title: The pig as preclinical model for laparoscopic vagus nerve stimulation.
abstract: OBJECTIVE
  Cervical vagus nerve stimulation (VNS) prevents manipulation-induced intestinal inflammation and improves intestinal transit in a mouse model of postoperative ileus (POI). Cervical VNS, however, is accompanied by cardiovascular and respiratory side effects. In view of potential clinical application, we therefore evaluated the safety and feasibility of abdominal VNS via laparoscopic approach in a porcine model.
  
  
  METHODS
  Six pigs were used in a non-survival study for both cervical and abdominal VNS. Two cardiac pacing electrodes were positioned around the right cervical and posterior abdominal vagus nerve and connected to an external stimulator. VNS was performed using four different settings (5 and 20 Hz, 0.5 and 1 ms pulse width) during 2 min with ECG recording. Laparoscopic VNS was timed and videotaped, and technical difficulties were noted. A validated National Aeronautics and Space Administration Task Load Index (NASA-TLX) questionnaire was used to evaluate the task and workload.
  
  
  RESULTS
  The procedure was completed in all pigs with 4-port laparoscopic technique. Cervical and abdominal VNS were performed after correct identification and isolation of the nerve, and positioning of the electrodes around the nerve. Median laparoscopic operating time was 16 min (range 8-33 min), and median NASA-TLX was 31 (range 11-74). No major complications were encountered. Reduction of heart rate was between 5.5 and 14% for cervical VNS and undetectable for abdominal VNS.
  
  
  CONCLUSIONS
  In a porcine model, laparoscopic VNS is feasible and safe with cardiac pacing electrodes and may lead to a similar novel approach in humans in the near future.
authors.affiliation: Department of Abdominal Surgery, University Hospital Gasthuisberg Leuven, Herestraat 49, 3000, Leuven, Belgium. albert.wolthuis@uzleuven.be.
authors.forename: A M
authors.initials: AM
authors.lastname: Wolthuis
authors.affiliation: Translational Research Center for GastroIntestinal Disorders (TARGID), University Hospital Gasthuisberg Leuven, Herestraat 49, 3000, Leuven, Belgium.
authors.forename: N
authors.initials: N
authors.lastname: Stakenborg
authors.affiliation: Department of Abdominal Surgery, University Hospital Gasthuisberg Leuven, Herestraat 49, 3000, Leuven, Belgium.
authors.forename: A
authors.initials: A
authors.lastname: D'Hoore
authors.affiliation: Translational Research Center for GastroIntestinal Disorders (TARGID), University Hospital Gasthuisberg Leuven, Herestraat 49, 3000, Leuven, Belgium.
authors.forename: G E
authors.initials: GE
authors.lastname: Boeckxstaens
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D005240:Feasibility Studies; D006339:Heart Rate; D010535:Laparoscopy / Q000009:adverse effects / Q000379:methods*; D013552:Swine; D055536:Vagus Nerve Stimulation / Q000009:adverse effects / Q000379:methods*
keywords: Abdominal vagus nerve; Porcine model; Postoperative ileus; Vagus nerve stimulation