inflammatory reaction to subside and scar tissue to mature. (See 'Missed injury' above.)

●Surgical repair – Most patients with TBI can undergo primary repair, although for some, lung resection may be required. Principles involved in operative repair of TBI include obtaining adequate exposure, conservative debridement to preserve adequate airway length for reconstruction, creating a tension-free anastomosis, preserving the laterally based tracheal blood supply, and possibly creating a tracheostomy, particularly in multiply injured patients. The approach to repair (transthoracic, transsternal) depends on the location of the injury. A tension-free anastomosis can generally be accomplished following resection of up to six tracheal rings. For concomitant esophageal injury, or anastomoses performed near the brachiocephalic artery, interposition of a muscle flap helps minimize complications. (See 'Surgical repair' above.)

●Mortality and complications – Tracheobronchial injuries are associated with high mortality at the time of injury as well as during subsequent treatment, in part due to difficulties in establishing a definitive airway and subsequent problems with oxygenation and ventilation. Patients with penetrating injuries tend to have better outcomes, possibly because of fewer associated injuries. Complications following repair of tracheal injuries can be serious and life-threatening. (See 'Complications' above.)