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:

1. to optimize the technique of intra-operative electrical vagus nerve stimulation
2. to show that electrical stimulation of the intra-abdominal vagus nerve reduces the inflammatory response to abdominal surgery
3. to evaluate whether electrical stimulation of the vagus nerve leads to clinical improvement (collect pilot data)

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))