Pilot Study: Anti-inflammatory Effect of Peroperative Stimulation of the Vagus Nerve

Study Overview
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Brief Summary
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Hypothesis: Electrical stimulation of the abdominal vagus nerve has an anti-inflammatory effect and represents a new therapeutic approach to shorten postoperative ileus. Aims: In the present pilot study, the investigators want to evaluate the anti-inflammatory effect of peroperative electrical stimulation of the vagus nerve. To this end, the following aims are formulated: to optimize the technique of intra-operative electrical vagus nerve stimulation to show that electrical stimulation of the intra-abdominal vagus nerve reduces the inflammatory response to abdominal surgery to evaluate whether electrical stimulation of the vagus nerve leads to clinical improvement (collect pilot data)

Official Title
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Pilot Study: Anti-inflammatory Effect of Peroperative Stimulation of the Vagus Nerve: Potential New Therapeutic Intervention to Shorten Postoperative Ileus

Conditions
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Postoperative Ileus

Intervention / Treatment
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* Procedure: Vagus stimulation 1
* Procedure: Vagus stimulation 2


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients with rectal carcinoma eligible for open rectal resection Age between 18 and 70 years Exclusion Criteria: Preoperative therapeutic abdominal radiation Evident intra-abdominal inflammation (diagnosed by imaging and/or laboratory test results, including abscess or cholecystitis) American Society of Anesthesiologists physical-health status classification (ASA-PS) >3 Poorly regulated diabetes (>200 mg/dl (=11mmol/l))

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 70 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| No Intervention: Sham stimulation<br>No stimulation of nervus vagus | |
| Active Comparator: Vagus stimulation 1<br>2 times 2 minutes (beginning and end of surgery) stimulation at 5 Hz, 500 micro s, 2.5 mA | Procedure: Vagus stimulation 1<br>* 2 times 2 minutes (beginning and end of surgery) stimulation at 5 Hz, 500 micro s, 2.5 mA<br>|
| Active Comparator: Vagus stimulation 2<br>2 times 2 minutes (beginning and end of surgery) stimulation at 20 Hz, 500 micro s, 2.5 mA | Procedure: Vagus stimulation 2<br>* 2 times 2 minutes (beginning and end of surgery) stimulation at 20 Hz, 500 micro s, 2.5 mA<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| levels of pro-inflammatory cytokines in serum, peritoneal lavage and supernatant of stimulated PBMCs (peripheral blood mononuclear cell) |  | From date of surgery until the date of lab analysis (in short time period after taking the blood sample) .Blood samples will be taken before surgery, 2, 24 and 48 hrs after surgery. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| gastric stasis (volume of gastric fluid produced by gastric tube on postoperative day 1) |  | From date of surgery until postoperative day 1. | 
| time to first flatus |  | From date of surgery until the date of discharge from the hospital. | 
| time to tolerance of oral food intake |  | From date of surgery until the date of discharge from the hospital | 
| time to tolerance of oral food intake AND first defecation |  | From date of surgery until the date of discharge from the hospital | 
| gastrointestinal symptoms (nausea, pain, bloating) |  | From date of surgery until the date of discharge from the hospital | 
| Time to first defecation |  | From date of surgery until the date of discharge from the hospital. |