A device (9) is disclosed for partially occluding a blood vessel such that an area of hemostasis within the blood vessel is created without interrupting the blood flow through the blood vessel. The device is particularly suited for performing a cardiac bypass procedure without the need to stop the patient's heart. The device comprises first and second partially occlusive portions (12, 14), spaced apart from one another, wherein the partially occlusive portions are inflatable to at least the inner diameter of the blood vessel. A tubular member (16) interconnects the first and second partially occlusive portions (12, 14) and forms a conduit which allows the blood to flow through. When the first and second partially occlusive portions (12, 14) are inflated, an area of hemostasis is created between an outer surface of the tubular member (16) and an inner wall of the blood vessel while blood continues to flow through the tubular portion. A tube (20) adapted to extend through an opening in the blood vessel to deploy the device includes multiple lumens, such as an inflation lumen (17) to inflate the device and a suture lumen (19) to collapse the device.