Devices, systems and methods related to endoscopic surgery, particularly related to robotic surgical operations, provide a tissue stabilizer for endoscopically stabilizing a target tissue within a patients body. For stabilizing a beating heart during a closed-chest coronary artery bypass grafting procedure, a stabilizer is inserted through an endoscopic cannula and provides sufficient surface area to contact the heart and effectively stabilize the target tissue area. The stabilizer can straddle a blood vessel, such as a coronary artery, which is targeted for an anastomosis. Vessel occlusion fasteners may occlude the target blood vessel prior to the anastomosis procedure.