Bridging collaterals

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 attempted 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.

rca-cto-post-cabg

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 comparitive 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 [1]. A study of over thousand six hundred CTOs showed that success rate of PCI declined with the presence of bridging collaterals [2].

References

  1. Singh S, Singh N, Gulati GS, Ramakrishnan S, Kumar G, Sharma S, Bahl VK. Dual-Source Computed Tomography for Chronic Total Occlusion of Coronary Arteries. Catheter Cardiovasc Interv. 2016 Oct;88(4):E117-E125.
  2. Han YL, Wang SL, Jing QM, Li Y, Zhang J, Ma YY, Luan B. Percutaneous coronary intervention for chronic total occlusion in 1263 patients: a single-center report. Chin Med J (Engl). 2006 Jul 20;119(14):1165-70.