Injuries to the chest are common following both blunt and penetrating trauma. Blunt thoracic injuries are responsible for approximately 8% of all trauma admissions in the United States, with motor vehicle crashes being the most common mechanism.^1,2,3 In one report, penetrating chest trauma accounted for 7% of all trauma admissions and 16% of penetrating trauma admissions overall.⁴

Despite the prevalence of thoracic injury following trauma, the majority of patients can be successfully managed nonoperatively. Between 18% and 40% of patients sustaining thoracic trauma can be treated with tube thoracostomy alone, and thoracotomy will be required for between 3% and 9% of patients. Even among those with penetrating chest trauma, only 14% of stab wounds and between 15% and 20% of gunshot wounds require thoracotomy.⁴

Operative mortality varies between 5% and 45%; approximately 30% of patients undergoing thoracotomy requiring a pulmonary resection.³ This wide variability is related to differences in mechanism of injury, inclusion of cardiac and major thoracic vascular injury in some of the datasets, the extent of pulmonary resection performed, and concomitant extrathoracic injuries.^3,5,6,7

Technological and imaging advances, particularly the expanded role of CT scanning, have allowed clinicians to characterize thoracic injury rapidly and accurately. Some injuries are minor, such as small pneumothoraces, which require no treatment. However, major injuries require rapid and definitive care. In an era of nonoperative management for many injuries, clinicians caring for trauma patients must appreciate the indications for operation and understand the treatment options in the emergency department as well as in the operating room. Sophisticated judgment is essential when evaluating the patient with multiple and often competing injuries.

While physiologically complicated, the lungs are anatomically simple, consisting primarily of alveoli and blood vessels. The paired large pulmonary artery and vein are high volume, low pressure circuits. The bronchial vascular bed is characterized by a higher systemic pressure but relatively small caliber vessels. Injury to the protective bony thorax serves as a marker for pulmonary injury following blunt trauma in adults. In contrast, the greater chest wall elasticity in children may result in significant pulmonary injury without associated thoracic wall injury.

The anatomic simplicity of the lungs suggests a limited parenchymal response to trauma regardless of the severity and mechanism of injury. The alveoli can rupture, causing a pneumothorax. Larger injuries can result in a continued air leak. The lung parenchyma can bleed causing a hemothorax or the architecture can be disrupted as with a pulmonary contusion. The chest wall, especially the intercostal and mammary arteries, may bleed when injured, as there is limited tissue to provide tamponade. Any of these injuries can range from relatively trivial to life-threatening.

Very large pneumothoraces produce tension by shifting the mediastinal structures toward the contralateral side with resulting anatomic distortion. Increased intrathoracic pressure causes decreased venous return, decreased cardiac output and, if untreated, cardiac arrest. In contrast, large hemothoraces generally produce symptoms through the effects of hypovolemia, although a massive hemothorax may also produce tension physiology.

Presentation and Evaluation

Any patient with blunt or penetrating chest trauma is at risk for lung injury. The mechanism of injury, time from injury, vital signs, and neurologic status at the scene and any changes during transport are critical components of an adequate history.

Physical examination alone may confirm the diagnosis of intrathoracic injury. The presence of distended neck veins, tracheal deviation, subcutaneous emphysema, chest wall instability, absent breath sounds, or muffled heart sounds may provide crucial information. Vital signs should be frequently monitored with careful attention to the work of breathing and arterial saturation. Hypoxia and increased work of breathing may be manifested by anxiety, confusion, combative behavior, dyspnea, or the use of accessory muscles. Any of these findings should prompt rapid evaluation for serious thoracic injury. Findings of subcutaneous air or decreased breath sounds should alert the clinician to the possibility of pneumothorax and/or hemothorax. Prompt placement of a tube thoracostomy in an unstable patient is wise, as radiographic confirmation may delay treatment.

Penetrating thoracic trauma in a hemodynamically unstable patient is virtually always an indication for operative exploration. Conversely, hemodynamically stable patients with penetrating thoracic injury may benefit from additional imaging, especially chest computed tomography. This modality provides high resolution, detailed and organ-specific information, including the vascular anatomy.^8,9,10

Following blunt trauma, stable patients require a rapid, yet thorough, evaluation for associated injuries. An arterial blood gas is essential and should be sent with the initial laboratory studies. It will yield critical information about oxygenation, ventilation, the presence and depth of shock. An electrocardiogram should be obtained, and a focused abdominal sonography for trauma (FAST), including the precordium, should be performed. A portable chest radiograph (CXR) is routinely obtained (Fig. 25-1) to examine for pneumothorax or hemothorax, although some authors question the utility of this study in stable patients with a normal chest examination.¹⁵ FAST may be as sensitive as CXR for diagnosing a pneumothorax.¹¹ CT scan is extremely useful in the multiply injured patient to evaluate for additional cavitary injuries. If indicated, thoracic ultrasound, esophagoscopy, bronchoscopy and, echocardiography should be obtained.

The modern, widespread utilization of CT imaging, with three-dimensional reconstruction, provides a more precise evaluation of the aorta and great vessels.^8,10 Pneumothoraces or hemothoraces not visualized on chest x-ray are often seen on CT. If they are small and patients are asymptomatic, observation is typically all that is required. For those patients undergoing operation for an associated injury, or intubation for positive pressure ventilation, the chances that these small pneumothoraces will become clinically significant is relatively low.¹²

In general, large pneumothoraces seen on CT, but not detected on CXR, are most often anterior. Treatment is tube thoracostomy. While it is possible that these can be treated without drainage, our experience has been that these patients may become symptomatic and we prefer to treat preemptively.

In general, hemothoraces are treated similarly to pneumothoraces. If they are small, observation is generally successful, monitoring with serial chest x-rays to document resolution. However, any moderate or large hemothorax should be drained with a tube thoracostomy. Blood left within the pleural cavity will clot and will not be evacuated with a chest tube. A retained hemothorax may progress to fibrothorax with lung entrapment or become infected resulting in an empyema.

Patients with significant lung lacerations will often have large air leaks or, less commonly, hemoptysis. Bronchoscopy is the modality of choice to diagnose a tracheobronchial injury. Blood and secretions must be suctioned clear, allowing unimpaired visualization of the entire airway. Large air leaks resulting in respiratory compromise generally require thoracotomy. While rare, significant hemoptysis can result in profound respiratory compromise, and bronchoscopy may localize the bleeding lobe or segment. Control of airway is essential; options include a double lumen endotracheal tube, selective mainstem intubation, bronchial blocker, lateral decubitus position, catheter-based therapy and surgery.

If the patient is stable, CT scanning can also be quite helpful in patients with hemoptysis (Fig. 25-2). CT scanning with intravenous contrast will define the pulmonary anatomy and may localize the site of parenchymal hemorrhage. The pulmonary vascular tree is a low-pressure system and radiographic vascular injuries do not carry the same prognosis as do arterial vascular injuries identified within solid viscera in the abdomen. If symptomatic, operative exploration is the preferred strategy. In a selective group of patients, including those who are a poor operative risk, transcatheter embolization offers an alternative to thoracotomy.

The majority of patients with a lung injury can be managed nonoperatively. Simple tube thoracostomy evacuates accumulated air and blood, allowing complete lung re-expansion with apposition to the chest wall. A number of patients, however, will require thoracotomy for pulmonary and/or chest wall injury. Intercostal or internal mammary artery hemorrhage following penetrating or blunt trauma can continue even after evacuation of the associated hemothorax. Additional bleeding sources that may require intervention include chest wall musculature and lung lacerations.

Rib fractures are the most common thoracic injury following blunt trauma and may be associated with an underlying pulmonary contusion. Treatment is supportive, the goal being prevention of the known sequelae. Pain with respiration and splinting can lead to atelectasis, hypoventilation, inability to clear secretion and pneumonia. The presence of a pulmonary contusion can exacerbate hypoxia and shunting. While upright positioning, incentive spirometry and analgesia are all important, the latter is essential. Multiple treatment options are available to achieve adequate analgesia. Some reports have demonstrated the superiority of an epidural analgesia, while others have shown similar efficacy among the various modalities.¹³ While it is well known that morbidity is increased among the elderly with rib fractures, it is important to note that morbidity is also higher in those older the 45 with multiple rib fractures.¹⁴

A flail chest occurs when three or more adjacent ribs are segmentally fractured leading to paradoxical chest wall motion. These patients often require mechanical ventilation, especially when there is an associated pulmonary contusion.¹⁵ In a recent review of flail chest injuries, over half the patients had a pulmonary contusion, and the same percentage required mechanical ventilation. Infections complications were common; mortality was 16% and related to concomitant head injury.¹⁶ With the advances in technology, materials, and operative techniques, rib stabilization has been performed with increasing frequency. The precise indications and patient population to benefit from the procedure are still not fully defined.¹⁷

Pulmonary contusions are common and range from clinically silent to causing severe respiratory distress. Although they can occur with any chest injury they are highly associated with rib fractures, especially flail chest. The clinical symptoms include respiratory distress, increase work of breathing, hypoxia and, less commonly hypercarbia. One of the hallmarks is that clinical symptoms and radiographic findings increase over time, generally over 3 days, and resolve in 1 week. Supportive treatment is typically all that is necessary including judicious volume administration, pulmonary toilet and supplemental oxygen. Mechanical ventilation is indicated for respiratory failure refractory to less invasive therapies.¹⁸

Indications for Operation

Massive hemothorax, defined as 1500 cc or more of blood in the pleural cavity or persistent chest tube output of 200 to 250 cc per hour for 3 consecutive hours, is generally considered an indication for thoracotomy. Thoracic trauma resulting in persistent hemodynamic instability, without another obvious source, should prompt emergent thoracic exploration. Delaying emergent thoracic exploration may result in increases in morbidity and/or mortality.¹⁹

Care must be exercised when evaluating chest tube output. While a dramatic decrease in output may signify a cessation of intrathoracic bleeding, it may be the result of clotted chest drains. There may be ongoing hemorrhage but the lack of chest tube output may give the clinician a false sense of security. Chest tubes may become clotted and, if poorly positioned, may not completely evacuate blood or air. An increasing hemothorax will be seen on subsequent CXR or chest CT. While a second chest tube may be helpful, patients with a large retained hemothorax should generally be explored and drained. A thoracoscopic approach is often successful, particularly if performed early within the first few days following injury, before the clot becomes organized, and loculations and adhesions form. We do not utilize video-assisted thoracoscopic surgery (VATS) for emergent exploration but perform a thoracotomy or sternotomy as indicated.

Delayed operative intervention may be indicated for a variety of traumatic complications, including retained hemothorax, persistent air leak, missed injury, and empyema. Early evacuation of retained hemothorax prevents the clot from becoming fibrotic and trapping the lung, and decreases the chance of empyema. Post-traumatic empyema is almost always best treated with operation. Many of these other non-emergent procedures can be performed using noninvasive methods, such as video-assisted thoracic surgery (VATS).^20,21

Surgical Exposure

There are a number of operative approaches to the thorax, each with advantages and disadvantages. Unlike an elective thoracotomy, in which the posterolateral approach is most commonly used, several important factors influence the choice of the incision for a traumatic injury. Foremost is whether the operation is performed for exploration, as for a patient in hemorrhagic shock, or alternately to repair a specific, defined injury, such as a tracheobronchial disruption. Regardless of the operative indication or approach, the incision must provide excellent exposure and versatility. The overall clinical condition, hemodynamic instability, results of the imaging studies and presence of concomitant injuries will influence the operative approach.

As a general rule, a median sternotomy or anterolateral thoracotomy, which can be extended as a clamshell, are the preferred incisions for exploring the hemodynamically unstable patient. Both of these incisions afford exceptional exposure to all but the posterior structures. Additionally, they can be extended for a laparotomy. Hemodynamically unstable patients may not tolerate the lateral position without further hemodynamic or respiratory compromise.

Commonly employed operative approaches include anterolateral, posterolateral, bilateral anterior thoracotomies (“clamshell”), and median sternotomy. The anterolateral approach is rapid and can be easily extended across the midline as a clamshell thoracotomy. This affords excellent exposure to both pleural spaces and the anterior mediastinum. Likewise, an anterolateral thoracotomy can be continued as a laparotomy for abdominal exploration, and is the preferred approach in the patient in shock. The main disadvantage of the anterolateral approach is the inability to provide adequate exposure of posterior structures. By extending the ipsilateral arm and placing a bump to elevate the thorax approximately 20°, the incision can be carried to the axilla improving posterior exposure (Fig. 25-3).

The posterolateral thoracotomy affords optimal exposure of the hemithorax, especially the posterior structures, and is the standard incision for most elective operations. Its lack of versatility limits the usefulness in unstable trauma, but is the preferred approach to repair intrathoracic tracheal and esophageal injuries.

Median sternotomy provides excellent access to the heart, great vessels, and anterior mediastinum. It is versatile and can be extended as an abdominal, periclavicular, or neck incision (Fig. 25-4). Widely incising the pleura provides access to either hemithorax, however, exposure of the posterior structure is quite limited. The “trapdoor” incision is rarely used since left-sided thoracic vessels can be approached via sternotomy with extension.^10,22

Operative Techniques

A double-lumen endotracheal tube dramatically improves operative exposure, and while it is widely used in elective thoracic operations, it is rarely used in trauma, especially for emergency thoracotomies. Lung isolation should be avoided in hemodynamically comprised patients. Single lung ventilation may not be tolerated and the time spent ensuring proper tube placement is not warranted in an emergency. One exception is massive hemoptysis where lung isolation may indeed be lifesaving. In the hemodynamically stable patient placing a double-lumen tube should be considered as it improves exposure and facilitates pulmonary resection. If a single lumen tube is used, intermittently holding ventilation is advantageous during pulmonary repair or resection.

However, if the patient’s respiratory status is tenuous, any extended interruption of ventilation and oxygenation may precipitate decompensation. In this case, manual compression of the adjacent lung tissue may provide sufficient exposure to facilitate operative repair or resection.

Upon entering the chest, blood and clot should be evacuated allowing a thorough examination and exploration of the hemithorax. The lung is mobilized by incising the inferior pulmonary ligament and lysing any adhesions. Exsanguinating hemorrhage demands immediate attention and initial control is achieved with digital pressure. This allows time for ongoing volume resuscitation and an improved assessment of the injury. Hilar bleeding is a particularly significant challenge. The low pressure pulmonary artery bleeds more like a major systemic vein than an artery. There are a several techniques for hilar compression including finger occlusion, and placing a Penrose drain around the hilum twice; tightening the drain will provide temporary vascular control. More definitive and secure control is achieved by placing a hilar vascular clamp. Finally, the lung can be twisted on itself at the level of the hilum. This latter maneuver occludes the pulmonary artery and vein, as well as the main stem bronchus. The hilar twist or clamping the hilar vessels may result in further decompensation in hemodynamically compromised patients. The rapid increase in pulmonary artery pressure can cause acute right heart dysfunction or failure, with catastrophic consequences.

There are a number of techniques for lung repair. The decision regarding the technique chosen will be influenced by the type and severity of the parenchymal injury, concomitant injuries and the patient’s physiologic status. Pneumonorrhaphy is the simplest technique and is generally used to treat superficial pulmonary lacerations. The laceration is closed with either a running simple or mattress suture. More extensive injuries require resection including simple wedge resection, tractotomy, nonanatomic and formal anatomic resections. Peripheral lacerations not amenable to simple repair can be treated by wedge resection using any of the commercially available staplers. It is crucial to determine the location of major pulmonary artery branches prior to firing the stapler. This is generally not a concern when resecting peripherally located injuries but is vitally important with more central lesions.

More significant lung injuries, particularly those from gunshot wounds, are often best treated with tractotomy^23,24,25 (Fig. 25-5). This is performed by placing the jaws of the stapler through the injury tract and firing it, similar to the technique used to expose and repair liver injuries. The resulting opening exposes the bleeding vessels and injured airways for individual ligation. The staple line can be oversewn with a running suture to achieve adequate hemostasis and an air tight seal. In general, peripheral injuries are treated with tractotomy but this method is not utilized for long central missile tracts.

Significant lobar injuries not amenable to tractotomy can be treated by nonanatomic resection or formal lobectomy. For the latter, the arterial and venous lobar branches must be dissected and either ligated or stapled. Similarly, the lobar bronchus is identified and generally divided using a stapler. Prior to firing the stapler, and with the bronchus occluded by the stapling device, the lung is inflated. The lobe to be resected will not inflate, ensuring the appropriate bronchus is transected.

Hilar injuries pose special challenges as hemorrhagic shock is almost always present and the anatomic challenges are significant. In very proximal hilar injuries, inflow occlusion is virtually always necessary in order to assess the extent of injury. Opening the pericardium and controlling the intra-pericardial pulmonary artery and vein is a useful maneuver. Hilar injuries are rarely amenable to direct repair and may require pneumonectomy. Unfortunately, mortality after pneumonectomy for patients in shock approaches 100%, with patients dying from either uncontrolled hemorrhage or acute right heart failure.^26,27 If pneumonectomy is considered, it should be performed early, and rapid treatment of right heart dysfunction and support with extracorporeal membrane oxygenation may improve survival in these devastating injuries.²⁸