Chronic total occlusions constitute about one-third of all coronary artery lesions, and remains a significant challenge for the interventionist. Over the last few years, several new developments have emerged. The retrograde approach is one of those new developments and certainly, in experienced hands, has improved success rates significantly. This approach, however, often requires more than one attempt and potentially uses the same septal branch between the donor and the occluded artery. We present 2 cases where a second attempt at the retrograde approach was unsuccessful because of changes in the septal collateral, which having previously allowed passage of the balloon, failed to do so on the subsequent attempt.