Endovascular therapy is a minimally invasive way to treat damaged or diseased blood vessels from the inside, without large surgical incisions. Instead of opening the body to directly access a blood vessel, a surgeon makes a small puncture (usually in the groin or wrist), threads a thin flexible tube called a catheter through the blood vessels, and guides it to the problem area using real-time imaging. From there, specialized tools delivered through the catheter can open blockages, reinforce weak vessel walls, remove blood clots, or seal off dangerous bulges.
The approach applies across the entire vascular system, from the brain’s smallest arteries to the body’s largest artery, the aorta. It has become a first-line treatment for conditions that once required major open surgery.
Conditions Treated With Endovascular Therapy
The range of problems treatable through a catheter has expanded dramatically over the past three decades. The most common include:
- Aneurysms: Bulging, weakened spots in blood vessel walls, particularly in the aorta (the large artery running through the chest and abdomen) and in the brain.
- Peripheral artery disease (PAD): Plaque buildup that narrows leg arteries, reducing blood flow and causing pain with walking.
- Carotid artery disease: Narrowing of the arteries in the neck that supply blood to the brain, which raises stroke risk.
- Acute ischemic stroke: A blood clot blocking a major brain artery, cutting off oxygen to brain tissue.
- Deep vein thrombosis: Blood clots forming in deep veins, most often in the legs.
Each condition uses different tools and techniques, but the core concept is the same: reach the damaged vessel through the bloodstream rather than through open surgery.
How It Works for Blocked Arteries
When plaque narrows an artery and restricts blood flow, several catheter-based techniques can reopen it. These are most commonly used for peripheral artery disease in the legs, though they apply to other arteries as well.
Balloon angioplasty is the foundational technique. A catheter with a tiny deflated balloon at its tip is guided to the blockage. Once in position, the balloon inflates, compressing the plaque against the artery walls and widening the channel for blood flow. Some balloons are coated with medication that helps the artery heal with less scarring afterward.
Stenting often follows angioplasty. A stent is a small mesh tube loaded onto the catheter in a collapsed state. Once delivered to the previously blocked area, it expands and locks into place, acting as a permanent scaffold to hold the artery open. This prevents the vessel from narrowing again.
Atherectomy physically removes plaque before the balloon is used. There are several variations. Laser atherectomy vaporizes plaque with a small laser on the catheter tip. Rotational atherectomy uses a diamond-coated spinning bead to grind plaque into particles small enough for the body to dispose of naturally. Directional atherectomy shaves plaque into a collection chamber and removes it. The choice depends on the type and location of the blockage.
Stroke Treatment: Mechanical Thrombectomy
One of the most time-sensitive applications of endovascular therapy is removing blood clots from the brain during a stroke. When a large artery in the brain is blocked, a catheter is navigated up through the blood vessels to the clot, which is then captured and pulled out. This procedure, called mechanical thrombectomy, can restore blood flow to brain tissue that would otherwise die.
The treatment window has expanded considerably. Patients can now be treated up to 24 hours from the time they were last known to be neurologically normal, provided brain imaging shows salvageable tissue. That said, roughly 10 percent of ischemic stroke patients have the type of large vessel blockage that qualifies for the procedure within the first 6 hours, and about 9 percent of those presenting between 6 and 24 hours may qualify. The treatment works regardless of whether the patient also receives clot-dissolving medication through an IV.
Procedural complications in stroke thrombectomy occur in 4 to 29 percent of cases, a wide range that reflects differences in patient complexity and the severity of the stroke at the time of treatment.
Treating Brain Aneurysms From the Inside
Brain aneurysms, balloon-like bulges in weakened artery walls, were historically treated by clipping them from the outside during open brain surgery. Endovascular therapy offers an alternative that avoids opening the skull entirely.
The earliest and still widely used technique involves threading soft platinum coils through a catheter into the aneurysm. The coils pack tightly inside the bulge, slowing blood flow and encouraging the body to form a stable clot that seals off the aneurysm from circulation. One limitation is that over time, the pulsing of blood with each heartbeat can compact the coils, sometimes allowing the aneurysm to reopen.
A newer approach uses flow diverters: fine mesh tubes placed inside the parent artery across the opening of the aneurysm. The mesh doesn’t plug the aneurysm directly. Instead, it disrupts the flow of blood into the bulge, dramatically reducing the force and speed of blood entering it. Over the following days to weeks, a stable clot forms inside the aneurysm. Over months to years, a new layer of healthy cells grows across the mesh, essentially rebuilding the artery wall and permanently excluding the aneurysm. The flow diverter acts as a scaffold for this natural healing process.
Aortic Aneurysm Repair
The aorta is the body’s largest artery, and when an aneurysm develops in the abdominal section, a rupture can be fatal. The endovascular alternative to open surgery, known as EVAR (endovascular aneurysm repair), involves placing a fabric-covered stent graft inside the weakened section of the aorta. The graft lines the artery from the inside, taking pressure off the weakened wall and preventing rupture.
The difference in outcomes compared to open surgery is significant, particularly in emergencies. For ruptured abdominal aortic aneurysms, 30-day mortality is about 21.5 percent with the endovascular approach compared to 35.5 percent with open surgery. Patients treated endovascularly are also far less likely to need extended time in the ICU. After adjusting for other health factors, the endovascular approach reduced the odds of needing more than three days of intensive care by more than half.
These advantages stem from the fundamental difference in surgical trauma. Open aortic repair requires a large abdominal incision, clamping the aorta, and significant blood loss. The endovascular approach requires only small puncture sites, typically in the groin arteries.
What Recovery Looks Like
Recovery from endovascular procedures is generally faster than from open surgery, though it varies by the type and complexity of the procedure performed. For aortic aneurysm repair, hospital stays are considerably shorter than the week or more typical of open surgery.
In the first day or two, the main restriction involves the puncture site. You’ll need to keep the area still initially to prevent bleeding, and showering is typically allowed 24 to 48 hours after the procedure. Strenuous activities like jogging, cycling, and weight lifting are off limits until your doctor clears you, which can range from a few days for simpler procedures like angioplasty to several weeks for aortic repair.
Most endovascular procedures require follow-up imaging to confirm the repair is holding. Stent grafts placed in the aorta, for example, need periodic scans to check for leaks around the graft. Stents in leg arteries may need monitoring to ensure they stay open. Flow diverters in the brain require imaging over months to confirm the aneurysm has fully sealed. The tradeoff for a less invasive procedure is often a longer surveillance period afterward.