**4. Mechanism of action of anti-obesity medical devices**

Anti-obesity medical devices can cause weight loss through different mechanisms by acting at different levels.

### **4.1 Decrease in food intake**

Although the primary impact of the anti-obesity medical devices is mechanical, the final effect may be achieved through changes in several factors controlling appetite and food intake, especially the gastrointestinal hormones (e.g., decrease in ghrelin, increase in glucagon-like peptide-1).

#### *4.1.1 Oral cavity*

An anti-obesity medical device can decrease the food intake by limiting the bite size in the oral cavity.

**241**

**6.1 USA**

*Anti-Obesity Medical Devices*

available stomach volume.

been or will be investigated.

*4.1.2 Stomach*

*4.1.3 Others*

*4.2.1 Stomach*

*4.2.2 Intestine*

part of the intestine.

processes in different countries.

*DOI: http://dx.doi.org/10.5772/intechopen.91697*

**4.2 Decrease in available/absorbed nutrient**

removing part of the gastric contents.

An anti-obesity medical device can decrease the food intake by reducing the

Other levels of impact to achieve food intake reduction are possible and have

An anti-obesity medical device can decrease the amount of available nutrient by

An anti-obesity medical device can decrease the absorbed nutrient by bypassing

The main challenges in the development of anti-obesity medical devices are due to lack of unique regulatory guidance and disparities in time and cost of approval

**6. Regulation and approval/clearance of anti-obesity medical devices**

The regulation of anti-obesity medical devices varies by countries or group of countries. There are important differences in the regulatory processes, cost, and

Over-the-counter anti-obesity medical devices may or may not need regulation

In the USA, the regulation of medical devices is centralized since 1976 through the FDA. This centralized process allows a better coordination and enforcement of rules. The CDRH is in charge of approval/clearance of anti-obesity medical devices. There are three regulatory classes of medical devices: Class I (low risk), Class II (moderate risk), and Class III (high risk). Based on the expected weight loss, two categories of anti-obesity medical devices have been defined: weight-loss devices ("more" weight loss) and weight-management devices ("less" weight loss). The approval/clearance is through premarket notification process [510(k)] or premarket

A new guidance using benefit-risk approaches is in preparation by the CDRH taking into account the weight loss (extent and duration), the rate of responders (≥ 5% weight loss), the reduction of comorbidities (e.g., hypertension, dyslipidemia, type 2 diabetes), and the safety [rate and severity of adverse events (AEs)].

**5. Challenges in developing anti-obesity medical devices**

time to approval between the USA and Europe [15].

and approval/clearance depending on the devices and countries.

approval (PMA) process and is based on safety and effectiveness.

### *4.1.2 Stomach*

*Weight Management*

orally in capsule.

prescription or as over-the-counter products.

**2. Heterogeneity of anti-obesity medical devices**

**3. General characteristics of anti-obesity medical devices**

**4. Mechanism of action of anti-obesity medical devices**

Anti-obesity medical devices can cause weight loss through different mecha-

Although the primary impact of the anti-obesity medical devices is mechanical, the final effect may be achieved through changes in several factors controlling appetite and food intake, especially the gastrointestinal hormones (e.g., decrease in

An anti-obesity medical device can decrease the food intake by limiting the bite

decades, the number of medical devices has increased exponentially. Anti-obesity medical devices are positioned to bridge the gap between more conservative treatments (e.g., lifestyle) and more aggressive interventions (e.g., bariatric surgery). Compared to bariatric surgery, they have the advantage of being less invasive, easier to perform, and reversible. Anti-obesity medical devices are available upon

Anti-obesity medical devices represent a heterogeneous family of devices in terms of presentation, usage/administration, mechanism of action, effectiveness, safety, regulation, availability, and cost [8, 11–14]. The devices can be as different as an intragastric balloon, a stomach aspiration system, or particles administered

Unlike anti-obesity drugs that act chemically through specific receptors, anti-obesity medical devices act rather mechanically. They do not have systemic absorption, specific metabolism, or receptors. Their research and development pattern follow specific models. The terminology used for medical devices differs slightly from that used for drugs (e.g., sham instead of placebo, effectiveness instead of efficacy). With some medical devices, it is not possible to use a sham for ethical and/or technical reasons. Compared to drugs, medical devices have different effectiveness dynamics. Unlike drugs, for some anti-obesity medical devices, there is no compliance issue with the device use since the device is placed in the body for several months and there is no need for repeated administration that might be affected by the subject's discipline. Because there is no systemic absorption, there are no side effects related to the impact of medical devices on different organs through the bloodstream. The regulatory systems ruling antiobesity medical devices are based on short product life cycles. The marketing and sales of anti-obesity medical devices are based on different models as compared

**240**

*4.1.1 Oral cavity*

size in the oral cavity.

to drugs.

nisms by acting at different levels.

ghrelin, increase in glucagon-like peptide-1).

**4.1 Decrease in food intake**

An anti-obesity medical device can decrease the food intake by reducing the available stomach volume.

### *4.1.3 Others*

Other levels of impact to achieve food intake reduction are possible and have been or will be investigated.

#### **4.2 Decrease in available/absorbed nutrient**

### *4.2.1 Stomach*

An anti-obesity medical device can decrease the amount of available nutrient by removing part of the gastric contents.
