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What is a Mini Gastric Bypass? (OAGB)

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.

mini gastric bypass illustration

There are basically two main steps to this operation:

  1. The surgeon creates a small tube-like stomach pouch which is detached from the rest of the stomach.
  2. 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.

Advantages

  • Technically easier to perform and a shorter operating time than the RYGB
  • Considered reversible
  • Significant weight loss
  • Maintain good quality of eating
  • Lower risk of internal hernia

Disadvantages

  • Risk of stomach ulcer
  • Risk of micronutrient deficiencies
  • Risk of dumping syndrome
  • Risk of bile reflux

Other weight loss surgery procedures

You should have access to all surgical options, as determined by your unique needs. Both surgeons are highly experienced general surgeons with sub-specialty training in bariatric and upper gastrointestinal surgery. Both trained in high-volume specialist bariatric centres in Brisbane as well as interstate and overseas.

This means they are able to perform the full range of weight loss surgeries, as well as revisional surgery. It’s about determining which procedure is right for you and your body.

Your surgeon will perform your weight loss surgery at the Mater Hospital in Pimlico. While your chosen surgeon will be your primary surgeon, both surgeons will attend. This means you get the unique benefit of two qualified specialist surgeons during your operation

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Weight loss surgery FAQs

What is bariatric surgery?
Bariatric surgery is another term for weight loss surgery. The two most common procedures are a Sleeve Gastrectomy and a Roux-en-Y Gastric Bypass. Other bariatric surgery procedures we offer are Mini Gastric Bypass, Revisional Bariatric Surgery and Intra-gastric Balloon. Read more about our range of bariatric surgery options.
Who can get weight loss surgery?
Weight loss surgery is an effective treatment for people who are struggling with obesity and/or experiencing other medical complications, such as obstructive sleep apnoea, coronary artery disease, type 2 diabetes, fatty liver, osteoarthritis/joint pain, cancers and decreased fertility.

While some people are able to manage excess weight through diet and exercise, 95% cannot and weight loss surgery provides another option.

Patients who have a BMI greater than 40, and patients with a BMI greater than 35 and experiencing health complications associated with excess weight are excellent candidates for bariatric surgery.

What will bariatric surgery cost?
At your initial consultation, we will go through our fee structure in detail and discuss, if insured, what your private health insurance will and will not cover. We are transparent in our pricing and you will be fully aware of all costs before surgery.

Costs include:

  • Dr Benedict Mackay or Dr Garth McLeod’s surgical time and a second surgeon assisting
  • The anaesthetist’s fee
  • Hospital fees
  • Medications, such as pain relief
  • Follow up consultations
  • Ongoing support from dietitians, exercise physiologists, psychologists and other allied health professionals
How long will recovery take?
You should expect to stay in hospital for two to three days after bariatric surgery. You should make arrangements for someone to take you home.

It’s also recommended to have someone at home to help you for the first five to seven days after surgery with tasks like cooking, laundry, housework and caring for children.

Most patients return to work two to four weeks after bariatric surgery.

How quickly will I lose weight?
Most patients experience a weight loss of 65 to 75% of excess weight over a period of 12 to 18 months.
What lifestyle changes will I need to make?
Bariatric surgery results in a substantially reduced stomach capacity, which will help you reduce the volume of food that you eat. You may have to eliminate some foods and drinks from your diet altogether.

For some patients, this can be mentally challenging, so we partner with allied health professionals to provide ongoing support on your weight loss journey before and after your bariatric surgery.

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