Thursday, March 9, 2017

MAGEC Growing Rods (Part 1)

In the last blog we talked about Growing Rods for the treatment of EOS.  The major downside to this treatment method is the need for repetitive anesthesia and open lengthening of the growing rods in the operating room.  Over the last 5 years there has been a number of studies assessing the impact of repetitive anesthetics in the growing child, specifically on brain development and behavior.  Despite the volume of research in humans and in animal models, there remains confusion as to who is at risk, what is at risk and the magnitude of the risk.  What we do know is that there is a significant amount of psychological stress on children, and the parents.

The other negative for traditional growing rods is the need for open lengthenings.  Every time growing rods are openly lengthened creates an opportunity for a deep wound or implant infection.  If infections involve the Growing Rods, they typically must be removed as it is very difficult to eradicate the infection (bacteria).  This means surgeons commonly must remove the Growing Rods, treat with antibiotics and then re-implant the Growing Rods at a later date. 

So it is easy to see that limiting the number of anesthetics the child is exposed to and minimizing the number of surgical procedures is optimal for the patients, and their families.  In the fall of 2014, a new device received FDA clearance for use in the U.S., the MAGEC (MAGnetic Expansion Control) system.  This new device is an actuator that can lengthen or distract when inside the patient, without the need for anesthesia or making an incision on the child.  This system permits lengthening of the growing rods without the need for anesthesia and open lengthening

The lengthening of the MAGEC rod is done by placing the device in a special magnet field.  The MAGEC rods can be lengthened painlessly in the clinic, without sedation or anesthesia.  In fact the lengthening of the MAGEC rods takes less than 1 minute by a device called an ERC or External Remote Controller, which creates the special magnetic field around the MAGEC device.

I have personally implanted 30 early-onset scoliosis patients with the MAGEC system; some patients were converted from a traditional Growing Rod system and others it was their first surgery.  This system has dramatically improved the ability to lengthen the growing rods, since even if the child is not well we can lengthen the MAGEC rods in the clinic.  Previously if the child had traditional growing rods, and was ill, their surgery may be cancelled because of concerns about their airway and breathing.  Also, as mentioned earlier, there is a lot less stress on the patient and family.  There is no need for placement of IVs, an anxiety-provoking and sometimes painful procedure, or general anesthesia so there is no post-anesthesia nausea and vomiting. 


However, MAGEC rods are not the answer for all patients with early-onset scoliosis.  The device can be difficult to place as it requires an almost perfectly straight area to be placed into the back, around 12 centimeters.  At first glance this looks like all patients would have a straight area to be able to place a MAGEC device, however it is not always the case in early-onset scoliosis.  Sometimes it is necessary to start with traditional growing rods and then change at a later date to MAGEC, after the child has grown more.