A 76-year-old woman with a history of coronary artery bypass graft surgery underwent percutaneous coronary intervention of a calcified left circumflex artery (LCx) lesion with proximal tortuosity and enlargement (Figure 1A-C). On a RotaWire Floppy, a 1.5-mm burr was managed to cross the lesion with a rotational speed of 220,000 rpm (Figure 1D, Supplementary Video 1). During a final polishing run, the burr collided with the lesion, and the driveshaft prolapsed into the distal left main coronary artery (LM). The driveshaft was suddenly fractured (Figure 1E, Supplementary Video 2), resulting in Ellis type III perforation (Figure 1F, Supplementary Video 3). After the implantation of two polytetrafluoroethylene-covered stents, left coronary angiography revealed no contrast extravasation (Figure 1G). Conversely, angiography of bypass graft elucidated persistent contrast extravasation from the distal LM, requiring surgical repair by filling and sealing the perforation site with surgical cotton (Figure 1H, Supplementary Video 4).