Bare Metal vs Covered Stent for Aortic Coarctation?

When your cardiologist recommends treating your coarctation of the aorta (CoA) with a catheterization procedure, they will likely place a small wire mesh tube called a stent inside the narrowed area to hold the blood vessel open. The main difference between a bare metal stent (BMS) and a covered stent is that a covered stent has an extra fabric-like lining—usually made of a material called ePTFE—attached to the metal frame. This extra layer acts as a protective sleeve or barrier against the aortic wall, while a bare metal stent is simply the open wire mesh. Both types of stents are safe, durable, and highly effective at opening the narrowed aorta and relieving high blood pressure ^[1][2].

Why might my doctor choose a covered stent?

Cardiologists often prefer covered stents for adolescents and adults, or for patients with complex anatomies ^[3]. The extra lining on a covered stent serves as a vital “safety net” to prevent or treat injuries to the aortic wall.

• Preventing and treating tears: The aorta can be fragile, especially if you have had a prior coarctation surgery or if the narrowing is severe. When the balloon expands the stent to open the narrowed aorta, there is a risk of creating a tear in the blood vessel wall. A covered stent seals the vessel wall, containing any potential tears and protecting against life-threatening internal bleeding ^[4][5].
• Aneurysm prevention and treatment: Over time, weakened areas of the aorta can balloon out, creating an aneurysm or a pseudoaneurysm (a contained leak or weakened bulge outside the vessel wall). Covered stents can seal off existing aneurysms and encourage them to shrink over time ^[6]. They are strongly preferred if a patient already has a weakened aortic wall from a previous procedure ^[5].
• Managing stent fractures: Over many years, the metal wire mesh in a stent can sometimes “fracture.” This does not mean the stent catastrophically snaps; rather, it means a wire strut weakens or loses its perfect shape. This is rarely an emergency and can usually be fixed with another balloon dilation. While some research suggests bare metal stents may have a slightly higher risk of this occurring ^[7], the primary benefit of a covered stent is that its lining provides extra structural stability and contains any potential irritation to the blood vessel if the metal does weaken ^[8].

Why might my doctor choose a bare metal stent?

While covered stents offer excellent protection, they aren’t right for everyone. A cardiologist might choose a bare metal stent based on your specific anatomy.

• Protecting side branches: The aorta has many smaller arteries branching off it that supply blood to your head, arms (such as the left subclavian artery), and spinal cord. Because a covered stent has a solid lining, it will block any artery it is placed across. A bare metal stent’s open mesh design allows blood to continue flowing into these branching arteries even if the stent crosses over them ^[9].
• Smaller delivery sizes: Depending on the specific device, some bare metal stents can be delivered through slightly smaller catheters. This can be an important consideration for smaller pediatric patients whose blood vessels are very small (though stenting in infants is extremely rare and usually reserved for highly specific cases) ^[10].

What else should I know about medications and follow-up?

You might wonder if getting a fabric-covered stent changes the daily medications you will have to take. It generally does not. After receiving either type of stent, standard practice typically involves taking an antiplatelet medication, such as low-dose aspirin, for about 6 months ^[11]. This prevents blood clots from forming on the stent while your body’s own tissue grows over the metal. Additionally, while stenting often improves blood pressure, many patients still require some antihypertensive (blood pressure) medication long-term ^[12].

If a stent is placed while a child is still growing, the stent will eventually need to be expanded. About 1 in 5 patients who receive a stent before age 18 will need a follow-up procedure to dilate the stent to adult size ^[7].

Regardless of which stent you receive, lifelong follow-up with a cardiologist is required. While covered stents provide extra protection against aneurysms, they do not completely eliminate the risk of one forming years later ^[7]. Routine imaging (like an MRI or CT scan) is necessary to ensure the stent remains in good condition and the aorta is healthy ^[12]. You can typically expect to need this routine imaging every 1 to 5 years, depending on your cardiologist’s recommendation.