Heart valve surgery. Image 1 of 2. Artificial heart valve with sutures attached ready to pull it through a hole (centre) in the patient's chest, and into position in the heart. The valve (white ring) will replace a defective heart valve. It is being held by a removable holder (red). This is keyhole heart surgery, a type of surgery that operates through holes between the ribs. This is less traumatic than open heart surgery (where the rib cage is opened). Heart valves control blood flow into and out of the heart, as well as between its chambers. Valve failure may be life- threatening. For a view of the valve inside the hole, see image M561/079.