In some situations, a catheter-based procedure offers a minimally invasive and relatively inexpensive treatment alternative to surgery. During the procedure, a thin tube called a catheter is inserted into a blood vessel through a very small cut made by the physician, then guided up through the blood vessel to the target area (e.g., the heart).

The physician tracks the course of the catheter by watching it on a fluoroscope, which displays the progress of the catheter through blood vessels on a viewing screen. Once the catheter has reached its location, the physician performs whatever procedure is planned. Catheters may be equipped with various special devices, such as balloons, baskets or suction devices, which allow physicians to open clogged arteries or otherwise treat medical conditions. More than one catheter-based procedure may be performed during the same intervention.

After the completion of the necessary procedure(s), the catheter is removed and the incision is either closed with stitches or with newer absorbable collagen plugs. After a closely monitored recovery period, most patients go home within 24 hours. Patients with collagen plugs may be allowed to leave the hospital within two hours after their procedure.

Catheters are highly useful tools in the diagnosis and treatment of heart disease. They can be used to diagnose conditions such as arrhythmias and coronary artery disease, and to treat these same conditions, as well as many others. In some cases, both diagnosis and treatment can be performed during the same catheter-based procedure. Because they cause less trauma than open heart surgery, catheter-based procedures are often referred to as minimally invasive alternatives to surgery.

During a catheter-based treatment to fix a cardiac condition, a physician inserts a small tube called a catheter into a patient’s blood vessel and passes the tube toward the heart. The catheter may be equipped with any number of special devices, such as balloons, grinding burrs, baskets, suction devices or stents. Examples of catheter-based procedures include:

• Balloon angioplasty. About 670,000 balloon angioplasties (sometimes called percutaneous coronary interventions) are performed annually in the United States, making this procedure more common than coronary artery bypass graft surgery. During a balloon angioplasty, the physician inflates a small balloon located at the tip of a catheter to crush plaque back against the artery wall, allowing for better blood flow through the artery. This procedure is usually accompanied by implantation of a stent. A stent is a small metal tube-shaped device that is implanted in the diseased portion of the artery after angioplasty. Just as scaffolding supports a weak building, stents support the damaged artery walls, reducing the chance that the vessel will close again (restenosis) after treatment. Stents called drug-eluting stents are coated with a drug that reduces the chances of restenosis. Newer studies have questioned the long-term effectiveness of drug-eluting stents, but in general, these devices are considered very safe and are used in the majority of stent procedures. 
  
  
• Atherectomy. If arterial plaque is particularly hard, the physician may choose to do an atherectomy. There are three types of atherectomy, all of which cut away plaque from a clogged artery. A stent may be implanted after an atherectomy.
  
  
• Transmyocardial revascularization (TMR). In some cases when patients suffer from severe coronary artery disease and is not a candidate for other techniques, a laser delivered by a catheter (or through a surgical incision) can be used to burn a series of small holes into the heart muscle to improve blood flow to relieve the pain of angina.
  
  
• Percutaneous balloon valvoplasty. A procedure in which a balloon at the end of a catheter is inflated to widen abnormally narrowed heart valves in newborns or adults. This procedure may also be called valvotomy.
  
  
• Percutaneous balloon pericardiotomy. A procedure where a balloon-tipped catheter creates a tear in the wall of the pericardium, through which a drainage tube can be inserted. This is a treatment option in cardiac tamponade.
  
  
• Rashkind procedure. A procedure in which a balloon-tipped catheter is snaked through an abnormal hole in the septum (the wall between the left and right sides of the heart). The balloon is first inflated and then drawn through the hole. The purpose is to enlarge the hole in order to temporarily stabilize a child born with a major congenital heart defect, such as transposition of the great arteries. When the child is strong enough, the defect will be repaired with another type of surgery.
  
  
• Closing a congenital heart defect, such as an atrial septal defect (a hole between the upper chambers of the heart) or a patent ductus arteriosus (an open blood vessel that should normally close by itself after birth). For example, coil embolization is a relatively new technique for closing a patent ductus arteriosus (PDA). Placed inside the PDA via a catheter, the coil is held in place while the fibers encourage the formation of a blood clot, sealing the PDA closed. The coil is left in place and, over time, a scar forms that keeps the PDA permanently closed. For atrial septal defect (and ventricular septal defect), catheter-based delivery of “patches” seals off the open hole. The patch eventually becomes covered with the body’s tissue.
  
  
• Ablation. During ablation, very small, carefully selected parts of the heart are destroyed either with electrical impulses or alcohol injection. This may be used to prevent tachycardia, an abnormally fast heartbeat, or reduce the size of abnormally large heart structures (alcohol septal ablation). Special catheters are also being developed to detect and “map” arrhythmic areas of the heart (e.g., atrial fibrillation, paroxysmal atrial fibrillation).
  
  
• Insertion of a temporary pacemaker or an intra-aortic balloon pump.
  
  
• Carotid angiograms. Similar to a coronary angiogram, this procedure is performed in the carotid artery, which lies in the neck and supplies oxygen-rich blood to the brain. Using this test, physicians can detect aneurysms in the brain, which may cause a stroke if they rupture. Catheters may also be used to treat these aneurysms by implanting tiny coils in the aneurysm that cause a blood clot to form and seal off the aneurysm.
  
  
• To deliver clot-busting drugs directly into a blood clot. This is a valuable technique in the treatment of ischemic stroke, which occurs when a blood clot obstructs blood flow to the brain.
  
  
• Heart valve replacement. Studies are ongoing to develop methods to replace certain heart valves using catheters instead of traditional heart surgery. Currently, however, these methods are highly experimental and are not part of clinical practice.
  
  
• Infusion therapy to deliver vasodilator drugs in patients with severe primary pulmonary hypertension, or for heart failure.
  
  
• Percutaneous in situ coronary venous arterialization (PICVA). This procedure may be recommended in very severe cases of coronary artery disease. During this procedure, blood flow is routed from a coronary artery into one of the coronary veins, which normally drain oxygen-poor blood from the heart muscle. Studies have shown that, by doing this, physicians can force oxygen-rich blood backward through the venous system, thus providing a new supply of oxygen-rich blood for the heart muscle. This procedure uses a system of highly specialized catheters and is still under development.

Catheter-based procedures are also being used in experimental gene therapy studies to inject genetically altered substances into the heart muscle. As an example, catheters are used to inject growth factors into the myocardium to promote the growth of new blood vessels (therapeutic angiogenesis). They are also used to inject stem cells into the heart for patients with heart failure. Other innovations include:

• Catheters to advance medical devices to “seal off” areas of the heart susceptible to blood clot formation. This may be particularly useful in patients with atrial fibrillation, which is associated with an increased risk of blood clots.
  
  
• Small sensors for heart failure and aneurysm patients. These are advanced by a catheter to a blood vessel to continuously measure pressure inside an artery.
  
  
• Photoangioplasty, where a special light-sensitive drug is injected directly into the patient’s veins about 24 hours before the procedure. In the bloodstream, the drug attaches itself to areas of fatty plaque buildup. A fiber-optic laser in then threaded through the body via a catheter and into the affected areas. Once in the target area, the laser is activated and its light triggers a reaction in the drug that dissolves the plaque and spares the local tissue. Although this procedure is still considered experimental, early clinical trials have yielded encouraging results.
  
  
• Catheter-vacuum extractors. These combination catheters are sometimes used during angioplasty following a heart attack. The metal tip of the catheter destroys the blood clot, and the vacuum extractor removes it.

The circumstances of a catheter-based procedure depend on the underlying condition. In some cases, catheter-based procedures may be performed in emergency situations, such as occurs after a heart attack or stroke. In other cases, they are performed as elective procedures meant to correct an existing condition or help reduce the risk of a more serious disease-related complication.

Before the day of a scheduled catheter-based procedure, patients (or the parents of an infant) should discuss the patient’s medical history with the physician and inform him or her of any medications being taken. Certain medications may need to be temporarily stopped or reduced. It is also recommended that patients with diabetes consult their physician regarding food and insulin intake, because people are usually asked to stop eating or drinking after midnight before the test.

Catheter-based procedures are performed in a hospital’s catheterization laboratory, which provides access to appropriate emergency facilities should problems arise.

On the day of the procedure, the patient is taken to the cool and sterile catheterization laboratory that may resemble an operating room with monitoring devices, video display equipment and x-ray cameras. A nurse or physician will explain what is going to happen, and the patient is encouraged to ask questions.

After the patient is made comfortable, an intravenous (I.V.) line is inserted into the patient’s arm. The I.V. allows the physician to give the patient a mild sedative and other necessary medications during the procedure. Small devices will be taped to the patient’s body, which allow the physician to monitor heart rate, rhythm and blood oxygen level.

The physician usually uses the groin/upper thigh area to insert the catheter that will be threaded to the heart, but some physicians may choose to use the elbow or wrist. The area chosen will be cleaned, shaved, swabbed with germ-killing solution and numbed with a local anesthetic. The catheter is then fed through the artery in that area (e.g., the femoral artery in the groin/upper thigh) and up into the heart. There may be some minor discomfort during this period.

After the catheter is in place, the necessary tests/procedures are performed. The optimal procedure for a given patient depends on the severity of the condition, the type of obstruction, the patient’s medical history and other factors. After these procedures are complete, the catheter is removed.

After the procedure is completed, the patient will be moved to a cardiac recovery room. He or she may feel groggy from the sedative. The catheter insertion site may be bruised and sore.

If the groin area was used as the point of catheter insertion, then the patient will be instructed to lie in bed with legs out straight. The physician may choose to use one of two techniques for removing the sheath that was placed at the initiation of the procedure. The traditional technique is to wait until the effects of the anticoagulant have passed (four to six hours) and then to apply pressure while removing the sheath from the femoral artery. A newly developed technique allows the sheath to be removed immediately after the procedure through the use of hemostatic devices that seal or stitch the femoral artery.

If the wrist or arm was used as the point of catheter insertion, then the patient does not need to stay in bed. Throughout the post-procedure monitoring, the point of catheter entrance will be checked for bleeding, swelling or inflammation. Vital signs will be continuously monitored during this observation period. The patient may stay overnight for further observation and is then typically free to go home. In many cases the procedure can be performed on an outpatient basis, with the patient discharged two to four hours later.

Patients are given instructions from the medical staff regarding the following:

The actual movement of the catheter should be painless, and the risk of complications during this procedure is very low. In recent years, the complication rate from catheter-based procedures has dropped considerably, due to improved equipment and aggressive use of anti-platelet medications to reduce the risk of blood clots. Today, although rare, risks include:

Though some studies have found slightly higher rates of life-threatening complications in the elderly, recent studies have found overall success in individuals 80 years and older. All patients are encouraged to thoroughly discuss with their cardiologist any questions or concerns they may have about the risks and benefits of these very common, minimally invasive treatment options.

Preparing questions in advance may help patients have more meaningful discussions with their physicians. Patients may wish to ask their doctors the following questions related to catheter-based procedures:

1. Why are you using this procedure rather than surgery?
   
   
2. How many of these procedures have you performed?
   
   
3. Does this procedure both diagnose and treat my condition?
   
   
4. If I get this repair with catheterization, is there a possibility I may need open surgery later?
   
   
5. I am extremely nervous. Can I receive a general anesthesia for this procedure?
   
   
6. Would you have to change your approach based on something you find during this catheter-based procedure?
   
   
7. Will I have pain after the procedure?
   
   
8. Will I have to stop any of my medications before this procedure?
   
   
9. Will this procedure need to be repeated if it does not repair my problem?
   
   
10. In the event something goes wrong during the procedure, what can I expect to happen?