**3.1 Cannula**

The current iteration of the cannula is in its third generation. It is available in either a 180- or 20-degree angled tip (**Figure 1**). The cannula itself is radiopaque with a self-expanding nitinol tip which allows for visualization under fluoroscopic imaging. The tip is funnel shaped which allows for greater contact surface area of the unwanted material and the cannula shaft supported by a flat stainless-steel coiled wire within the catheter body to support greater pushability, kink resistance, and column strength. The cannula is further supported by a slide over sheath (**Figure 2**), which allows the user to maintain the desired angle needed to engage the unwanted material.
