Cerebral infarction and an ascending aortic thrombus in a patient with systemic capillary leak syndrome: a case report

Abstract Background Systemic capillary leak syndrome (SCLS) is a rare disorder characterised by recurrent episodes of hypovolaemic shock, haemoconcentration, and hypoalbuminaemia, caused by transient increases in vascular permeability. Although venous thromboembolic complications have been reported in patients with SCLS, arterial thrombosis involving the ascending aorta is rare. Herein, we report a case of cerebral infarction in a patient with SCLS and an ascending aortic thrombus, which was considered the most likely embolic source. Case presentation A 62-year-old man presented with generalised oedema, oliguria, severe hypotension, marked haemoconcentration (haematocrit, 70%), acute kidney injury, and hypoalbuminaemia. He was clinically diagnosed with SCLS based on the characteristic findings during the current episode and history of a previous similar episode; the presence of a serum immunoglobulin G-kappa monoclonal protein further supported this diagnosis. During the acute leak phase, the patient developed compartment syndrome requiring a decompressive fasciotomy. Two days after admission, he suddenly developed aphasia and right hemiplegia while eating breakfast. Magnetic resonance imaging of the brain revealed an acute cerebral infarction due to occlusion of the left internal carotid artery. Endovascular thrombectomy achieved successful reperfusion (Thrombolysis in Cerebral Infarction grade 2b). Contrast-enhanced computed tomography angiography revealed a filling defect in the ascending aorta without evidence of aneurysm, dissection, or significant atherosclerosis. Anticoagulation therapy with heparin, followed by warfarin, resulted in complete resolution of the thrombus filling defect on follow-up imaging. Histopathological examination of the thrombus retrieved from the occluded cerebral artery during thrombectomy revealed a fibrin-rich thrombus with neutrophil and lymphocyte infiltration, compatible with an early stage thrombus. Conclusions This case suggests that severe haemoconcentration during the acute leak phase of SCLS, potentially in combination with endothelial dysfunction, may have contributed to ascending aortic thrombus formation. While the ascending aortic thrombus was considered the most likely embolic source of the cerebral infarction, a causal relationship could not be established. Cerebral infarction may be a thrombotic complication of SCLS; atypical arterial embolic sources such as an ascending aortic thrombus may occur. Further accumulation of similar cases is required to clarify the mechanisms and optimal management of arterial thrombotic complications in SCLS.