These devices are parts of the The HeartWare Ventricular Assist System (HVAD). They attach to the HeartWare HVAD pump which helps the heart deliver blood to the rest of the body. The clamp screws are at risk of breaking when tightening the strain relief clamp and outflow graft tears have been observ

http://www.fda.gov/medical-devices/medical-device-recalls/medtronic-recalls-heartware-hvad-pump-outflow-graft-and-outflow-graft-strain-relief-due-risk-breaks