A method of occluding an appendage of the heart with a clamp including at least first and second elongate clamping portions, the first and second elongate clamping portions including tissue engaging surfaces that promote tissue ingrowth. The method includes implanting the clamp by positioning the first and second elongate clamping portions on opposite sides of the appendage. At least one of the first or second elongate clamping portions is biased toward the other of the first and second elongate clamping portions to place the clamp into a clamping position on the appendage. Tissue ingrowth into the tissue engaging surfaces retains the clamp in place on the appendage.