Tissue-removing catheter

A tissue-removing catheter for removing tissue in a body lumen, the tissue-removing catheter comprising:

• an elongate body having an axis and proximal and distal end portions spaced apart from one another along the axis, the elongate body being sized and shaped to be received in the body lumen;
• a handle mounted to the proximal end portion of the elongate body and operable to cause rotation of the elongate body;
• a tissue-removing element mounted on the distal end portion of the elongate body, the tissue-removing element being configured to remove the tissue as the tissue-removing element is rotated by the elongate body within the body lumen;
• an inner liner received within the elongate body and coupled to the handle at a proximal end of the inner liner, the inner liner defining a guidewire lumen;
• and
• a sensor arranged with respect to the elongate body and inner liner and configured to detect wear of the inner liner caused by the elongate body contacting the inner liner during use.