One-anastomosis gastric bypass is an attractive bariatric procedure. It is effective in weight loss and comorbidity resolution. It is a relatively simple and fast operation with low complication rates that make it a suitable option in super-obese individuals.
The procedure is known as an omega loop bypass, mini gastric bypass or single-anastomosis bypass. It is similar to a RYGB and is suitable for patients with small bowel adhesions or for those patients in which a RYGB would be too risky. This procedure works through several mechanisms
A restrictive component. The new smaller stomach pouch helps to reduce portion sizes (and thus calories) that can be consumed.
A malabsorptive component. A portion of the small bowel is bypassed allowing fewer calories and nutrients to be absorbed.
Hormonal effect. The surgery effects gut hormones that impact several factors including appetite and glycaemic control. Following surgery, patients often show immediate improvement of their diabetes, often reducing and even ceasing diabetic medications within a few days post-surgery.
Restricts the amount of food the stomach can hold and allows for reduced portion sizes. Induces rapid and significant weight loss. You can expect to lose between 55% and 85% of your excess weight in the first 12–24 months following surgery.
Causes favourable changes in gut hormones that suppress hunger, reduce appetite and improve satiety.
Shorter operating time than the Roux-en-Y gastric bypass and less re-routing of the intestines.
One fewer anastomosis (connection of intestines), which in theory means less chance complications. Theoretically this procedure can be reversed.
Similar weight loss, diabetic control and recovery to the Roux-en-Y Gastric Bypass (RYGB).
Often causes an intolerance to sweets and high-density carbohydrates (fatty foods). Rapid absorption of these foods by the small bowel can lead to unpleasant symptoms called ‘dumping’. This encourages patients to steer clear of foods that may cause these symptoms.
Has a potential for long-term vitamin and mineral deficiencies, thus requiring lifelong supplementation in addition to adopting a healthy balanced diet to maintain good health and prevent future complications.
Complications such as gastric staple line or anastomotic leak can be potentially difficult to manage.
May potentially induce oesophageal gastric reflux disease or worsening of the symptoms.
Often leads to unpleasant symptoms of ‘dumping syndrome’ often associated with gastric bypass surgery.
Gall stones due to rapid weight loss.