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Magnetic Mini-Mover Trial Study

The Magnetic Mini-Mover Trial Study is now closed for enrollment. 

We are conducting the Magnetic Mini-Mover Trial to study the safety and benefit of this procedure on healthy patients, between the ages of 8 and 14 years, with pectus excavatum. Ten patients have completed participation in the pilot study of the 3MP (FDA Investigational Device Exemption # G050196).
The results from the pilot clinical trial have been published and posted in June 2011. The FDA has now approved a new clinical trial of this next generation Mini-Magnetic Mover device (FDA IDE #G090006), which will be tested for effectiveness in 15 patients in a multicenter clinical trial.

Currently, enrollment is open at UCSF, UC Davis Medical Center, and Shriners Hospital in Sacramento.

Video: What is the Magnetic Mini-Mover Procedure?

Video: What is the UCSF Pectus Clinical Trial?

Video: What is an FDA Clinical Trial?

For more information on how this procedure works review our Magnetic Mini-Mover Procedure page.

How will the study work?

This is a medical research study. The study doctors, Michael R. Harrison, M.D. and Shinjiro Hirose, M.D., clinical study nurse from the UCSF Division of Pediatric Surgery, and orthotics specialist Darrell Christensen from the UCSF Department of Orthopedic Surgery will explain this study to you and your child in detail during an office appointment.

If your child is a candidate for this experimental treatment and if you agree to allow your child to participate in this study, then the following will happen:

Video: What happens during the first pectus clinic visit?

Video: What is the consent process?

Video: Can I leave the study at any time?

Before your child begins the main part of the study...

Your child will need to have the following procedures:

Computer Tomogram (CT scan)

A normal chest CT scan will be done and the Pectus Severity Index calculated-this is a measurement of the severity of the defect. If your child has had a previous Chest CT scan, then another one will not be done. You can bring a copy of the scan to our office.

Electrocardiogram (EKG)

An EKG will be performed to measure heart activity and make sure everything is normal before starting treatment.

Left Hand-Wrist X-ray

A left hand-wrist x-ray will be done to determine your child's bone age and where your child is in regards to their pubertal growth as part of the inclusion criteria for the clinical trial.

Plastic Mold of Your Child's Deformity

A plastic putty-like material will be used so that, when hardened, it produces an exact copy of your child's particular deformity. This mold will be used to create a brace fitted exactly to your child's chest. This external brace will contain a magnet (Magnatract), which your child will wear on the front of his/her chest. If wearing the Magnatract is acceptable to your child and you, then your child can go on to have the internal magnet implanted. If your child does not like to wear this brace, you do not have to proceed with the study.

Video: How is the external brace made?

During the main part of the study...

If your child wants to wear the Magnatract, then you will be given a standard consent form for surgery and anesthesia to read and sign before the surgery is done to implant the magnet.

Your child will have the magnimplant, a titanium-encased magnet (a little bigger than the size of a quarter), attached to his/her sternum. This is an outpatient procedure (your child does not have to stay in the hospital overnight) under a brief general anesthesia. The operation will take about 1/2-hour. Your child will go home a few hours after the surgery, and can resume normal activity the next day.

After the incision has healed (one week)

Your child will start to wear the fitted Magnatract brace. The Magnatract must be worn as much as possible, including while sleeping at night. Wearing the brace should not interfere with your child's activities. The brace is easily removed for bathing and relieving any discomfort.

Video: How long should I wear the brace each day?

Video: How do we know if you are wearing the brace?

During the first month after the procedure

Your child will have weekly visits to see Micheal Harrison, M.D. and the study nurse to make sure that everything is working and there is no problem or discomfort.

After the first month

One month after the magnet has been placed your child will have an X-ray of the chest to monitor the implant. Your child will also have a second EKG. At this time, you and your child will also complete a questionnaire to help us find out how your child's physical and mental health have been affected by wearing the Magnatract brace.

Video: How often is the brace adjusted?

Your child will have monthly visits to assess the progress of the repair, and make sure there is no problem such as discomfort or skin problems. Your child will have these monthly visits until the deformity has been corrected. The amount of time it takes to correct the deformity varies with each patient.

Your child will keep a diary to record how many hours the brace is worn each day and if pain medication was necessary.

Video: What is the purpose of the patient diary?

When the deformity is corrected

Your child will have a chest CT scan to document the result. Then, the magnet will be removed from your child's sternum in an operation like the one used to place the magnet. Your child will go home the same day and resume full activity the next day.

When the magnet is removed...

Participation in the main part of the study will take 18 to 24 months, depending on how long it takes to correct your child's pectus excavatum defect. After the magnet is removed from your child's sternum, Dr. Harrison and his team will ask you to visit the office for follow-up exams.

  • Your child will have another EKG taken and another chest CT scan so we can re-calculate the Pectus Severity Index at one month following removal of the implant.
  • Your child and you will be asked to complete a questionnaire. This is the same questionnaire that you and your child completed one month after the magnet was implanted.

One year after the magnet has been removed...

Participation in this study will also involve long-term follow-up. You and your child will be contacted six months after the magnet is removed to be seen for a clinic visit and complete a questionnaire. This is the same questionnaire that you and your child completed one month after the magnet was implanted and again after the magnet was removed. Your answers will help us find out how your child's physical and mental health have been affected by wearing the Magnatract brace. This visits will be repeated at twelve, eighteen, and twenty-four months following removal of the implant.

What side effects or risks are there of the study procedures?

The risk of the operation to place the magnet on the breastbone (and later to have it removed) is small, but does require outpatient surgery under general anesthesia, similar to having an inguinal hernia repaired. The medical risks involved in undergoing this type of treatment and participating in this study are the following:


As a result of participating in this study, your child will receive a small amount of radiation similar to that received in many standard X-ray procedures, but far more than your child would receive from natural daily exposure.

CT Scans

CT scans involve the risks of radiation (see above). In addition, if contrast material (iodine dye) is used, there is a slight risk of developing an allergic reaction, from mild (itching, rash) to severe (difficulty breathing, shock, or rarely, death). The contrast material may also cause kidney problems, especially if your child is dehydrated or has poor kidney function. The study doctors will ask you about any allergies or related conditions your child has before the procedure. If your child has any of these problems, your child may not be allowed to have a CT scan.

Having a CT scan may mean some added discomfort for your child. In particular, your child may be bothered by feelings of claustrophobia when placed inside the CT scanner, or by lying in one position for a long time. If contrast material is used, your child may feel discomfort when it is injected. Your child may feel warm and flushed and get a metallic taste in his/her mouth. Rarely, the contrast material may cause nausea, vomiting or a headache.

Surgery to Implant the Magnet

There are the risks associated with the surgery itself to implant a titanium-encased magnet to your child's sternum. These include:

  • A small risk from the brief general anesthesia. The side of effects of general anesthesia may include nausea and vomiting, aspiration, or the inability to maintain normal breathing requiring placement of a breathing tube into the trachea.
  • There is a small chance (less than 1%) of injury to the surrounding structures, and the possibility of getting some air into the sac surrounding the lung (entrained air or "pneumothorax").
  • All surgery carries a risk of blood loss. The risk of significant bleeding in this procedure is very small (less than 1%).
  • There is small risk of infection that can be treated with antibiotics but might require removal of the device (less than 1%).
  • There is a small risk of developing a seroma (pocket of fluid) near the implant or following removal of the implant (less than 1%). If a seroma develops, the area will need to be monitored for infection risk.

Failure to Correct the Deformity

There is a risk that the pull on the sunken breast bone will not be strong enough to correct the deformity completely in the time that your child is willing to wear the magnetic brace. If this proved to be the case, you could always choose another form of treatment.

Surgery to Remove the Magnet

There is the same small risk from the procedure to remove the magnet from the sternum as with the procedure to place the magnet.

Unknown Risks

This experimental treatment may involve unforeseeable risks to your child. The experimental treatment may have side effects that no one knows about yet. The researchers will let you know if they learn anything that might make you change your mind about participating in the study.

For more information about risks and side effects, you can ask us. You can also talk to us about any side effects your child experiences while taking part in the study.

What side effects or risks are there of the implanted magnet?

There is no known risk of having a magnet or any static ("unchanging") magnetic field in your child's body, even close to the heart. While magnetic fields changing rapidly [for example, magnetic resonance imaging (MRI)] can induce weak electric fields that can have minor biologic effects, static magnetic fields do not.

Video: Can I be hurt by the magnet inside me?

Metal Screening Devices

There is a potential problem with having any implanted metal device in that it might be detected by metal screening devices, such as those found in airport security. The Magnetic Mini-Mover's magnetic field could interact with security systems like electronic surveillance devices. You and your child will be given a letter to keep that explains that your child has an implanted metallic device.

Attracting Metal Objects

There is a small danger that metal objects would be attracted to the device and stick on your child's skin overlying the magnet in the lower chest. Your child will have to be careful around small metal objects and particularly other magnets.

Injury to the Skin and Discomfort

Wearing the external Magnatract brace may cause discomfort or even injury if it is allowed to pull too hard. The strength with which the external magnet pulls on the magnet on the sternum is adjustable. However, it is possible that the device could pull hard enough to cause damage to the skin over the sternum.

Risks from Magnetic Resonance Imaging (MRI)

There is a risk of injury from having magnetic resonance imaging (MRI). Your child should not have any MRI or be near any strong magnetic field like an MRI machine. Your child will need to wear a necklace or bracelet that carries the warning that he/she cannot undergo an MRI study.

Video: Why can't I have an MRI with the magnet inside me?"

Risks to Others with Pacemakers or Other Medical Devices

There is a risk that the internal and external magnets might be a danger to others such as people who use heart pacemakers or nerve stimulation devices. You and your child must be careful not to come in close contact with other people with those devices. A safe distance from your child's magnet to an implanted device in another person is 6 inches. Therefore, your child should never have his/her chest wall magnet any closer than 6 inches from another device.

Video: Can the magnet damage anything around me?

Choosing To Leave the Study

Taking part in this study is your child's and your choice. You and your child may choose either to take part or not to take part in the study. If you and your child decide to take part in this study, your child may leave the study at any time. No matter what decision you make, there will be no penalty to your child and your child will not lose any of his/her regular benefits. Leaving the study will not affect your child's medical care. Your child can still get your medical care from our institution.

Video: Can I leave the study at any time?

Further Information

More information on the study can be found on our Magnetic Mini-Mover Procedure FAQ page or on

You can read our Magnetic Mini-Mover Procedure page for more information on how this procedure works and comparison to other forms of treatment.

Also you can download our article from the Journal of Pediatric Surgery: Magnetic Mini-Mover Procedure for pectus excavatum [pdf]

Current Status of the Trial

The trial is now closed for enrollment.

Magnetic Mini-Mover Study Trial in the News

  • CBS5 Magnet TherapyMagnet Therapy Corrects South Bay Boy's Birth Defect

    CBS5 - Apr 07, 2010
    Magnets have a brand new use. They are being tested in a new procedure to correct a rare birth defect , Pectus Excavatum, in a Los Gatos boy. Dr. Kim Mulvihill reports.

    Magnet Therapy (CBS5 News Video)

  • Pectus Illustration smallNovel magnet treatment used to correct sunken chest - Nov 08, 2007
    UCSF has created a groundbreaking new procedure to treat chest deformities in children and teens. This minimally invasive procedure is already transforming one 14-year-old's life.

    View ABC News Highlights

    Read Full Story in San Francisco Chronicle

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