Delayed thromboembolic risk in recovered Covid -19 patient, emerging evidence and call for action:Unusual imaging pattern of vascular disease in Covid treated patient.

We document a case of 55-year-old male recovered from covid-19, was admitted in ICU, treated symptomatically & given routine thrombosis prophylaxis was discharged after two negative RT-PCR reports again presented a week later with complaints of fever, breathlessness and bluish discolouration of lower limbs & had elevated D-dimer level

Initially, chest X-ray was normal and computed tomography (CT) chest showed fibro parenchymal changes with architectural distortion and subpleural bands in posterior segments with small areas of consolidation in bilateral lung fields with no evidence of pulmonary thrombosis. Splenic infarct with splenic vein thrombosis was noted incidentally in limited sections of abdomen. Bilateral lower limb arterial Doppler revealed thrombosis and decreased attenuation of arteries of bilateral lower limbs, following this lower limb CT angiography was performed which showed patent visualised part of the aorta, the origin of celiac trunk, bilateral iliac and internal and external iliac arteries, with atherocalcific focus along the wall of infrarenal aorta with complete thrombosis of right deep femoral artery, right tibioperoneal trunk, bilateral anterior tibial(ATA), left popliteal, left posterior tibial and left peroneal artery and right dorsalis pedis artery with attenuated calibre of right popliteal, right proximal ATA, right PTA, left proximal and distal ATA and DPA with recanalization of right middle one-third peroneal artery.

At the end of 2019, a novel coronavirus was identified as the cause of pneumonia cases in Wuhan, China. On March11,2020, WHO declared coronavirus disease(COVID-19) as pandemic [1].Droplets and contact are the main means of transmission [2]. Fever, cough, breathing difficulties, digestive issues and loss of smell and taste are the most common symptoms of novel SARS-CoV2 infection but vascular manifestations have not been highlighted much. It is increasingly evident that COVID-19 is a systemic disease and can lead to systemic coagulation activation and thrombotic complications including thrombosis of extracorporeal circuits for continuous venovenous hemofiltration (CVVH), central venous catheter-associated thrombosis, and deep venous thrombosis (DVT) and pulmonary embolism (PE). Most but not all of these complications occurred in patients during the infection and hospital stay, with most patients receiving routine thrombosis prophylaxis but delayed complications are also seen even after recovery(3,4).In our patient, who was a non-smoker & had no associated comorbidities, the development of thrombosis post-recovery is alarming. Thromboembolism(TE) is a frequent complication in COVID-19 patients but after recovery is rare.

The occurrence rate of TE in critically ill COVID patients is estimated at 20-25%, which is higher than in the overall ICU population and having higher d-dimer scores (3,4,5). Similarly, the development of arterial thrombosis in our patient was heralded by a dramatic increase in d-dimer level evidenced by normal fibrinogen and elevated WBC and CRP levels around the time of the thrombotic event. A recently published cohort study from Lombardy, Italy, demonstrated a higher-than-expected incidence of Acute limb ischemia (ALI)due to arterial thrombosis in COVID-19 patients(6).ALI is a limb-threatening thromboembolic event that is considered a surgical emergency. It is hypothesized that COVID-19 induces a hypercoagulable state, which may have predisposed to development of thrombosis after recovery. Typically, an episode of ALI in a patient without significant peripheral arterial occlusive disease would be an embolic phenomenon (7). Although elevated d-dimer has been shown to be a negative prognostic marker, associated with increased risk of both ARDS and death, it may provide additional information regarding thromboembolic events(8). Given this risk, pharmacologic thromboprophylaxis should be strongly considered in all hospitalized COVID-19 patients (9).

The case herein reported is characterized by an anomalous thrombus formation in healthy limb vessels of a 55-year-old patient recovered from covid, which led to peripheral embolization. Despite the similarity with those cases, a word of caution should be said before considering the SARS-CoV-2 a highly thrombotic virus which can affect patients post-infection also. Both medical and surgical therapies delivered to that recovered COVID-19 patient were successful, with no recurrences.