Brand Name: Maestro Rechargeable System

Device Class: Implanted weight loss device
Manufacturer: Enteromedics, Inc.
FDA Approval Date: January 14, 2015

What is the Maestro Rechargeable System and how does it work?

The Maestro Rechargeable System (MRS) is an FDA approved device for weight loss treatment. It has a series of implantable and external components. These components are a rechargeable neuroregulator, mobile charger, transmit coil, AC recharger, and a clinician programmer and programmer cable.

The Maestro device is implanted under the skin, on the muscle layer in the right side of the body just below the rib cage. The device is rechargeable though the skin via the transmit coil. This coil should be worn for approximately 30-40 minutes per day to ensure a full charge of the MRS. When not worn, the transmit coil may be charged from an appropriate power source. 

The surgical implantation of the Maestro System is performed by a bariatric surgeon in an outpatient setting under general anesthesia. The surgery takes approximately 1 hour to perform. 

The Maestro device promotes weight loss by applying rhythmic electrical pulses that block nerve signals to the anterior and posterior trunks of the vagus nerve. This is called vagal nerve blocking therapy or VBLOC therapy. The vagus nerve signals to brain whether the stomach is full or empty and is involved in regulating stomach emptying. VBLOC suppresses brain communication to the stomach promoting the feeling of fullness for a prolonged period of time, leading to decreased caloric intake. The exact mechanism responsible for weight loss from using the Maestro System is still unclear.

What is the Maestro Rechargeable System used for?

The Maestro System is used for promoting weight loss in morbidly obese 18 year old and older patients typically with a Body Mass Index (BMI) of 40-45 kg/m², or a BMI of 35-39.9 km/m² with one or more obesity related conditions who have failed at least one supervised weight reduction program within the last 5 years. Obesity related conditions include diabetes, hypertension, and high cholesterol. 

How effective is the Maestro Rechargeable System?

The safety and efficacy of Maestro was evaluated in 239 patients. 157 patients received VBLOC therapy with the Maestro device while in 76 patients (control group) the Maestro device was implanted but was not turned on. After 12 months 52.5% of patients that received VBLOC treatment showed at least 20% or greater excess weight loss and 38.3% showed at least a 25% excess weight loss. The control group had 32.5% of patients with 20% or greater excess weight loss and 23.4% of patients with 25% or greater excess weight loss. The average weight loss in the treatment group was 24.14 pounds while the average weight loss was 15.9% pounds in the control group.

How safe is the Maestro Rechargeable System?

According to the ReCharge trial the rate of serious adverse events related to the implantation procedure, device or therapy through 12 months after implantation was 3.7%. Some patients chose to discontinue treatment due to pain at the neuroregulator site or because they were diagnosed with a new condition (for example, diabetes mellitus, hypertension, congestive heart failure). No patient discontinued participation from the study due to device malfunction. 

Serious adverse events related to the device, implant or therapy were neuroregulator malfunction, atelectasis (collapsed lung), gallbladder disease, vomiting, and pain at the regulator site. Serious adverse events related to the surgical procedure include nausea, cirrhosis, generalized ileus, and oozing during surgery. 

Risks associated with using the Maestro Rechargeable System include:

• Allergic or immune responses to the implanted equipment
• Pain at neuroregulator and/or lead site
• Malfunction of components of Maestro System including loss of power, and lead migration
• Abdominal pain (7.1%), constipation (21.4%), nausea (10.7%), chest pain (7.1%), and other device therapy related events
• Damage to vagal nerve trunks

Does this procedure interfere with the ability to receive an MRI?

Yes, this device contains leads that are labeled as unsafe for an MRI. Therefore this device must be surgically removed before receiving an MRI.

What are the warnings and precautions for the Maestro Rechargeable System?

Patients are not considered candidates for the Maestro device if they have any of these medical conditions:

• Cirrhosis
• Portal hypertension
• Esophageal varices
• Hiatal hernias that are uncorrectable by surgery

Patients who are at high risk for surgical complications, have another permanently implanted electrically powered device (pacemaker, defibrillator, or neurotransmitter) or have a high anticipation for magnetic resonance imaging in the future are not considered candidates for the Maestro device.

The Maestro Rechargeable System may interact with other implanted devices such as insulin pumps, defibrillators, pacemakers, and nerve stimulators. 

Patients cannot receive any type of shortwave, microwave, or ultrasound treatment.

Can a pregnant woman use the Maestro System?

The Maestro device should not be used by pregnant women. Females of child bearing age/potential must show a negative urine pregnancy test at initial screening and also within 2 weeks of the implantation. A physician approved contraceptive regimen must be followed for the duration of treatment.

What is the cost of the Maestro Rechargeable System?

The cost of the Maestro Rechargeable System is not yet available. This is because contracts with distributors have not been finalized (cost information will be updated when it is available). The cost of surgery may vary in different parts of the US.

References

Maestro Rechargeable System Instructions for Use

EnteroMedics Maestro Rechargeable System - P130019