Unprovoked Aortic Root Thrombus Mimicking a Type A Aortic Dissection

P0367 

Case Video Submission 

Timothy Guenther (1), SATORU OSAKI (1), Chris Rokkas (1), Andreas de Biasi (1)

(1) Division of Cardiothoracic Surgery, University of Wisconsin Department of Surgery, Madison, Madison, WI

Timothy Guenther    -  Contact Me
Division of Cardiothoracic Surgery, University of Wisconsin Department of Surgery, Madison

SATORU OSAKI    -  Contact Me
Division of Cardiothoracic Surgery, University of Wisconsin Department of Surgery, Madison

Chris Rokkas    -  Contact Me
Division of Cardiothoracic Surgery, University of Wisconsin Department of Surgery, Madison

Andreas de Biasi    -  Contact Me
Division of Cardiothoracic Surgery, University of Wisconsin Department of Surgery, Madison

Timothy Guenther    -  Contact Me
University of California - Davis

Objective: Aortic thrombus formation is a potentially life threatening condition that is typically seen in patients with known risk factors for a hypercoagulable state such as certain genetic conditions, malignancy, and some infections (COVID-19). Thrombus associated with the aortic root is most commonly observed in patients with left ventricular assist devices (LVAD) secondary to changes in flow within the aortic root. We present a patient with an abnormality in the aortic root, thought to be a Type A aortic dissection, but was subsequently diagnosed with an unprovoked aortic root thrombus.

Case Video Summary: A 52 year old woman with past medical history of COPD, DM2, and unprovoked pulmonary embolism presented to a referring hospital with acute onset vomiting and chest pain. CTA chest showed a luminal irregularity in the ascending aorta at the level of the sinuses of Valsalva which was favored to represent an intimal flap vs angiosarcoma of the aortic wall. Review of the patient's prior imaging showed no proximal aortic pathology when the patient was diagnosed with her pulmonary embolism 6 months prior. The patient was transferred to our institution where an EKG gated CT scan failed to better characterize the proximal aorta. Given the presumptive diagnosis of a subtle Type A dissection, the patient was taken to the operating room where transesophageal echocardiogram (TEE) showed an 8 x 14 mm filamentous mobile mass arising from the right sino-tubular junction. No wall motion abnormalities or other pathology was identified. Given the size of the mass, acute onset, and unclear diagnosis, the decision was made to proceed with surgical exploration/resection. With a lower suspicion for an aortic dissection, axillary/femoral cannulation was not pursued and a median sternotomy was performed. An epi-aortic ultrasound corroborated the findings of the TEE showing a pedunculated mass arising from the wall of the aorta. The distal ascending aorta and right atrium were cannulated and the heart was arrested. A transverse aortotomy was performed and a 1 x 1 x 3 cm thrombus like mass was found arising from the middle of the right coronary sinus. (Figure 1) This was removed with gentle dissection and the underlying intima appeared intact. Of note, no ostium of the right coronary artery could be identified and with retrograde delivery of cardioplegia, efflux was only observed from the left main coronary artery. Given the lack of wall motion abnormalities and normal pre-operative serum troponin, the right coronary artery was not bypassed. The patient's post-operative course was uncomplicated and she was discharged on POD 5. A hematology consult was obtained prior to discharge and the recommendation was given to obtain a hypercoagulable work-up as an outpatient. The patient was seen at 2 weeks post-op in our clinic and was doing well, but unfortunately has since been lost to follow up. Pathology of the mass resulted as vascular tissue with organizing thrombus.

Conclusions: In patients presenting to the ED with acute onset chest pain, cross sectional imaging remains an important diagnostic modality to evaluate for potential life threatening conditions. In patients with equivocal cross sectional findings, especially in the root, TEE remains an important adjunct to defining the anatomy and guiding operative decision making. This case also highlights a rare case of an unprovoked aortic root thrombus not associated with the presence of an LVAD.

Aortic Surgery Forum (Basic Aortic Research, Venue for Residents, Fellows, Junior Attendings)