One-Year Experience with Tantalus^™: a New Surgical Approach to Treat Morbid Obesity

Background: Increased caloric density in modern processed foods may be an important factor underlying the prevalence of obesity, because low-volume, high-caloric food intake may delay activation of volume-dependent gastric mechanical activity known to induce the feeling of fullness. We therefore hypothesized that enhancement of gastric contractions by electrical stimulation at an early stage of the meal will reduce food intake and body weight in morbidly obese subjects. Methods: The study was a prospective, non-randomized, open-label, single-center trial. 12 subjects (age 36.1 ± 2.8 years, BMI 43.2 ± 2.7 kg/m², weight 128.8 ± 5.2 kg, means±SEM) underwent laparoscopic implantation with the Tantalus^™ system. A pulse generator with 3 bipolar leads was implanted: 2 pairs in the antrum and a 3rd pair in the fundus. The system was activated at week 6. All subjects were followed for 20 weeks and 9 of them for 52 weeks. Results: All subjects finished the initial 20-week observation period. Following activation of the Tantalus^™ System, a reduction (P<0.05) in hunger and an increase in cognitive control (P<0.05) as assessed by the Three-Factor Eating Questionnaire (TFEQ) could be observed. Body weight decreased (P<0.05) from 128.8±5.2 to 119.9+5.9 (17.6+4.3% EWL, N=12) after 20 weeks (14 weeks of treatment). In the 9 subjects continuing for 52 weeks (46 weeks of treatment), body weight further decreased to 112.4 ± 3.8 kg (26.6 ± 8.5 %EWL, N=9). Blood pressure decreased (P<0.05) from 142 ± 6.1/91 ± 3.2 to 125.5 ± 4.0/83 ± 2.6 mmHg by week 20 and 128.8 ± 3.8 / 86.3 ± 3.6 mmHg after 1 year. The frequency and severity of device and/or procedure-related adverse events indicate that the method is safe and well-tolerated. Conclusion: This data suggests that gastric stimulation by the minimally invasive Tantalus^™ System is safe and leads to favorable changes in eating behavior, clinically significant weight loss and reduction in blood pressure. Treatment with the Tantalus^™ System is therefore a promising minimally invasive treatment for obesity.