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Effect of Vagal Nerve Stimulation on Gastric Motor Functions

Not Applicable
Recruiting
Conditions
Depression
Epilepsy
Interventions
Device: Vagal nerve stimulant
Registration Number
NCT06038929
Lead Sponsor
Mayo Clinic
Brief 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.

Detailed 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.

Recruitment & Eligibility

Status
RECRUITING
Sex
All
Target Recruitment
16
Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Study & Design

Study Type
INTERVENTIONAL
Study Design
SINGLE_GROUP
Arm && Interventions
GroupInterventionDescription
vagal nerve stimulantVagal nerve stimulantThe aim is to measure gastric emptying and gastric accommodation in response to a caloric meal before and 3 months after activation of VNS. Therefore, prior to surgery, subjects will undergo combined gastric emptying/accommodation test. Subsequently, participants will undergo a second identical study approximately 3 months after insertion of the VNS.
Primary Outcome Measures
NameTimeMethod
Gastric emptying T1/2during 4 hour gastric emptying test

time to empty 50% of the whole stomach contents

Gastric accommodationduring first 1 hour of gastric emptying test

gastric delta volume (postprandial minus fasting) for the whole stomach

Secondary Outcome Measures
NameTimeMethod
Fasting whole volume volumebaseline

volume of whole stomach before ingestion of meal

Gastric emptying 25%1 day (during gastric emptying test)

time to empty 25% of the whole stomach

Gastric emptying at 2 hours2 hours (during gastric emptying test)

% emptied from the whole stomach at 2h

Gastric emptying lag time1 day (during gastric emptying test)

time to empty 10% of the whole stomach

Gastric emptying at 4 hours4 hours (during gastric emptying test)

% emptied from the whole stomach at 4h

Fasting proximal gastric volumebaseline

volume of proximal half of stomach before ingestion of meal

Postprandial whole gastric volume10-30 minutes after meal ingestion

volume of whole stomach 10-30 minutes after ingestion of meal

Postprandial proximal gastric volume10-30 minutes after meal ingestion

volume of proximal half of stomach 10-30 minutes after ingestion of meal

Trial Locations

Locations (2)

Mayo Clinic in Rochester

🇺🇸

Rochester, Minnesota, United States

University of Minnesota

🇺🇸

Minneapolis, Minnesota, United States

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