Chapter 12 Operative Exposure in Thoracic Trauma: Exposure of Injuries to the Trachea and Esophagus

This chapter will discuss the thoracic exposure of injuries of the trachea and esophagus. It should be noted that portions of the esophagus and trachea are best approached in the neck, and details of those exposures are discussed in chapter 8 of this manual.

Learning Objectives

By the end of the ASSET course, participants should be able to do the following:

1. Detail the physical findings associated with injuries to the thoracic esophagus and trachea.
2. Discuss the diagnostic options for injuries to the thoracic esophagus and trachea.
3. Demonstrate exposure of the thoracic trachea and esophagus.
4. Describe the incision(s) best suited to injuries of the distal trachea (carina).
5. Describe the incision(s) best suited for exposure of thoracic esophageal injuries.

General Considerations

• The majority of injuries of the intrathoracic trachea are due to penetrating trauma.
• Only 1–2 percent of patients with penetrating thoracic trauma will have significant tracheobronchial trauma.
• Blunt trauma involving the intrathoracic trachea and main stem bronchi is commonly associated with additional (and potentially life-threatening) major injuries.
• Distal tracheal injuries are much less common than cervical tracheal injuries due to the protection afforded by the chest wall.
• Despite the importance of identifying tracheoesophageal injuries, they are often diagnosed in a delayed fashion.
• Dyspnea, hemoptysis, and respiratory distress are the most frequent symptoms of tracheobronchial injury.
• Findings of deep cervical emphysema and pneumomediastinum are suggestive of tracheobronchial injury, and approximately 70 percent of affected patients will have a pneumothorax. A pneumothorax that persists or has excessive air leakage after placement of a chest tube should increase suspicion of an intrathoracic tracheal or bronchial injury.
• A high index of suspicion of injuries to the tracheobronchial structures will allow operative planning for exposure and repair of these uncommon but devastating injuries.
• In most cases, CT scan is the diagnostic modality of choice for stable patients.
• In a hemodynamically unstable patient, CT scan is contraindicated.
• A nondiagnostic CT does not obviate the need for bronchoscopy, esophagoscopy, contrast esophagogram, and/or laryngoscopy to identify the injury and its location.
• Consider timely subspecialist consultation (thoracic surgery and/or ENT).
• In patients with significant injury, surgical treatment should be undertaken as early as possible.

Injuries to the Trachea

Exposure of the Trachea

• The proximal half of the trachea can be reached by a low collar incision, and the cervical esophagus via a left neck incision, as described in chapter 8.
• The middle third of the trachea and the upper thoracic esophagus can be exposed with a collar (“T”) incision or a neck incision extended to a partial or complete sternotomy (Figures 1 and 2).
  • Dividing the subcutaneous tissues exposes the manubrium. The midline of the manubrium is then marked using electrocautery, and the upper sternum can be split (Figure 2) using a powered sternal saw or a Lebsche knife, taking care not to injure the underlying innominate vein.
  • Partial (upper) sternotomy allows for complete exposure of the middle third of the trachea (Figure 2). Completing the sternotomy adds little to tracheal exposure but may be indicated to fully evaluate the great vessels. Though most of the proximal (cervical) trachea can be accessed via a cervical incision, exposure of the middle third of the trachea will require more caudal exposure.
• The distal third of the trachea, the carina and right main-stem bronchus, the azygos vein, the superior vena cava, the right atrium, and most of the intrathoracic esophagus can be easily approached by a right thoracotomy; optimal exposure is obtained through a right posterolateral thoracotomy, which may not be practical in acute trauma.
  • Upon entering the pleural cavity, the trachea can be identified in the posterior mediastinum.
  • It is helpful to have a double-lumen endotracheal tube or a bronchial blocker if the patient is stable. In an unstable patient, the orotracheal tube can be advanced into the left main-stem bronchus (with or without bronchoscopic guidance) to allow deflation of the right lung.
  • The upper-posterior mediastinal pleura is incised between the esophagus (posteriorly) and the trachea (anteriorly). Placing an NG tube may make the esophagus easier to identify.
  • In many cases, the azygos vein will need to be divided to completely expose the most distal trachea, carina, and bilateral main- stem bronchi.
• Left thoracotomy provides exposure to the left main-stem bronchus, the distal part of aortic arch, the descending thoracic aorta, the proximal left subclavian artery, and the distal esophagus.
  • It is hard to reach the proximal left main- stem bronchus, carina, distal trachea, or right main-stem bronchus through a left thoracotomy due to the overlying aortic arch.
• It is important to be flexible and extend or make additional incisions to gain necessary exposure.
• Alternatively, a “clamshell” incision can be utilized to visualize the upper thoracic portion of the trachea, as well as the first portion of the esophagus in the chest (Figures 3 and 4). Division of the innominate vein will assist in the exposure.

Technical Considerations

• Preserve tracheal length at all costs, and minimize dissection to avoid devascularization.
• Simple, clean lacerations can be repaired with interrupted absorbable suture.
• Routine tracheostomy is not necessary in most patients and may complicate healing of the repair.
• In cases with serious tracheobronchial damage, all devitalized tissue should be debrided, taking care to preserve as much viable airway as possible. Circumferential resection and end-to- end anastomosis is preferable to partial wedge resection, except in the carina.
  • Injuries to the carina should be repaired primarily if at all possible, as resection and reconstruction are difficult. If complex repair is required, involvement of thoracic surgery and/or ENT is warranted.
  • Only 3–4 cm of the airway, including the carina, can be safely resected and still enable reconstruction. There are a variety of tracheobronchial releasing maneuvers described to enable a tension-free repair, but these are best relegated to specialist care.
  • If resection and primary anastomosis is required, the neck should be maintained in flexion postoperatively.
  • The posterior membranous portions of the trachea should be reconstructed with pleural or pericardial flaps.

Pearls and Pitfalls

• Concomitant esophageal repairs should be separated from tracheal repairs via the placement of a vascularized muscle pedicle between the two repairs.
  • In the neck, the sternal head of the sternocleidomastoid is preferred. In the thorax, a vascular intercostal flap is generally the best option.
• Stenosis occurs in approximately 5 percent of cases and may be managed with dilation and stenting but generally requires airway resection and reconstruction in three to six months.
• Other potential complications include tracheoinnominate and tracheoesophageal fistulae.

Injuries to the Esophagus

General Principles

• Injuries to the esophagus can occur from a variety of mechanisms, including penetrating, blunt, iatrogenic, or ingestion (e.g., of a sharp object or caustic substance).
• Symptoms of esophageal injury are highly variable and can range from relatively minor (dysphagia, pain, tachycardia, fever) to severe sepsis, mediastinal abscess, empyema, and death.
• These injuries may be difficult to diagnose, and multiple diagnostic modalities may be required.
  • Chest radiographs may show mediastinal air or pleural fluid.
  • Chest CT with oral contrast may demonstrate extravasation, pleural fluid, or mediastinal air.
  • Contrast study of the esophagus should be done if the CT is suspicious but not conclusive. (Remember, Gastrografin has a high false-positive rate and is much more toxic to the lungs if aspirated; barium, while more sensitive, creates intense local reaction with extravasation).
• Esophagoscopy may show an injury but has a significant incidence of false-negative results.
• Surgical procedures to repair the esophagus range from simple closure to total resection with later reconstruction.

Exposure of the Esophagus

• The upper thoracic esophagus is classically exposed via a right fourth interspace posterolateral incision.
• The lower thoracic esophagus is classically exposed via a left fifth or sixth interspace posterolateral thoracotomy.
• In an unstable patient, posterolateral positioning may be contraindicated, and a “clamshell” incision may be more useful.
• Placing a double-lumen endotracheal tube or a bronchial blocker aids in exposure of the esophagus. If the operation is more urgent, the endotracheal tube may be advanced into the main-stem bronchus.
• The posterior mediastinal pleura is incised directly over the esophagus. Placement of a nasogastric tube or bougie will help with identification of the esophagus.
• The most distal portion of the esophagus can be visualized from either the left chest (Figure 5) or the abdomen.

Pearls and Pitfalls

• Most injuries can be repaired primarily with a two-layer (mucosa and muscle) closure. Care should be taken to identify the true extent of the mucosal injury, which may require extending the injury to the muscular layer of the esophagus.
• Through-and-through esophageal injuries should be ruled out.
• All repairs should be buttressed with local tissue, ideally a muscle flap. Pericardial or pleural flaps have also been described but are often less robust.
• Patients with delayed diagnosis or extensive contamination occasionally require more complex techniques, including diversion with a cervical esophagostomy, wide drainage, or exclusion. In these cases, involvement of a thoracic surgeon may be warranted. A T-tube placed in the injury, as well as multiple chest tubes, will allow for the formation of a contained fistula. Distal feeding access should be established.
• Outcomes are best with early diagnosis. Any concern for esophageal injury should prompt immediate and thorough workup.
• Diversion or drainage should be limited to cases where there is widespread contamination and/ or a significant delay in diagnosis.
• Cervical esophagostomy is rarely indicated.
• An isolated esophageal injury is rarely immediately life-threatening. This allows time to plan the appropriate procedure with appropriate expertise.
• Covered stent placement combined with pleural drainage is an evolving modality that may be considered.