Abstract: The purpose of this invention is to provide simple, however highly effective technical solution to guide and track thrombectomy aspiration catheter through vessels anatomy with easy and prompt drive to the thrombus area. This is achieved by a Delivery assist wire which has a variable diameter which has a thicker diameter at the distal working part where major driving and steering forces are needed to push an aspiration catheter through challenging and torturous vessel anatomies. A major innovation is to have a thicker distal part of the Delivery assist wire that is configured to fill into an aspiration catheter distal working part inner lumen and improve deliverability of catheter through torturous vessels. The Delivery assist wire-catheter assembly is configured to remove the thrombus clot out of the vessel without any additional devices.