Method of making recessed features on inner surface of tubular structure by thermal ablation

A method of forming at least one recessed feature on an inner surface of a fenestrated stent structure, comprising the steps of:

• providing an electrically conductive fenestrated stent structure having a central lumen, an inner concave surface and an outer convex surface;
• mounting the fenestrated stent structure in a dielectric holding fixture;
• coupling a bearing block assembly to the fenestrated stent structure;
• introducing an electrode into the central lumen of the fenestrated stent structure in cooperation with the bearing block assembly, the electrode having a predefined pattern corresponding to a pattern of the at least one recessed feature to be formed on the inner concave surface of the fenestrated stent structure and the electrode being rotatable within the central lumen;
• applying electrical current to the electrode and the predefined pattern;
• and
• transferring the electrical current to the inner concave surface of the fenestrated stent structure thereby cutting the at least one recessed feature on the inner concave surface.