Acute limb ischemia in COVID-19 patients: Could aortic floating thrombus be the source of embolic complications?

Bellosta et al1 recently demonstrated a significantly higher incidence of acute limb ischemia (ALI) in COVID-19 patients. In addition, an increased failure rate after revascularization occurred. The colleagues must be complemented for their clinical and scientific com- mitments. The increased thromboembolic complica- tions in COVID-19 patients have been reported even in those receiving anticoagulant therapy and in nonathero- sclerotic patients.1-3 More than 27,000 COVID-19 cases were registered in our region (Emilia-Romagna). Our unit represents the unique vascular surgery service in the province of Modena. As a tertiary COVID center, we did not observe ALI in such patients. It must be taken into account that Bellosta et al1 provide care in an Italian region with a higher incidence of COVID-19 (Lombardia). However, this difference of incidence in northern Italy remains unclear. We observed two COVID-19 patients with concomitant pulmonary embolism (PE) and aortic floating thrombus (AFT; Fig). They were asymptomatic for peripheral embolism and without a source for the PE. Because of the PE, anticoagulant therapy and low- dose antiplatelet therapy were initiated. A significant reduction of the AFT was observed with resolution of the PE in both patients. The AFT is a rare but serious clin- ical condition able to cause dramatic peripheral embo- lism.4 Aortic stent implantation, abnormal coagulation function, and aortic diseases were reported as predictors of AFT.4 Medical therapy was proposed as the treatment of choice in asymptomatic AFT patients.4 Following the plethora of procoagulant modifications described in COVID-19 patients and the above-mentioned trends to intrastent thrombus relapse, we preferred to avoid inva- sive procedures.4,5 Indeed, the AFT may be a more common source of ALI in COVID-19. The preoperative workup reported by Bellosta et al1 did not include thoracic computed tomography (CT) angiog- raphy. COVID-19 patients are usually diagnosed by means of CT scans, and our observations were possible thanks to the use of contrast medium. Finally, thoracoabdominal CT angiography should be considered a routine evaluation in COVID-19 patients presenting with embolic complications. Clearly, further investigations are required: the throm- botic mechanism; the type, dose, and duration of the anti- coagulant therapy; and the indications for and timing of surgical management of thrombus and emboli.1-3,5