Ann Thorac Surg 2000;70:955-957
© 2000 The Society of Thoracic Surgeons
Case report
Main pulmonary artery laceration after blunt trauma: accurate preoperative diagnosis
Gunaseelan Ambrose, MDa,
Leonard O. Barrett, MDa,
George L.D. Angus, MDa,
Tauriq Absi, MDa,
Gerald W. Shaftan, MDa
a Department of Surgery, Nassau County Medical Center, East Meadow, New York, USA
Address reprint requests to Dr Angus, Department of Surgery, Nassau County Medical Center, 2201 Hempstead Turnpike, East Meadow, NY 11554
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Abstract
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Blunt chest trauma is associated with a variety of lethal injuries, many of which are responsible for prehospital mortality. Major intrathoracic vascular injury accounts for a vast majority of these fatal injuries. Patients surviving after main pulmonary artery injury are rare. We present the case of a patient who sustained a main pulmonary artery laceration as a result of a blunt motor vehicle crash. He was diagnosed accurately by computed tomography and underwent successful repair.
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Introduction
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Pulmonary artery injury (PAI) is rare, even among those patients who do not survive transport to the hospital. We describe the case of a patient who sustained such an injury, his presentation, accurate diagnosis and successful surgical outcome.
A 69-year-old male unrestrained driver was involved in a motor vehicle collision where he collided with the back of a bus. The patient was hemodynamically unstable both at the scene and upon arrival in the trauma bay. Examination in the trauma bay revealed a pulse of 115/min, systolic blood pressure of 80 mm Hg, and a respiratory rate of 10/min with no gross neurologic deficits. Examination of the chest revealed a well-healed median sternotomy scar (the result of coronary artery bypass grafting performed approximately one year previously), multiple rib fractures bilaterally, and decreased air entry in the left hemithorax. He had a Glasgow coma scale score of 11 and the remainder of the assessment was unremarkable. Diagnostic peritoneal lavage was negative.
A portable chest roentgenogram revealed a wide mediastinum with a left pleural effusion. A left chest tube was inserted and drained 300 ml of blood. The patient was subsequently transported to the radiography department to evaluate his abnormal chest findings. A chest computed tomographic scan revealed a large mediastinal hematoma with active extravasation from the main pulmonary artery (Fig 1). The image also revealed persistence of hemothorax, in spite of the presence of a functioning chest tube, which by the end of the procedure had drained a total of 1200 ml of blood.
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Fig 1. A computed tomography (CT) scan of the chest reveals tear in the main pulmonary artery (small black arrow), extravasation of CT contrast dye (solid white arrow), and a large mediastinal hematoma (outline white arrow).
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The patient was emergently taken to the operating room. A left thoracotomy showed an expanding hematoma with a laceration involving half of the circumference of the main extrapericardial pulmonary artery. The laceration was controlled with digital compression, followed by repair using 3-0 Prolene sutures (Ethicon, Somerville, NJ) on pledgets. The patient was transferred to the intensive care unit, where he remained hemodynamically stable. He had several surgical and medical setbacks but did well subsequently. He was weaned off the ventilator and transferred to a long term nursing care facility for rehabilitation.
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Comment
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Isolated case reports continue to be the main source of information about injury of this type. There are no large series related to this injury because of its rarity and the paucity of survivors. The commonest site of blunt injury to intrathoracic structures is at the hilum; patients commonly present with hemothorax. Table 1 summarizes the available literature on this type of injury.
Blunt chest trauma occurs in up to 50% of all fatal motor vehicle accidents and is the primary cause of death in 12% to 25%; yet only 15% of patients with chest trauma arriving alive to the emergency department require early thoracotomy [1]. Pulmonary artery disruption from blunt trauma is extremely rare and is even rarer in trauma patients seen in the hospital setting. Aside from our case report, there has been only one other citation in the literature on main PAI following blunt trauma. Kermmerer and associates in a series of 585 autopsies found only four cases of pulmonary artery laceration [1]. According to Mattox the vast majority of such patients succumb in the field, with an survival rate of less than 30% [2].
The key to management of this type of injury is a high index of suspicion, leading to early recognition. History that may suggest PAI includes deceleration injury, fall from a height, or deformity of the steering wheel. Indicative physical findings are seat belt or steering wheel imprint on the thorax, multiple rib fractures, and flail chest [2]. The radiologic finding suggestive of this injury is widening of the mediastinum, although that is more common with aortic injury. Chest computed tomography (CT) provides additional information that is not available from aortography alone, although aortography remains the gold standard in the evaluation of intrathoracic vascular injuries. Other signs that may be indicative of major chest trauma are first rib fracture, scapular fracture, and pleural capping. Although none of the findings we have listed are alone specific for pulmonary artery laceration, several of them in combination should suggest a more thorough evaluation for this type of injury. Our case is the first report of this type of injury diagnosed definitively by CT of the chest (Fig 1).
Case reports indicate that the clinical presentation of PAI can vary. Hemodynamic instability should always alert the caregiver to the possibility of an intrathoracic vascular injury, in the absence of other obvious causes for hypotension. Even if another possible cause is located, one must be vigilant for PAI since the severe trauma associated with the other injury may contribute to intrathoracic vascular injury.
Patients who do survive to arrive in the hospital fall into one of several main clinical presentations [3]. The first and most common is massive hemothorax, which leads to direct thoracotomy. It is usually due to hilar injury and may require pneumonectomy. A second presentation is contained hemorrhage leading to formation of an aneurysm. The patient may remain asymptomatic or exhibit symptoms of respiratory distress, similar to those of pulmonary embolism. The third presentation is delayed onset of large pleural effusion, which may require an angiogram for confirmation of the site of the tear. A final presentation is pericardial tamponade, which can be diagnosed by ultrasound, by pericardiocentesis, or by placement of a subxiphoid pericardial window [4]. Tension pneumothorax, which is indicative of significant chest trauma, should raise the suspicion of major intrathoracic vascular injury.
In the vast majority of cases of intrathoracic vascular injury, the patient must be taken to the operating room emergently, based on the clinical suspicion of an injury. If the patient arrives hemodynamically stable or can be stabilized rapidly, further diagnostic workup may be done. Chest CT will confirm the diagnosis and allow for a more planned procedure, because extension of an inappropriate chest incision is difficult. Chest CT is more likely than aortography to be diagnostic in suspected pulmonary artery lacerations. In our patient, the chest CT gave us an accurate anatomical confirmation of the diagnosis, ruled out aortic injury, and allowed a more systematic surgical approach.
Once the diagnosis is made, several approaches may be undertaken. As in our patient, who had CT chest confirmation of active extravasation of dye into the left chest, a left thoracotomy may be performed. Left thoracotomy allows exposure of the left main pulmonary artery as well as the main pulmonary trunk, since it is directed to the left and upwards from the pulmonary outflow tract. If the injury is discovered after a pericardial window is placed, the incision may be extended upwards as a median sternotomy. This allows access to the main pulmonary artery as well as to the right and left main branches. The right main pulmonary artery may be exposed by retraction of the superior vena cava. Intrapericardial exposure of the proximal pulmonary arteries may be necessary for control of hemorrhage [5]. Trauma surgeons should be familiar with this technique.
PAI can be classified as either intrapericardial or extrapericardial. Intrapericardial injuries present with tamponade and may often be repaired without cardiopulmonary bypass. In our patient, the prior history of coronary artery bypass grafting may have predisposed him to suffer a hemothorax instead of a pericardial tamponade. Anterior main pulmonary artery injuries can be managed by direct pressure and repair. Anterior and posterior lacerations may require cardiopulmonary bypass. Most bleeding can be controlled by direct pressure, but that from intrapericardial pulmonary artery lacerations is more difficult to restraint. It may be managed by placing a balloon catheter such as a Foley or Fogarty catheter to temporarily occlude the tear.
In summary, blunt PAI is a rare and often fatal injury; with improvement in emergency medical services, many more of these patients will be seen in the trauma room early enough so that salvage is possible. Early recognition, appropriate diagnostic studies in stabilized patients, and early intrathoracic intervention can decrease the high mortality associated with this injury. Chest CT is a test to be considered early in the workup of such patients, since it may be more diagnostic in PAI than the standard aortogram. It also must be emphasized that cardiopulmonary bypass is rarely indicated and that simple digital pressure and direct suture is all that is required in the vast majority of cases.
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References
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Mattox K. Approaches to trauma involving the major vessels of the thorax. Surg Clin North Am 1989;69:81-86.
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Daon E., Gorton M. Traumatic disruption of the innominate and right pulmonary arteries. J Trauma 1997;43:701-702.[Medline]
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Kemmerer W.T., Eckert W.G., Garthright J.B., Reemtsma K., Creech O., Jr Patterns of thoracic injuries in fatal traffic accidents. J Trauma 1961;1:595-599.[Medline]
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Clements R.H., Wagmeister L.S., Carraway R.P. Blunt intrapericardial rupture of the pulmonary artery in a surviving patient; Ann Thoracic Surg 1997;64:258-260.[Abstract/Free Full Text]
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Hawkins M.L., Carraway R.P., Ross S.E., Johnson R.C., Tyndal E.C., Laws H.L. Pulmonary artery disruption from blunt thoracic trauma. Am Surg 1988;54:148-152.[Medline]
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Nishimoto T., Fukumoto H., Irie H. Main pulmonary artery injury caused by golf-swing. Nippon Kyobu Geka Gakkai Zasshi 1991;10:1953-1955.
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Katz D.S., Groskin S.A. Pulmonary artery laceration and tension pneumothorax in blunt chest trauma. J Thorac Imaging 1993;8:156-158.[Medline]
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Ohta Y., Satoh H., Seki M., Endoh Y., Tsubota M., Iwa T. Injury of pulmonary artery and intrathoracic artery—a surgical case report. Nippon Kyobu Geka Gakkai Zasshi 1993;41:3327-3340.
Accepted for publication January 10, 2000.
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Abstract
Introduction
