This invention relates generally to coronary artery surgery and is directed particularly to an improved method and means for the surgical treatment of stenotic or occluded major coronary vessels while the heart is beating and without the use of the heart and lung machine, although it can also be used with these modalities with the heart in fibrillation or arrest.
In recent years occlusive coronary artery disease has been surgically treated with the use of various artery by-pass techniques involving cardiopulmonary by-pass. Although these techniques have been highly successful and can be performed with minimal risk, the unusual surgical skill required, and the complexity of the procedure, limits the operation to a small percentage of those patients who could otherwise be benefited. In attempts to surgically treat the vast number of coronary artery disease patients to whom the usual open heart coronary artery by-pass operation was not available or otherwise not indicated, various surgical techniques have heretofore been devised to effect myo-cardial revascularization and neo-vascularization. These procedures can be performed on the beating heart without cardio-pulmonary by-pass, thereby greatly simplifying the procedure with an attendant lessening of the risk. These new techniques, moreover, have been greatly advanced by the comparatively recent development of cine-coronary arteriography.
Most promising of the new surgical techniques has been the direct approach to increase the diameter of the coronary arteries narrowed or obstructed by the disease. One technique involves longitudinal incision of the myo-cardial side of the coronary artery at the site of the stenosis or occlusion, with the insertion of a scalpel through a small incision made in the wall of the coronary artery distal to the occlusion. This procedure effects an immediate increase in the size of the lumen for restored blood flow, but in the calcific rigid artery the lumen may remain small. Upon healing, the inside myo-cardial tissue assumes an intima-like surface defining, with the contiguous decompressed arterial zone, a new lumen having an approximately normal diameter.
In another of the new surgical techniques, known as percutaneous translumenal coronary angioplasty, an inflatable balloon carried at the end of a catheter or the like is passed through the affected artery to the site of the stenosis as observed in cine-coronary arteriography, and then inflated to compact the stenonic plaque and thereby increase the lumen size by dilation. A distinct advantage of this technique is that the catheter can be inserted through a peripheral artery, thereby obviating surgical opening of the chest wall to expose the heart. This technique, however, has limited application because of major problems in its use in the treatment of stenoses associated with coronary artery rigidity, obstruction, and with single severe and multiple stenoses.