Degree of Surgical Trauma Caused By the Abdominal Access -comparing Open Surgical, Laparoscopic and Notes Transgastric Access Routes in a Porcine Model

Per-Ola Park, Professor¹, Jorge Alberto Arroyo Vazquez, MD¹, Asghar Azadani, MD², Monder Abu-Suboh-Abadia, MD³, Joan Dot, MD³, Jose Ramon Armengol Mirro, Professor³, Maria Bergstrom, MD, PhD¹. ¹Dept of Surgery, South Alvsborg Hospital & Gothenburg University, ²Dept of Surgery, Carlanderska Hospital, Gothenburg, Sweden, ³3Hospital Universitario Val d’Hebron,Wider-Barcelona, Barcelona, Spain

Introduction

Previous experimental investigations indicate that transgastric NOTES procedures induce a less pronounced postoperative inflammatory response compared with open and laparoscopic surgery. One theory is that a transgastric incision induces less trauma than a skin-incision. In this study we compare the postoperative inflammatory response, by measuring CRP and TNF-a during and after open, laparoscopic and transgastric abdominal access.

Methods

27 pigs were randomized to open surgical, laparoscopic or transgastric NOTES abdominal access, mimicking accesses for cholecystectomy. Procedures were performed by trained surgeons and endoscopists on anaesthetised animals. After completion of the different accesses no further surgery was performed. All accesses were left open for forty minutes and then closed. Animals were survived for 7 days, post mortem was performed after euthanasia.

Open surgery: An 11cm subcostal incision was made, retractors were inserted and left in place for 40 minutes. Closure was performed in layers, including the skin, using resorbable suture.

Laparoscopy: Four laparoscopic ports were placed after skin incision, 10+10+5+5 mm, and left in situ for 40 minutes. Incisions were closed in layers using resorbable suture.

Transgastric NOTES: Stomachs were not washed. Access was created using a needleknife-guide-wire-balloon-dilatation technique. The gastroscope was introduced into the abdominal cavity and left in situ for 40 minutes. Gastric incisions were closed using Brace-bars from Olympus.

Blood samples were taken before the procedures, at start of the accesses, at 20 and 40 minutes of the procedure, at 24 h postoperatively (POD1) and at postoperative day (POD) 3 and 7. Analyses of CRP and TNF-a were performed. Animal weight was recorded.

Results

There was no difference in access time between the groups. Closure took significantly longer time in the open group (p<0.001). Mean weight was 32 kg at start and 34 kg at POD7 with no differences between the groups.

CRP showed no differences between the groups during the procedures (20 min and 40 min). The open group had a significant increase until POD1. However there were no differences between the groups at POD1, 3 or 7.

TNF- a showed an increase during the procedure from start to 20 and 40 min with normalisation at POD1, for all animals with no statistically significant differences between the groups. However there was a clear trend towards a lower increase and lower TNF- a -levels at 20 and 40 min for the NOTES animals.

At post mortem 1/3 of the pigs in both the laparoscopic and open groups had wound infections while no animals in the NOTES group had infections. The laparoscopic animals had significantly less intra abdominal adhesions compared with the open group and NOTES animals. 9/10 NOTES animals had adhesions between the omentum and the stomach closure site.

Conclusion

This study shows no statistically significant differences in CRP or TNF- a response between the access-techniques but it shows a trend towards a lower TNF- a response during the procedure in the NOTES group, indicating a lower inflammatory response resulting in a lower degree of surgical trauma. Whether this is clinically relevant needs further investigations.