collateral circulation
Alternative blood flow pathways that develop or become prominent when primary vessels are occluded or severely stenotic.
Full Definition
Collateral circulation refers to the network of alternative vascular pathways that can provide blood supply to brain tissue when primary arteries are compromised by occlusion, stenosis, or other pathology. These pathways may include existing vessels that dilate and become more prominent, or new vessel formation through angiogenesis. Assessment of collateral circulation is crucial in stroke evaluation as it influences tissue viability, treatment decisions, and clinical outcomes. Good collaterals can maintain tissue perfusion and extend the therapeutic time window, while poor collaterals may lead to rapid infarct progression. Imaging evaluation includes assessment of leptomeningeal collaterals, anterior-posterior circulation connections, and other compensatory pathways.
Usage
Usage note: Specify quality/grade when assessable (good, moderate, poor).
In Context
- "Robust collateral circulation via leptomeningeal anastomoses maintained tissue viability despite M1 occlusion." — Stroke imaging report
- "Poor collateral circulation on CT angiography predicted rapid infarct progression." — Prognostic assessment