The acute effects of a new type of implantable gastric electrical stimulators featuring varied pulse widths on beagle dogs' food intake and gastric accommodation

abiliti Closed-Loop Gastric Electrical Stimulation System for Treatment of Obesity: Clinical Results with a 27-Month Follow-Up

Background

The aim of the study was to evaluate the safety and effectiveness of a novel closed-loop gastric electric stimulation device (abiliti^® system) featuring a transgastric sensor to detect food intake and an accelerometer to record physical activity to induce and maintain lifestyle changes to treat obesity.

Methods

In a prospective, multi-center study, 34 obese subjects (BMI of 42.1 ± 5.3 kg/m²) who passed an eligibility evaluation were implanted with the abiliti system. Safety evaluation included an endoscopic exam to assess the intragastric electrode healing. Efficacy evaluation at 1 year of therapy included weight loss, improvements in eating, and exercise behavior and quality of life.

Results

The transgastric implant controlled by endoscopy was stable for all participants. At 12 months (12 M) the mean excess weight loss (EWL) was 28.7 % (95%CI, 34.5 to 22.5 %), and mean reduction in BMI was 4.8 ± 3.2 kg/m². At 27 months (27 M), the EWL was 27.5 % (95 % CI, 21.3 % to 33.7 %). Eating behavior, evaluated by the “Three Factor Eating Questionnaire”, showed a significant increase in the cognition factor and decrease in the disinhibition and hunger factors at 12 M in comparison to baseline (p < 0.001). Participants significantly increased their weekly physical activity (p < 0.001). Quality of life was improved in 55.2 % of the patients.

Conclusions

Gastric electrical stimulation with abiliti system in obese participants is well tolerated and leads to significant 12 M weight loss, which was stable to 27 M. We suggest that weight loss is achieved due to the assessed alteration of eating behavior in particular the reduction in disinhibition and hunger, and the measured increase in physical activity.

Effects of colonic electrical stimulation using different individual parameter patterns and stimulation sites on gastrointestinal transit time, defecation, and food intake

PURPOSE

This study aimed to compare the effects of colonic electrical stimulation (CES) on gastrointestinal transit time (GITT), energy consumption, stool frequency, stool consistency, and food intake using different individual parameter patterns and stimulation sites.

METHODS

Eight beagle dogs underwent surgery and CES. First, CES was conducted to determine the individual parameters with different pulse configurations, based on symptoms. Second, influences on energy consumption and GITT were compared between CES sessions with different pulse configurations. Third, GITT, stool frequency, stool consistency, and food intake were compared to assess the effects of CES at different stimulation sites.

RESULTS

The individual parameters varied greatly among the dogs. In proximal colon electrical stimulation (PCES) and rectosigmoid colon electrical stimulation (RCES), energy consumption was lower with the constant pulse width mode than with the constant pulse amplitude mode (p = 0.012 and p = 0.018, respectively). There was no statistical difference between the two pulse configurations in GITT assessment. The PCES, RCES, and sequential CES sessions significantly accelerated GITT compared to sham stimulation. There was no statistical difference in GITT between PCES, RCES, and sequential CES sessions. Compared to sham CES session, RCES and sequential CES sessions exhibited significant higher stool frequency (p < 0.001 and p = 0.001, respectively), and PCES and RCES sessions inhibited food intake (p = 0.003 and p = 0.002, respectively).

CONCLUSIONS

Constant pulse width mode is an appropriate pulse configuration for individual CES. At different stimulation sites, CES may exert different effects on stool frequency and food intake. This study provides an experimental basis for the clinical application of CES.