The described invention provides endovascular devices that share the following general features: a working segment, a support segment, a working lumen, a support lumen, a side hole, and an angled extension. A described endovascular device includes an outer support catheter and an inner catheter with a side hole optionally containing an angled extension disposed at least partially within the lumen defined by the outer support catheter. The inner catheter can be connected to sets of grips on the outer catheter and the inner catheter, which are used by the operator to rotate one catheter relative to the other so as to position the side hole or the angled extension of the inner catheter in the targeted vessel. A radiopaque marker or intravascular ultrasound can be used to identify the position of the distal side hole in vivo. In some devices, the distal segment beyond the side hole (the support segment) for each of the described devices is effective to provide stability to each endovascular device, to provide strength to the endovascular device, to provide support for the endovascular device, to facilitate placement of the endovascular device, to anchor the endovascular device within a blood vessel, to reduce kickback of the endovascular device, or a combination thereof. The endovascular devices described can include additional support elements, for example, a balloon, a stent, a wire, or a combination thereof. The described selectively inflatable balloon is of two dimensions, a diameter and a length, sized to fit within the diameter of a vessel, for positioning the endovascular device. It may be disposed in a circumferential array of selectively inflatable balloons, as a single distal inflatable balloon or both. The circumferential array of selectively inflatable balloons is effective to position the endovascular device within a target blood vessel. The single distal balloon is effective to anchor the endovascular device within a target blood vessel. Each inflatable ba