Abstract: An in-situ fenestration device. The device includes a sheath including a proximal end and a distal end. The device also includes an expandable cone including a proximal end, a distal end, and a body extending between the proximal end and the distal end. The expandable cone includes a heating element. The expandable cone is configured to expand from a crimped state within the sheath into an expanded state extending from the distal end of the sheath. The heating element of the expandable cone is configured to be energized with an energy source to form a fenestration in a graft material at a fenestration site of a stent graft.