Intracardiac Penetrating Injury with Right Femoral Artery Embolism due to Blast Injury.

Embolization due to blast injury with projectiles entering the bloodstream from the heart is a rare event that is unlikely to be suspected during the initial assessment of trauma patients. We report a case in which a missile penetrating the heart chambers managed to embolize and occlude the right common femoral artery. This was successfully managed by means of a multidisciplinary approach that included exploration, cardiorrhaphy, and embolectomy.

INTRODUCTION

To the best of our knowledge and after literature review, this case is the first reported blast injury with cardiac penetration and embolization causing occlusion of the right femoral artery. In spite of high mortality of such injuries, patient's life was saved successfully with early surgical intervention. This case demonstrates how important early surgical intervention is in managing penetrating chest injuries.

CASE REPORT

A 28-year-old male presented to the emergency department after exposure to an industrial blast injury, involving the chest and anterior abdominal wall. He was unconscious with labored breathing and pain. His Glasgow Coma Scale deteriorated to 8, and a definitive airway was placed without any incident. Positive pressure ventilation was instituted. The primary survey showed decreased air entry on the left side of the chest. All peripheral pulses were palpable and symmetrical on initial presentation.

Investigations

Chest radiograph showed the left side chest opacification indicating hemothorax [Figure 1]. Thoracostomy was performed with an initial gush 450 ml of dark blood. Pericardial focused assessment with sonography for trauma was equivocal, and chest X-ray demonstrated a failure to fully evacuate the hemothorax.

Figure 1

Chest radiograph showed the left side hemothorax

The secondary survey showed superficial left hand, thigh, and leg cut wounds. Pieces of shrapnel were embedded in the left arm, anterior chest, and abdominal wall. He was stabilized and had CT of the brain, cervical spine, chest and abdomen. CT of the brain and cervical spine were normal. CT of the chest revealed fractures of the left first and second ribs. A hyperdense foreign body was seen penetrating the anterior chest wall soft tissue guarded by ribs without deep penetration to the heart [Figure 2]. There was evidence of retrosternal soft tissue hematoma and left-sided hemopneumothorax with underlying pulmonary contusion. Mild hemopericardium with air was seen within the pericardial sac but no significant major vessel injury. The left lateral chest wall and anterior wall surgical emphysema was also seen. CT of the abdomen [Figure 3] showed pellets within the anterior abdominal wall with related surgical emphysema but no evidence of peritoneal penetration. A transthoracic echocardiogram demonstrated mild pneumohemopericardium without tamponade.

Figure 2

Computed tomography of the chest shows hyperdense foreign bodies is seen penetrating the anterior chest wall soft tissue, retrosternal hematoma, and left-sided hemopneumothorax with underlying pulmonary contusion

Figure 3

Computed tomography of the abdomen shows pellets within the anterior abdominal wall with related surgical emphysema but no deep penetration or major organ injury

Repeat examination of the lower limb revealed a palpable diminution in the right dorsalis pedis pulsation. Ankle-brachial pressure index was performed which revealed a significant discrepancy between the two lower limbs (right 0.4 vs. left 1.1). Review of the original CT revealed evidence of a foreign body in the right groin with no clear point of entry and a lack of subcutaneous air. With further deterioration in the status lower limb pulsation, he was shifted for CT angiography which revealed a metallic foreign body in proximity to the right common femoral artery (CFA) masking its bifurcation point with streaky artifact, just a few millimeters distally. A filling defect was noted within the superficial femoral with no pseudoaneurysm. Although there was no subsequent drop in his systolic blood pressure, an arterial line tracing revealed evidence of pulsus paradoxus.

Treatment

A joint decision was made to proceed with an emergency median sternotomy and right femoral artery exploration by the cardiac, trauma, and vascular surgery services. Intraoperatively, blood in pericardium with clots was evacuated. There was a large laceration about 4 cm in the inferior surface of right ventricle without active bleeding and just opposite, a 4 cm tear in the diaphragm tendon.

Cardiorrhaphy with pledgeted sutures and diaphragm repair was performed. The left pleura was opened, and clots were evacuated. Transesophageal echocardiography was performed intraoperatively, and no ventricular septal defect (VSD) was visualized. Shrapnel, lodged in the anterior chest wall muscles, was removed. Simultaneously, right groin exploration was performed. The proximal, distal, and profunda femoris were individually controlled. The foreign material was felt and removed from the CFA at the bifurcation by means of an arteriotomy [Figure 4]. A 4F Fogarty catheter was passed to 60 cm with good backflow and return of thrombus and debris. Right, lower limb pulses were regained. A primary repair of the artery was performed.

Figure 4

An arteriotomy for foreign material removal from the common femoral artery at the bifurcation

Outcome and follow-up

The patient was shifted to the Cardiac Intensive Care Unit in stable condition. His hemodynamics was normal without inotropic support. His lower limb pulses remained palpable. On the second postoperative day, upper limb numbness was noted, and a CT arteriogram of the head and neck was performed to rule out further embolic disease in the distribution of the carotid artery; this was negative. The patient did well in the following days and was discharged with no complications. He presented to the clinic for removal of symptomatic-retained foreign bodies from the hand and anterior abdominal wall which was successfully extracted and with further follow up he was recovered totally.

DISCUSSION

Penetrating cardiac trauma constitutes a highly lethal constellation of injuries. Those surviving to hospital are noted to have an overall mortality approaching 80%.[1] In a retrospective, population-based study of 20,181 consecutive trauma admissions over 7 years, Rhee et al. determined the incidence was 1/100,000 man-years and 1/210 admissions. The overall survival was 19.3% with only a modest improvement over time.[2]

The survival rate is related to the extent and mechanism of injury, the need for an emergency operation, and the presence of complex cardiac lesions. Survival has been noted to be highly dependent on the mechanism, with the vast majority of injuries being secondary to firearms followed by stab wounds. This likely explains the high overall mortality as stab wound survival is comparatively rather favorable (65%) when compared to firearm-associated injuries.[3] The presence of cardiac tamponade, right ventricular injury, single chamber injury, and sole injury has been found to be associated with improved survival.[4] When the left ventricle and the coronary arteries are injured, mortality rates as high as 40% have been reported.[5]

Ventricular injuries are more common than atrial injuries, and the right side is involved more often than the left side considering its more exposed anatomical location covering the greatest portion of the anterior chest wall. In 1997, Brown and Grover noted the following distribution of penetrating cardiac injuries: Right ventricle – 43%; left ventricle – 34%; right atrium – 16%; and left atrium – 7%.[6]

The vast majority of patients with penetrating cardiac trauma will be symptomatic. The two most common clinical manifestations of penetrating cardiac injury are hemorrhage and pericardial tamponade. Hemorrhage can lead to hemorrhagic shock with tachycardia and decreased systolic and mean arterial blood pressures. Amazingly, among those patients with cardiac penetration arriving at the trauma center, 70% do not exhibit symptoms suggestive of cardiac injury as in our case.[7]

The most frequent complications of cardiac injury are cardiac tamponade and VSD, which can be raised by persistent hemodynamic instability or the incidental discovery of a cardiac murmur.

Echocardiography has an important role in the assessment of patients with acute penetrating chest trauma. It can provide both the diagnosis and the anatomical details necessary for the surgical approach. Transthoracic echocardiography is the most useful imaging modality in confirming the presence of hemopericardium.[8]

In stable patients, the sensitivity, specificity, and accuracy of CT in detecting hemopericardium are highly reliable. However, the management of patients during CT examination may be very difficult; if these patients deteriorate, then echocardiographic examination with a portable device is the preferred method.[9]

The nature of the pericardial wound is very important. If the pericardium remains open and the extravasated blood can pass freely into the pleural cavities or mediastinum, then cardiac tamponade will not develop, at least initially, and the presenting signs and symptoms will be those of a hemothorax, exactly what happened in our case. If the pericardium does not permit free drainage, tamponade may occur within minutes or hours.[10] In our case, the patient hemodynamics deteriorated later as tamponade developed slowly over hours.

Slobodan et al. mention that more than 70% of cases of missiles penetrate into the arterial circulation through either the thoracic or abdominal aorta or even through the heart.[111213141516] However, there have been isolated reports of distal arterial embolization from peripheral arteries.[1718]

In our patient, the only explanation of the missile passage was it passed through the anterior abdominal wall passing through the diaphragm to the right ventricle, interventricular septum and to the left ventricle which then migrated to the right CF A and occluded the pulses in the right leg. The initial and subsequent serial echocardiography did not show any VSD possibly secondary to muscular spasm or blood clot sealing the defect. Another possibility is that a small traumatic VSD close spontaneously. The embolism in our case might have occurred shortly after the initial injury or in the perioperative resuscitative phase that is why it was not detected during the initial survey.

The importance of prompt removal of the peripherally located projectile after embolisms is generally stressed in the literature.[19] Missile embolism not only causes acute ischemia or infarction but also may result in displacement, erosion, further embolization into the vascular tree, delayed vascular compromise, proximal clot formation, or septicemia, or it may even lead to intoxication and even death.[2021] Cardiac bullet embolus can cause cardiac irritability, delayed embolism,[22] and recurrent pericardial effusions and may even interfere with valvular functioning.[21]

Learning points

Penetrating injuries to the heart can be potentially lethal

The possibility of projectile embolization should be considered in all cases of penetrating thoracic trauma with a missing or fragmented projectile, particularly when no exit wound is identified

Unexplained peripheral ischemia, sudden loss of peripheral pulse, or abrupt onset of new, unexpected neurologic findings should trigger the suspicion of missile embolism.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.