Sleeve gastrectomy and Roux-en-Y gastric bypass are two of the more commonly performed bariatric procedures in Australia, the other being gastric banding. They 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?
This procedure 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.
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.
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.
Average weight loss with a sleeve gastrectomy is around sixty per cent of the patient’s excess weight.
After the initial period of loss, many people will regain some of their lost weight. Weight regain can be minimised with maintenance of good eating behaviours and food choices.
In this complex operation a small pouch is made from the top section of the stomach and is 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.
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.
The risks associated with gastric bypass include bleeding, leakage, infection and bowel obstruction.
The average result is losing 60-70% of the initial excess weight.
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. Commonly, the patient will be restricted to fluids for 1-2 weeks. After this, if tolerated, they can commence purees. Some weeks after that the patient can try solid foods.
Eating too much food or solid food too soon can lead to vomiting. It is important to give the staple lines time to heal.
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.
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.
For further information, visit the Obesity Surgery Society of Australia and New Zealand website.