The New Route for Cardiac Cath: Via the Wrist's Radial Artery, Patients Are Back on their Feet with Fewer Complications
Heart patients in the U.S. undergo more than a million cardiac catheterizations each year, making this procedure the most common invasive diagnostic and treatment step in cardiology. To accomplish it, cardiac specialists thread a thin plastic tube called a catheter into an artery near the groin. But today, interventional cardiologists at Lourdes perform an increasing percentage of these procedures by inserting cardiac catheters through an artery at the wrist. Patients and doctors have increasingly embraced the new approach in cardiac cath, the advantages of which include:
- easier catheter access;
- fewer complications;
- faster recovery;
- greater patient satisfaction.
Lourdes interventionalists offer the radial option as part of their effort to make every procedure easier to undergo, more comfortable and safer for patients.
Catheterization via the radial artery in the wrist permits catheter entry into the circulatory system with a puncture at an easily accessible site just behind the hand, at the underside of the wrist. The newer strategy is meant to address a number of challenges inherent in femoral artery catheterization.
A Chance to Improve Upon Femoral Access
In catheterization procedures used for both diagnosis or treatment, specialists make a small incision at a peripheral artery and advance a catheter into other vessels in the body, including the arteries supplying blood to the heart muscle (coronary arteries), the interior chambers of the heart, the aorta (the main artery of the body), or the arteries that supply blood to the kidneys, lower body or brain, among other vessels. The ability to get catheters into the circulatory system has been such an important advance that it has significantly changed the practice of medicine.
In the vast majority of the cases, the interventional specialist gains this access to the circulatory system by making a small incision at the top of the thigh at the groin and inserting the catheter through a puncture into the femoral artery. While in most patients the femoral artery makes a large and easy target, it is also a more deeply embedded vessel than is the wrist's radial artery.
Certain patients make up groups in which femoral artery access is more difficult and the risk of bleeding, especially after the procedure, is higher than average. Groups at risk for these difficulties include obese patients, women and the elderly, patients with peripheral vascular disease or patients who have kidney failure or other causes of bleeding disorders. Patients who are taking blood thinners (to prevent blood clots) or are receiving them as part of their acute care are also at increased risk for bleeding. These anticoagulants can include aspirin and plavix, as well as heparin or Integrin. In unusual cases, bleeding after catheterization can be severe enough to require a transfusion.
In all cases, routine or otherwise, the cardiology staff must place heavy pressure against the site of femoral artery needle insertion once the needle is removed, in order to prevent bleeding after the procedure is completed. This requires applying and administering compression techniques against the insertion site for four to six hours after the procedure is completed, during which time the patient must lie still on his or her back. This extended requirement for immobility can result in muscle cramping and other discomfort. This waiting period can prove difficult and painful for some patients, particularly elderly patients and those with hip or back pain.
Furthermore, In unusual instances, patients may continue to bleed at the internal wound site of a femoral puncture—a situation that is not easily visible because the femoral artery is relatively deep under the skin. When the femoral artery bleeds unnoticed beneath the skin, blood can pool in the lower back or abdomen. In the rare case, this may even necessitate surgery to repair the vessel or prevent dangerous infection.
In addition, femoral access leaves patients with bruising and soreness at the access site. Though it happens seldomly, femoral artery catheterization can also result in nerve damage in the thigh area, due to the proximity of the femoral artery to the femoral nerve. In the rare case, catheterization at this site can also cause a blood clot that blocks the vessel or adds to risk of stroke or heart attack.
All of these types of complications pose a risk for patient outcomes, and can add days and significant cost to a patient's hospital stay when they occur. In addition, they can delay a patient's return to normal activity for weeks.
Nearly Identical Procedure But with Simpler Aftercare
The radial access kit includes a puncture needle, access sheath and catheter wire. Through the needle, the team places the thin, flexible wire into the radial artery. The specialists withdraws the needle and passes the strawlike tube (the introducer sheath or access sheath) into the artery. The cardiac catheterization team then threads additional devices through this sheath and across the wire, and advances them to arteries leading to the heart. Injecting contrast material through the catheter permits clear "road-map" X-rays of the path through the arteries. The interventionalist uses catheters tipped with small inflatable balloons or other devices to reopen coronary arteries.
With its large size, the femoral artery has been good for accommodating catheter interventions of all kinds. However catheters have advanced by becoming smaller. Such improvements helped to make possible the first use of radial catheterization in the late 1980s, followed by further study of the approach in the 1990s.
"Though it's slightly smaller than the femoral artery, the radial artery is large enough to allow entry of smaller catheters that we use today to reach the coronary anatomy," says Lourdes cardiac interventionalist Theirry Momplaisir, MD. "We can now choose from a variety of smaller-diameter catheter systems."
To perform the radial catheterization procedure, the team first checks for adequate blood supply in the ulnar and radial arteries. Confirmng that, it administers local anesthetic at the puncture site and usually mild sedation to the patient, then uses a small, short needle to access the radial artery, after which the procedure continues virtually identically to a femoral catheterization, permitting high-definition imaging of coronary arteries, often followed by insertion of a balloon catheter or other angioplasty technique, typically completed with coronary stenting.
Afterwards, the staff uses a simple inflatable wristband to maintain the modest pressure needed on the radial artery to prevent bleeding. With this simple solution, patients can get on their feet almost immediately after the catheter is removed.
Because femoral access has been a standard for more than three decades, and because the radial artery is thinner and the route from it to the heart less direct, the radial approach offers some additional technical challenges to interventionalists who have not used it before, and these practitioners require additional training as well as experience in order to be able to offer the procedure confidently.
Furthermore, because radial catheterization does not accommodate large catheters, and access by this route is less direct to most areas of the body, specialists currently perform radial catheterizations almost exclusively for purposes of coronary angiography and angioplasty. As a point of access for this purpose, though, radial catheterization yields a number of advantages.
Patients and Practitioners Appreciate Plusses of Radial Cath
The radial artery in the wrist is close to the skin surface, providing readier access to the cardiologist than the does the femoral artery for a needle puncture. In obese patients, in particular, the radial artery is more dependably accessible.
In addition, peripheral vascular disease tends to compromise the condition of arteries in the wrist much less than in it does the femoral artery, making them more reliable and pliable targets for catheterization.
Radial catheterization provides a gentler approach to coronary catheterization than does inserting catheters at the groin. It also offers a minimized and more consistently dependable amount of recovery time.
What's more, the radial artery is more easily compressible and thus responds quickly to pressure after the procedure, to prevent bleeding. Plus, any bleeding that might be present is more clearly apparent at the radial site than at the femoral site.
Most importantly, radial access has been shown to result in significantly fewer vascular complications compared to femoral access, especially for patients in higher-risk groups. In fact, this reduction in the already low likelihood of bleeding decreases the risk of this complication to nearly negligible. The approach also has the potential to decrease the risk of heart attack or stroke due to procedure-related blood clotting.
Finally, radial catheterization has a number of practical advantages that affect all patients:
- This type of catheter access involves no intrusion into sensitive and private body areas.
- Patients are mobile almost immediately after the procedure, with only a wristband to maintain pressure on the puncture site.
- The approach leaves noticeably less pain and bruising at the site after the procedure.
All of these advantages combined mean less stress for patients and shorter (if any) hospitals stay on average.
"We have seen many radial-cath patients go home the same day who otherwise would have ended up staying over night after cardiac catheterization," says Dr. Momplaisir. "They definitely recover faster and, in fact, most go home same day, especially if their procedure is early in the day. If they must stay over in the hospital, it's usually for other reasons."
Patients with wrist arteries that are small or that spasm, or that are otherwise abnormal or compromised, are probably better candidates for traditional femoral access at the groin. The experienced staff at Lourdes assesses every person individually to determine the best approach in each case based on a number of factors related to the patient and to the type of intervention needed.
Image shows track to heart from radial artery access point (lower left).
The Chance for a Stride in Safety, Convenience and Cost
Radial artery access still probably accounts for less than 10 percent of cardiac catheterizations in the U.S., but that percent has been steadily rising. Heart specialists use the approach much more commonly outside the U.S. In China, Japan, Canada and Western Europe, for example, the portion of cases undergoing radial catheterization approaches or significantly exceeds 50 percent.
The radial approach requires practice in order for an interventional cardiac specialist to become fully skilled in the procedure. So far only a small percentage of medical centers in the U.S. offer this option; but, as more doctors train in the procedure, more patients will benefit from it. (Complicated stentings or technologically difficult endovascular procedures such as those for repair of the heart valve or aorta are best done through the femoral artery, as are catheterizations for noncardiac procedures such as those to correct blockages or abnormalities in the renal or distal, peripheral vessels.)
"Experience is important, because with it the cardiologists can accomplish radial access as dependably and readily as femoral access," says Momplaisir, who notes that in 2012 Lourdes' "transradialists" will have treated hundreds of patients by this approach.
Patients have embraced the radial-catheterization strategy. Many of those who have experienced both radial and femoral access express a heavy preference for the radial approach. In addition, radial access offers the very real prospect for cost savings for the patient and healthcare system because:
Compression to prevent additional bleeding after a radial catheterization requires only a simple, inflatable wristband.
- The approach makes it more likely that a patient can undergo cardiac catheterization on an outpatient basis, and it produces fewer complications than does catheterization via the femoral artery—thus generating less hospital days and postprocedure care.
- Radial catheterization requires less staff time to monitor patients after the procedure.
- With less recovery time necessary, patients return to normal activity and productivity faster.
Multiply these benefits across the million-plus cardiac catheterizations performed each year in the U.S. and the opportunity presented by this advance is significant.
Jolly S, Amlani S, Hamon M, et al. Radial versus femoral access for coronary angiography or intervention and the impact on major bleeding and ischemic events: A systematic review and meta-analysis of randomized trials. Am Heart J, 2009 Jan; 157(1):132-140.
Brueck M, Bandorski D, Kramer W, et al. A randomized comparison of transradial versus transfemoral approach for coronary angiography and angioplasty. J Am Coll Cardiol Intv, 2009; 1047-1054.
Eichhöfer J, Horlick E, Ivanov J, et al. Decreased complication rates using the transradial compared to the transfemoral approach in percutaneous coronary intervention in the era of routine stenting and glycoprotein platelet IIb/IIIa inhibitor use: a large single-center experience. Am Heart J, 2008; 156(5):864-870.
Rao S, Ou F, Wang T, et al. Trends in the prevalence and outcomes of radial and femoral approaches to percutaneous coronary intervention. J Am Coll Cardiol Intv, 2008; 1:1379-86.