A radio frequency probe is positioned in a body lumen, and the body lumen is heated, using the radio frequency probe, to stabilize the body lumen for insertion of a stent graft or stent. Specifically, the heating shrinks a diameter the body lumen. In one example, blood is allowed to flow through the body lumen during the heating, and in another example, blood flow is blocked through the body lumen during the heating. Another method inserts a metallic mesh in an aneurysmal sac of an aortic aneurysm and expanding the metallic mesh to contact a wall of the aneurysmal sac. The metallic mesh is used to electro-coagulate blood from a Type II endoleak.