Typically, if an infant is receiving a pacemaker, open-chest surgery is required. Should a new prototype miniature pacemaker reach commercialization, however, all that will be required is a single small incision – that means shorter surgeries, less pain and faster recoveries.
Developed via a collaboration between the US Children's National Health System and medical technology company Medtronic PLC, the device is about one cubic centimeter in size, or "about the size of an almond." Images aren't being made public just yet.
To implant it, a 1-cm incision is made just below the ribcage, which a two-channel access port (kind of a double-barrelled tube) is temporarily inserted into. An endoscopic camera is then fed up one of those channels, going to the heart, while the pacemaker's electrical lead wire goes up the other.
Guided by live video from the camera, the surgeon then attaches the lead to the epicardium, which is a membrane that forms the innermost layer of the pericardium (a sack that surrounds the heart) and the outer surface of the heart itself. The access port is then withdrawn – along with a sheath that was inserted to guide the lead – and the pacemaker is tucked into the chest via the incision. After that, the incision is closed.
The procedure has been successfully trialled on eight anesthetized piglets, taking less than an hour on average. By contrast, traditional open-chest procedures can take several hours.
"Placing a pacemaker in a small child is different than operating on an adult, due to their small chest cavity and narrow blood vessels," says Dr. Rohan Kumthekar, who led the research under the guidance of Dr. Charles Berul. "By eliminating the need to cut through the sternum or the ribs and fully open the chest to implant a pacemaker, the current model, we can cut down on surgical time and help alleviate pain."
Once further testing and clinical trials have been completed, it is hoped that the pacemaker could be used not only on infants but also on adults with limited vascular access, such as those with congenital heart defects or who have had multiple previous heart surgeries.
Kumthekar will be presenting one of the prototypes on Nov. 11th at the American Heart Association's Scientific Sessions 2018, in Chicago.
