Now, researchers at Northwestern University and George Washington University have created a temporary pacemaker that dissolves in place and is reabsorbed by the body when it’s no longer needed, making surgery to remove it unnecessarily. Their findings were published in Nature Biotechnology last month.
Fred Kusumoto, MD, president of the Heart Rhythm Society, calls the pacemaker “an exciting and innovative advance." Kusumoto was not involved in the study.
Disappearing Act
The new dissolvable pacemaker is a small, flat, patch-like device that is placed on the surface of the heart and sutured in place. All of the components dissolve (or “bioresorb”) over the course of five to seven weeks—similar to dissolvable stitches. This process eliminates the need for another surgery to remove the device.
Unlike other pacemakers, which use wire leads connected to a battery outside of the body, the new transient device is powered by radio frequency communication. The small amounts of metal in the device are made of magnesium and tungsten that are biocompatible and bioresorbable.
John A. Rogers, PhD, the Louis Simpson and Kimberly Querrey Professor of Materials Science and Device Engineering at the McCormick School of Engineering at Northwestern, tells Verywell that the time that it takes for the pacemaker to dissolve and be bioresorbed can be adjusted by making the device thinner or thicker or by changing the composition of the parts. Rogers was a co-author on the study.
A permanent pacemaker is implanted under the skin of a person’s chest and is attached to the leads, which stay in place permanently. The pacemaker itself is changed out every few years when the battery runs low.
A traditional temporary pacemaker is like a permanent one, but instead, the leads are attached to the heart during surgery and exit the chest to connect to a unit outside the body. The unit has a battery that emits the pacing pulses.
Although the leads are removed when the pacemaker is no longer needed, the insertion of the leads carries a small risk of infection. There is also a risk that a lead could become dislodged from the right position.
Removing the leads carries the risk of infection as well. If scar tissue has formed around the lead, it can make removal difficult and possibly damage the heart.
Study co-author Rishi Arora, MD, professor of medicine at the Feinberg School of Medicine at Northwestern and co-director of the Center for Arrhythmia Research, tells Verywell that “instead of using wires that can get infected and dislodged, we can implant this leadless biocompatible pacemaker.”
The circuitry is implanted on the heart’s surface, and Arora says that doctors can then “activate it remotely.” Rogers adds that “wireless, transient pacemakers overcome key disadvantages of traditional temporary devices.”
According to Rogers, the device also has the potential to reduce costs and improve patient outcomes over traditional temporary pacemakers; the materials are not expensive and are made in the same way that devices used in the consumer electronics industry are.
When Will the Pacemaker Be Ready for Human Hearts?
The dissolving pacemaker has not been tested in human patients but has passed muster in several animal models, including mice, rats, and dogs, as well as in human hearts obtained from cadavers. It will probably be another two to three years before the device can be tested in human patients.
Igor Efimov, PhD, the Alisann and Terry Collins Professor of Biomedical Engineering at George Washington University and co-leader of the study, tells Verywell that having medical devices that dissolve in place without having to be removed “opens an entirely new chapter in medicine and biomedical research.”
Kusumoto says that the two main disadvantages to the dissolvable temporary pacemaker are that it is currently hard to identify which patients will not need long-term pacing therapy and that the current model does not allow the top and bottom chambers of the heart (the atria and ventricles) to be coordinated.
Rogers says that eventually, the transient pacemaker will undergo improvements. The ability to pace and synchronize the beat of both atria and ventricles might even be possible with newer designs, though the device should be able to pace the atria alone in its current form.
Even with the kinks that need to be worked out in future research, Kusumoto says the device is “an important advance” in the field.
