To improve post-operative recovery, medical device was developed combining low-pressure pneumoperitoneum and heated and humidified Carbon Dioxide (95˚F & 95% RH) during laparoscopic surgery to reduce the harmful effects of cold/dry insufflation.

A double-blind, prospective, randomized, controlled, monocentric trial is designed in the aim to assess the impact of low-pressure pneumoperitoneum with warm and humidified gaz on post-operative pain at 24 hours without taking opioids. It is compared with low-pressure laparoscopy with cold and dry gaz in patients undergoing colorectal surgeries.

Laparoscopy is the gold standard in colorectal surgery with many benefits in term of morbidity, post-operative pain and analgesic consumption. However, the pneumoperitoneum created for the laparoscopy has several negatives impact and limits (specific pain following abdominal distension, visibility, physiological repercussion).

To improve recovery after colorectal laparoscopic surgery it was realized a first study (PAROS 1) which showed that low-pressure laparoscopic colectomy for benign or malign disease was feasible and safe with shorter length of stay (3 vs. 4 days; p=0.001), and decrease post-operative pain (VAS ≤ 3 à H8: 87% vs. 72% ; p=0.039) with reduction of analgesic consumption (step II analgesics: 73% vs. 88% ; p=0.032 and step 3 analgesics: (10% vs.23% ; p=0.042) (Br J Surg. 2021 Aug 19;108(8):998-1005) Simultaneously, the development of humidification medical device, referring to the administration of heated and humidified CO2 during laparoscopic surgery, aims to reduce the effects of cell drying and evaporative heat loss when the body is exposed to cold CO2. and dry during laparoscopic surgery. The state of the CO2 traditionally used during laparoscopic surgery and the ambient air during open surgery is very different from that of the human body, as it directly extracts heat and humidity from the already fragile patient.

The introduction of heated and humidified CO2 provides an environment that reflects the physiological state of the peritoneum.

Added to the benefits of low pressure, the advantages of surgical humidification seem very positive. During surgery, surgical humidification would reduce the incidence of perioperative hypothermia, improve local tissue oxygenation and local tissue perfusion. After surgery, it would improve core body temperature, reduce local peritoneal inflammation, surgical site infection rate and recovery time. The benefits of a warmed and humidified CO2 also seem very positive in terms of reducing postoperative pain and analgesic consumption. In the long term, it would reduce adhesion formation, tumor burden, metastases, and economic cost.

The aim of the study is to assess the impact of low-pressure pneumoperitoneum with warm and humidified CO2 insufflation on post-operative pain without taking opioids, compared with low-pressure laparoscopy with cold and dry gas insufflation.

Inclusion Criteria:

• Colorectal surgery for malignant or benign pathology
• Surgery without stoma
• Patient operable by laparoscopy or robot assisted under low pressure pneumoperitoneum
• Age ≥ 18 years old
• Patient affiliated to a social security system or beneficiary of the same
• Informing the patient and obtaining free, informed, and written consent, signed by the patient and his investigator.

Exclusion Criteria:

• Laparotomy procedure
• Total or Subtotal Colectomy
• Transverse segmental colectomy
• Proctectomy with stoma or Total Coloproctectomy
• Procedure associated with colorectal surgery (except appendectomy or liver biopsy)
• Patient with stoma
• Probable realization of a stoma during the operation
• Crohn's disease, Hemorrhagic Rectocolitis (UC) with VAS > 3
• Diverticulitis or Sigmoiditis with VAS > 3
• Endometriosis with VAS >3
• VAS before surgery> 3
• BMI ≥ 30
• ASA ≥ 3 (except if ASA 3 for non-cardiac and/or vascular diseases)
• History of laparotomy
• Emergency surgery
• Pelvic Sepsis or Preoperative Fistula
• Pregnant woman, likely to be, or breastfeeding
• Persons deprived of their liberty or under measure of judicial protection (curators or guardianship) or unable to give their consent
• Persons undergoing psychiatric treatment without their consent
• Persons admitted to a health or social establishment for purposes other than research
• Inability to undergo medical monitoring of the trial for geographic, social or psychological reasons