Many of the early procedures pioneered by interventional radiologists were used to treat disorders of the blood vessels. This field has evolved rapidly in conjunction with vascular surgery and is now also referred to as endovascular surgery.
Endovascular procedures have been used to open clogged arteries and to maintain the integrity of weakened blood vessels, such as the aorta. At NYU Medical Center, we specialize in performing the following vascular procedures:
Atherosclerosis, or hardening of the arteries, involves a buildup of "plaque" that decreases a vessel's elasticity and narrows the artery, making it more difficult for blood to flow through it. Although atherosclerosis commonly develops in the arteries of the heart, it can strike any vessel, such as those feeding the brain, legs, or the kidneys -- reducing the flow of vital oxygen-rich blood to these organs. Balloon angioplasty (also called "percutaneous transluminal angioplasty") is a technique commonly employed to increase the size of the opening within the artery.
During this procedure (which is performed under local anesthesia), the physician threads a narrow balloon-tipped catheter into the patient's femoral artery (in the groin) using x-ray guidance, and advances it to the site of obstruction in the affected artery. Once the balloon is in place, the doctor inflates and deflates it -- several times if necessary -- to eliminate the arterial obstruction. The deflated balloon is then removed. The patient may need to stay one day in the hospital, but in some cases the procedure can be performed on an outpatient basis.
Although balloon angioplasty is often successful in enlarging the opening of an obstructed artery, an affected artery may close again. When this happens, the doctor may choose to perform another angioplasty and place a stent within the artery to keep it open. In some patients whose arteries are likely to narrow again, the doctor may place the stent during the first procedure, potentially eliminating the need for another procedure.
A stent is a tiny wire mesh tube that acts as a scaffolding to maintain and support the opening of an artery. It can be placed in virtually any artery of the body where blood flow is especially vital, including those of the heart, kidneys, and the carotid arteries (which supply blood to the brain).
A stent placement procedure is much the same as angioplasty, except that an unexpanded stent is slipped over the deflated balloon on the catheter that is threaded into the femoral artery. When the doctor has inserted the catheter to the site of the obstruction, the balloon is inflated, causing the stent to expand. The physician then removes the balloon, leaving the open stent in place and allowing blood to once again flow freely through the artery. Stents remain in place permanently.
Advanced Endovascular Techniques
As pioneers of endovascular therapy for treating the entire spectrum of vascular disorders, interventional radiologists are doctors who are especially suited to providing solutions to difficult clinical problems which would otherwise require more invasive or complicated therapy. Our current technology for treating vascular conditions includes not only the balloons and stents described above, but also special “covered” stents to seal off defects in blood vessels, materials known as embolics which block off abnormal openings or tears in blood vessels, and devices which suck out blood clots from arteries and veins. A combination of these technologies may be needed in challenging cases, such as the one illustrated below.
Endovascular Repair of Renal Artery Aneurysm
Rotational 3D-angiogram in a middle aged woman with hypertension and an aneurysm of the right renal artery. Treatment of the aneurysm would have traditionally required removal of the entire kidney since performing a surgical bypass around the aneurysm would have been limited by a lack of sufficient renal artery beyond the aneurysm.
Rotational 3D-angiogram following endovascular repair of the aneurysm by NYU interventional radiologists. A stent was placed across the “neck” of the aneurysm to provide a scaffold to “pack” the aneurysm sac with special metal coils to seal off the aneurysm while preserving the blood flow to the kidney. This was performed through a tiny nick in the skin near the groin and the patient was discharged home the following morning.