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Stenting of Completely Blocked Coronary Arteries May Represent “Final Frontier” in Interventional Cardiology

Media Contact Joe Poelker
Release Date: 01/17/2017 By Gus Theodos, MD, FACC
Gus Theodos, M.D.

Gus Theodos, MD, FACC, is a cardiologist with St. Anthony’s Heart Specialty Associates. He is board certified in interventional cardiology and cardiovascular disease with expertise that includes CTO PCI.
Complete blockages of coronary arteries, known as chronic total occlusions (CTO), are quite common; they occur in up to 20 percent of all patients undergoing cardiac catheterization. Despite the relatively common occurrence, procedures to open these blockages are attempted in less than 10 percent of patients, or those patients are referred for bypass surgery.
Most CTOs are left alone because they are among the most difficult arteries to treat successfully. Placing a stent in a completely blocked vessel has for years been successful less than 70 percent of the time with twice the complication rate. When an artery is 99 percent blocked, placing a stent is successful in more than 95 percent of patients.
In most cases, the body will create its own bypasses or collateral blood vessels that help supply blood to those areas of the heart. That can keep the muscle alive, but these collaterals rarely prevent symptoms of fatigue, shortness of breath, and chest pain. Patients end up altering their activities and daily habits to avoid things that provoke symptoms. Sometimes bypass surgery is not a good option or their bypass grafts have failed. This is where new techniques can benefit our patients.
Chronic total occlusion percutaneous coronary intervention (CTO PCI) involves dual-access coronary injection, which allows us to visualize the beginning and the end of the vessel and the length of the blockage. We then use a hybrid approach to treat the artery. We send various types of coronary wires down the artery beyond the blockage. Sometimes the wire goes into the wall of the artery. While this can be a concern in an open artery, an artery that is 100 percent blocked generally tolerates it easily; and it can help reduce the time of the procedure. We then use newer equipment to pop back into the true artery further downstream. Alternatively, we can use newly developed microcatheters to fix the artery backwards by going through the tiny collateral blood vessels.
No matter which method is attempted initially, it is important not to get bogged down with one method – it truly is a hybrid approach which requires switching when methods are not successful after a short duration.
CTO PCI should not be attempted by all interventional cardiologists. Specialized training in these newer techniques is essential, with a steep learning curve. Despite the improved success rate, there is still higher risk of complication along with the possibility that two or more procedures may be needed to be successful. The reward for these new techniques is the ability to improve the lives of patients who currently go untreated.


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