By Janice Neumann, Special to the Tribune
December 5, 2012
Dr. Mansour Razminia used to worry about exposing patients to repeated bouts of radiation during lengthy surgery to correct heart rhythm problems. That is, until he began using such alternatives as 3-D imaging and high-frequency ultrasound.
The Chicago-based cardiac electrophysiologist rarely uses radiation during surgery now and recently published the results of a study he conducted comparing the effectiveness of the newer alternatives with X-rays.
The study follows 60 patients who received surgery using imaging and intracardiac echocardiography, utilizing high-frequency ultrasound, and 60 who underwent the procedure with X-rays. The two procedures were equally effective at reducing or eliminating abnormal heart rhythms, according to the study results published in the October issue of Journal of Cardiovascular Electrophysiology.
X-rays are typically used during the surgery to guide catheters inserted into blood vessels going to the heart to destroy small areas of tissue causing the abnormal rhythm. Razminia, who directs the cardiac electrophysiology lab at Advocate Illinois Masonic Medical Center in Chicago, said the method can add as much as 100 millisieverts of radiation exposure. Some also undergo the surgery several times.
"Imagine this patient keeps coming and is going to be exposed to this kind of radiation during the procedure and undergoes a CAT scan beforehand," said Razminia. "This is a huge dose of radiation and unfortunately this may really predispose the patient to a lot of side effects, including skin burns and cancer."
Doctors, nurses and technicians performing the procedure with X-rays need to use lead aprons to protect themselves, which can prove cumbersome during surgeries that can last up to four hours. Pregnant nurses and physicians, as well as child patients, need to avoid the surgery.
Razminia had already been looking for ways to reduce radiation exposure, when he realized a 3-D mapping system — already available in most labs — and ultrasound could be used.
So Razminia headed to the University of Iowa Hospitals and Clinics, where Dr. Ian Law was one of the few pediatric cardiologists using the procedure. Law showed him how to use the technique in a daylong session. Razminia now trains his fellows on how to do the technique.
"It is the tradition, everybody gets trained with X-ray," said Razminia about the reasons X-rays are almost always used. "They (doctors in training) go out and they start learning what they learned in their fellowship," he said.
Law, of the University of Iowa, who uses the technique on patients as young as infants and as old as 65, said the surgery can be especially important in individuals who have been exposed to radiation during other medical or surgical procedures in the past. Law said doctors might not even know how much radiation a patient had received in the past since there is no national database that keeps track.
"More and more, we're finding out that radiation is increasing the risk of solid tumors," Law said. "Unfortunately we only had the option of radiation (in the past) but it's well-known that radiation exposure to children puts them at much greater risk."
Law and his colleague Dr. Nicholas Von Bergen began using the radiation-free technique in about 2005 and have performed about 800 surgeries without radiation or with a limited amount. He said only a smattering of pediatric electrophysiology labs across the country are using the technique and even fewer adult facilities.
Von Bergen said he and Law had long been concerned about using radiation. Then, in 2000, 3-D mapping became more widely available. Initially they simply wanted to reduce the amount of radiation exposure from the surgery but gradually switched to using almost none.
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