Randomized trial on the physiologic impact of NOTES.

Area of Science:

• Minimally Invasive Surgery
• Surgical Physiology
• Endoscopic Procedures

Background:

• Previous research indicated less acidosis in swine undergoing Natural Orifice Translumenal Endoscopic Surgery (NOTES) with air insufflation versus standard laparoscopy.
• The current study aimed to differentiate the effects of CO2 insufflation versus intra-abdominal pressure on acidosis.
• Endocrine stress responses were compared between NOTES peritoneoscopy with CO2 and standard laparoscopy with CO2.

Purpose of the Study:

• To evaluate the differential effects of CO2 insufflation versus intra-abdominal pressure on acidosis during NOTES.
• To investigate the endocrine stress response in swine undergoing NOTES with CO2 insufflation compared to standard laparoscopy with CO2.

Main Methods:

• Twenty-eight female pigs were divided into four groups: NOTES with CO2, NOTES with air, laparoscopy (12 mmHg), and laparoscopy (7 mmHg).
• Pneumoperitoneum was maintained for 90 minutes, with arterial blood gas analysis at multiple time points.
• Serum TNF-α and urine adrenaline levels were measured to assess the endocrine stress response.

Main Results:

• Significant differences in blood pH were observed among the groups.
• Serum TNF-α levels were significantly higher on postoperative day 1 in the NOTES CO2 group compared to standard laparoscopy (p = 0.03).
• NOTES with CO2 showed a stronger stress response compared to other methods.

Conclusions:

• While initial pH levels were similar between NOTES CO2 and standard laparoscopy, NOTES CO2 animals recovered to levels seen in low-pressure laparoscopy and NOTES with air.
• NOTES with CO2 insufflation appears to induce a more pronounced stress response than standard laparoscopy, low-pressure laparoscopy, or NOTES with air in this swine model.
• Findings suggest careful consideration of insufflation gas and pressure in NOTES procedures to mitigate stress responses.