Bridging collaterals are a feature of chronic total coronary occlusions (CTO). They bridge between the proximal and distal parts of a coronary artery which is chronically occluded in between. Presence of bridging collaterals, though physiologically useful for providing distal perfusion, could create problem during attempts of percutaneous coronary intervention (PCI). A guidewire passed from the proximal segment, instead of passing into the occluded segment, is likely to take the easy way out into the bridging collaterals.
The coronary angiogram shows bridging collaterals in a post coronary artery bypass right coronary CTO. Sternal wires indicate the post CABG status. A short segment of the right coronary artery is not opacified. The missing segment is bridged by small bridging collaterals.
In a comparative study using conventional coronary angiography (CAG) and computerized tomography (CT), bridging collateral were documented in 15% by CAG while none were picked up by CT . A study of over thousand six hundred CTOs showed that success rate of PCI declined with the presence of bridging collaterals .
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