A catheter is disclosed for creating a lesion in nerve-containing tissue spaced from a body lumen while protecting tissue forming and adjacent to a wall of the body lumen from injury. The catheter includes a catheter body having at least one fluid passage therein, a balloon in communication with the at least one fluid passage to receive cooling fluid for inflating the balloon, a microwave antenna carried by the catheter that emits microwave energy omnidirectionally, thereby heating the tissue spaced from the body lumen to a temperature sufficient to cause thermal damage while the tissue forming and adjacent to the wall of the body lumen are maintained at a temperature where thermal damage does not occur, and a tip structure located at an end of the catheter body, configured to receive a guide wire extending through the at least one fluid passage in the catheter body.