Sustained Weight Loss with Vagal Nerve Blockade but Not with Sham: 18-Month Results of the ReCharge Trial

Abstract

Background/Objectives. Vagal block therapy (vBloc) is effective for moderate to severe obesity at one year. Subjects/Methods. The ReCharge trial is a double-blind, randomized controlled clinical trial of 239 participants with body mass index (BMI) of 40 to 45 kg/m or 35 to 40 kg/m with one or more obesity-related conditions. Interventions were implantation of either vBloc or Sham devices and weight management counseling. Mixed models assessed percent excess weight loss (%EWL) and total weight loss (%TWL) in intent-to-treat analyses. At 18 months, 142 (88%) vBloc and 64 (83%) Sham patients remained enrolled in the study. Results. 18-month weight loss was 23% EWL (8.8% TWL) for vBloc and 10% EWL (3.8% TWL) for Sham (P < 0.0001). vBloc patients largely maintained 12-month weight loss of 26% EWL (9.7% TWL). Sham regained over 40% of the 17% EWL (6.4% TWL) by 18 months. Most weight regain preceded unblinding. Common adverse events of vBloc through 18 months were heartburn/dyspepsia and abdominal pain; 98% of events were reported as mild or moderate and 79% had resolved. Conclusions. Weight loss with vBloc was sustained through 18 months, while Sham regained weight between 12 and 18 months. vBloc is effective with a low rate of serious complications.

Two-Year Outcomes of Vagal Nerve Blocking (vBloc) for the Treatment of Obesity in the ReCharge Trial

“…The effect of vBloc on weight loss in the ReCharge Trial has been previously reported up to 18 months [3, 6]. The estimated mean percentage of excess weight loss (%EWL) was 26 % (10 % total weight loss [%TWL]) for vBloc and 17 % (6 % TWL) for Sham at 12 months ( p  < 0.001).…”

“…The study design and methods of the ReCharge Trial study have been described previously [3, 6]. The study participants were enrolled both in the USA (eight sites) and in Australia (two sites).…”

“…The estimated mean percentage of excess weight loss (%EWL) was 26 % (10 % total weight loss [%TWL]) for vBloc and 17 % (6 % TWL) for Sham at 12 months ( p  < 0.001). From 12 to 18 months, the vBloc arm maintained its weight loss while the Sham arm regained 40 % of weight lost at 12 months, so that at 18 months the mean %EWL was 24 % (9 % TWL) for vBloc versus 10 % EWL (4 % TWL) for the Sham arm ( p  < 0.001) [6]. Sham participants crossed over to active vBloc therapy or withdrew from the study after the 18-month visit.…”

Treatment of Obesity

“…The intermittent blockade is hypothesized to avoid neural adaptation as occurred in the past with truncal vagatomy. A device for this purpose has been approved by the Food and Drug Administration 13 .…”

“…Regarding gastrointestinal endoscopic devices, the literature looks promising but does not have long-term data 13 . Weight loss is modest while the device safety is good.…”