Fig. 12.

Sometimes, a less traumatic approach is not possible as the microwire and distally fitted microcatheter (green) are not stiff enough and will slip off ( a ). In such cases, a stiffer diagnostic wire and diagnostic catheter (purple) are used, which provide more stability. The wire is navigated past the site of occlusion ( b ), followed by the diagnostic catheter ( c ). Then, a guide catheter (either a balloon guide catheter as shown in d ) or a regular guide catheter) is advanced and aspiration is applied to clear out clot from the internal carotid artery ( e ).