The pathobiology of chronic total occlusion (CTO) is complex.1) In such lesions, 4 arterial zones (lumen, intimal plaque, media, adventitia) are reached by substantial inflammatory processes, and each layer is equally affected.2) In some cases, stents for recanalization are partially in an extraluminal-intramedial position, and the specific evolution and endothelization have not been studied. We report here 3 cases for which a CTO Percutaneous Coronary Intervention has been performed with reverse-Controlled Anterograde and Retrograde Tracking (CART) techniques by 2 expert operators with an unusual aneurysmal evolution (Figure 1). The stent did not appear to be undersized with a classic late acquired stent malapposition. We know that after a CTO procedure, the mean artery diameter increases by a small percentage, especially in its distal portion.3) Here, the “lumen” artery increased by more than 100%, and each time, it occurred in the reverse CART target zone. Two combined options could probably explain the aneurysmal evolution. First, the reverse CART technique with large knuckle wires created a media hematoma that could partially or totally disappear several weeks after stenting. Second, due to a lack of constrained elastic tunics, the blood pressure flow shreds the media. The walls are no longer held by a consistent media or elastic tunics, and thus, they become aneurysmal: a progressively shredding acquired aneurysm of the neo-lumen without variation in the adventitia diameter. Therefore, each complex revascularization of CTO should be controlled, with intravascular optical coherence tomography if necessary.