Effect of Vagal Nerve Stimulation on Gastric Motor Functions

Depression Clinical Trial

Official title: REVEAL - Research Evaluating Vagal Excitation and Anatomical Linkages Gastric Emptying Ancillary Project: Effect of Vagal Nerve Stimulation on Gastric Motor Functions

Status Not yet recruiting

Clinical Trial Summary

The specific aim of this study is to compare simultaneous assessment of gastric emptying and gastric accommodation in response to the same caloric meal before and three months after activation of left cervical VNS. Our hypothesis is that cervical VNS increases gastric accommodation and accelerates gastric emptying.

Clinical Trial Description

Objectives To compare simultaneous assessment of gastric emptying and gastric accommodation in response to the same caloric meal before and three months after activation of left cervical Vagal Nerve Stimulation.

Design and Outcomes Single cohort study in 16 Vagus Nerve Stimulant-implanted subjects with drug-resistant epilepsy with seizures, aged 18 years or older who were consented for the main VESPA REVEAL Common Study Protocol.

Prior to surgery, subjects will undergo combined gastric emptying/accommodation test. Subsequently, participants will undergo a second identical study within 1 week of completing the second Late Effects Visit in CSP, approximately 3 months after insertion of the VNS. There are only 2 total visits needed, with an average time commitment of 4.5 hours.

Participants will keep their planned VESPA REVEAL study visits Interventions and Duration In this single cohort study in 16 Vagus Nerve Stimulant-implanted subjects, each participant will undergo combined gastric emptying/accommodation test prior to implantation and a second identical study within 1 week of completing the second Late Effects Visit in CSP Sample Size and Population Sample size assessment. This will be based on results of the primary endpoints in our Mayo Clinic lab. We expect 80% power, α=0.05, assuming paired t-test analysis with n=16 first tested at baseline (no VNS) and 3 months after VNS activation with parameters as described above. Demonstrable differences (Table 1) will be based on the variation (SD) observed from our Mayo Clinic prior studies

. Table 1. Effect size demonstrable for primary endpoints of interest, based on 80% power at α=0.05 for n=16 Response Mean SD Effect size detectable [absolute (% of mean)] Fasting gastric volume, mL 273 57 42.7mL (15.6%) Post-meal gastric volume, mL 848 111 83.2mL (9.8%) Gastric emptying T1/2, min 122 29.8 22.33 (18.3%)

In addition, these effect sizes are feasible in response to vagal intervention, whether it turns out to be stimulatory or inhibitory, and a 20-minute difference in GE T1/2 is clinically significant, as documented in a published meta-regression from our research team.

Human subjects. Participants will be recruited primarily from the Mayo Clinic but also from the University of Minnesota (90-minute drive away). With only limited added burden on participants, we anticipate that the majority of n-VNS REVEAL participants from these two sites (total = 16) will be amenable to undergo our procedures. There are only 2 total visits needed, with an average time commitment of 4.5 hours.

The patients will have undergone placement of the n-VNS for clinical indications. The objective of the study is to evaluate the effects of this treatment on gastric functions, rather than any therapeutic intent, or the development of a new indication to be submitted to regulatory agencies for an additional therapeutic indication. Therefore, it is perceived that an application for an investigational device exemption (IDE) is not required. ;

Related Conditions & MeSH terms

• Depression
• Epilepsy

• NCT number: NCT06038929
• Study type: Interventional
• Source: Mayo Clinic
• Status: Not yet recruiting
• Phase: N/A
• Start date: July 1, 2024
• Completion date: June 30, 2025