The present invention involves a surgical device and method of use, particularly an assembly and method incorporating a shaped expandable member along the distal region of an ablation device to facilitate ablation of a circumferential region of tissue engaged by the expandable member. The ablation device assembly includes an elongate body with a proximal end portion, a distal end portion, and a longitudinal axis. A contact member is located along the distal end portion of the elongate body. The contact member has a circumferential wall and is expandable from a radially collapsed condition to a radially expanded condition. The contact member also includes a single chamber having a single bulbous section. The single bulbous section has a plurality of longitudinally adjacent circumferential regions wherein adjacent regions have dissimilar wall thicknesses. The ablation device also has an ablation element having an ablative energy source that is located along the distal end portion, wherein the ablation element cooperates with the contact member such that the ablative energy source emits a substantially circumferential pattern of energy through the circumferential wall.