Penetrating Chest Trauma 

Updated: Nov 20, 2019
Author: Rohit Shahani, MD, MS, MCh; Chief Editor: Jeffrey C Milliken, MD 

Overview

Practice Essentials

Thoracic injuries account for 20-25% of deaths due to trauma and contribute to 25-50% of the remaining deaths. Approximately 16,000 deaths per year in the United States alone are attributable to chest trauma.[1]  Therefore, thoracic injuries are a contributing factor in as many as 75% of all trauma-related deaths. Any organ within the chest is potentially susceptible to penetrating trauma, and each should be considered in the evaluation of a patient with thoracic injury.

The increased prevalence of penetrating chest injury (associated with the "drug war" in the United States) and improved prehospital and perioperative care have resulted in an increasing number of critically injured but potentially salvageable patients presenting to trauma centers.[2] The classic "trimodal" temporal distribution of trauma deaths has been questioned, even though it has been widely taught in the design of trauma systems.[3]

Current management of penetrating chest trauma (PCT) is a hurried, brute-force approach necessitated by the life-threatening nature of many of these injuries. As surgical experience with less invasive techniques and minimal incision approaches increases, these methods will likely find their appropriate places in the treatment of these patients. At present, however, traditional approaches and techniques predominate in the treatment of critically injured and frequently unstable patients.

One of the earliest written descriptions of thoracic injury was in the Edwin Smith Surgical Papyrus (~3000 BCE). Galen reported attempts to treat gladiators with chest injuries with open packing. In 1635, Cabeza de Vaca first described operative removal of an arrowhead from the chest wall of a Native American. In 1814, Larrey (Napoleon's military surgeon) reported various injuries to the subclavian vessels. Rehn performed the first successful human cardiorrhaphy in Germany in 1896. Hill performed the first cardiorrhaphy in the United States in 1902 and initiated the modern treatment of the wounded heart.

Penetrating trauma to the thoracic vessels was not extensively reported until the 20th century because of the absence of survivors. In 1934, Alfred Blalock was the first American surgeon to successfully repair an aortic injury. Guidelines for treating thoracic trauma were not established until World War II.

Additional experience in the treatment of penetrating trauma to the thorax was gained in later military experiences, including the conflicts in Korea and Vietnam, and, to a lesser degree, US actions in Grenada, Panama, the Balkans, Somalia, and the Persian Gulf. Other large international experiences have derived from the Falkland Island conflict, various Middle Eastern engagements, and multiple conflicts in the African states.

Significant experience has also been gained from large US metropolitan areas as a result of assaults involving firearms and handheld weapons and impalements resulting from falls or leaps from elevations. Researchers from Houston, Los Angeles, Atlanta, Detroit, and Denver, have been particularly productive in their treatments of thoracic penetrating trauma. The number of trauma patients in these large metropolitan areas rose so rapidly in the 1970s and 1980s that the military sent its medical personnel to train caregivers at these centers.[4, 5]

With advances in wartime medical care and access to the Joint Theater Trauma Registry (JTTR), thoracic injury patterns have changed dramatically. As a result of improvements in body armor and the establishment of excellent medical care at the battlefield, mortal thoracic wounds seem to have decreased, allowing many patients who previously would have died to live long enough to receive treatment.[6]

For more information, see the Trauma Resource Center. For patient education resources, see the Procedures Center and Skin, Hair, and Nails Center, as well as Bronchoscopy and Puncture Wound.

Anatomy

The anatomy of the thoracic cage is well known and encompasses the area beneath the clavicles and superior to the diaphragm, bound laterally by the rib cage, anteriorly by the sternum and ribs, and posteriorly by the rib and vertebral bodies. The thorax may be entered via three main approaches, as follows:

  • Sternotomy
  • Thoracotomy (incising between selected ribs, most commonly the fourth and fifth) on either the right or left side
  • Clamshell incision, consisting of left and right thoracotomy incisions traversing the sternum to join the two

Additional modifications of each of these approaches exist but are not discussed in detail here.

Particular care must be exercised laterally near the sternum, where the internal thoracic (mammary) artery lies 2-4 cm on either side. Similarly, it must be remembered that immediately inferior to each rib body are the intercostal artery, vein, and nerve, from which voluminous bleeding can occur. Patients have required reexploration for injuries to these various vessels and have exsanguinated as a result of missed injuries to these structures.

Anteriorly, injuries to the heart should be presumed to have occurred if entry points are present anywhere between the two midclavicular lines. On occasion, significant injury to the heart has occurred from entry points lateral to these margins, as in gunshot or missile injuries.

Exceptionally long penetrating instruments and weapons (eg, arrows, swords, or lances) can also directly penetrate the heart from a distant entry point. Similarly, injuries to any of the intrathoracic structures can be effected with long penetrating devices; accordingly, the possibility of injuries to the diaphragm, great vessels, or posterior mediastinal structures must be considered in these cases.

The right atrium and right ventricle are the anterior portions of the heart; these areas are the primary sites involved in penetrating injuries of the heart.

Pathophysiology

As noted by Inci et al in a 1998 study of 755 patients with thoracic injuries, PCT comprises a broad spectrum of injuries and severity.[7] The injuries and the number of patients (some with more than one injury) in this study were as follows:

  • Hemothorax - 190
  • Hemopneumothorax - 184
  • Pneumothorax - 144
  • Open hemopneumothorax - 95
  • Pulmonary contusion - 50
  • Open pneumothorax - 24
  • Rib fracture - Fewer than 2 fractures, 16; more than 2 fractures, 13
  • Subcutaneous emphysema - 14
  • Bilateral pneumothorax - 9
  • Open bilateral hemopneumothorax - 13
  • Pneumomediastinum - 6
  • Thoracic wall lacerations - 4
  • Bilateral hemopneumothorax - 3
  • Open bilateral pneumothorax - 3
  • Sternal fracture - 3
  • Bilateral diaphragmatic rupture - 2

The clinical consequences depend on the mechanism of the injury, the location of the injury, associated injuries, and underlying illnesses. Organs at risk, in addition to the intrathoracic contents, include the intraperitoneal viscera, the retroperitoneal space, and the neck.

Etiology

Mechanism of injury

The mechanism of injury may be categorized as low-, medium-, or high-velocity, as follows:

  • Low-velocity injuries include impalement (eg, knife wounds), which disrupts only the structures penetrated
  • Medium-velocity injuries include bullet wounds from most types of handguns and air-powered pellet guns and are characterized by much less primary tissue destruction than wounds caused by high-velocity forces
  • High-velocity injuries include bullet wounds caused by rifles and wounds resulting from military weapons

Shotgun injuries, despite being caused by medium-velocity projectiles, are sometimes included within management discussions for high-velocity projectile injuries. This inclusion is reasonable because of the kinetic energy transmitted to the surrounding tissue and subsequent cavitation, as described by the following equation:

  • KE = ½mv 2

where KE is kinetic energy, m is mass, and v is velocity.

Ballistics may be divided into three major categories, as follows:

  • Internal ballistics describes the characteristics of the projectile within the gun barrel
  • External ballistics examines the factors that affect the projectile during its path to the target, including wind resistance and gravity
  • Terminal ballistics evaluates the projectile as it strikes its target

The amount of tissue damage is directly related to the amount of energy exchange between the penetrating object and the body part. The density of the tissue involved and the frontal area of the penetrating object are the important factors determining the rate of energy loss.

The energy exchange produces a permanent cavity inside the tissue. Part of this cavity is a result of the crushing of the tissue as the projectile passes through. The expansion of the tissue particles away from the pathway of the bullet creates a temporary cavity. Because this cavity is temporary, one must realize that it was once present in order to understand the full extent of injury.

Penetrations from blast fragments or from fragmentation weapons can be particularly destructive because of their extremely high velocities. Weapons designed specifically for antipersonnel effects (eg, mines and grenades) can generate fragments with initial velocities of 4500 ft/s, a far greater speed than even most rifle bullets. The tremendous energy imparted to tissue from fragments with such velocity causes extensive disruptive and thermal tissue damage.

Weaponry of the 21st century consists mostly of improvised explosive devices (IEDs). These devices are homemade bombs, and they create a deadly triad of penetrating, blast, and burn wounds. Of the thoracic trauma that is seen in the current Global War on Terror, 40% is penetrating chest trauma.

Prognosis

The outcomes of treating patients with PCT are directly related to the extent of their injuries and the timeliness with which treatment is initiated. Patients arriving in a stable condition may expect full recovery, but those presenting with lesser levels of stability have diminishing probabilities of survival. No attempt should be made to resuscitate, let alone definitively treat, patients presenting with no vital signs or with obviously nonsurvivable injuries (eg, massive cardiac destruction).

Guidelines for initiation of emergency department (ED) thoracotomy (EDT) were published in 2014 by the American College of Surgeons (ACS), the American College of Emergency Physicians (ACEP), the National Association of EMS Physicians (NAEMSP), and the American Academy of Pediatrics (AAP)[8] ; the Eastern Association for the Surgery of Trauma (EAST) published its own guideline in 2015 (see Guidelines).[9]

In a 2010 report from a single center that included 158 patients who underwent thoracotomy within 24 hours after PCT, those patients who died had a significantly lower systolic blood pressure (42 ± 36 mm Hg) than those who survived (83 ± 27 mm Hg).[10]

 

Presentation

History and Physical Examination

Admission history and physical examination are usually brief and are oriented to the injury. Evaluations of vital signs, consciousness, airway competency, vascular integrity, and pump (cardiac) function are rapidly performed before devoting attention to the point of injury. If the patient is stable and no significant injury is found that requires immediate surgery, a full diagnostic evaluation can be performed (see Workup).

Any entry wound below the nipples (front) and the inferior scapular angles (dorsum) should be considered an entry point for a course that may have carried the missile into the abdominal cavity.

Missiles from gunshot wounds (GSWs) can penetrate all body regions regardless of the point of entry. Any patient with a gunshot entry wound for which a corresponding exit wound cannot be identified should be considered to have a retained projectile, which could embolize to the central or distal vasculature.

A patient with combined intrathoracic and intra-abdominal wounds has a markedly greater chance of dying.

For information on treating penetrating abdominal wounds, see Abdominal Stab Wound Exploration.

 

Workup

Laboratory Studies

Laboratory examinations are rarely required in the acute treatment of patients with penetrating chest trauma (PCT).

Hemoglobin or hematocrit values and arterial blood gas determinations offer the most useful information for treating these patients; however, tests may be temporarily delayed until patients are stabilized. Blood chemistry results, serum electrolyte values, and white blood cell (WBC) and platelet counts add little information for initial treatment but can establish a baseline by which to follow the course of the patient through his or her therapy.

Underlying medical conditions (eg, diabetes, chronic renal insufficiency), either known or discovered via the laboratory examinations, should be noted and treated when appropriate.

Imaging Studies

With improvements in modern imaging, a number of different diagnostic modalities have become available to aid in precisely defining the extent of trauma. Various groups have championed their own protocols as preeminent. In reality, any number of acceptable algorithms can help in the treatment of a patient with PCT.

As noted, the history and physical examination are usually brief and oriented to the injury. If the patient is stable and no significant injury is found that necessitates immediate surgery, a full diagnostic evaluation can be performed.

Chest radiography remains the basis for initiating other investigations.

Computed tomography (CT) is rapidly evolving into a primary diagnostic tool because of its ability to image various intrathoracic structures and to differentiate substances of different densities (eg, solid vs air-containing fluid collections). The advent of multidetector CT (MDCT) in clinical practice has dramatically increased the speed of data acquisition and image reconstruction, and many reports emphasizing this change in imaging approach have been published.[11]

Delayed radiographs have been the standard of care for stable patients with PCT. Initial chest CT obviates the need for repeat chest radiography after PCT.[12]

Aortography, once considered the criterion standard for determining vascular injuries, has gradually fallen out of favor and been largely supplanted by faster, less invasive, and better-tolerated imaging techniques. The revival of aortography with endovascular intervention for trauma to the thoracic aorta or branches of the aortic arch (innominate, carotid, and subclavian arteries) is largely a product of modern technology. Endovascular stent graft arterial repair has altered the approach to vascular trauma.[13]

Penetrating injuries traversing the mediastinum or in proximity to posterior mediastinal structures dictate esophageal and tracheal evaluation, preferably via direct visualization (eg, esophagoscopy or bronchoscopy).

Specialized windows for ultrasonography (US) have been developed to allow imaging of some intrathoracic structures despite the presence of lung air. With the focused sssessment with sonography for trauma (FAST) protocols, evaluation of the thorax and the abdomen can be completed within minutes.

Readily available in most centers, echocardiography has developed to the point where it is indispensable in helping evaluate injuries to the heart and the ascending and descending aortas. Studies have demonstrated that echocardiography can also be used to detect hemothoraces and pneumothoraces with accuracy.[14]

In appropriate settings, close observation (without thoracotomy) may be considered. However, the limitations of each of the above-noted diagnostic modalities must be remembered, and these modalities must not be extended beyond their functional limits, especially if patient safety is compromised.

Other Tests

Because most trauma patients are young, extensive cardiac evaluations are often unnecessary. Admission electrocardiography (ECG) can be deferred until the patient is stable, unless cardiac injury is considered likely. Frequently, however, immediacy of resuscitation and definitive treatment preclude obtaining ECGs. In elderly patients, ECG evidence of prior myocardial infarctions may assist in the management of dysrhythmias or potential cardiac failure.

 

Treatment

Approach Considerations

Any organ within the chest is potentially susceptible to penetrating trauma, and each should be considered in the evaluation of a patient with thoracic injury.[15] These organs include the following:

  • Chest wall
  • Lung and pleura
  • Tracheobronchial system, including the esophagus, diaphragm, thoracic blood vessels, and thoracic duct
  • Heart and mediastinal structures

There has been an incremental increase in the utilization of cardiothoracic surgeons for operative intervention in thoracic trauma; although relatively little data are available, this does appear to have resulted in improved patient outcomes.[16]

Current management of penetrating chest trauma (PCT) is a hurried, brute-force approach necessitated by the life-threatening nature of many of these injuries. As surgical experience with less invasive techniques and minimal incision approaches increases, these methods will likely find their appropriate places in the treatment of these patients.

Already, interventional radiologic techniques can safely treat many patients with intrathoracic vascular injuries and have been successfully used to retrieve intracardiac missiles. Traumatically disrupted aortae have been treated with stenting; in stable patients with penetrating injuries to the thoracic vessels, use of this modality should be considered. Currently, however, traditional approaches and techniques have little competition in the treatment of critically injured and frequently unstable patients.

The mechanism of thoracic injury in modern battles is shifting, with a lower frequency of penetrating injuries and a higher frequency of combination blast injuries. The mortality of those injured has increased (12% vs 3% in Vietnam) and may represent the devastation caused by improvised explosive devices (IEDs) and the subsequent multisystem injuries they cause. Whereas the overall killed-in-action rate has decreased, the died-of-wounds rate has increased. Half of all thoracic injuries reported from the battle front on the Global War on Terror occurred in the civilian population.[6]

Initial Management

As always in trauma, management begins with establishing the ABCs (airway, breathing, and circulation). Indications for emergency endotracheal intubation include the following:

  • Apnea
  • Profound shock
  • Inadequate ventilation

Chest radiography is not indicated in patients with clinical signs of a tension pneumothorax, and immediate chest decompression is accomplished with either a large-bore needle at the second intercostal space or, more definitively, with a tube thoracostomy. A sucking chest wound must be appropriately covered to permit adequate ventilation and to prevent the iatrogenic development of a tension pneumothorax.

Damage control appears to be the current mantra in the advanced care of PCT.[17] Damage control requires modification of the ABCs of trauma, in that resuscitative and diagnostic techniques are used simultaneously in the immediate time after the unstable patient's presentation. Quickly and solely controlling hemorrhage and contamination to expedite reestablishing a survivable physiology is the essence of thoracic damage control. Additionally, aggressive correction of the acidosis, coagulopathy, and hypothermia occurs in the intensive care unit (ICU).[18]

Volume replenishment is the cornerstone of treating hemorrhagic shock but can also cause significant compromise of other organ systems. Continuous infusions of even blood or normotonic fluids cause significant peripheral tissue edema, frank acute respiratory distress syndrome (ARDS), or a tremendous increase in lung water ("soggy lungs") and cardiac compromise. Newer approaches, described in both military and civilian literature, are emphasizing the use of hypertonic solutions in an effort to minimize these complications.

Alternatively, several groups have championed the concept of "scoop and run" in the treatment of injuries in the field.[19]  With the development of modern (civilian) emergency medical services,[20] field care of injured patients has improved. Rapid assessment to identify life-threatening injuries along with key interventions (ie, management of the airway and control of hemorrhage) and avoidance of massive volume increases before rapid transport to the closest appropriate facility is the current standard of care. This is in contrast to the concept of "stay and play," during which trained personnel make major triage and treatment decisions in the field.

If the patient has persistently low systemic pressure, a source of ongoing blood loss or some other mechanisms to explain the hypotension (eg, cardiac tamponade or tension pneumothorax) should be preferentially sought. Additionally, some data suggest that continued volume resuscitation before surgical control of bleeding may worsen both the bleeding process and final outcome.

Fluid collections in either hemithorax should be treated with percutaneous thoracostomy tubes. (See the image below and Hemothorax.)

Upright posteroanterior chest radiograph of patien Upright posteroanterior chest radiograph of patient with right-side hemothorax.

A review by Kamarova et al found strong evidence for antibiotic prophylaxis in patients with chest wounds requiring tube thoracostomy.[21]  A systematic review and meta-analysis by Ayoub et al found that in patients with penetrating and blunt chest injuries that necessitated the insertion of a chest drain, prophylactic antibiotic administration was associated with a reduced risk for posttraumatic empyema and pneumonia.[22]

Surgical Indications

Thoracotomy

Thoracotomy may be indicated for acute or chronic conditions. Acute indications include the following:

  • Cardiac tamponade
  • Acute hemodynamic deterioration/cardiac arrest in the trauma center
  • Penetrating truncal trauma (resuscitative thoracotomy)
  • Vascular injury at the thoracic outlet
  • Loss of chest wall substance (traumatic thoracotomy)
  • Massive air leak
  • Endoscopic or radiographic evidence of significant tracheal or bronchial injury
  • Endoscopic or radiographic evidence of esophageal injury
  • Radiographic evidence of great vessel injury
  • Mediastinal passage of a penetrating object
  • Significant missile embolism to the heart or pulmonary artery
  • Transcardiac placement of an inferior vena caval shunt for hepatic vascular wounds

Patients who arrive in cardiac arrest or who arrest shortly after arrival may be candidates for emergency resuscitative thoracotomy.[23] A right chest tube must be placed simultaneously. The use of emergency resuscitative thoracotomy has been reported to result in survival rates of 9-57% for patients with penetrating cardiac injuries and survival rates of 0-66% for patients with noncardiac thoracic injuries, but overall survival rates are approximately 8%.[24]

The Eastern Association for the Surgery of Trauma (EAST) developed an evidence-based practice management guideline for the use of emergency department (ED) thoracotomy (EDT) in patients who present pulseless with signs of life after penetrating thoracic injury (see Guidelines).[9]

The proportion of patients with PCT who can be treated without operation has been reported to be in the range of 29-94%.[24]

Chronic indications for thoracotomy include the following:

  • Nonevacuated clotted hemothorax
  • Chronic traumatic diaphragmatic hernia
  • Traumatic cardiac septal or valvular lesion
  • Chronic traumatic thoracic aortic pseudoaneurysm
  • Nonclosing thoracic duct fistula
  • Chronic (or neglected) posttraumatic empyema
  • Infected intrapulmonary hematoma (eg, traumatic lung abscess)
  • Missed tracheal or bronchial injury
  • Innominate artery/tracheal fistula
  • Traumatic arterial/venous fistula

Another indication for acute thoracotomy is often based on chest tube output. Immediate evacuation of 1500 mL of blood is a sufficient indication; however, the trend in output is more important. If bleeding persists with a steady trend of more than 250 mL/hr, thoracotomy is probably indicated.

Thoracoscopy

The role of video-assisted thoracoscopic surgery (VATS) in the management of penetrating chest trauma has been expanding rapidly.[25] Initially promoted for the management of retained hemothoraces and the diagnosis of diaphragmatic injury, VATS is being used by trauma and thoracic surgeons for treatment of chest-wall bleeding, diagnosis of transmediastinal injuries, pericardial window, and persistent pneumothoraces.[26] The major contraindication for VATS is hemodynamic instability.

Surgical Treatment of Specific Injuries

Chest-wall injury

The chest serves the important functions of respiration and of protection of the vital intrathoracic and upper abdominal organs from externally applied force and is composed of the rigid structure of the rib cage, clavicles, sternum, scapulae, and heavy overlying musculature. Most wounds to these structures can be managed nonoperatively or by means of simple techniques such as tube thoracostomy. The treatment of a stable patient with a normal initial chest radiograph remains controversial.

Ammons et al further defined the role of outpatient observation of selected patients with nonpenetrating thoracic gunshot wounds (GSWs) and stab wounds.[27] In their study, observation for 6 hours with subsequent repeat chest radiography revealed a 7% rate of delayed pneumothorax, and hospitalization was avoided in 86% of patients treated according to this protocol.

Closure of a large open chest-wall defect can be a formidable task. When techniques involving closure with autogenous tissue of myocutaneous flaps based on the trapezius, rectus abdominis, pectoral, or latissimus dorsi muscles fail, prosthetic material (eg, polypropylene mesh, expanded polytetrafluoroethylene, or cyanoacrylate) may be used.

Rarely, chest-wall hemorrhage from the muscular, intercostal, and internal mammary arteries can result in exsanguination and may require operative control.

First- and second-rib fractures are often accompanied by serious associated injuries, particularly if multiple rib fractures are evident. Treatment of any associated injuries must be expeditious.

Severe thoracic injury that causes paradoxic motion of segments of the chest wall has been termed flail chest, which may be categorized by size or location. In adults, pulmonary contusion accompanies flail chest injuries in approximately half the patients.

Primary treatment of chest-wall injuries involves a combination of pain control, aggressive pulmonary and physical therapy, selective use of intubation and ventilation, and close observation for respiratory decompensation. Sufficient evidence supports the notion that the pathophysiologic findings associated with severe chest-wall trauma are related to the underlying injuries, chiefly pulmonary contusion and parenchymal injuries, and have little to do with the movement of the chest wall.

Indications for operative fixation of the chest wall or sternum include the following:

  • Need for thoracotomy for other reasons
  • Large flail segments in patients with borderline premorbid pulmonary status
  • Severe instability and pain and failure to wean from the ventilator after an adequate trial
  • Secondary infections

Lung injuries

Injuries related to the pleural space can generally be divided into two main categories, pneumothorax and hemothorax. Most patients with such injuries can be cared for with a simple tube thoracostomy. A massive hemothorax is defined as more than 1500 mL of blood in the pleural space. Usually, 200-300 mL of blood must collect in the pleural space before a hemothorax can be detected on a chest radiograph.

Although tube thoracostomy is often a lifesaving procedure and is relatively straightforward, it should not be taken too lightly. A review of almost 600 tube thoracostomies revealed a complication rate of 21%.[28]

Pulmonary parenchymal lacerations result in bleeding and air leaks, and the vast majority of these lacerations can be treated with tube thoracostomy. These lacerations extend from the surface of the lung toward the hilum or the trajectory of the penetrating object. They can range from minor lacerations to lobar bisection. Of penetrating injuries that require thoracostomy, 80-90% can be managed with simple measures (eg, stapling, tractotomy, and oversewing).

Fewer than 3% of all patients who require thoracotomy require a pneumonectomy, and this procedure is reserved for patients with severe hilar vascular injuries.[29] Postoperatively, aggressive diuresis and selective lung ventilation may reduce the prevalence of pulmonary edema and stump dehiscence.

Tracheobronchial injuries

As many as 75-80% of penetrating injuries involve the cervical trachea, whereas 75-80% of blunt injuries occur within 2.5 cm of the carina. These injuries always occur with other injuries, especially to the great vessels; without early recognition and prompt intervention, they frequently are fatal.

Respiratory distress, subcutaneous emphysema, pneumothorax, hemoptysis, and mediastinal emphysema are the most common manifestations. Occasionally, complete or near-complete transection results in the "fallen lung" sign on chest radiographs. If possible, bronchoscopy should be performed on any patient in whom tracheobronchial injury is suggested.

Patients with small injuries without appreciable leaks who do not require positive-pressure ventilation (PPV) can be treated nonoperatively; however, most patients require urgent repair. The principles of operative repair include debridement with a tension-free end-to-end anastomosis while preserving the blood supply. The preferred suture technique is debatable but usually requires a monofilament suture with knots tied on the outside.

In cases where primary surgical repair is not possible (eg, because of coexisting comorbid conditions, multiple associated trauma injuries, patient instability, or lack of local expertise), endobronchial techniques may be considered.[30]

Delay or lack of recognition is common, and subsequent complications of stenosis and obstruction are the rule in missed tracheobronchial injuries.

Esophageal injuries

The exact prevalence of injury to the esophagus due to external trauma is unknown but is lower than 1% among injured patients admitted to hospitals. The majority of esophageal injuries are due to penetrating trauma from a variety of instruments (ie, iatrogenic trauma).

Recognizing injury to the esophagus following trauma is difficult because of the rarity of injuries to this organ, the paucity of clinical signs in the initial 24 hours, and the frequent presence of multiple other injuries. Delayed treatment results in the rapid development of sepsis and an associated high risk of death; therefore, any possibility of injury must prompt aggressive investigation, including radiography, endoscopy, and thoracoscopy (when warranted). The combined use of these techniques has a sensitivity of almost 100%.

Operative management is dictated by the following:

  • Site of primary injury
  • Presence and severity of associated injuries
  • Condition of the patient
  • Degree of local suppuration
  • Condition of the esophageal tissues
  • Delay since injury

Primary repair with adequate tissue buttressing and drainage is the preferred method. Exclusion-diversion procedures have been advocated when primary repair is thought to be contraindicated. Esophageal replacement, when required, is, at best, a poor substitute for the original organ.

Complications after esophageal repair include the following:

  • Esophageal leaks and fistulae
  • Wound infections
  • Mediastinitis
  • Empyema
  • Sepsis
  • Pneumonia

Long-term complications, such as esophageal stricture, are also possible.

Diaphragmatic injury

The diaphragm is frequently injured in penetrating thoracoabdominal trauma. Such injury occurs in 15% of stab wounds and in 46% of GSWs. Only 15% of the injuries are longer than 2 cm; therefore, herniation of abdominal contents is rarely immediate. Blunt injuries tend to result in larger lacerations.

No distinctive signs and symptoms are associated with penetrating diaphragmatic injuries. A high index of suspicion is usually required for diagnosis.

Penetrating diaphragmatic injuries are frequently difficult to diagnose without laparoscopy or laparotomy. Diagnostic peritoneal lavage (DPL) appears to be the best-studied procedure, though no consensus has been reached regarding the best red blood cell (RBC) count to use. Laparoscopy and thoracoscopy can be useful in both diagnosing and treating penetrating diaphragmatic injuries.

In general, acute injuries are approached via laparoscopy or laparotomy because of associated injuries, and chronic injuries are approached via thoracoscopy because of dense adhesions that arise between the abdominal contents and the lung. Most injuries require repair with heavy nonabsorbable sutures; some large tears may require mesh closure. Lateral tears may require resuspension from the chest wall.

As many as 13% of injuries are missed in emergency settings, and the patient may present years later when visceral herniation occurs (85% within 3 years), manifesting as decreased cardiopulmonary reserve, obstruction, or frank sepsis. Bowel strangulation and gangrene are associated with a high mortality.

Practice guidelines for the management of traumatic diaphragmatic injuries were published by EAST in 2018.[31]

Thoracic great-vessel injury

The great vessels of the chest include the aorta, its major branches at the arch (eg, innominate, carotid, and subclavian), and the major pulmonary arteries. The primary venous conduits include the superior and inferior vena cavae and their main tributaries, as well as the pulmonary veins. Damage to vascular structures depends on the specific location and degree of vessel disruption; arterial injuries are more rapidly fatal. The prevalence of great-vessel injuries ranges from 0.3% to 10%.

More than 90% of thoracic great-vessel injuries are caused by penetrating trauma (eg, from GSWs, shrapnel woulds, stab wounds, or therapeutic misadventures). Historically, thoracic injuries are associated with a high morbidity; however, Pate et al reported a 71% survival rate in patients who reach the hospital alive after PCT. The trauma surgeon must resuscitate, diagnose, and treat the patient within minutes following admission to the trauma emergency unit.

A patient's hemodynamic stability dictates the next phase of managing a penetrating great-vessel injury. Patients who are stable after initial resuscitation are best served by a further diagnostic workup. Helical computed tomography (CT), CT angiography (CTA), and transesophageal echocardiography (TEE) offer several advantages over other diagnostic studies.

Helical CT is a noninvasive, sensitive test for assessing mediastinal hematomas and evaluating aortic wall and intraluminal abnormalities. The development of multidetector CT (MDCT) has allowed significantly shorter acquisition times (< 2 minutes for a whole-body CT scan), the ability to retrospectively reconstruct thinner sections, and improvements in three-dimensional (3D) reconstructions.

CTA has developed into a primary method of determining vascular injuries, obviating the much more invasive and operator-dependent conventional angiographic techniques, long held to be the criterion standard for assessment of vascular trauma.

The role of TEE is evolving. Whereas its usefulness for characterizing and confirming traumatic aortic dissections has long been established, it is only comparatively recently that it has come to be used directly in trauma evaluation. The previous lack of experienced operators in the ED setting is being addressed, and continued exposure of the technique will undoubtedly increase its use in the evaluation of trauma patients.

If required, conventional angiography or digital subtraction angiography (DSA) is performed with a surgeon in attendance. The role of intravascular ultrasonography in the evaluation of the trauma patient remains to be determined.

Patients who remain in extremis or show continued rapid hemodynamic deterioration are best served by an emergency thoracotomy for rapid descending aortic cross-clamping and manual control of bleeding. Patients who are successfully resuscitated but remain hemodynamically unstable or who demonstrate continued massive blood loss are unable to undergo a further diagnostic workup and are immediately taken to the operating room.

Proper choice of an incision in order to gain adequate exposure for control and repair of the injury is of prime importance. A median sternotomy with supraclavicular extensions for access to the subclavian vessels is the most useful incision. A posterolateral thoracotomy is the incision of choice for access to the descending thoracic aorta. The trapdoor, or book, incision is of purely historical significance.

Operative repair of thoracic aortic injuries is virtually always possible by means of lateral aortorrhaphy with extremely short cross-clamp times. Rarely, if ever, is an interposition graft required. Adjunctive measures of cardiopulmonary bypass, temporary bypass shunts, or active aortic shunts (eg, a centrifugal pump) are usually not described for use in patients with penetrating trauma but are almost exclusively used for blunt injury. Paraplegia has only rarely been reported after successful repair of penetrating thoracic aortic injury, even after prolonged aortic cross-clamping following emergency thoracotomy.

Because of the proximity of other organs to the thoracic great vessels, an additional diagnostic workup that includes bronchoscopy, esophagoscopy, and echocardiography may be necessary. The timing of these interventions continues to be debated.

Patients with great-vessel injuries have a higher prevalence of associated venous, esophageal, and bronchial plexus injuries than patients without great-vessel injuries do. Trauma patients with severe concomitant injuries who are unlikely to tolerate operative repair may be treated more frequently with endovascular stenting in the future. Mitchell's series of stent-graft repair of thoracic aortic lesions included seven posttraumatic cases.

The Society for Vascular Surgery (SVS) published data regarding the use of endovascular grafts in the treatment of acute aortic transections; 97% were due to a motor vehicle accident. Sixty symptomatic patients were treated with an aortic endograft, with a mean operating time of 125 minutes and an all-cause mortality of 9.1% at 30 days.[32]

Nonoperative treatment predominantly applies to patients with blunt aortic injuries who are unlikely to benefit from immediate repair (eg, those with minor intimal defects or small pseudoaneurysms). The long-term natural history of these minor vascular injuries remains uncertain; therefore, careful follow-up monitoring, including serial imaging studies, is a critical component of nonoperative treatment.

Cardiac injuries

Traumatic cardiac penetration is highly lethal, with case fatality rates of 70-80%. The degree of anatomic injury and occurrence of cardiac standstill, both related to the mechanism of injury, determine survival probability. Patients who reach the hospital before cardiac arrest occurs usually survive. Those patients surviving penetrating injury to the heart without coronary or valvular injury can be expected to regain normal cardiac function on long-term follow up.[33]

Ventricular injuries are more common than atrial injuries, and the right side is involved more often than the left side. In 1997, Brown and Grover noted the following distribution of penetrating cardiac injuries:[34]

  • Right ventricle - 43%
  • Left ventricle - 34%
  • Right atrium - 16%
  • Left atrium - 7%

The Beck triad (ie, high venous pressure, low arterial pressure, and muffled heart sounds) is documented in only 10-30% of patients who have proven tamponade.[35]

Pericardiocentesis can be both diagnostic and therapeutic, though some centers report a false-negative rate of 80% and a false-positive rate of 33%. This procedure is reserved for patients with significant hemodynamic compromise without another likely etiology.

Echocardiography is a rapid, noninvasive, and accurate test for pericardial fluid. It has a sensitivity of at least 95% and is incorporated into the focused assessment with sonography for trauma (FAST) protocol.

Once again, the management algorithm is based on the patient's hemodynamic status, with patients who are in extremis or who are profoundly unstable benefiting from emergency thoracotomy with ongoing aggressive resuscitation. In patients with GSWs from high-caliber missiles, the absence of an organized cardiac rhythm portends a grave prognosis. For patients with stab wounds or GSWs from low-caliber missiles who are apparently lifeless upon arrival, resuscitative thoracotomy is justified.

Stable patients with cardiac wounds may be diagnosed by using a subxiphoid pericardial window.[36] Bleeding must be rapidly controlled using finger occlusion, sutures, or staples. Inflow occlusion and cardiopulmonary bypass are rarely necessary. Distal coronary injuries are usually ligated, whereas proximal injuries may require bypass grafts. Intracardiac shunts or valvular injuries in patients who survive are usually minor and do not require emergency repair. Foreign bodies in the left cardiac chambers must be removed.

Postoperative deterioration may be due to bleeding or postischemic cardiac myocardial dysfunction. Residual and delayed sequelae include postpericardiotomy syndrome, intracardiac shunts, valvular dysfunction, ventricular aneurysms, and pseudoaneurysms. Wall et al, in a classic 1997 paper, described in detail the management of 60 complex cardiac injuries.[37]

Complications

Retained pulmonary parenchymal foreign bodies

The decision to remove a retained foreign body depends on its size, its location, and any specific problems associated with it. Objects larger than 1.5 cm in diameter, centrally located missiles, irregularly shaped objects, and missiles associated with evidence of contamination may be prophylactically removed. Typically, such removal is best performed 2-3 weeks following the acute injury.

Chest-wall hernia

A chest-wall hernia is usually a complication of thoracotomy. A patient with a chest-wall hernia presents with pain and an obvious defect, but occasionally a lung may be entrapped and become necrotic. Management includes resection of nonviable tissue and closure with tissue flaps or artificial material

Posttraumatic lung cyst

Pseudocyst of the lung is a rare development and usually manifests as a well-circumscribed, rounded, central air cavity identified on chest radiographs or CT scans. Most do not require specific treatment and resolve spontaneously within a few weeks. Patients with secondary infection present with a lung abscess and should be treated with standard therapy, including antibiotics and drainage.

Pulmonary hematoma

Hematomas form in 4-11% of patients with pulmonary contusions and are observed more frequently in patients with blunt trauma. Symptoms of fever and hemoptysis usually abate in 1 week, though chest radiographs usually demonstrate resolution within 4 weeks. Hematomas are associated with an increased prevalence of abscess formation.

Systemic air embolism

Systemic air embolism is usually described following central penetrating lung injury and is a special risk following primary blast injuries to the lungs. Air can enter the left side of the heart through bronchial and pulmonary venous fistulae and embolize to the coronary and systemic circulations. A precipitating factor is often the institution of PPV with resulting air being forced into the low-pressure pulmonary venules. Embolism can also occur with any thoracic great-vessel injury.

Manifestations include seizures, arrhythmias, and cardiac arrest. Resuscitation requires thoracotomy, clamping of the pulmonary hilum, and aspiration of air from the left ventricle and ascending aorta. Experience with hyperbaric oxygen therapy has generally been good but is usually reserved for those centers with access to larger chambers (ie, to support associated medical personnel).

Bronchial stricture

Missed tracheobronchial laceration may result in significant strictures. Patients present with variable degrees of dyspnea. Evaluation with bronchoscopy and CT is followed by treatment with open operative repair or stenting.

Tracheoesophageal fistula

Delayed tracheoesophageal fistula is rare, generally manifesting approximately 10 days following injury, possibly from delayed necrosis following a blast injury. Usually, the airway at or just above the carina is involved. The timing of surgery or intervention is unclear and depends on the degree of ventilatory leak and the overall condition of the patient.

Persistent air leak and bronchopleural fistula

Traumatic air leaks that last longer than 7 days are unlikely to resolve spontaneously, and judicious manipulation of the chest tube to increase or decrease the suction may be appropriate in order to facilitate healing. Bronchopleural fistulae imply a direct communication between the major airways and the pleural space and usually require some form of intervention for closure.

Empyema

Empyema occurs in 2-6% of patients with PCT. Traumatic empyema differs from nontraumatic forms because it is more often loculated and requires operative debridement. Initial treatment is tube drainage. Thoracoscopy, particularly if performed within 7-10 days, is effective for draining the infection.

Ventilator-associated pneumonia

Ventilator-associated pneumonia occurs in 9-44% of ventilated patients. It increases the mortality in patients who do not have ARDS from 26% to 48% and in patients with ARDS from 28% to 67%. Management consists of ventilator support and appropriate systemic antibiotic therapy.

Missile embolization

Embolization to the pulmonary arteries is usually treated with surgical removal or interventional techniques. A chest radiograph taken immediately preceding incision or intraoperative fluoroscopy is mandatory in order to detect more distal embolization that may occur during positioning. Asymptomatic patients with small distal fragments may be treated expectantly. Occasionally, missile emboli may migrate through a patent foramen ovale or from central parenchymal or vascular injuries to gain access to the left side of the heart and then to the systemic circulation.

Cardiovascular fistulae

Most cardiovascular arterial-to-venous fistulae occur following stab wounds. Virtually all manifest as a machinery murmur after approximately 1 week. Innominate artery-to-vein fistulae are the most common. Patients with coronary artery fistulae, usually to the right ventricle, present with ischemia, cardiomyopathy, pulmonary hypertension, or bacterial endocarditis. Aortocardiac, aortopulmonary, and aortoesophageal fistula are quite rare because the probability of survival from the acute injury is slim.

In the past, PCT patients with cardiovascular fistulae typically required open repair, but in current practice, many such patients can be treated with interventional techniques.

Thoracic duct injury and chylothorax

Injuries to the thoracic great vessels may be complicated by concomitant thoracic duct injury, which, if unrecognized, may produce devastating morbidity due to severe nutritional depletion. Initial management of a delayed chylothorax is always aggressive but nonoperative. Hyperalimentation with total enteral foodstuff restriction (ie, parenteral hyperalimentation) may result in a significant number of spontaneously sealing thoracic duct injuries.

Failure to spontaneously seal after 5-7 days indicates the need for surgical intervention, which should be individualized because the optimal approach is controversial. The number of proponents for direct suture control is equal to the number of those preferring a right thoracotomy to ligate the vessel as it traverses the diaphragm. Experienced personnel can approach the duct thoracoscopically or with video assistance, thus minimizing additional discomfort to the patient.

 

Guidelines

EAST Guideline on Traumatic Diaphragmatic Injuries

In 2018, the Eastern Association for the Surgery of Trauma (EAST) published guidelines on evaluation and management of traumatic diaphragmatic injuries.[31] Recommendations included the following:

  • In left thoracoabdominal stab wound patients who are hemodynamically stable and without peritonitis,  laparoscopy is conditionally recommended rather that computed tomography (CT) to decrease the incidence of missed diaphragmatic injury.
  • In penetrating thoracoabdominal trauma patients in whom a right diaphragm injury is confirmed or suspected and who are hemodynamically stable without peritonitis, nonoperative management is conditionally recommended over operative management in weighing the risks of delayed herniation, missed thoracoabdominal organ injury, and surgical morbidity (procedural complications, length of stay [LOS], surgical-site infection [SSI], empyema).
  • In hemodynamically stable trauma patients with acute diaphragm injuries, the abdominal approach, rather than the thoracic approach, is conditionally recommended for repairing the diaphragm to decrease mortality, delayed herniation, missed thoracoabdominal organ injury, and surgical approach–associated morbidity (procedural complications, LOS, SSI, empyema).
  • In patients who present with delayed visceral herniation through a traumatic diaphragmatic injury, no recommendation is made in regard to the routine surgical approach (abdominal or thoracic) to decrease mortality and surgical approach–related morbidity (procedural complications, SSI, LOS, empyema).
  • In patients with acute penetrating diaphragmatic injuries without concern for other intra-abdominal injuries,  laparoscopic repair is conditionally recommended over open repair in weighing the risks of mortality, delayed herniation, missed thoracoabdominal organ injury, and surgical approach–associated morbidity (procedural complications, LOS, SSI, empyema).

EAST Guidelines for Emergency Department Thoracotomy

In 2015, EAST published guidelines for emergency department (ED) thoracotomy (EDT) in common presenting scenarios after critical injury.[9] Recommendations included the following:

  • In patients presenting pulseless to the ED with signs of life after penetrating thoracic injury, EDT is strongly recommended.
  • In patients presenting pulseless to the ED without signs of life after penetrating thoracic injury, EDT is conditionally recommended.
  • In patients presenting pulseless to the ED with signs of life after penetrating extrathoracic injury, EDT is conditionally recommended. This recommendation does not pertain to patients with isolated cranial injuries.
  • In patients presenting pulseless to the ED without signs of life after penetrating extrathoracic injury, EDT is conditionally recommended. This recommendation does not pertain to patients with isolated cranial injuries.
  • In patients presenting pulseless to the ED with signs of life after blunt injury, EDT is conditionally recommended.
  • In patients presenting pulseless to the ED without signs of life after blunt injury, it is conditionally recommended that EDT not be performed.