What is Deep Hypothermic Circulatory Arrest (DHCA)? | MedStar Health

Cooling the body to stop blood circulation and protect the brain during surgery

If you need surgery to repair damaged or abnormal blood vessels that lead to or from the brain, your doctor may recommend deep hypothermic circulatory arrest (DHCA), also known as circulatory arrest under deep hypothermia — cooling your body to stop blood circulation and brain function for up to 40 minutes. Also known as a stand-still surgery, this therapy protects the brain while providing a bloodless operating site.

At a normal body temperature of 98.6 degrees Fahrenheit, you would suffer brain damage after only a few minutes if blood were kept from the brain. But when your body is cooled below 57 degrees Fahrenheit, blood circulation can be stopped safely for much longer, allowing surgeons to make necessary repairs to damaged blood vessels.

Your doctor may recommend DHCA if, for example, you need surgery to remove certain venous tumors called Venous Tumors, or to repair an aortic arch aneurysm or arteriovenous malformation in the neck or head.


You’ll be put to sleep using general anesthesia and placed on a cardiopulmonary bypass, a machine that replaces the function of the heart and lungs. Your blood will be cooled by the heart-lung machine until your heart stops beating. The machine will continue to circulate cooled blood until your brain function ceases as well. The machine will then be turned off, and surgery will begin.

After surgery is completed, the heart-lung machine will be turned back on and will slowly raise your temperature by circulating warmed blood throughout the body. The length of the surgery and recovery will depend on the specific type of procedure you need.



An aneurysm is a ballooning or expansion of a blood vessel. Aneurysms most often develop in arteries, though they also can develop in veins or even inside the heart.

Aortic Arch Aneurysm

An aortic arch aneurysm is a bulge in the wall of the curve of the candy cane-shaped aorta, the body’s largest artery that carries blood from the heart to the rest of the body.

Venous Tumors

Venous tumors are tumors that grow on or in veins.

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