Hemorrhage/Contrast Staining Areas after Mechanical Intra-Arterial Thrombectomy in Acute Ischemic Stroke: Imaging Findings and Clinical Significance

Abstract

BACKGROUND AND PURPOSE:The aim of this study was to report the CT evolution and clinical significance of HCA after intra-arterial mechanical thrombectomy (revascularization by using retrievers and/or other mechanical devices without concomitant delivery of intra-arterial thrombolytics) in our patients. These lesions are common after intra-arterial thrombolysis, being considered a negative prognostic sign. Their significance after pure mechanical thrombectomy remains unknown.

Evaluation of the CT High-density Area after Endovascular Treatment for Acute Ischemic Stroke

“…10) Parrilla et al 11) first reported HA immediately after mechanical thrombectomy but observed that their appearance was unrelated to the clinical outcome and was not a prognostic factor. HA have been suggested to be caused by multiple factors including contrast enhancement due to the contrast medium, contrast extravasation into the brain parenchyma, and hemorrhage, and no consensus has been established.…”

“…For mechanical thrombectomy, a stent retriever has been used in 87%-100% of our patients and patients reported to have been treated with a known device. 11,23) Since the thrombectomy procedure using a stent retriever involves mechanical injury of the intracranial vessels with the stent and multiple intracranial injections of the contrast medium through the microcatheter, the differences in the procedure may have contributed to an increase in the incidence of HA.…”

“…The quality of FPCT images is sufficient for the assessment of novel lesions after endovascular treatment for acute ischemic stroke, but it is insufficient for the differentiation between hemorrhage and contrast extravasation similar to conventional CT. 28) Recently, the contrast extravasation as a result of an improvement in the recanalization rate. 11) Second, involvement of IV-tPA. In this study, HA occurred in four (67%) of the six patients in whom IV-tPA was performed concomitantly.…”

“…After excluding one article not providing details of the recanalization procedure, a total of 705 patients consisting of those reported in the remaining 13 articles and our patients were analyzed. [10][11][12][16][17][18][19][20][21][22][23][24][25] Concerning the recanalization procedure, the method for endovascular treatment differed after the report in 2012, and the treatments described in the 13 reports that we reviewed were IAT or clot disruption alone before 2012 and mechanical thrombectomy alone after 2012. IV-tPA was performed concomitantly in both groups.…”

“…[5][6][7][8][9] High-density areas occasionally appear on head CT performed early after endovascular treatment for acute ischemic stroke. However, there is no consensus as to the cause of these findings, which have been described as hyperdense areas (HA), 10) hemorrhage/contrast staining areas, 11) contrast enhancement and contrast extravasation, 12) and contrast staining, 13) or their relationship with the clinical outcome.…”