We read with great interest the recent publication of Maloberti and colleagues [1] who presented a rare case of thoracic aorta mural thrombosis (TAMT) in a patient without predisposing factors who was treated conservatively with excellent short-term results (no long-term follow-up presented). By taking advantage of this case, we aim to answer some scientific queries born on the subject.
TAMT in non-atherosclerotic background is indeed rare (0.8–9%) with potential catastrophic consequences due to the recognized likelihood of visceral and peripheral embolization [2]. Due to its rarity - underdiagnosis or true low prevalence - and heterogeneity of causes, there is still controversy about the appropriate treatment algorithm, since it does not represent a primary disease, but epiphenomenon of other underlying disorders expressed with the same identification mark. So individual and careful evaluation of each case tips the scales against invasive or conservative treatment.
It seems that the patient in this case was not asymptomatic since she developed angina-like, though unexplained, symptoms that could raise the suspicion of a potential unusual trigger. Thus, in cases of embolic episodes (central or peripheral) in young patients without risk factors (atherosclerosis, smoking, coagulopathy, vasculitis, connective tissue disease, trauma and inflammatory bowel disease) [3], TAMT should gain ground in the differential diagnosis. By taking advantage of the imaging improvements (transoesophageal echography, magnetic resonance), the diagnosis could be easily reached without the need of invasive diagnostic procedures.
At the present time, there are many treatments available to our armamentarium, and treatment by anticoagulants is the cornerstone of primary approach. Surgery (open or endovascular) and thrombolysis are used in cases when medical treatment has failed or was contraindicated. The efficacy of antiplatelets on disease recurrence is debatable since there are equivocal results in the literature [2, 4]. Of interest would be the evaluation of NOACs in this setting.
The main disadvantage of conservative treatment seems to be its high recurrence rate that fluctuates from 26.4%–50% [2, 3, 5] and a trend towards higher incidence of limb loss and complications [3] whereas in the surgical group, recurrence is much lower (5.7%) [3]. High risk for recurrence are these cases of TAMT that present with persistent symptoms, are located in aortic arch or ascending aorta and have concomitant atherosclerotic background [3]. Mortality rate of surgery fluctuates from 2.6%–5.7% [2, 3] whereas patients in anticoagulants reach a mortality rate of 6.2% [3].
The decision which treatment modality should be chosen is based on the location, the mobility and the morphology of the thrombus as well as the persistence of symptoms under anticoagulants and the high risk of recurrence. As in the presented case, pedunculated fibrinocruoric thrombus floating in the aortic lumen is the most common morphology [2] and is correlated with increased embolic episodes [4]. The size of the thrombus should not be evaluated as the main criterion for the choice of treatment modality [3].
All in all, treatment of TAMT is a dynamic thought debatable scientific query. It seems that life-long anticoagulation is compulsory with surgery as primary approach being indicated in cases of young, symptomatic patients with high risk of recurrence. New meta-analyses and the evaluation of the role of NOACs and endografts in treatment, will shed some light to the uncharted waters.
Conflict of interest: none declared.
References
- 1.Maloberti A, Oliva F, De Chiara B, Giannattasio C. Asymptomatic aortic mural thrombus in a minimally atherosclerotic vessel. Interact CardioVasc Thorac Surg 2016;22:371–4. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2.Choukroun EM, Labrousse LM, Madonna FP, Deville C. Mobile thrombus of the thoracic aorta: Diagnosis and treatment in 9 cases. Ann Vasc Surg 2002;16:714–22. [DOI] [PubMed] [Google Scholar]
- 3.Fayad ZY, Semaan E, Fahoum B, Briggs M, Tortolani A, D'Ayala M. Aortic mural thrombus in the normal or minimally atherosclerotic aorta. Ann Vasc Surg 2013;27:282–90. [DOI] [PubMed] [Google Scholar]
- 4.Tsilimparis N, Hanack U, Pisimisis G, Yousefi S, Wintzer C, Rückert RI. Thrombus in the non-aneurysmal, non-atherosclerotic descending thoracic aorta - an unusual source of arterial embolism. Eur J Vasc Endovasc Surg 2011;41:450–7. [DOI] [PubMed] [Google Scholar]
- 5.Morris ME, Galinanes EL, Nichols WK, Ross CB, Chauvupun J. Thoracic mural thrombi: A case series and literature review. Ann Vasc Surg 2011;25:1140 e17–21. [DOI] [PubMed] [Google Scholar]