Table of Contents

Asymptomatic intracranial hemorrhage following endovascular intervention

Asymptomatic intracranial hemorrhage (ICH) following endovascular intervention is a condition where bleeding within the skull occurs after a minimally invasive procedure to treat vascular issues in the brain, but the patient does not exhibit any symptoms. Here are key points to understand this condition:

Causes and Risk Factors: Endovascular Procedures: These include treatments like coil embolization for aneurysms, stent placement for stenosis, and thrombectomy for stroke. The manipulation of blood vessels and use of anticoagulants or thrombolytics can contribute to the risk of ICH. Device-Related Factors: The type and size of the device used, as well as the complexity of the procedure, can influence the risk. Patient-Related Factors: Age, hypertension, anticoagulant/antiplatelet use, previous history of stroke, and general health can affect the likelihood of ICH. Diagnosis: Imaging: Asymptomatic ICH is typically identified through routine post-procedure imaging such as CT scans or MRI, often conducted to ensure the success of the intervention or to check for complications. Types of Hemorrhage: The bleeding can be classified based on location (e.g., subarachnoid, subdural, intracerebral) and the amount of bleeding observed. Clinical Significance: Management Decisions: The absence of symptoms does not necessarily mean the hemorrhage is benign. The management approach can range from careful monitoring to more aggressive treatments if there is a risk of the hemorrhage expanding or causing delayed symptoms. Prognosis: Many patients with asymptomatic ICH may not experience any adverse effects, but close follow-up is essential. The prognosis can vary based on the size and location of the hemorrhage and the overall health of the patient. Management Strategies: Monitoring: Regular neuroimaging to track the progression or resolution of the hemorrhage. Medications: Adjusting anticoagulant or antiplatelet therapy, if applicable. Intervention: In rare cases, surgical intervention might be necessary if there is a significant risk of expansion or if the patient develops symptoms. Preventive Measures: Pre-procedural Assessment: Thorough evaluation of patient risk factors and appropriate planning of the intervention. Intra-procedural Techniques: Utilizing techniques and devices that minimize trauma to blood vessels. Post-procedural Care: Implementing protocols for monitoring and managing potential complications promptly. Understanding the nuances of asymptomatic intracranial hemorrhage following endovascular intervention is crucial for healthcare providers to ensure optimal outcomes and patient safety.

Systematic Review and Meta-Analysis

Harker et al. performed a systematic review and meta-analysis to evaluate the long-term effects of postendovascular thrombectomy aICH.

Methods and results: The meta-analysis protocol was submitted to the International Prospective Register of Systematic Reviews a priori. PubMed, Scopus, and Web of Science were searched from inception through September 2023, yielding 312 studies. Two authors independently reviewed all abstracts. Included studies contained adult patients with ischemic stroke undergoing endovascular thrombectomy with follow-up imaging assessment of ICH reporting comparative outcomes according to aICH versus no ICH. After screening, 60 papers were fully reviewed, and 10 studies fulfilled inclusion criteria (n=5723 patients total, 1932 with aICH). Meta-analysis was performed using Cochrane RevMan v5.4. Effects were estimated by a random-effects model to estimate summary odds ratio (OR) of the effect of aICH versus no ICH on primary outcomes of 90-day modified Rankin Scale 3 to 6 and mortality. The presence of aICH was associated with a higher odds of 90-day mRS 3 to 6 (OR, 2.17 [95% CI, 1.81-2.60], P<0.0001, I2 46% Q 19.15) and mortality (OR, 1.72 [95% CI, 1.17-2.53], P:0.005, I2 79% Q 27.59) compared with no ICH. This difference was maintained following subgroup analysis according to hemorrhage classification and recanalization status.

The presence of aICH is associated with worse 90-day functional outcomes and higher mortality. Further studies to evaluate the factors predicting aICH and treatments aimed at reducing its occurrence are warranted 1)

Propensity-score matching studies

Zhang et al. enrolled patients between January 2015 and December 2022 in a prospective database. Eligible patients with occlusions in the anterior circulation were given endovascular treatment and achieved successful reperfusion. The primary outcome was functional independence (modified Rankin Scale (mRS) score 0-2). Propensity score (PS)-weighted multivariable logistic regression analyses were adjusted and were repeated in subsequent 1:1 PS-matched cohorts.

732 patients, 516 without any intracranial hemorrhage (ICH) and 216 with aICH, were included. 418 and 348 patients were identified after matching in the aICH substudy and hemorrhagic infarction type aICH substudy, respectively. In the postmatched population, patients with aICH had worse functional outcomes (mRS score 0-2) at 90 days than patients without any ICH (37.8% vs 55.5%: P<0.001). Worse functional outcomes were seen in patients with aICH who were older (OR=5.59 (95% CI 2.91 to 10.74)), had higher baseline National Institutes of Health Stroke Scale score (OR=6.80 (95% CI 3.72 to 12.43)), lower baseline Alberta Stroke Program Early CT Score (OR=2.08 (95% CI 1.23 to 3.51)), and who received general anesthesia (OR=3.37 (95% CI 1.92 to 5.90)).

This matched control study largely confirmed that asymptomatic ICH after EVT is associated with worse functional outcomes, and the harmful effect is more significant in older patients and those with severe baseline clinical and radiological features 2)

1)
Harker P, Aziz YN, Vranic J, Chulluncuy-Rivas R, Previtera M, Yaghi S, DeHavenon AH, Tsivgoulis GK, Khatri V, Mistry AM, Khatri P, Mistry EA. Asymptomatic Intracerebral Hemorrhage Following Endovascular Stroke Therapy Is Not Benign: A Systematic Review and Meta-Analysis. J Am Heart Assoc. 2024 Feb 20;13(4):e031749. doi: 10.1161/JAHA.123.031749. Epub 2024 Feb 13. PMID: 38348800; PMCID: PMC11010099.
2)
Zhang X, Shen F, Rui L, Hanchen L, Shen H, Hongye X, Manyue G, Hua W, Zhang L, Zhang Y, Xing P, Li Z, Liu J, Yang P. Acute ischemic stroke with or without asymptomatic intracranial hemorrhage after endovascular treatment: a propensity-score matching study. J Neurointerv Surg. 2024 Aug 6:jnis-2024-022048. doi: 10.1136/jnis-2024-022048. Epub ahead of print. PMID: 39107096.