The sleeve gastrectomy involves the permanent removal of 85-90% of the stomach, performed under a general anaesthetic using video assisted surgery (key hole surgery).
Although the physical size of the stomach is reduced, the normal direction of the food stream through the stomach and the rest of the intestinal tract are not altered. This means that all nutrients including vitamins, minerals and protein will continue to be absorbed normally. It simply reduces the holding capacity from about 1.5 litres of food and liquid to approximately 150 mls. This is the size of a banana. This allows a person to feel comfortably satisfied and full with a meal size approximately equivalent to a cup of food.
Typically, sleeve gastrectomy patients will have between 4-6 small meals per day, which is actually the ideal way to eat. Dietitians recommend small frequent meals as a way of avoiding big swings in Insulin levels and achieving a more even intake of calories as part of a healthier eating pattern. Despite being smaller, the stomach sleeve still functions normally- food and nutrients continue to enter and leave in the same way, acid continues to be made to assist in digestion, and essential vitamins and minerals such as B12, calcium, folate and iron can be absorbed normally. There appears to be a change in way that fatty foods are handled by the digestive track. Patients frequently report losing their taste for foods high in sugar and fat such as chocolate, fried food and soft drink, which seem to make them feel more bloated, unsettled, or queezy. This adverse side affect is very helpful as it assists the person in adopting healthier food options.
Which weight loss procedure is best for me?
Unfortunately no current weight loss procedure is perfect. They all have their advantages and disadvantages.
With respect to sustained long term weight loss and the obvious long term health benefits, both procedures are similar and very successful. The International Diabetes Federation (IDF) has recently delivered a statement designed to address the rapid increase in Type-2-Diabetes (T2D) globally. The strategic paper advocates the early introduction of Bariatric (weight loss) Surgery, in addition to standard behavioural and medical approaches, to control diabetes in severely obese patients. Early introduction of Bariatric Surgery in T2D patients with a BMI ≥ 35, is now recognised by the IDF as a positive step in normalising blood glucose levels, reducing or avoiding the need of medications and a potentially cost effective approach to treating T2D. The IDF recognises both the adjustable gastric band and sleeve gastrectomy as proven and reliable weight loss procedures.
Bariatric Surgical and Procedural Interventions
Both the adjustable gastric band and sleeve gastrectomy are completed as laparoscopic video assisted procedures (key hole surgery) with a very high procedural success rate. As a result, there is minimal pain, excellent cosmetic result, short hospital stays and a quick return to normal activities.
The procedures do differ with respect to technique and therefore have different immediate and long term problems. In gastric banding a soft adjustable band is placed around the upper end of the stomach and the access port secured to the front of the abdominal muscles. The dissection as a result is very minimal and straight forward. Post procedural bleeding and injury to other organs can happen, but is very uncommon. The key to the device working is its adjustability. As a result, the follow up needs to be very frequent, as often as once a month if necessary. The device is for life, and therefore a proportion of patients do experience problems with the gastric band which requires surgical revision (re-operation). The access port and tubing can leak with time, or flip upside down and need replacement or resiting. The gastric band itself can migrate into the stomach (erosion) or along the stomach (slippage). The life-long risk of these gastric band problems occurring is about 5%.
In sleeve gastrectomy the stomach itself has to be divided with a cutting stapler and a large portion removed from the abdomen. As a result, there are some additional risks over the adjustable gastric band in the early post-operative period. The staple line can bleed and another problem is that gastric fluid may leak through the staple line if healing along the staple line is not perfect. This causes infection around the outside of the gastric sleeve, and can be quite serious. Recovery may take several weeks, and treatment usually involves the use of antibiotics, surgical drains, and gut rest. Fortunately because of technological improvements in stapling devices and the use of tissue glues, only 1% of patients experience these problems.
The Gastric Bypass does not involve a device or removal of a portion of the stomach. It is a procedure which is both restrictive and malabsorptive. It also involves two joinings (anastomoses). In the short term there is a risk that an anastomosis may leak, although this is usually less challenging to treat than a staple line leak from the sleeve.
In the short term the Gastric Bypass is very safe with better weight loss than the band and the sleeve, however in the long term weight loss is not dissimilar. In the long term, the Bypass can be troubled by vitamin deficiency, dumping syndrome, internal hernia, adhesive bowell obstruction, pouch dilatation and weight regain. Fortunately, with continuing advances in technique fewer Gastric Bypass patients will experience these side effects.
Because no device is inserted in sleeve gastrectomy and Gastric Bypass, the follow up is not as intense to achieve expected weight loss. In the long term it has been argued that the weight loss may not be durable as the stomach has a tendency to dilate. Long term follow up studies throughout the world do not support this argument, and this is why the sleeve gastrectomy is now a well recognised and successful weight loss procedure.