An advanced hybrid approach to revascularize chronic total occlusions (CTO) holds much promise for patients, particularly those with a known CTO for whom medical therapies aren’t sufficient.

Interventional cardiologist Anbukarasi (Arasi) Maran, M.D., leads the CTO team at MUSC Health’s Heart & Vascular Center, which specializes in this advanced hybrid algorithm.

CTO, wherein a heart blood vessel has been closed for more than 3 months, happens gradually. This allows the heart to develop its own bypass or collateral flow to supply the muscle beyond the blockage.

Unlike the conventional percutaneous coronary intervention (PCI) CTO, which uses wire escalation techniques with access through a single vessel, the hybrid approach attempts access on both vessels.

This new approach offers multiple benefits—including significantly higher success rates. It’s a complex technique that requires the type of specialized training that Dr. Maran has.

Dr. Maran learned the intricacies of this technique from internationally renowned CTO expert William Lombardi, M.D., at the University of Washington. She now performs increasing numbers of this niche procedure at MUSC Health.

Chronic Total Occlusion: A Common Cardiac Concern

Dr. Maran estimates 10 to 30 percent of her patients present with a CTO. Patients who don’t experience success through more conventional treatments are often left to continue with medical management alone.

The problem, according to Maran, is that success rates for a conventional PCI CTO can hover around 20%.

If an attempt at opening the vessel using regular techniques fails, patients are offered only medical therapy. Yet many patients still experience significant symptoms with the medical therapies that typically come after an unsuccessful revascularization procedure.

Now, with improved technology and an advanced technique, many of those patients may have another way to achieve complete revascularization—and thus, improved symptoms and quality of life.

Treating Chronic Total Occlusion With a Hybrid Approach

In this hybrid approach for CTO PCI, Dr. Maran says she gains access via two points. This allows her to visualize the blood vessel from the native blood vessel as well as the blood vessel that’s feeding the collateral flow.

“For example, if a patient has a blockage in the right coronary artery, right-side blood vessel, and it is getting fed by collaterals from the left coronary artery: We pass a catheter and a wire into the left coronary artery; engage into the bypass vessel via the septal collaterals; get into the right side blood vessel and externalize the wire across; and then deliver stents,” explains Dr. Maran.

Improved technologies, such as superior wires, catheters and tools, allow Dr. Maran and her team to better navigate blood vessels and establish continuity of flow.

Overall, Dr. Maran describes this approach as easier to learn, safer and more successful—with a success rate around 85 percent.

The beauty of the hybrid procedure is in its fluidity. “We first try to attempt it antegrade but if that fails, we quickly switch approach and go retrograde,” she says. “The team is prepared to switch from one method to another, if necessary. We can either go through the parent vessel or come through the back through the feeding vessels into the parent vessel.”

In MUSC Health’s cath lab, a team of specialists work predominantly with CTO procedures, ensuring expertise in CTO equipment and allowing for efficiency and successful outcomes.

Patients best served by this approach include anyone who has a CTO and who has significant symptoms that are not controlled medically. Those symptoms may include shortness of breath or chest pain on exertion or low energy in spite of medication therapy.

The main risks with this approach are bleeding complications from the groin access, bleeding and injury to other blood vessels and contrast-related injury.

Complete Revascularization, Realized

Data show that complete vascularization improves overall morbidity and quality of life, says Dr. Maran. With this new technique, many more patients can realize that outcome and the improvements that come with it.

“Complete revascularization is better for the patient, and now there are options to treat chronic total occlusions,” she says.

For more information, contact Dr. Maran at