This non-invasive method can tell the cardiovascular surgeon and anesthesiologists how successful the surgeon has been in removing air from the heart and if further action is needed.
"Our investigation basically related to brain function during cardiac surgery in children," Dr. Rosendo A. Rodriguez said. "Several problems may occur during this surgery that may potentially damage the brain."
Rodriguez and other investigators at the Children's Hospital of Eastern Ontario in Ottawa, Canada, have studied about 60 patients from infants to 18 year olds and intend to double this number by the end of the study.
The investigators will present their findings August 14th at the International Neurosonology '97 meeting here sponsored by the World Federation of Neurology and the Bowman Gray School of Medicine of Wake Forest University.
One concern is the small particles and bubbles of air that are ejected from the heart to systemic circulation during surgery, Rodriguez said. "We don't know exactly the effect on the brain. These emboli travel through the arteries in the brain and reach the brain tissue."
The surgeon goes through a process called de-airing to remove the air that has entered the heart during surgery, Rodriguez said. Transcranial Doppler has the ability to detect this air in the brain circulation when it is ejected from the heart. "The amount of air that is ejected to circulation is related to the effectiveness of the de-airing procedure," Rodriguez said.
The investigators looked for the correlation between how well the surgeon thought that the heart was de-aired versus the readings from the transcranial Doppler. This system is a good indicator of how much air is ejected, Rodriguez said.