Through innovative technologies - such as robotics and intravascular ultrasound - surgeons are developing and employing less invasive techniques to heal patients and make their recoveries less traumatic.
For coronary disease, the treatment mainstay for years has been bypass surgery or percutaneous coronary interventions - with the lines between the two procedures increasingly blurred as percutaneous interventions became more complex with stent placement and other related applications.
While some form of intervention is the rule rather than the exception in the great majority of cases, physicians agree that less invasion is always the most prudent route.
"One of the important concepts may be that as procedures become less invasive, we also have more patients who may not need anything at all," says Jack A. Ziffer, PhD, MD, director of cardiac imaging for the Miami (Fla.) Cardiac & Vascular Institute and chief of radiology at Baptist Hospital of Miami.
The first step in making surgery less invasive is to have a patient's work-up become less invasive by avoiding procedures such as coronary angiographies whenever possible. Unfortunately, when it comes to assessing cardiac disease, there is seldom a way around a coronary angiogram or diagnostic catheterization prior to either percutaneous intervention or minimally invasive cardiac surgery.
In the next few years, however, Ziffer believes that will change, particularly with CT-based approaches for coronary angiography. Between the ever-expanding technologies of multislice CT and electron-beam CT (EBCT), faster scans and higher-resolution images will offer physicians and surgeons more insightful views into the cardiovascular system. Whether multislice CT or EBCT will be the premier technology, Ziffer says it is too soon to say, but adds that both forms of CT will be beneficial to coronary imaging.
IMAGING BEFORE AND AFTER
Using CT and MRI, surgeons can follow the success of interventions. MRI and positron emission tomography (PET) are regarded as the best tools to assess myocardial viability and whether a patient would benefit from revascularization.
While the hybrid combination of PET and CT has been used extensively for oncology imaging, Ziffer says Miami Cardiac & Vascular Institute soon will ramp-up its two PET-CT systems for cardiac work.
"PET has phenomenal sensitivity and specificity," Ziffer adds. "What it doesn't tell you is what the vascular anatomy is. CT will let the cardiologist and surgeon know whether the patient is a surgical patient or non-invasive patient."
Ziffer emphasizes that diagnostic catheter procedures will not disappear completely, because there always will be patients for whom a surgeon needs to be completely sure about what he or she is about to encounter in the operating room and the highest possible resolution is necessary. However, he adds that it is "realistic to expect in the next three years that we will get the quality of non-invasive coronary angiography sufficient so that diagnostic angiography won't be required in many patients."
Being able to see and anticipate what they are about to encounter is an obvious - albeit preferable where possible - requisite for any surgeon.
"Traditionally for surgeons, if they can't see it, they can't do it," notes Randall K. Wolf, MD, professor of surgery and biomedical engineering at the University of Cincinnati (UC) and director of UC's Center for Surgical Innovation. "Our unaided human performance is limited by a 200-micron accuracy due to our visual discrimination or motor coordination. If we use sophisticated, computer-assisted or robotic systems along with imaging, we can do a lot more. We can get down to almost the nano level."
For more than a decade, Wolf has collaborated with companies such as Intuitive Surgical Inc., Ethicon Endosurgery and ArtiCure Inc. to develop new devices. About eight years ago, he began to develop a technique to perform heart surgery using what he describes as a "remote telemanipulator." That robotic device today is known as Intuitive Surgical's da Vinci surgical system. Wolf aided in the U.S. trials to gather clinical data for the da Vinci's FDA clearance. The first da Vinci was installed at Ohio State University in 1999 under Wolf's direction.
The da Vinci takes a surgeon's hand motion, turns it into a binary code, and transmits that information through servomotors to tiny instruments in the patient's chest.
"One of the things we would like to do is take a CT