CALCIO is a multicentre, prospective, observational cohort study that will collect real world data on the use of intravascular Lithotripsy (IVL) with the Shockwave IVL system to disrupt calcified femoropopliteal and crural lesions in patients with chronic limb-threatening ischemia (CLTI). The primary objective of CALCIO is to understand the effectiveness of IVL in promoting wound healing and preventing amputation. The secondary objectives of CALCIO are to evaluate the immediate effectiveness of the treatment in restoring vessel patency as well as its safety and impact on patients' quality of life.