Randomized study of natural orifice transluminal endoscopic surgery and endoscopy shows similar hemodynamic impact in a porcine model

Background: A previous porcine study showed a significant difference in heart rate and diastolic blood pressure (DBP) between natural orifice transluminal endoscopic surgery (NOTES) and laparoscopy. This study evaluated the hemodynamics during endoscopy, laparoscopy, and transluminal access. Methods: For this study, 37 female swine were randomized and invasively monitored in terms of blood and abdominal pressure, heart rate, and arterial blood gas (ABG) during 90-min procedures. Group 1 (n = 11) underwent NOTES peritoneoscopy; group 2 (n = 14) underwent 45-min diagnostic endoscopy, a 10-min washout period, and 35-min laparoscopy with mesh placement; and group 3 (n = 12) NOTES had transgastric mesh placement. The groups were compared using a mixed model and a Spearman trend test. This study was approved by Institutional Animal Care and Use Committee (IACUC). Results: No difference in the systolic blood pressure (SBP) was noted. During the initial 30 min, DBP increased significantly from baseline in groups 1 (p < 0.001) and 2 (p = 0.01), but not in group 3 (p = 0.08). The mean DBP did not differ between the groups. During laparoscopy, the average end-tidal carbon dioxide (CO₂) level was 6.6 mmHg higher in group 2 than in group 1 (p = 0.01). The heart rate and ABG values did not differ between the groups (p ≥ 0.10). Conclusion: Heart rate and DBP were similar for NOTES and endoscopy. The differences seen in a previous trial comparing NOTES and laparoscopy were not duplicated. The initial DBP increased for the endoscopy and diagnostic NOTES animals. Differences in end-tidal CO₂ were encountered again during the shortened laparoscopy segment.