Since the 1950s, cardiologists have used cardiac catheterization to diagnose and treat coronary artery disease. Through a catheter inserted into the femoral artery in the groin, the physician can perform angioplasty and insert stents into blocked arteries.
A new approach to this procedure – accessing the heart though the radial artery in the wrist – is gaining momentum among interventional cardiologists and generally results in fewer complications for patients.
While use of this procedure began on a small scale in the 1990s, it has only been in recent years that use of the radial approach has become more widespread. Early equipment used for balloon angioplasties and stents was too large to use in the smaller radial artery, but development of smaller catheters by medical suppliers has made it possible to use the radial artery for most catheter-based procedures, says Jacob Townsend, MD, an interventional cardiologist at Birmingham Heart Clinic, P.C.
“Use of this procedure still is not widespread. Only five percent of cases five years ago were done radially,” Townsend says. “In my practice, 80 percent of cases are performed via the radial artery. The use of radial artery access has been growing for several reasons: patients are requesting it because it doesn’t require groin access and bed rest, and because the chance of bleeding from this procedure is less.”
A Baylor University Medical Center study shows that patients undergoing the radial artery approach have a statistically significant reduction in both major and minor bleeding and the incidence of death, heart attack and stroke is significantly reduced. “One of the biggest predictors of mortality is blood loss, so your chance of death is higher if you lose a lot of blood,” Townsend says. “It is almost impossible to have significant bleeding from the radial artery. We see post-procedure bleeding in three to six percent of femoral access cases, but in less than one percent of procedures performed through the radial artery.”
Patient satisfaction increases with radial artery access for a number of reasons. Discomfort following the procedure is greatly decreased in most patients. “An inflatable cuff is placed on the patient’s wrist to stop the bleeding, so the person can sit up immediately following the catheterization and can eat immediately,” Townsend says. “It also reduces the back pain that many patients experience while lying flat of their back for several hours following the femoral procedure. If all goes well, most patients go home the same day.”
The cost for the radial access catheterization is about the same as the femoral procedure, Townsend says, because equipment is now made specifically for radial access. However, indirect cost savings may result from a reduced need for post-procedure observation, a reduction in complications from bleeding, and same-day discharge of patients.
Unfortunately, not all patients are candidates for the radial artery access procedure. The patient must have a good blood supply in the hand, which is determined through the Allen test. “In the Allen test, the physician presses one thumb against the patient’s ulnar artery and the other thumb on the radial artery. The patient then opens and closes the hand until it turns pale,” Townsend says. “The doctor then releases pressure on the ulnar artery. If normal color returns to the hand in eight seconds or less, we know that the ulnar artery can supply all the blood the hand needs in the rare event that the radial artery occludes.”
Townsend says they can’t perform the radial access procedure on patients with a radial loop, and patients who experience radial artery spasm may not be able to undergo the procedure. “In these cases, we will have to perform the catheterization through the femoral artery,” he says.
The radial access approach is also being used to reach the carotid and renal arteries, and Townsend expects its use will continue to increase and to be applied to other diagnostic and interventional procedures. “Radial access can be used for anything you can reach from the arm. Companies are now making longer shafts that will reach to the legs,” he says. “We are excited about the possibilities of using this method for easier and safer diagnosis and treatment of our patients.”