You are in: eMedicine Specialties > Thoracic Surgery > Trauma Penetrating Chest TraumaArticle Last Updated: Oct 10, 2008AUTHOR AND EDITOR INFORMATIONAuthor: Rohit Shahani, MD, MS, Consulting Staff, Department of Cardiothoracic Surgery, Hudson Cardiothoracic Surgeons and Vassar Brothers Medical Center Rohit Shahani is a member of the following medical societies: American College of Cardiology, American College of Surgeons, American Medical Association, and Society of Thoracic Surgeons Coauthor(s): Jan David Galla, MD, PhD, Assistant Professor, Department of Cardiothoracic Surgery, Mount Sinai Medical Center Editors: Jeffrey C Milliken, MD, Chief, Division of Cardiothoracic Surgery, University of California at Irvine Medical Center; Clinical Professor, Department of Surgery, University of California at Irvine School of Medicine; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine; Daniel S Schwartz, MD, FACS, Clinical Assistant Professor of Cardiothoracic Surgery, New York University School of Medicine; Consulting Staff, Department of Surgery, Division of Thoracic Surgery, North Shore University Hospital/Long Island Jewish Medical Center; Paolo Zamboni, MD, Professor of Surgery, Chief of Day Surgery Unit, Chair of Vascular Diseases Center, University of Ferrara, Italy; Mary C Mancini, MD, PhD, Professor, Department of Surgery, Louisiana State University Health Sciences Center Author and Editor Disclosure Synonyms and related keywords: PCT, thoracic trauma, thoracic penetrating trauma, penetrating chest injury, thoracoabdominal trauma, stab injuries, gunshot wounds, GSWs, impalement, shrapnel wounds, missile wounds, endotracheal intubation, thoracotomy, emergency resuscitative thoracotomy, ERT, pneumothorax, hemothorax, sucking chest wound, hemorrhagic shock, acute respiratory distress, ARDS, cardiac tamponade INTRODUCTIONThoracic 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 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. Recently, the classic "trimodal" temporal distribution of trauma deaths has been questioned, even though it has been widely taught in the design of trauma systems.2 For more information, visit Medscape’s Trauma Resource Center. History of the ProcedureOne of the earliest writings of thoracic injury was noted in the Edwin Smith Surgical Papyrus, written in 3000 BCE. Galen reported attempts to treat gladiators with chest injuries with open packing. In 1635, Labeza 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, in 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, Tex; Los Angeles, Calif; Atlanta, Ga; Detroit, Mich; and Denver, Colo, 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.3, 4 ProblemAny 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 eMedicine article Abdominal Stab Wound Exploration. EtiologyMechanism of injury The mechanism of injury may be categorized as low, medium, or high velocity. 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 in which KE is kinetic energy, M is mass, and V is velocity: KE = ½ MV2 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, 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. PathophysiologyAs noted by Inci and colleagues in a 1998 study of 755 patients with thoracic injuries, penetrating chest trauma (PCT) comprises a broad spectrum of injuries and severity.5 The injuries and number of patients (some with >1 injury) is listed as follows:5
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. ClinicalInitial management As always in trauma, management begins with establishing ABCs. Indications for emergency endotracheal intubation include apnea, profound shock, and 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. 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" when treating injuries in the field. With the development of modern (civilian) emergency medical services, the field care of injured patients has improved. Rapid assessment to identify life-threatening injuries along with key interventions, namely 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, 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 hemothorax should be treated with percutaneous thoracostomy tubes (see Hemothorax). INDICATIONSThoracotomy Thoracotomy may be indicated for acute or chronic conditions. Acute indications include the following:
Patients who arrive in cardiac arrest or who arrest shortly after arrival may be candidates for emergency resuscitative thoracotomy. 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%.6 The proportion of patients with PCT who can be treated without operation has been reported to vary from 29-94%.6 Chronic indications for thoracotomy include the following:
Another indication for acute thoracostomy 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/h, thoracotomy is probably indicated. The role of video-assisted thoracoscopic surgery in the management of penetrating chest trauma is expanding rapidly. Initially promoted for the management of retained hemothoraces and the diagnosis of diaphragmatic injury, trauma and thoracic surgeons are now using thoracoscopy for treatment of chest wall bleeding, diagnosis of transmediastinal injuries, pericardial window, and persistent pneumothoraces.7 RELEVANT ANATOMYThe 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. Entry into the thorax may be made by sternotomy; thoracotomy (incising between selected ribs, most commonly the fourth and fifth) on either the right or left side; or a clamshell incision, consisting of left and right thoracotomy incisions traversing the sternum to join the two. Additional modifications of each of these approaches 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, remember 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 vessels. Anteriorly, injuries to the heart should be presumed to have occurred if entry points are present anywhere between the 2 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, 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; consider the possibility of injuries to the diaphragm, great vessels, or posterior mediastinal structures 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. CONTRAINDICATIONSContraindications to various explorations and techniques are discussed in their respective sections. WORKUPLab Studies
Imaging Studies
Other Tests
Diagnostic Procedures
TREATMENTSurgical TherapySpecific Organ InjuriesAny organ within the chest is potentially susceptible to penetrating trauma, and each should be considered when evaluating a patient with thoracic injury. These organs include the chest wall; the lung and pleura; the tracheobronchial system, including the esophagus, diaphragm, thoracic blood vessels, and thoracic duct; and the heart and mediastinal structures. 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 simple techniques such as tube thoracostomy. The treatment of a stable patient with a normal initial chest radiograph remains controversial. Ammons and coworkers further defined the role of outpatient observation of selected patients with nonpenetrating thoracic GSWs and stab wounds. 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. Large, open, chest wall defect closure can be a formidable task. When techniques involving closure with autogenous tissue of myocutaneous flaps based on the trapezius, rectus abdominus, pectoral, or latissimus dorsi muscles fail, prosthetic material (eg, polypropylene mesh, expanded polytetrafluoroethylene, 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 paradoxical 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. The primary treatment of chest wall injuries is a combination of pain control, aggressive pulmonary and physical therapy, selective use of intubation and ventilation, and close observation for respiratory decompensation. Sufficient evidence now 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:
Lung injuries Injuries related to the pleural space can generally be divided into pneumothorax or 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%.11 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 vary from minor lacerations to lobar bisection. Of penetrating injuries that require thoracostomy, 80-90% can be managed using simple measures (eg, stapling, tractotomy, oversewing). Less than 3% of all patients who require thoracotomy require a pneumonectomy, and this procedure is reserved for patients with severe hilar vascular injuries. Postoperatively, aggressive diuresis and selective lung ventilation may reduce the prevalence of pulmonary edema and stump dehiscence. Tracheobronchial injuries Up to 75-80% of penetrating injuries involve the cervical trachea, while 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, perform bronchoscopy on any patient in whom tracheobronchial injury is suggested. Patients with small injuries without appreciable leaks who do not require positive-pressure ventilation can be treated nonoperatively; however, most patients require urgent repair. The principles of operative repair include debridement with 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. 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 less than 1% of patients with injuries 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/or the 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 site of primary injury, associated injuries, condition of the patient, degree of local suppuration, condition of the esophageal tissues, and 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 esophageal leaks and fistulae, wound infections, mediastinitis, empyema, sepsis, and 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 more than 2 cm long; therefore, herniation of abdominal contents is rarely immediate. Blunt injuries tend to result in larger lacerations. Importantly, 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 appears to be the best-studied procedure, although no consensus has been reached regarding the best RBC count to use. Newer diagnostic modalities, such as laparoscopy and thoracoscopy, can be useful in both diagnosing and treating penetrating diaphragmatic injuries. In general, acute injuries are approached with laparoscopy or laparotomy because of associated injuries and chronic injuries are approached with 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. Up to 13% of injuries are missed in emergent settings, and the patient may present years later when visceral herniation occurs (85% within 3 y), manifesting as decreased cardiopulmonary reserve, obstruction, or frank sepsis. Bowel strangulation and gangrene are associated with a high mortality rate. Thoracic great vessel injury The great vessels of the chest include the aorta, its major branches at the arch (eg, innominate, carotid, 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 0.3-10%. More than 90% of thoracic great vessel injuries are caused by penetrating trauma (ie, gunshot, shrapnel, stab wounds, therapeutic misadventures). Historically, thoracic injuries are associated with a high morbidity rate; however, Pate and coworkers reported a 71% survival rate in patients who reach the hospital alive after penetrating chest injuries. 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 CT scanning, CT angiography, and transesophageal echocardiography offer several advantages over other diagnostic studies. Helical CT scanning is a noninvasive, sensitive test to assess mediastinal hematomas and to assess aortic wall and intraluminal abnormalities. The development of multidetector-row CT scanning allows for significantly shorter acquisition times (<2 min for whole body CT scan), the ability to retrospectively reconstruct thinner sections, and improvements in 3-dimensional reconstructions. CT angiography is rapidly developing 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 transesophageal echocardiography is evolving. While the usefulness of transesophageal echocardiography to characterize and confirm traumatic aortic dissections is undisputed, it has only recently begun to be used directly in trauma evaluation. The lack of experienced operators in the emergency department setting is apparently being overcome, and continued exposure of the technique will undoubtedly increase its use in the evaluation of trauma patients. If required, conventional angiography or digital subtraction techniques are performed with a surgeon in attendance. The role of intravascular ultrasound in the evaluation of the trauma patient has yet to be clarified. 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. A choice of proper incision in order to gain adequate exposure for control and repair of the injury is of prime importance. The median sternotomy with supraclavicular extensions for access to the subclavian vessels is the most useful incision. The posterolateral thoracotomy is the incision of choice for access to the descending thoracic aorta. The trapdoor, or book, incision has historic significance only. Operative repair of thoracic aortic injuries is virtually always possible by 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 following 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 including 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 compared with patients without great vessel injuries. 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 includes 7 posttraumatic cases. Nonoperative treatment predominantly applies to patients with blunt aortic injuries who are unlikely to benefit from immediate repair (eg, minor intimal defects, 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. 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:
The Beck triad (ie, high venous pressure, low arterial pressure, muffled heart sounds) is documented in only 10-30% of patients who have proven tamponade (Reed, 2001). Pericardiocentesis can be both diagnostic and therapeutic, although 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 now incorporated into the Focused Assessment with Sonography for Trauma 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 using a subxiphoid pericardial window. 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 emergent 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.12 Follow-upFor excellent patient education resources, visit eMedicine's Procedures Center and Skin, Hair, and Nails Center. Also, see eMedicine's patient education articles Bronchoscopy and Puncture Wound. COMPLICATIONSRetained 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 using 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, although chest radiograph findings 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 positive-pressure ventilation 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 scanning 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 rate 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. While requiring open repair in the past, interventional techniques may be used in a large number of these patients. 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. OUTCOME AND PROGNOSISThe outcomes of treating patients with PCT are directly related to the extents of patients' injuries and the timeliness of initiation of treatments. Patients arriving in a stable condition may expect full recovery, but patients presenting with lesser levels of stability have diminishing probabilities of survival. Do not attempt 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 thoracotomy were published in 2003.13 FUTURE AND CONTROVERSIESThe current management of penetrating thoracic injury 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. REFERENCES
Penetrating Chest Trauma excerpt Article Last Updated: Oct 10, 2008 |