Collateral miracle: adequate cerebral circulation with only right ICA

Objective: Collateral circulation is essential for cerebral perfusion and the maintenance of cerebral metabolism and function. The clinical factors affecting the collateral circulation in the brain is still unknown. In the presence of slowly developing stenosis, the decrease in cerebral blood flow can be compensated by adequate collateral circulation, and signs of cerebral hemodynamic deterioration may not be observed. Case: This case with a 6-year retrospective record and adequate cerebral circulation with only right Internal Carotid Artery (ICA) is presented.