Bariatric Surgery - The Other Two Procedures


Published: 26 May 2016

Sleeve gastrectomy and Roux-en-Y gastric bypass are two of the most commonly performed bariatric procedures in Australia, along with gastric banding (Shannon, Gervasoni & Williams 2013).

These procedures are usually done laparoscopically. As with banding, sleeve and bypass operations result in less hunger and reduced portion sizes. Additionally, after a bypass, there is a reduction in energy and other nutrient absorption, as the food skips part of the small intestine.

So, what exactly is the difference between the two?

Sleeve Gastrectomy

Sleeve Gastrectomy involves removing the majority of the stomach, reducing its capacity and leaving only a narrow sleeve. The patient will subsequently eat much smaller portions as they achieve earlier satiety or fullness (ASMBS 2015).

The operation has a hormonal effect on the patient known as reduced ghrelin, which reduces the effects of hunger over the first year or two. As the effects fade in time, it is vital that good eating habits are established early and maintained (TBC 2018).

The sleeve gastrectomy operation carries a higher risk of blood loss and higher mortality than gastric banding. There is also a risk of leakage through the staple line, where the remainder of the stomach was joined together (ASMBS 2015; Mayo Clinic 2018a).

Average weight loss with sleeve gastrectomy is around 60% of the patient’s excess weight (Mayo Clinic 2018).

After the initial period of loss, patients may regain some of their lost weight. Weight regain can be minimised by maintaining good eating behaviours and food choices (Mayo Clinic 2018a).

sleeve gastrectomy diagram

Roux-en-Y Gastric Bypass

In roux-en-Y gastric bypass, a small pouch is made from the top section of the stomach and connected to a loop of jejunum (bypassing the duodenum and the first part of the jejunum). Smaller portions of food are consumed, and as a large section of the small intestine is skipped, the energy absorbed from the food is consequentially less (Mayo Clinic 2017).

As the bypass procedure is a more drastic alternative, many surgeons reserve this as an option for revision surgery for patients who have not had a good result with banding or a sleeve (John Hopkins Medicine n.d.).

The risks associated with gastric bypass include bleeding, leakage, infection and bowel obstruction (Mayo Clinic 2017).

The average result is losing more than 60% of the initial excess weight (Mayo Clinic 2017).

roux-en-Y gastric bypass diagram

Post-op Care

Following a sleeve or bypass operation, oral intake is initially confined to fluids. Under the guidance of a dietitian, a plan for gradually including more solid textures is designed. The patient will often be restricted to fluids for one to two weeks. After this, if tolerated, they can commence purees. Some weeks after that the patient can try solid foods (Mayo Clinic 2018b).

Eating too much food or solid food too soon can lead to vomiting. It is important to give the staple lines time to heal (Mayo Clinic 2018b).

Bariatric operations require long term follow up consultations to monitor any complications or nutritional deficiencies encountered. Deficiencies are more likely to occur with a sleeve or bypass operation compared with gastric banding. Vitamin and mineral supplementation is advised, commencing with chewable tablets initially (John Hopkins Medicine 2020).

The professional input of a dietitian is invaluable to maximise the nutritional quality of patient’s meals when such a small volume of food is being consumed.

Other Factors To Optimise Results

  • Learning to eat slowly and mindfully;
  • Serving oneself small portions;
  • Taking small mouthfuls and chewing them well;
  • Avoiding eating and drinking at the same time;
  • Avoiding liquid calories;
  • Eating a variety of whole foods: grains, legumes, eggs, vegetables/salad, fruit, lean meats, low-fat dairy, and a judicious amount of nuts, seeds and oils;
  • Limiting refined, processed, high-energy foods;
  • Addressing unhelpful eating behaviours such as bingeing or any kind of non-hungry eating and
  • Learning to stop eating when just satisfied rather than continuing to eat until uncomfortably full.

For further information, visit the Obesity Surgery Society of Australia and New Zealand website.