Evaluation of Low Pressure Pneumoperitoneum in Bariatric Surgery (ELOPES Study)

This will be a prospective study in patients aged between 18 and 70 years old who have already been screened and planned for elective bariatric surgery. In bariatric surgery, a large portion of the stomach will be removed. Pneumoperitoneum is also known as the abdominal pressure which will be the experimental aspect in this study. Laparoscopy surgery will be performed by introducing the camera (optical trocar) after making an incision at the belly button (umbilicus), and carbon dioxide which will be given at a rate of 5 L/min until the intra-abdominal pressure of either 8-10 mmHg (low-pressure group) or 12-15 mmHg (standard pressure group) is achieved. The remaining three standard ports will be placed and the laparoscopic sleeve gastrectomy will be performed at an insufflation rate of 15 L/min. The greater omentum will be divided at the greater curvature of the stomach using an ultrasonic dissector, beginning from the proximal antrum until the fundus. The omentum will be divided close to the stomach wall hence preserving the gastro-epiploic vessels. Short gastric vessels will be divided entirely from the stomach and this dissection will continue until the left crus of the diaphragm are exposed. Endoscopic staplers will then be used to staple and divide the stomach until the angle of His. A 39Fr gastric calibration tube will be placed along the lesser curvature of the stomach, acts as a guide during the division of the stomach. Finally, the divided stomach will be removed through a 12mm port site and the incision will be closed with sutures.

Towards the end of the surgery, all residual pneumoperitoneum will be evacuated by keeping the trocar valves open under direct telescopic vision. The duration of surgery or any intraoperative complications will be recorded. The starting of surgery will be regarded after the induction of anaesthesia and the end of surgery is regarded when the end of skin closure. Operating field or also known as surgical view is defined as the view of the intra-abdomen. A clear operating field allows a good working space for the surgeon. Numeric rating score will be used to access the operating field during the surgery. Post-operative pain will be rated on a Visual Analog Scale at rest and with movement.

Inclusion criteria

• Age 18-70 years
• Ability to give informed consent
• Patients who are approved by the anaesthetics to undergo bariatric surgery.

Exclusion criteria

• Age below 18 and above 70
• Inability to give informed consent
• Patient unfit for bariatric surgery including who has poor respiratory, cardiac, renal and liver function.
• Patient with Body Mass Index (BMI) >50
• Patient with American Society of Anesthesiologists (ASA) >3