**8. CVD and similar conditions**

The lesions can be partial but significant (>60% stenosis, for intervention purpose, however, venography demonstrating more than 50% stenosis of the subclavian, brachiocephalic vein, and superior vena cava in the upper extremity or the iliac vein or inferior vena cava in the lower extremity is considered central venous occlusion) or complete thrombotic occlusion [or chronic total occlusion (CTO)]. In addition, patients with TCC present with catheter malfunction and may have catheter-related sheath (CRS) (old term: fibrin sheath), with or without clot at the catheter tip (called catheter-related atrial thrombus, CRAT).
