Angiography is a minimally invasive procedure to access the coronary circulation and blood filled chambers of the heart using a catheter. It is performed for both diagnostic and interventional (treatment) purposes. A thin plastic tube is inserted into an artery in the groin or arm. A long, narrow, hollow tube, called a catheter, is passed through the sheath and guided up the blood vessel to the arteries surrounding the heart. A small amount of contrast liquid is injected through the catheter and is photographed with an X-ray as it moves through the heart’s chambers, valves, and major vessels. From the digital pictures of the contrast material, the doctors can tell whether the coronary arteries are narrowed and whether the heart valves are working correctly.Depending on the type of angiogram, access to the blood vessels is gained most commonly through the hand artery (radial approach) or thigh / groin artery ( femoral approach) to look at the left side of the heart and the arterial system or the jugular or femoral vein, to look at the right side of the heart and the venous system. Using a system of guide wires and catheters, a type of contrast agent (which shows up by absorbing the x-rays), is added to the blood to make it visible on the x-ray images.
RADIAL APPROACH (Hand approach)
For a long time, coronary angiography and angioplasty procedures have been performed through the thigh (transfemoral approach). Today, transradial access for coronary procedures is preferred by patients, and complex angioplasties are being performed through the radial approach.
Some of the significant advantages of the transradial approach over the conventional approach (via a thigh artery) are:
- Although more difficult for the interventionalist to perform, it is pertinent to note that this new approach is complication-free and very comfortable for the patient.
- The transradial approach allows the patient to be mobile immediately after the procedure while in the conventional approach the patient has to lie down flat on the bed for atleast six-eight hours post-procedure.
- The conventional approach is associated with several problems due to prolonged immobilization. These are a) Backache b) Urinary retention c) Patients of bronchial asthma and heart failure find it extremely uncomfortable to lie in bed for extended durations. All these conditions are virtually absent in the transradial approach.
- Femoral artery used as the access site in the conventional angiography/ angioplasty lies deep and is not easily compressible. Therefore, the chances for major hematoma requiring blood transfusions and residual femoral artery defects requiring surgical correction are as high as 2-8 per cent in the transfemoral approach. These complications are nearly nil in transradial procedures.
- Thigh vein and nerve that accompany the thigh artery, which is the access site in the conventional procedure, are liable for damage in conventional angioplasties. But the risk and complications of damage to these is virtually absent in the transradial approach.
Dr. G. Sengottuvelu says “Transradial interventions have fewer complications, but are technically more difficult to perform. The level of complexity for the surgeon makes the procedure exceptional and rare. This modern technique promises lower morbidity and improves patient satisfaction. Among patients undergoing diagnostic cardiac catheterisation, transradial access leads to better quality of life immediately after the procedure. It is strongly preferred by patients and it reduces hospital stay and thereby costs.”
The transradial approach to coronary interventions is both feasible and safe in patients with acute myocardial infraction (sudden heart attack). This option may be most appealing in patients at high risk for developing vascular complications of arterial access.