Related Experiment Video
Updated: Jul 29, 2025
Optimization of the Longa Middle Cerebral Artery Occlusion Method for Complete Reperfusion
Published on: November 22, 2024
How much of the outcome improvement after successful recanalization is explained by follow-up infarct volume
Helge Kniep1, Lukas Meyer2, Gabriel Broocks2
1Department of Diagnostic and Interventional Neuroradiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany h.kniep@uke.de.
Background:
Follow-up infarct volume (FIV) is used as surrogate for treatment efficiency in mechanical thrombectomy (MT). However, previous works suggest that MT-related FIV reduction has only limited association with outcome comparing MT independently of recanalization success versus medical care. It remains unclear to what extent the relationship between successful recanalization versus persistent occlusion and functional outcome is explained by FIV reduction.
Objective:
To determine whether FIV mediates the relationship between successful recanalization and functional outcome.
Methods:
All patients from our institution enrolled in the German Stroke Registry (May 2015-December 2019) with anterior circulation stroke; availability of the relevant clinical data, and follow-up-CT were analyzed. The effect of FIV reduction on functional outcome (90-day modified Rankin Scale (mRS) score ≤2) after successful recanalization (Thrombolysis in Cerebral Infarction ≥2b) was quantified using mediation analysis.
Results:
429 patients were included, of whom, 309 (72 %) had successful recanalization and 127 (39%) had good functional outcome. Good outcome was associated with age (OR=0.89, P<0.001), pre-stroke mRS score (OR=0.38, P<0.001), FIV (OR=0.98, P<0.001), hypertension (OR=2.08, P<0.05), and successful recanalization (OR=3.57, P<0.01). Using linear regression in the mediator pathway, FIV was associated with Alberta Stroke program Early CT Score (coefficient (Co)=-26.13, P<0.001), admission National Institutes of Health Stroke Scale score (Co=3.69, P<0.001), age (Co=-1.18, P<0.05), and successful recanalization (Co=-85.22, P<0.001). Successful recanalization increased the probability of good outcome by 23 percentage points (pp) (95% CI 16pp to 29pp). 56% (95% CI 38% to 78%) of the improvement in good outcome was explained by FIV reduction.
Conclusion:
56% (95% CI 38% to 78%) of outcome improvement after successful recanalization was explained by FIV reduction. Results corroborate pathophysiological assumptions and confirm the value of FIV as an imaging endpoint in clinical trials. 44% (95% CI 22% to 62%) of the improvement in outcome was not explained by FIV reduction and reflects the remaining mismatch between radiological and clinical outcome measures.
Insights
Follow-up infarct volume reduction explains over half of the outcome improvement seen after successful mechanical thrombectomy (MT) for stroke. This confirms the value of imaging endpoints in clinical trials for stroke treatment efficiency.
Area of Science:
- Neurology
- Radiology
- Clinical Trials
Background:
- Mechanical thrombectomy (MT) uses follow-up infarct volume (FIV) to assess treatment efficiency.
- Previous studies show limited association between MT-related FIV reduction and patient outcomes.
- The extent to which FIV reduction explains the link between recanalization success and functional outcome remains unclear.
Purpose of the Study:
- To determine if FIV reduction mediates the relationship between successful recanalization and functional outcome in stroke patients.
Main Methods:
- Analysis of patients from the German Stroke Registry (May 2015-December 2019) with anterior circulation stroke.
- Quantification of FIV reduction's effect on 90-day functional outcome (modified Rankin Scale score ≤2) after successful recanalization (Thrombolysis in Cerebral Infarction ≥2b) using mediation analysis.
Main Results:
- Successful recanalization was achieved in 72% of 429 analyzed patients.
- FIV reduction explained 56% of the outcome improvement following successful recanalization.
- Good functional outcome was associated with younger age, lower pre-stroke mRS, lower FIV, hypertension, and successful recanalization.
Conclusions:
- FIV reduction accounts for a significant portion (56%) of outcome improvement after successful mechanical thrombectomy.
- These findings support the use of FIV as a valuable imaging endpoint in clinical trials for stroke.
- The remaining unexplained outcome improvement highlights a mismatch between radiological and clinical measures.
