A balloon arrangement provided at a distal end of the catheter is configured for deployment within a vessel and comprises a distal balloon and a proximal balloon spaced apart from the distal balloon. An ablation arrangement is provided at the distal end of the catheter and configured to ablate target tissue proximate the vessel. A vessel deformation arrangement comprises at least a portion of the balloon arrangement and is configured to draw a wall segment of the vessel and the target tissue inwardly towards the ablation arrangement. The vessel deformation arrangement may include a port provided in a section of the shaft between the distal and proximal balloons. The port and balloon arrangement are configured to cooperatively draw the wall segment of the vessel and the target tissue inwardly towards the ablation arrangement in response to a negative pressure developed at the port.
