Research progress on inflammation and hemorrhagic transformation after mechanical thrombectomy in acute ischemic stroke_West China Medical Journal

Authors：

CHANG Yuan ¹ , ZHANG Canfei ² ,  FU Qizhi ³

1. The First Affiliated Hospital of Henan University of Science and Technology / Clinical Medical College of Henan University of Science and Technology, Luoyang, Henan 471003, P. R. China;
2. Department of Neurology, the First Affiliated Hospital of Henan University of Science and Technology, Luoyang, Henan 471003, P. R. China;
3. Department of Intensive Care Medicine, the First Affiliated Hospital of Henan University of Science and Technology, Luoyang, Henan 471003, P. R. China;

Corresponding?author：

FU Qizhi, Email: fuqizhi33@sina.com

Keywords：

Acute ischemic stroke; mechanical thrombectomy; hemorrhagic transformation; inflammatory factor

DOI：

10.7507/1002-0179.202604032

Video：

Export PDF Favorites Scan Get Citation

Abstract Full text Figures/Tables Video References Cited by

Mechanical thrombectomy is an important reperfusion treatment for acute ischemic stroke, but postoperative hemorrhagic transformation can affect the patient’s neurological function recovery and long-term prognosis. In recent years, the role of inflammatory response and related biomarkers in the hemorrhagic transformation after mechanical thrombectomy has gradually received attention. This article reviews the relationship between inflammation and hemorrhagic transformation after mechanical thrombectomy in acute ischemic stroke. It mainly introduces the research progress in C-reactive protein, interleukin, peripheral blood inflammatory cell ratio, matrix metalloproteinase-9, and fibrinogen, and discusses their value and limitations in risk assessment of hemorrhagic transformation.

Citation： CHANG Yuan, ZHANG Canfei, FU Qizhi. Research progress on inflammation and hemorrhagic transformation after mechanical thrombectomy in acute ischemic stroke. West China Medical Journal, 2026, 41(5): 827-832. doi: 10.7507/1002-0179.202604032 Copy

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(12): e344-e418.
2.	Fiorelli M, Bastianello S, von Kummer R, et al. Hemorrhagic transformation within 36 hours of a cerebral infarct: relationships with early clinical deterioration and 3-month outcome in the European Cooperative Acute Stroke Study I (ECASS I) cohort. Stroke, 1999, 30(11): 2280-2284.
3.	von Kummer R, Broderick JP, Campbell BC, et al. The heidelberg bleeding classification: classification of bleeding events after ischemic stroke and reperfusion therapy. Stroke, 2015, 46(10): 2981-2986.
4.	Kim S, Yi HJ, Lee DH, et al. Association of high-sensitivity C-reactive protein with patient prognosis following mechanical thrombectomy for acute ischemic stroke. Curr Neurovasc Res, 2020, 17(4): 402-410.
5.	Venditti L, Chassin O, Ancelet C, et al. Pre-procedural predictive factors of symptomatic intracranial hemorrhage after thrombectomy in stroke. J Neurol, 2021, 268(5): 1867-1875.
6.	Rodrigues RF, Hidalgo RCT, Batista S, et al. Prognostic biomarkers in ischemic stroke treated with mechanical thrombectomy: a systematic review. Arq Neuropsiquiatr, 2025, 83(10): 1-7.
7.	Wang H, Tian X, Liao Z, et al. Inflammatory biomarkers may be associated with poor outcomes after mechanical thrombectomy. Thromb J, 2024, 22(1): 58.
8.	Peng Q, Hou J, Wang S, et al. Hypersensitive C-reactive protein-albumin ratio predicts symptomatic intracranial hemorrhage after endovascular therapy in acute ischemic stroke patients. BMC Neurol, 2021, 21(1): 47.
9.	Dogan H, Ozmuk O, Memi? Z, et al. C-reactive protein-to-lymphocyte ratio as a prognostic biomarker in acute ischemic stroke patients undergoing mechanical thrombectomy: a multicenter study. Diagnostics (Basel), 2025, 15(22): 2872.
10.	Bao L, Wang Y, He S. Immunoinflammatory biomarkers as predictors of hemorrhagic transformation in acute ischemic stroke patients after endovascular thrombectomy. Front Neurol, 2025, 16: 1606563.
11.	Sukhanov A, Netliukh A, Ivanova R, et al. Prognostic significance of interleukin-6 in patients with acute ischemic stroke undergoing thrombectomy. Wiad Lek, 2025, 78(10): 2127-2132.
12.	Mechtouff L, Bochaton T, Paccalet A, et al. Association of interleukin-6 levels and futile reperfusion after mechanical thrombectomy. Neurology, 2021, 96(5): e752-e757.
13.	Swanson KV, Deng M, Ting JP. The NLRP3 inflammasome: molecular activation and regulation to therapeutics. Nat Rev Immunol, 2019, 19(8): 477-489.
14.	Bellut M, Papp L, Bieber M, et al. NLPR3 inflammasome inhibition alleviates hypoxic endothelial cell death in vitro and protects blood-brain barrier integrity in murine stroke. Cell Death Dis, 2021, 13(1): 20.
15.	Lin Z, Li Q, Zhang X, et al. Elevated serum NLRP3 inflammasome level potentially predicts haemorrhagic transformation and unfavourable outcome in acute ischemic stroke patients. Ann Med, 2025, 57(1): 2601437.
16.	Goyal N, Tsivgoulis G, Chang JJ, et al. Admission neutrophil-to-lymphocyte ratio as a prognostic biomarker of outcomes in large vessel occlusion strokes. Stroke, 2018, 49(8): 1985-1987.
17.	Pikija S, Sztriha LK, Killer-Oberpfalzer M, et al. Neutrophil to lymphocyte ratio predicts intracranial hemorrhage after endovascular thrombectomy in acute ischemic stroke. J Neuroinflammation, 2018, 15(1): 319.
18.	Shen H, Ma Q, Jiao L, et al. Prognosis and predictors of symptomatic intracranial hemorrhage after endovascular treatment of large vessel occlusion stroke. Front Neurol, 2022, 12: 730940.
19.	Aly M, Abdalla RN, Batra A, et al. Follow-up neutrophil-lymphocyte ratio after stroke thrombectomy is an independent biomarker of clinical outcome. J Neurointerv Surg, 2021, 13(7): 609-613.
20.	Wu B, Liu F, Sun G, et al. Prognostic role of dynamic neutrophil-to-lymphocyte ratio in acute ischemic stroke after reperfusion therapy: a meta-analysis. Front Neurol, 2023, 14: 1118563.
21.	Hao Y, Hu Z, Zhu X, et al. Neutrophil-to-lymphocyte ratio predicts parenchymal hematoma after mechanical thrombectomy in basilar artery occlusion. Front Neurol, 2022, 13: 920349.
22.	Sharma D, Bhaskar SMM. Prognostic role of the platelet-lymphocyte ratio in acute ischemic stroke patients undergoing reperfusion therapy: a meta-analysis. J Cent Nerv Syst Dis, 2022, 14: 11795735221110373.
23.	Feng X, Ye G, Cao R, et al. Identification of predictors for hemorrhagic transformation in patients with acute ischemic stroke after endovascular therapy using the decision tree model. Clin Interv Aging, 2020, 15: 1611-1624.
24.	Diestro JDB, Parra-Farinas C, Balas M, et al. Inflammatory biomarkers and intracranial hemorrhage after endovascular thrombectomy. Can J Neurol Sci, 2022, 49(5): 644-650.
25.	Cao W, Song Y, Bai X, et al. Systemic-inflammatory indices and clinical outcomes in patients with anterior circulation acute ischemic stroke undergoing successful endovascular thrombectomy. Heliyon, 2024, 10(10): e31122.
26.	Yang Y, Cui T, Bai X, et al. Association between systemic immune-inflammation index and symptomatic intracranial hemorrhage in acute ischemic stroke patients undergoing endovascular treatment. Curr Neurovasc Res, 2022, 19(1): 83-91.
27.	Qian A, Zheng L, He H, et al. Predictive value of the systemic immune-inflammation index for outcomes in large artery occlusion treated with mechanical thrombectomy-a single-center study. Front Neurol, 2025, 15: 1516577.
28.	Han L, Miao T, Zheng LY, et al. Systemic immune-inflammation index associated with functional outcomes after endovascular thrombectomy in anterior circulation acute ischemic stroke. Front Neurol, 2025, 16: 1663299.
29.	Rosell A, Cuadrado E, Ortega-Aznar A, et al. MMP-9-positive neutrophil infiltration is associated to blood-brain barrier breakdown and basal lamina type IV collagen degradation during hemorrhagic transformation after human ischemic stroke. Stroke, 2008, 39(4): 1121-1126.
30.	Mizuma A, You JS, Yenari MA. Targeting reperfusion injury in the age of mechanical thrombectomy. Stroke, 2018, 49(7): 1796-1802.
31.	Mechtouff L, Bochaton T, Paccalet A, et al. Matrix metalloproteinase-9 relationship with infarct growth and hemorrhagic transformation in the era of thrombectomy. Front Neurol, 2020, 11: 473.
32.	Iwamoto T, Kitano T, Oyama N, et al. Predicting hemorrhagic transformation after large vessel occlusion stroke in the era of mechanical thrombectomy. PLoS One, 2021, 16(8): e0256170.
33.	Bani-Sadr A, Mechtouff L, De Bourguignon C, et al. Blood-brain barrier permeability and kinetics of inflammatory markers in acute stroke patients treated with thrombectomy. Neurology, 2023, 101(5): e502-e511.
34.	Huang JA, Wu YH, Chen PL, et al. MMP-9 upregulation may predict hemorrhagic transformation after endovascular thrombectomy. Front Neurol, 2024, 15: 1400270.
35.	Kollikowski AM, Pham M, M?rz AG, et al. MMP-9 release into collateral blood vessels before endovascular thrombectomy to assess the risk of major intracerebral haemorrhages and poor outcome for acute ischaemic stroke: a proof-of-concept study. EBioMedicine, 2024, 103: 105095.
36.	Lin C, Pan H, Qiao Y, et al. Fibrinogen level combined with platelet count for predicting hemorrhagic transformation in acute ischemic stroke patients treated with mechanical thrombectomy. Front Neurol, 2021, 12: 716020.
37.	Aboul-Nour H, Jumah A, Mohamed G, et al. Fibrinogen depletion and the risk of intracerebral hemorrhage following endovascular mechanical thrombectomy. Interv Neuroradiol, 2025, 29: 15910199251336948.
38.	Long J, Chen J, Huang G, et al. The differences of fibrinogen levels in various types of hemorrhagic transformations. Front Neurol, 2024, 15: 1364875.

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(12): e344-e418.
2. Fiorelli M, Bastianello S, von Kummer R, et al. Hemorrhagic transformation within 36 hours of a cerebral infarct: relationships with early clinical deterioration and 3-month outcome in the European Cooperative Acute Stroke Study I (ECASS I) cohort. Stroke, 1999, 30(11): 2280-2284.
3. von Kummer R, Broderick JP, Campbell BC, et al. The heidelberg bleeding classification: classification of bleeding events after ischemic stroke and reperfusion therapy. Stroke, 2015, 46(10): 2981-2986.
4. Kim S, Yi HJ, Lee DH, et al. Association of high-sensitivity C-reactive protein with patient prognosis following mechanical thrombectomy for acute ischemic stroke. Curr Neurovasc Res, 2020, 17(4): 402-410.
5. Venditti L, Chassin O, Ancelet C, et al. Pre-procedural predictive factors of symptomatic intracranial hemorrhage after thrombectomy in stroke. J Neurol, 2021, 268(5): 1867-1875.
6. Rodrigues RF, Hidalgo RCT, Batista S, et al. Prognostic biomarkers in ischemic stroke treated with mechanical thrombectomy: a systematic review. Arq Neuropsiquiatr, 2025, 83(10): 1-7.
7. Wang H, Tian X, Liao Z, et al. Inflammatory biomarkers may be associated with poor outcomes after mechanical thrombectomy. Thromb J, 2024, 22(1): 58.
8. Peng Q, Hou J, Wang S, et al. Hypersensitive C-reactive protein-albumin ratio predicts symptomatic intracranial hemorrhage after endovascular therapy in acute ischemic stroke patients. BMC Neurol, 2021, 21(1): 47.
9. Dogan H, Ozmuk O, Memi? Z, et al. C-reactive protein-to-lymphocyte ratio as a prognostic biomarker in acute ischemic stroke patients undergoing mechanical thrombectomy: a multicenter study. Diagnostics (Basel), 2025, 15(22): 2872.
10. Bao L, Wang Y, He S. Immunoinflammatory biomarkers as predictors of hemorrhagic transformation in acute ischemic stroke patients after endovascular thrombectomy. Front Neurol, 2025, 16: 1606563.
11. Sukhanov A, Netliukh A, Ivanova R, et al. Prognostic significance of interleukin-6 in patients with acute ischemic stroke undergoing thrombectomy. Wiad Lek, 2025, 78(10): 2127-2132.
12. Mechtouff L, Bochaton T, Paccalet A, et al. Association of interleukin-6 levels and futile reperfusion after mechanical thrombectomy. Neurology, 2021, 96(5): e752-e757.
13. Swanson KV, Deng M, Ting JP. The NLRP3 inflammasome: molecular activation and regulation to therapeutics. Nat Rev Immunol, 2019, 19(8): 477-489.
14. Bellut M, Papp L, Bieber M, et al. NLPR3 inflammasome inhibition alleviates hypoxic endothelial cell death in vitro and protects blood-brain barrier integrity in murine stroke. Cell Death Dis, 2021, 13(1): 20.
15. Lin Z, Li Q, Zhang X, et al. Elevated serum NLRP3 inflammasome level potentially predicts haemorrhagic transformation and unfavourable outcome in acute ischemic stroke patients. Ann Med, 2025, 57(1): 2601437.
16. Goyal N, Tsivgoulis G, Chang JJ, et al. Admission neutrophil-to-lymphocyte ratio as a prognostic biomarker of outcomes in large vessel occlusion strokes. Stroke, 2018, 49(8): 1985-1987.
17. Pikija S, Sztriha LK, Killer-Oberpfalzer M, et al. Neutrophil to lymphocyte ratio predicts intracranial hemorrhage after endovascular thrombectomy in acute ischemic stroke. J Neuroinflammation, 2018, 15(1): 319.
18. Shen H, Ma Q, Jiao L, et al. Prognosis and predictors of symptomatic intracranial hemorrhage after endovascular treatment of large vessel occlusion stroke. Front Neurol, 2022, 12: 730940.
19. Aly M, Abdalla RN, Batra A, et al. Follow-up neutrophil-lymphocyte ratio after stroke thrombectomy is an independent biomarker of clinical outcome. J Neurointerv Surg, 2021, 13(7): 609-613.
20. Wu B, Liu F, Sun G, et al. Prognostic role of dynamic neutrophil-to-lymphocyte ratio in acute ischemic stroke after reperfusion therapy: a meta-analysis. Front Neurol, 2023, 14: 1118563.
21. Hao Y, Hu Z, Zhu X, et al. Neutrophil-to-lymphocyte ratio predicts parenchymal hematoma after mechanical thrombectomy in basilar artery occlusion. Front Neurol, 2022, 13: 920349.
22. Sharma D, Bhaskar SMM. Prognostic role of the platelet-lymphocyte ratio in acute ischemic stroke patients undergoing reperfusion therapy: a meta-analysis. J Cent Nerv Syst Dis, 2022, 14: 11795735221110373.
23. Feng X, Ye G, Cao R, et al. Identification of predictors for hemorrhagic transformation in patients with acute ischemic stroke after endovascular therapy using the decision tree model. Clin Interv Aging, 2020, 15: 1611-1624.
24. Diestro JDB, Parra-Farinas C, Balas M, et al. Inflammatory biomarkers and intracranial hemorrhage after endovascular thrombectomy. Can J Neurol Sci, 2022, 49(5): 644-650.
25. Cao W, Song Y, Bai X, et al. Systemic-inflammatory indices and clinical outcomes in patients with anterior circulation acute ischemic stroke undergoing successful endovascular thrombectomy. Heliyon, 2024, 10(10): e31122.
26. Yang Y, Cui T, Bai X, et al. Association between systemic immune-inflammation index and symptomatic intracranial hemorrhage in acute ischemic stroke patients undergoing endovascular treatment. Curr Neurovasc Res, 2022, 19(1): 83-91.
27. Qian A, Zheng L, He H, et al. Predictive value of the systemic immune-inflammation index for outcomes in large artery occlusion treated with mechanical thrombectomy-a single-center study. Front Neurol, 2025, 15: 1516577.
28. Han L, Miao T, Zheng LY, et al. Systemic immune-inflammation index associated with functional outcomes after endovascular thrombectomy in anterior circulation acute ischemic stroke. Front Neurol, 2025, 16: 1663299.
29. Rosell A, Cuadrado E, Ortega-Aznar A, et al. MMP-9-positive neutrophil infiltration is associated to blood-brain barrier breakdown and basal lamina type IV collagen degradation during hemorrhagic transformation after human ischemic stroke. Stroke, 2008, 39(4): 1121-1126.
30. Mizuma A, You JS, Yenari MA. Targeting reperfusion injury in the age of mechanical thrombectomy. Stroke, 2018, 49(7): 1796-1802.
31. Mechtouff L, Bochaton T, Paccalet A, et al. Matrix metalloproteinase-9 relationship with infarct growth and hemorrhagic transformation in the era of thrombectomy. Front Neurol, 2020, 11: 473.
32. Iwamoto T, Kitano T, Oyama N, et al. Predicting hemorrhagic transformation after large vessel occlusion stroke in the era of mechanical thrombectomy. PLoS One, 2021, 16(8): e0256170.
33. Bani-Sadr A, Mechtouff L, De Bourguignon C, et al. Blood-brain barrier permeability and kinetics of inflammatory markers in acute stroke patients treated with thrombectomy. Neurology, 2023, 101(5): e502-e511.
34. Huang JA, Wu YH, Chen PL, et al. MMP-9 upregulation may predict hemorrhagic transformation after endovascular thrombectomy. Front Neurol, 2024, 15: 1400270.
35. Kollikowski AM, Pham M, M?rz AG, et al. MMP-9 release into collateral blood vessels before endovascular thrombectomy to assess the risk of major intracerebral haemorrhages and poor outcome for acute ischaemic stroke: a proof-of-concept study. EBioMedicine, 2024, 103: 105095.
36. Lin C, Pan H, Qiao Y, et al. Fibrinogen level combined with platelet count for predicting hemorrhagic transformation in acute ischemic stroke patients treated with mechanical thrombectomy. Front Neurol, 2021, 12: 716020.
37. Aboul-Nour H, Jumah A, Mohamed G, et al. Fibrinogen depletion and the risk of intracerebral hemorrhage following endovascular mechanical thrombectomy. Interv Neuroradiol, 2025, 29: 15910199251336948.
38. Long J, Chen J, Huang G, et al. The differences of fibrinogen levels in various types of hemorrhagic transformations. Front Neurol, 2024, 15: 1364875.

West China Medical Journal

Research progress on inflammation and hemorrhagic transformation after mechanical thrombectomy in acute ischemic stroke

Abstract Full text Figures/Tables Video References Cited by

Previous Article

Next Article

Format

Content