Acute limb ischemia (ALI) is a severe complication in coronavirus disease-2019 (COVID-19). Neutrophil extracellular traps (NETs) may play a pathogenic role in systemic thrombosis by propagating inflammation in vessel walls. In COVID-19, NET-related thrombosis can occur in small arteries, including in lung tissue and the coronary artery (1). We detected NETs in a thrombus in a patient with ALI. This thrombus had unique features of difficulty of removal with a Fogarty catheter and requiring a stent for sealing.
A 67-year-old man with paroxysmal atrial fibrillation was diagnosed with COVID-19. Three days later, he suddenly felt left leg pain. ALI was diagnosed by lower extremity arterial ultrasonography, and the patient was immediately transferred to our hospital for revascularization. A balloon-assisted guiding catheter (OPTIMO PPI, Tokai Medical Products) was inserted through the right common femoral artery (CFA) to the left common iliac artery (CIA) ostium to control blood flow. After left CFA cutdown, antegrade thrombectomy was performed using a Fogarty catheter (Edwards Lifesciences) with OPTIMO catheter inflation to control bleeding. The removed thrombus was reddish-black and soft. Angiography showed a residual thrombus in the left proximal CIA, and retrograde thrombectomy with a Fogarty catheter was performed via the left CFA (Figure 1 ). This thrombus was white and elastic and differed markedly from the first thrombus (Figure 2 ). Angiography revealed a small amount of thrombus in the proximal CIA, and a 10.0/40-mm S.M.A.R.T. vascular stent (Cordis, Cardinal Health) was implanted to seal the thrombus. Final angiography showed optimal revascularization without complications (Figure 3 ). Ten days later, the patient was discharged walking unaided. A pathological image of the thrombus sticking to the vessel wall suggested a relationship with NETs (Figure 4 ). Thrombectomy and sealing with a stent are among the important treatments for patients with ALI and COVID-19.
Figure 1.
Initial Angiography and Thrombectomy
(A) Initial angiography. (B) Thrombectomy with a Fogarty catheter in the left iliac artery.
Figure 2.
Thrombi
Thrombi were soft and red (white arrows) and hard and red-white (yellow arrowheads).
Figure 3.
Angiography After Thrombectomy and Stent Sealing
(A) Angiography after thrombectomy. (B) Angiography after stent sealing.
Figure 4.
Staining of Thrombus
(A) Hematoxylin and eosin staining of the hard and reddish-white thrombus showed many aligned neutrophils. (B) CD61 staining showed platelets gathered along the linearly arranged neutrophils. (C) Myeloperoxidase staining showed myeloperoxidase around neutrophils, implying degranulation.
Funding Support and Author Disclosures
The authors have reported that they have no relationships relevant to the contents of this paper to disclose.
Footnotes
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Reference
- 1.Zuo Y., Zuo M., Yalavarthi S., et al. Neutrophil extracellular traps and thrombosis in COVID-19. J Thromb Thrombolysis. 2021;51:446–453. doi: 10.1007/s11239-020-02324-z. [DOI] [PMC free article] [PubMed] [Google Scholar]