Case Presentation: 19th-century scientist Rudolf Virchow is credited with outlining three factors predisposing one to the development of a venous thrombus. These factors include endothelial injury, hemostasis, and hypercoagulability. Formed thrombi can cause significant morbidity and mortality if the patient also has a concurrent patent foramen ovale (PFO), allowing the clot to pass to the left side of the heart and into systemic circulation. Common end organ damage includes ischemic stroke, renal artery infarction, and acute limb ischemia. Majority of the time these emboli are never captured in transit through the PFO via imaging, but rather are discovered after the emboli has traveled onward and the damage has already been done. This extremely rare event has fewer than 100 cases documented in the literature.This is the case of a 48-year-old male with medical history significant for type 2 diabetes mellitus, hypertension, and an epidural abscess spanning L2-L5 levels requiring hemilaminectomy and evacuation. The patient was transferred to a rehabilitation facility to receive intravenous antibiotics after the spinal operation. Initially, he appeared to be recovering well, however suddenly developed hypotension and diarrhea requiring transfer to our facility for further management. Here he was admitted for undifferentiated shock and responded well to fluid resuscitation and a norepinephrine drip. As part of the work up, a transthoracic echocardiogram was performed and revealed a thrombus extending from the inferior vena cava to the right atrium, through a PFO, and into the left atrium and left ventricle. The imaging also revealed evidence of right atrial dilation and right ventricle dysfunction. The patient was immediately taken to the operating room where the cardiothoracic surgery team was able to perform an emergent median sternotomy, thrombectomy, and closure of the PFO. During the operation, bilateral thrombi in the pulmonary arteries were visualized and subsequently removed. Ejection fraction pre-bypass was noted to be 30% and improved to 45-50% post-bypass. The patient is recovering in the intensive care unit and pending any complications, is expected to make a full recovery.
Discussion: What makes this case unique is not only that we were able to capture imaging of the clot as it was moving through the PFO, but also the sheer size burden of this thrombus which began in the right heart and extended into the left heart beyond the mitral valve. Once a thrombus is suspected it is important to determine the degree of dysfunction, particularly in the right ventricle to help determine next steps. Due to the rare nature of the event described above, there are not standard of practice guidelines in place to guide providers in the management of these transient thrombi. Previous literature has suggested surgical intervention being the most effective in those patients without other co-morbidities, while anticoagulation appears to be a sufficient alternative in those who are not appropriate surgical candidates.
Conclusions: A pulmonary embolism should be at the top of the differential for any patient with recent history of surgery presenting with undifferentiated shock. Obtaining an echo is an important part of the work-up to not only assess for right ventricular dysfunction, but also to identify potentially rare events like a thrombus in transit through a PFO. Despite limited data regarding therapy, an urgent consult to cardiothoracic surgery should be pursued with plans for mechanical thrombectomy if possible.