From Recanalization to Failed Recovery: No Reflow, No Rescue, and No Regrow After Thrombectomy

Area of Science:

• Neurology
• Vascular Medicine
• Regenerative Medicine

Background:

• Endovascular thrombectomy (EVT) achieves high recanalization rates in acute ischemic stroke with large vessel occlusion (LVO).
• However, successful reperfusion does not consistently lead to functional independence, a phenomenon termed futile recanalization (FR).
• FR underscores the limitations of macrovascular reperfusion alone in stroke recovery.

Purpose of the Study:

• To propose a mechanistic framework for futile recanalization (FR) in acute ischemic stroke.
• To examine the determinants of FR, including microvascular failure, secondary neuronal injury, and impaired neuroplasticity.
• To identify strategies for improving functional outcomes after EVT.

Main Methods:

• Review of clinical, imaging, procedural, and molecular factors contributing to FR.
• Analysis of the "3 R's" of stroke recovery: No-Reflow, No-Rescue, and No-Regrow.
• Synthesis of current understanding of the mechanisms underlying futile recanalization.

Main Results:

• Futile recanalization (FR) is driven by microvascular dysfunction (No-Reflow), secondary neuronal loss (No-Rescue), and impaired neuroplasticity (No-Regrow).
• No-Reflow involves capillary obstruction and endothelial injury.
• No-Rescue results from neuroinflammation and blood-brain barrier breakdown.
• No-Regrow is characterized by failed neurogenesis and axonal degeneration.

Conclusions:

• Understanding the multifactorial nature of FR is crucial for improving EVT outcomes.
• Future strategies must address microvascular injury, inflammation, and neuroplasticity.
• Adjunctive therapies targeting downstream perfusion and neuroinflammation are needed to translate angiographic success into functional recovery.