stays. There is an unmet need for methods to perform coronary artery bypass grafting without the need for a full thoracotomy. There are numerous “minimally invasive” approaches that have been taken to bypass surgery and the area is one of rapid experimentation and development.
One method that may be useful is that of robotic-assisted, coronary artery bypass grafting. With advanced technology and computer systems it is now possible for a surgeon to manipulate sensors and effectors that permit the anastomosis of an internal mammary artery to the left anterior descending coronary artery without the need for a thoracotomy. Research on such a technique is underway at several institutions and robotic-assisted, coronary artery bypass grafting has been performed in living patients in Europe. This is an area in which further device development is expected and needed.
A method has also been proposed to perform coronary artery bypass grafting of total coronary occlusions with the use of the neighboring coronary vein. This method has been developed by Dr. Stephen Oesterle, formerly of Stanford University, and has been entitled percutaneous in situ coronary artery bypass grafting (PICAB). The PICAB method utilizes an approach through the femoral vein, involving puncture of the coronary vein adjacent to the left anterior descending coronary artery. Both distal and proximal punctures are made around a 100% stenosis. Connections are then made to the coronary vein, and the vein is blocked both distal and proximal to the conduit portion. This method could make it possible to perform bypass without the need for thoracotomy.
In addition to the methods mentioned above to treat stenosis, there is an urgent need to identify and treat plaques that are not stenotic but that are vulnerable to rupture. Such plaques are the most frequent cause of myocardial infarction and sudden cardiac death. There are multiple technologies capable of characterizing tissue that could be utilized for these purposes. Optical coherence tomography (OCT) has been successfully utilized to obtain very high-resolution images of coronary tissue in living patients. It is also possible to utilize near infrared spectroscopy, both diffuse reflectance and Raman forms, to identify the chemical composition of tissue. Other techniques proposed to identify vulnerable plaque include increased temperature detection, and, in non-invasive tests, ultra fast CT, and magnetic resonance imaging. From this broad range of technology and potential devices, it is highly likely that plaques vulnerable to rupture can be identified before they rupture. This could permit randomized trials of numerous types of plaques stabilization therapy that could be developed.
An additional area in which device development is needed is that of electrophysiology. New forms of energy delivery including radio frequency, thermal, and photonic-based energy sources are under development for the ablation of tracts that cause arrhythmia.
In summary, the cardiovascular area is one of major importance because of the severity and prevalence of cardiovascular disease. The diseases that are causing the major morbidity and mortality for the country in the cardiovascular area are amenable to therapy with a broad range of devices that can definitely be improved, given the current level of development of technology.