A device for clamping a tissue, the device having a clamp (100) with at least one magnetic portion. In at least one embodiment, the clamp (100) has two oppositely polarized magnets (102, 104) and a mounting structure (106) for the magnets. In some other embodiments, a clamp has an electromagnetic collar (500) and a power source (300) to provide power to the collar (500) via an electrical connector (302). In at least some embodiments, the clamps (100) may also be electromagnetic.