The OAGB is also known as the ‘single loop bypass’ and the mini-bypass. It is a minimally invasive procedure performed with a laparoscopic technique.
There are basically two main steps to this operation:
- The surgeon creates a small tube-like stomach pouch which is detached from the rest of the stomach.
- This gastric pouch is then connected up to the intestine, bypassing up to 200cm of the total length of the small bowel.
This technique differs from the Roux-en-Y gastric bypass, which has an extra join between the small bowel.
The OAGB typically results in 30 to 40% weight loss or up to 80% excess weight loss over a period of about 18 months. The most rapid weight loss is usually in the first 6 months. This weight loss is achieved through both the restrictive effect of the small pouch and the metabolic effect of bypassing the small intestine.
The OAGB has a good complication profile with a low complication rate of around 5%. A small proportion of those patients may require revisional surgery for bile reflux or malnutrition. A significant advantage is that the OAGB does result in a lower incidence of small bowel obstruction from internal hernia formation.
