Peripheral ischemic limb necrosis (Acro-ischemia) associated with severe COVID-19 patients (COVID-19 limbs): A report of three cases

AbstractObjectivesTo describe challenges in diagnosis and treatment of congenital neonatal gangrene lesions associated with history of maternal coronavirus disease 2019 (COVID-19) infection.Case presentationA preterm neonate was born with upper extremity necrotic lesions and a history of active maternal COVID-19 infection. The etiology of his injury was challenging to deduce, despite extensive hypercoagulability work-up and biopsy of the lesion. Management, including partial forearm salvage and hand amputation is described.ConclusionsNeonatal gangrene has various etiologies, including compartment syndrome and intrauterine thromboembolic phenomena. Maternal COVID-19 can cause intrauterine thrombotic events and need to be considered in a differential diagnosis.

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1097. PPE-1-Regulated Endothelial-Specific Gene Therapy Using VEGF and PDGF-B Induced Angiogenesis and Vessel Maturation in Ischemic Limb Model

Molecular Therapy ◽

10.1016/s1525-0016(16)43927-4 ◽

2002 ◽

Vol 5 (5) ◽

pp. S356

Keyword(s):

Gene Therapy ◽

Specific Gene ◽

Ischemic Limb ◽

Vessel Maturation

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Abstract 15312: Genetic Deletion of Toll-like Receptor 9 Accelerates Blood Flow Recovery after Hindlimb Ischemia

Circulation ◽

10.1161/circ.130.suppl_2.15312 ◽

2014 ◽

Vol 130 (suppl_2) ◽

Author(s):

Sachiko Nishimoto ◽

Daiju Fukuda ◽

Yasutomi Higashikuni ◽

Kimie Tanaka ◽

Yoichiro Hirata ◽

...

Keyword(s):

Endothelial Cells ◽

Blood Flow ◽

Femoral Artery ◽

Cpg Odn ◽

Toll Like Receptor ◽

Artery Ligation ◽

Ischemic Limb ◽

Tnf Α ◽

Genetic Deletion ◽

Inflammatory Molecules

Background: Peripheral artery disease causes significant functional disability and results in impaired quality of life. Toll-like receptor (TLR)-2, 3 and 4 are suggested to participate in blood flow recovery in ischemic limb by modulating inflammation and angiogenesis, however, the role of TLR9 remains unknown. TLR9 recognizes bacterial unmethylated DNA and plays a role in innate defense, although it can also provoke inflammation in response to fragmented DNA released from regenerated mammalian cells. This study tested the hypothesis that genetic deletion of TLR9 accelerates blood flow recovery after femoral artery ligation by inhibiting inflammation and improving endothelial cell function. Methods and Results: Unilateral femoral artery ligation was performed in TLR9-deficient (TLR9KO) mice and wild type (WT) mice. Femoral artery ligation significantly increased RNA expression of TLR9 (20-times) in WT mice and plasma levels of single-stranded DNA and double-stranded DNA, endogenous ligands for TLR9, in both strains of mice compared with each sham-operated group (P<0.05). Laser Doppler perfusion imaging demonstrated that TLR9KO mice significantly improved the ratio of the blood flow in the ischemic to non-ischemic limb compared with WT mice at 2 weeks after ligation (P<0.05). TLR9KO mice showed less accumulation of macrophages and less expression of inflammatory molecules (e.g., TNF-α, MCP-1 and IL-1β in ischemic muscle compared with WT mice (P<0.05, respectively). In vitro experiments using thioglycolate-stimulated peritoneal macrophages demonstrated that CpG ODN, agonistic oligonucleotide for TLR9, promoted the expression of pro-inflammatory molecules (e.g., MCP-1 and TNF-α) in WT macrophages (P<0.05, respectively) but not in TLR9 KO macrophages. Furthermore, activation of TLR9 by CpG ODN inhibited migration and proliferation of endothelial cells as determined by scratch-wound assay and MTS assay, respectively (P<0.05). Conclusion: Our results suggested that TLR9 enhances inflammation and affects migration and proliferation of endothelial cells, leading to impaired blood flow recovery in ischemic limb. TLR9 may serve as a potential therapeutic target for ischemic limb disease.

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The Role of Thermography in the Assessment of the Ischemic Limb

Recent Advances in Medical Thermology ◽

10.1007/978-1-4684-7697-2_47 ◽

1984 ◽

pp. 345-350

Author(s):

M. Dewar ◽

T. Coddington ◽

P. Jarman ◽

K. Robinson

Keyword(s):

Ischemic Limb

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Observations on the perfusion recovery of regenerative angiogenesis in an ischemic limb model under hyperoxia

Physiological Reports ◽

10.14814/phy2.13736 ◽

2018 ◽

Vol 6 (12) ◽

pp. e13736 ◽

Cited By ~ 6

Author(s):

Luis Monteiro Rodrigues ◽

Henrique Silva ◽

Hugo Ferreira ◽

Marie-Ange Renault ◽

Alain-Pierre Gadeau

Keyword(s):

Ischemic Limb

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Abstract 663: Angiotensin-(1-7)-MAS Receptor Gene Knockout Impairs Post-ischemic Hindlimb Neovascularization

Hypertension ◽

10.1161/hyp.60.suppl_1.a663 ◽

2012 ◽

Vol 60 (suppl_1) ◽

Author(s):

Jousie M Pereira ◽

Robson A Santos ◽

Brigida G Schirmer ◽

Lucía S Barcelos

Keyword(s):

Blood Flow ◽

Perfusion Imaging ◽

Gene Knockout ◽

Receptor Gene ◽

Vascular Density ◽

Protective Effects ◽

Hindlimb Ischemia ◽

Ischemic Limb ◽

Mas Receptor ◽

Adductor Muscles

Introduction: Angiotensin-(1-7) is known by its cardiovascular protective effects by activating MAS receptor. It has been shown that Angiotensin-(1-7) stimulates proliferation of endothelial progenitor cells in vitro, but exerts antiangiogenic effects both in inflammatory and tumor environments in vivo. The role of Angiotensin-(1-7)-MAS axis on ischemic conditions was never reported. Hypothesis: We assessed the hypothesis that MAS receptor signaling plays a role in reparative neovascularization after hindlimb ischemia in mice. METHODS: C57BL/6 wild-type (WT) and MAS receptor knockout (MAS-KO) mice (8-10 weeks) were subjected to unilateral permanent left femoral artery occlusion (FAO). Hindlimb blood flow was measured before and immediately after FAO, and 7 and 14 days after FAO by laser Doppler perfusion imaging (LDPI).To further assess the vascularization in the ischemic limb, 28 days after FAO, we used the technique of microbubles contrast enhanced ultrasound perfusion imaging that enables a more sensitive discrimination of blood flow in deep microvessels. Capillary and arteriole density were evaluated by histological analysis at day 14 after FAO. Results: Vascular density was similar in normoperfused muscles from MAS-KO and WT mice. However, the neovascularization response to hindlimb ischemia was significantly reduced in MAS-KO muscles at capillary (p<0.05; n=4/group) and arteriole (p<0.05; n=4/group) level, which led to lesser perfusion recovery of the ischemic limb of MAS-KO mice as evaluated by LDPI (Day 7: 0.67±0.04 vs 0.85±0.04 ischemic/contralateral ratio, p <0.01; Day 14: 0.62±0.15 vs 0.91±0.03, p<0.001; n=8-12/group). In accordance, we observed that MAS-KO mice require shorter time to peak enhancement of microbubles contrast in ischemic adductor muscles compared with WT mice (p<0.01; n = 5-6/group). Conclusion: In conclusion, our data suggests that post-ischemic hindlimb neovascularization and blood flow recovery are impaired in Angiotensin-(1-7)-MAS receptor knockout mice.

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