Coronary sinus and atrioventricular groove avulsion after motor vehicle crash.

Simultaneous cardiac and pericardial rupture from blunt chest trauma is a highly lethal combination with rarely reported survival. We report of a case of young patient with a right atrioventricular groove injury, pericardial rupture and a unique description of a coronary sinus avulsion following blunt chest trauma. Rapid recognition of this injury is crucial to patient survival, but traditional diagnostic adjuncts such as ultrasound, echocardiography and computed tomography are often unhelpful. Successful repair of these injuries requires high suspicion of injury, early cardiac surgery involvement of and possible even placement of the patient on cardiopulmonary bypass.

INTRODUCTION

Simultaneous cardiac and pericardial rupture secondary to blunt chest trauma is a highly lethal combination with a rarely reported survival.[123456] This combined injury pattern presents an unique diagnostic and management challenges. We present a young patient with a right atrioventricular groove injury, pericardial rupture and a unique and previously undescribed coronary sinus avulsion.

CASE REPORT

A 17-year-old male presented to our hospital after a high-speed motor vehicle crash that required prolonged extrication followed by rapid-sequence intubation. He required one unit of packed red blood cells for hypotension. On arrival to the trauma bay, he was normotensive with a heart rate of 70 beats/min. A 36-French chest tube was placed for left hemothorax. Initially, a sample of 1500 ml of blood was evacuated before output ceased. Patient remained hemodynamically stable. A focused abdominal sonogram for trauma (FAST) was negative for fluid in the abdominal and cardiac windows.

Full-body computed tomography (CT) scan revealed a retained left hemothorax and subtle irregularity of the proximal descending aorta concerning for aortic disruption [Figure 1]. Following imaging, the chest tube resumed high output requiring further resuscitation and emergent exploration. Cardiothoracic surgery was called to the operating room due to concern for aortic disruption. Upon exploring the left chest through a thoracotomy, there was no active hemorrhage in the left pleural space. The aorta was uninjured. The pericardium was traumatically ruptured, but the avulsed and skeletonized left phrenic nerve was intact [Figure 2].

Figure 1

Chest computed tomography scan image showing aortic irregularity (arrow) and retained left hemothorax

Figure 2

Traumatic rupture of the pericardium with exposed left phrenic nerve (arrow)

Control of bleeding was attempted by placing a large sheet of surgifoam along the atrioventricular groove at the base of the heart. Shortly thereafter, the heart distended and the patient arrested requiring emergent cardiopulmonary bypass achieved by cannulating the left apex and right atrium. Further, inspection revealed avulsion tears of the coronary sinus extending to the inferior vena cava. There was a separate avulsion of the right atrial appendage near the right coronary artery. Avulsion tears were repaired using pledgeted polypropylene sutures carefully avoiding adjacent coronary arteries. Excellent hemostasis was achieved and cardiopulmonary bypass was weaned. Post-operatively the patient recovered without further cardiac events and has been discharged from rehabilitation.

DISCUSSION

Autopsy studies show that cardiac injury in up to 32% of blunt trauma deaths with 64% of those injuries being cardiac rupture.[56] Isolated pericardial rupture is less prevalent. Fulda et al. reported only twenty-two pericardial ruptures out of over 20,000 blunt trauma admissions with a mortality rate of 63.6%.[2] In the setting of cardiac rupture, the rate of associated pericardial tear is 10-30%.[127] Cardiac rupture carries a high mortality rate of 50-86%[127] and when combined with pericardial rupture, the mortality is nearly 100%.[2368] There are no previously published reports of coronary sinus avulsion following blunt chest trauma.

The clinical signs of these combined injuries are often subtle, but rapid diagnosis is paramount as exsanguinating hemorrhage can quickly ensue. Isolated cardiac rupture often presents with cardiac tamponade,[127] but with simultaneous pericardial rupture, the pericardium is decompressed preventing these classic signs. Ultrasonography and CT scan can be misleading since pericardial fluid may be absent. In our case, FAST revealed no pericardial fluid and chest CT led to a misguided concern for aortic injury.

May et al. proposed an algorithm to aid in an early diagnosis of combined pericardial and cardiac rupture.[3] CT scan and/or pericardial window with lavage are indicated for patients with no pericardial fluid on FAST with otherwise unexplained hypotension or enlarging mediastinal hematoma. If no blood is initially identified in the pericardial window, pericardial lavage is performed by instilling 100-200 ml of saline into the pericardial sac. If minimal fluid returns, a second rinse is recommended. Failure to return both rinses suggests pericardial injury and necessitates sternotomy.

The surgical approach to these injuries is debated. In stable patients, median sternotomy is preferred allowing for excellent mediastinal exposure and potential placement on cardiopulmonary bypass or extension to laparotomy.[138] Lateral thoracotomy is advocated for unstable patients due to efficiency and relative simplicity.[2] We selected a posterolateral thoracotomy due to concern for an aortic injury since the remainder of the CT was unremarkable. Historically, a cardiopulmonary bypass is rarely required and is reported in only 10% of cardiac repairs for blunt trauma;[4] however, in our case the patient arrested in the operating room requiring emergent cardiopulmonary bypass. For cardiac repair, pledgeted polypropylene sutures placed in horizontal mattress fashion are recommended.[1478]

CONCLUSION

We report a rare survival of combined pericardial and cardiac rupture and a unique coronary sinus avulsion following blunt chest trauma. In addition, we propose an algorithm for its diagnosis and management [Figure 3]. This injury pattern is rare in blunt trauma is usually a highly lethal event. Traditional diagnostics such as FAST and CT are often unhelpful due to the unique combination of injuries. Rapid recognition of this injury is crucial for patient survival. Repair of this spectrum of injuries requires early involvement of cardiac surgery expertise and possibly placement of patient on cardiopulmonary bypass.

Figure 3

Proposed algorithm for diagnosis and management of a blunt cardiac and pericardial rupture