During angioplasty, the balloon inflation stretches the arterial walls, which can cause injury to the endothelial cells. This can lead to a process called re-endothelialization, where new endothelial cells form to repair the damaged area. Additionally, the mechanical stress can affect the smooth muscle cells in the tunica media, potentially initiating a response that leads to cell proliferation and extracellular matrix production. This reaction can sometimes cause restenosis, where the artery narrows again after the procedure.
