Chronic total occlusion--use of a 5 French guiding catheter in a 6 French guiding catheter.

We present a case of a chronic total occlusion that required the use of a 5 Fr in a 6 Fr guiding catheter. The 5 Fr in a 6 Fr guiding catheter method allows ultra-deep seating to increase backup support and assist stent delivery. This technique was paramount in this case, as there were technical challenges with failure to track drug-eluting stents due to vessel tortuosity and lack of support.