Eon, Eon Mini and Brio implantable pulse generators (IPG)

The Eon and Eon Mini implantable pulse generators (IPG) are medical devices used to help manage chronic pain. The Brio IPG is used in deep brain stimulation in some patients with Parkinson's disease to help control motor symptoms.

The TGA advises consumers and health professionals of two potential issues with Eon, Eon Mini and Brio IPGs:

• Increased temperature at IPG site when charging.
  • Eon, product code 65-3716
  • Eon Mini, product code 65-3788
  • Brio, product code 65-6788.
• Loss of IPG function due to malfunctioning battery.
  • Eon Mini, product code 65-3788
  • Brio, product code 65-6788.

Information for consumers

Increased temperature when charging

A relatively small proportion of patients have reported increased heat at the IPG site during charging of the above devices. While heat generation during charging is normal and should be expected, it should not cause the patient to feel discomfort or pain.

If you are experiencing this, you should:

Align the charging wand and the IPG

Make sure that the charging wand and the IPG are aligned properly while the battery is being charged. Testing indicates that excessive heating can occur when the alignment is incorrect. Flashing lights on the charging wand indicate when misalignment is greater than 3 cm, but excessive heating can occur even when misalignment is less than 3 cm.

What to do if the temperature increases

If you experience uncomfortable or painful temperature increases during charging:

• stop charging until the discomfort subsides
• try repositioning the charging wand over the IPG implant site
• consider charging more frequently for less time.

Safety precautions while charging

When charging the battery:

• do not charge the device when you are likely to fall asleep
• do not insert the charging wand tightly between the body and a surface that may trap heat, such as a bed or chair
• do not use topical anaesthetics, medicated balm, and/or pain relief patches on the implant site before or during charging
• do not consume alcohol or other sedatives immediately before or while charging.

When to contact your treating clinician

• if the temperature when charging continues to be uncomfortable.

Loss of IPG function due to malfunctioning battery

The manufacturer, St Jude Medical, has received reports of the above devices losing the ability to communicate with the charging wand and/or recharge. This can result in loss of function, namely pain relief for Eon and Eon Mini IPGs, and control of motor symptoms for Brio IPGs. The majority of devices will continue to operate normally, as only a small number of devices may present with this potential malfunction.

Contact your treating clinician if:

• your IPG is losing its ability to communicate with the charging wand or recharge
• your IPG is not as effective at relieving your pain or controlling your motor symptoms as it used to be.

Information for health professionals

St Jude Medical has written a 'Dear Doctor' letter to implanting physicians, advising of these issues.

Patients experiencing increased temperature when charging

If a patient has one of the above IPGs and experiences uncomfortable temperature increases at the site during charging:

• advise them of the recommendations for consumers outlined above
• arrange for a St Jude Medical representative to evaluate the device.

Patients experiencing loss of IPG function due to malfunctioning battery

If a patient has one of the above IPGs and it is losing its ability to communicate with the charging wand, or the duration between recharges becomes significantly shorter, or there is a sudden loss of power, arrange for a St Jude Medical representative to evaluate the device to see whether:

• the recharge is sufficient to cover normal operating conditions based on the patient’s device program
• the device is approaching its normal end of life, and/or
• a device replacement is warranted.

It is not necessary to explant the device if it is functioning as intended.

If device replacement is required and analysis confirms weld failures within the inner battery, St Jude Medical has committed to replace the explanted IPG with an unaffected one at no charge.

Further information

Increased temperature at IPG site when charging

Testing indicates that the temperature of IPGs can rise by up to 6°C to 9°C.

As of 30 June 2012, the worldwide rates of reporting of excessive heating while charging for each of the models remain relatively low (Eon 0.44%, Eon Mini 0.47% and Brio 0.21% of devices implanted).

St Jude Medical is implementing a design change to the charging systems to prevent excessive heating while charging. Once the charging system changes are complete and are approved by appropriate authorities, replacement chargers will be made available to patients.

Loss of IPG function due to malfunctioning battery

In instances of IPGs losing the ability to communicate with the charging wand and/or recharge (and hence lose function), weld failure had caused the batteries to leak. This prevented the devices from holding a charge. It is important to note that the battery is contained within the sealed IPG case and cannot leak outside of the device.

As of 30 June 2012, the worldwide rate for this particular problem is relatively low (0.62%).

St Jude Medical has already implemented changes to address this problem in all new devices, but will continue to evaluate information on all failures reported to them to eliminate all possible root causes.

Reporting problems to the TGA

Consumers and health professionals are encouraged to report problems with medical devices. Please refer to the TGA Internet site for more information on the TGA Incident Reporting and Investigation Scheme (IRIS).

The TGA cannot give personal advice about an individual's medical condition. You are strongly encouraged to talk with a health professional if you are concerned about a possible adverse event associated with a medical device.