Balloon pump finds new use in bypass
A common mechanical balloon pump may have some exciting extra uses.
The intra-aortic balloon pump normally helps ensure oxygen and blood delivery to the heart aftermath of coronary bypass surgery, but physicians are normally told not to use the balloon pump if heart surgery patients also have aortic insufficiency.
This occurs when the aortic valve's inability to close completely prompts oxygen-rich blood to backwash into the left ventricle. The heart chamber which pumps blood out to the body becomes larger and less efficient as a result.
But now, a team from the US has reported using the balloon pump to wean a 63-year-old man with moderate aortic insufficiency off bypass when standard approaches failed.
“This tells us that the intra-aortic balloon pump may be an option for patients with mild to moderate aortic insufficiency who don't have severe atherosclerosis in their aorta, and whose left ventricular dysfunction is reversible,” said Dr. Mary Arthur, cardiovascular anaesthesiologist at the Medical College of Georgia and Georgia Regents Health System.
“The pumps are listed in every textbook as contraindicated in these patients... but we felt like we had no other option. The patient continued to deteriorate despite maximal support.”
“We had a difficult time weaning him off bypass: his blood pressure was extremely low, his cardiac output was extremely low, and his heart was not pumping well,” and he was immediately placed back on bypass, says Dr Arthur’s colleague Dr Tiffany Richburg, anaesthesiology resident at the college.
The patient had experienced a heart attack and had a history of diabetes and asthma. His aortic insufficiency was found during the usual cardiac workup before surgery to bypass his four diseased coronary arteries.
The intra-aortic balloon pump was inserted through the femoral artery in the groin up into the aorta, the largest blood vessel in the body, to help strengthen the left ventricle.
When inflated, the balloon can also increase leaks around the aortic valve, which is why it is not usually recommended with aortic insufficiency.
“Once you go back on bypass you have to start thinking: What do I need to do differently to get him off bypass?” Dr Arthur said.
“We felt this was his best option... we had to make sure his heart did not sustain more damage from not getting enough oxygen,” added Dr Richburg.
“It completely worked,” she said.
Almost immediately, the patient's blood pressure and cardiac output increased and his heart started beating stronger. The physicians were able to take him back off bypass and to intensive care with the balloon still in place. They removed the balloon the next morning.
While she now considers the pump a reasonable last option for this very specific group of patients, Dr Arthur wants to do a small clinical trial to ensure that the findings can be repeated.