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. 2022 Jan;14(1):neurintsurg-2020-017163.
doi: 10.1136/neurintsurg-2020-017163. Epub 2021 Mar 24.

Dynamics of cerebral perfusion and oxygenation parameters following endovascular treatment of acute ischemic stroke

Gianluca Brugnara  1 , Christian Herweh  1 , Ulf Neuberger  1 , Mikkel Bo Hansen  2 , Christian Ulfert  1 , Mustafa Ahmed Mahmutoglu  1 , Martha Foltyn  1 , Simon Nagel  3 , Silvia Schönenberger  3 , Sabine Heiland  1 , Peter Arthur Ringleb  3 , Martin Bendszus  1 , Markus Möhlenbruch  1 , Johannes Alex Rolf Pfaff  1 , Philipp Vollmuth  4
Affiliations

Dynamics of cerebral perfusion and oxygenation parameters following endovascular treatment of acute ischemic stroke

Gianluca Brugnara et al. J Neurointerv Surg. 2022 Jan.

Abstract

Background: We studied the effects of endovascular treatment (EVT) and the impact of the extent of recanalization on cerebral perfusion and oxygenation parameters in patients with acute ischemic stroke (AIS) and large vessel occlusion (LVO).

Methods: Forty-seven patients with anterior LVO underwent computed tomography perfusion (CTP) before and immediately after EVT. The entire ischemic region (Tmax >6 s) was segmented before intervention, and tissue perfusion (time-to-maximum (Tmax), time-to-peak (TTP), mean transit time (MTT), cerebral blood volume (CBV), cerebral blood flow (CBF)) and oxygenation (coefficient of variation (COV), capillary transit time heterogeneity (CTH), metabolic rate of oxygen (CMRO2), oxygen extraction fraction (OEF)) parameters were quantified from the segmented area at baseline and the corresponding area immediately after intervention, as well as within the ischemic core and penumbra. The impact of the extent of recanalization (modified Treatment in Cerebral Infarction (mTICI)) on CTP parameters was assessed with the Wilcoxon test and Pearson's correlation coefficients.

Results: The Tmax, MTT, OEF and CTH values immediately after EVT were lower in patients with complete (as compared with incomplete) recanalization, whereas CBF and COV values were higher (P<0.05) and no differences were found in other parameters. The ischemic penumbra immediately after EVT was lower in patients with complete recanalization as compared with those with incomplete recanalization (P=0.002), whereas no difference was found for the ischemic core (P=0.12). Specifically, higher mTICI scores were associated with a greater reduction of ischemic penumbra volumes (R²=-0.48 (95% CI -0.67 to -0.22), P=0.001) but not of ischemic core volumes (P=0.098).

Conclusions: Our study demonstrates that the ischemic penumbra is the key target of successful EVT in patients with AIS and largely determines its efficacy on a tissue level. Furthermore, we confirm the validity of the mTICI score as a surrogate parameter of interventional success on a tissue perfusion level.

Keywords: CT perfusion; angiography; intervention; stroke; thrombectomy.

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Conflict of interest statement

Competing interests: Additionally, the authors disclose the following relationships with companies unrelated to this research project. SN: consultancy: Brainomix, Boehringer Ingelheim; payment for lectures including service on speakers' bureaus: Pfizer, Medtronic, Bayer AG. CH: consultancy: Brainomix, Oxford, UK; comments: <€10,000. CU: travel/accommodation/meeting expenses unrelated to activities listed: MicroVention, Stryker. SH: grants/grants pending: Deutsche Forschungsgemeinschaft (DFG) - SFB 1118. MB: board membership: Data and Safety Monitoring Board for Vascular Dynamics, Guerbet, Boehringer Ingelheim; consultancy: Codman, Roche Diagnostics, Guerbet, Boehringer Ingelheim, BBRaun, Merck; grants/grants pending: DFG, Hopp Foundation, Novartis, Siemens, Guerbet, Stryker, Covidien, EU; payment for lectures including service on speakers' bureaus: Novartis, Roche Diagnostics, Guerbet, Teva Pharmaceutical Industries, Bayer AG, Codman. MM: board membership: Codman; consultancy: Medtronic, MicroVention, Stryker; payment for lectures including service on speakers' bureaus: Medtronic, MicroVention, Stryker; grants/grants pending: Balt. *Money paid to the institution. JARP: payment for lectures including service on speakers' bureaus: Siemens; travel/accommodation/meeting expenses unrelated to activities listed: Stryker, MicroVention. PAR: consultancy: Bayer, Pfizer, Daiichi Sankyo; personal fees: Boehringer Ingelheim.

Figures

Figure 1
Figure 1
Example of processed computed tomography perfusion (CTP) data before and after mechanical thrombectomy. Time-to-maximum (Tmax) maps are shown both in color and grayscale, and the segmentation of the baseline alteration of perfusion (voxels Tmax >6 s) is also overlayed onto both the baseline and post-interventional grayscale Tmax images to improve referencing of the changes in the initially affected area. In the upper row, a patient with modified Treatment in Cerebral Infarction (mTICI) = 2a, demonstrating a largely unchanged perfusion alteration after intervention. In the lower row, a patient with mTICI = 2c, demonstrating a dramatic reduction of the perfusion alteration after interventional therapy, with only a small area of focally elevated Tmax adjacent to the left lateral ventricle, indicating a successful reperfusion of the vast majority of the initially affected tissue.
Figure 2
Figure 2
Quantitative perfusion (A) and oxygenation (B) metrics before and after mechanical thrombectomy, stratified by modified Treatment in Cerebral Infarction (mTICI) outcome. nCBF, normalized cerebral blood flow; nCBV, normalized cerebral blood volume; nCMRO2, normalized metabolic rate of oxygen; nCOV, normalized coefficient of variation; nCTH, normalized capillary transit time heterogeneity; nMTT, normalized mean transit time; nOEF, normalized oxygen extraction fraction; nTmax, normalized time-to-maximum; nTTP, normalized time-to-peak.
Figure 3
Figure 3
(A) Total volumes before and after interventional treatment for the total affected area of hypoperfusion, the ischemic penumbra and the ischemic core, stratified by modified Treatment in Cerebral Infarction (mTICI) outcome. (B) Plotted correlations between the percentage-wise change in volume after endovascular treatment for total ischemic area, ischemic penumbra and ischemic core, stratified by mTICI outcome.
Figure 4
Figure 4
Plotted correlations between baseline core volumes and final infarction, stratified by modified Treatment in Cerebral Infarction (mTICI) outcome.
See this image and copyright information in PMC

References

    1. Powers WJ, Rabinstein AA, Ackerson T, et al. . Guidelines for the early management of patients with acute ischemic stroke: 2019 update to the 2018 guidelines for the early management of acute ischemic stroke: a guideline for healthcare professionals from the American Heart Association/American Stroke Association. Stroke 2019;50:e344–418. 10.1161/STR.0000000000000211 - DOI - PubMed
    1. Goyal M, Ospel JM, Menon B, et al. . Challenging the ischemic core concept in acute ischemic stroke imaging. Stroke 2020;51:3147–55. 10.1161/STROKEAHA.120.030620 - DOI - PubMed
    1. Goyal M, Menon BK, van Zwam WH, et al. . Endovascular thrombectomy after large-vessel ischaemic stroke: a meta-analysis of individual patient data from five randomised trials. Lancet 2016;387:1723–31. 10.1016/S0140-6736(16)00163-X - DOI - PubMed
    1. Brugnara G, Neuberger U, Mahmutoglu MA, et al. . Multimodal predictive modeling of endovascular treatment outcome for acute ischemic stroke using machine-learning. Stroke 2020;51:3541–51. 10.1161/STROKEAHA.120.030287 - DOI - PubMed
    1. Zaro-Weber O, Fleischer H, Reiblich L, et al. . Penumbra detection in acute stroke with perfusion magnetic resonance imaging: validation with 15O-positron emission tomography. Ann Neurol 2019;85:875–86. 10.1002/ana.25479 - DOI - PMC - PubMed