Technology & Innovations
North American Arctic Front Stop-AF Trial
Results from the North American Arctic Front STOP-AF trial did show a PV stenosis rate of 3.1% which did not show up in the European trials. This may have come from the use of a smaller 23 mm balloon which possibly penetrates too far into the Pulmonary Vein opening.)
VIDEO: To see a video demonstration of the CryoBalloon Catheter, go to http://www.cryocath.de/en/4.products/af.presentation.asp
Preliminary anecdotal comments from doctors indicate that Cryo ablations may have more reconnection/reconduction problems than RF (perhaps because Cryo doesn’t damage heart tissue as much as RF). And the two sizes of Cryo balloons don’t always fit neatly into pulmonary vein openings.
The Cryo (freezing) can affect the Phrenic Nerve and cause breathing problems, but these usually resolve over time.
The North American Arctic Front STOP-AF trial showed a Phrenic Nerve Palsy (paralysis, weakening) of 11.2 %. Some of these cases did not resolve within 12 months (18 %). This Phrenic Nerve damage may have come from the use of the smaller 23 mm balloon which gets closer to the Phrenic Nerve. Dr. Kuck has had good results using only the larger 28 mm balloon.) Doctors doing CryoBalloon ablations now pace the Phrenic Nerve during the ablation. If they notice that the Phrenic Nerve is affected by the Cryo (freezing), they immediately stop the ablation. The Phrenic Nerve “defrosts” and returns to normal. This technique reportedly eliminates cases of Phrenic Nerve Palsy.
In some centers the CryoBalloon catheter has to be withdrawn and RF non-balloon catheters inserted to “touch up” areas the balloon catheter missed, which often requires considerable time and more fluoroscopy exposure. This also increases the cost of an A-Fib ablation, so that hospitals and insurance companies may actively discourage the use of additional catheters.
However, with more experience doctors may overcome these problems.
(The CryoBalloon catheter may be a “Gateway Technology” allowing many more doctors to enter the field. The number of A-Fib doctors today can take care of less than 1% of the A-Fib population annually. An increase in the number of doctors able to perform successful A-Fib ablations would be a major help in our current A-Fib epidemic. But in these first days of CryoBalloon ablation, patients should be cautious and seek out high volume, experienced centers.)
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Last updated: Wednesday, August 26, 2015