Weight gain after sleeve gastrectomy is a problem that occurs at different rates over time and can be analysed in three stages.The first group are those who do not lose enough weight in the first 6 months after surgery. This usually happens when the stomach cannot be reduced sufficiently in the standard way. Rarely, even in sedentary women over the age of 45, there is insufficient weight loss even with standard gastric banding.

The second group are those who lose weight after surgery but regain it in less than 3 years. This may indicate that the stomach has not been reduced enough or that lifestyle changes have not been made.The third group are those who gain weight after 5 years. This usually happens if lifestyle changes are not made.Revision surgery is the process of reducing the size of the growing stomach tube by re-cutting or folding and sewing. This is a common and effective procedure. It has almost no malabsorption effect.

As it is more difficult for the re-shrunk stomach to grow back, the risk of weight gain after re-sleeve is reduced.

An intragastric balloon is a small silicone balloon filled with saline or air that fills the stomach to create a feeling of fullness. It is placed in the stomach non-surgically to promote weight loss and is usually left in place for 4-6 months. The balloon contributes to weight loss by reducing the portion size and frequency of the person's meals.

When the balloon is removed, the patient has adopted healthier eating habits and the weight loss becomes permanent. There are different types of intragastric balloons, which are either endoscopically placed or swallowable. Swallowable balloons remain in the stomach for a short time and are passed out through the bowel after about four months. Some balloons can also be inflated endoscopically for more effective weight loss.

Mini gastric bypass was described by the American Dr Rutledge in 1997 and is also known as omega bypass. It has a greater malabsorptive effect than RNY bypass. Mini gastric bypass is often used as a second option for weight gain after sleeve gastrectomy.

Mini-gastric bypass surgery is performed by reducing the capacity of the stomach and bypassing the first 2 metres of the small intestine. This significantly reduces the absorption of food. The operation can be done laparoscopically.For people who are overweight, a sleeve gastrectomy is usually enough to lose weight and relieve co-morbidities.

However, if weight is gained for various reasons, the sleeve gastrectomy can be revised and a minigastric bypass can be performed.

Before 2013, RNY gastric bypass was the most popular weight loss surgery, but it has now been overtaken by sleeve gastrectomy. While RNY bypass is still preferred for patients with severe reflux problems, it is considered a second option for weight regain after sleeve gastrectomy. If bile reflux is severe after minibypass, another RNY bypass can be performed.American surgeons first attempted to create bypasses in the intestines of obese people, but this method was abandoned because it caused serious side effects.

They then tried the method of inserting a silicone ring into the stomach (gastric clamp), but this was abandoned because it caused damage to the stomach. Surgeons found that reducing the volume of the stomach was effective and developed gastric bypass surgery. This operation achieved a two-way effect by reducing the size of the stomach and creating a shortcut in the bowel.

However, as the laparoscopic operation took a long time and complications increased, it was decided to divide the operation into two stages. Unexpectedly, however, the patients did not go through with the second stage and lost weight only after the stomach reduction surgery. This accidental situation led to the discovery of sleeve gastrectomy, the most popular weight loss surgery today.

Gastric bypass surgery, inspired by the American experience, was moved to the second stage. Although sleeve gastrectomy is usually sufficient for weight loss and relief of co-morbidities, if weight regain occurs for any reason, the sleeve gastrectomy can be revised and converted to gastric bypass.Although there are several types of gastric bypass, the most common is the RNY gastric bypass, followed by the mini gastric bypass and the duodenal switch.

One of the most commonly used endoscopic applications in recent years is gastric botulinum toxin (BTX). BTX is a neurotoxin produced by Clostridium botulinum bacteria and is associated with botulism in humans.

The BTX-A isotype, which has long been used in clinical practice, is effective in the treatment of some diseases. BTX-A, which is used in particular to treat achalasia, a motility disorder of the gastrointestinal tract, prevents contraction of smooth and skeletal muscles by inhibiting the release of acetylcholine at the neuromuscular junction.

When injected into the stomach, BTX-A delays gastric emptying by reducing gastric motility, thereby producing a feeling of satiety. However, studies in the literature do not support a sustained effect of gastric Botox administration.

Duodenal switch surgery, also known as biliopancreatic diversion with duodenal switch, is a long-established surgical procedure. A more modern and safer version of this procedure is SADI-S (Single Anastomosis Duodeno-Ileal Bypass with Sleeve Gastrectomy), which combines restrictive and absorptive effects for weight loss and diabetes management.

SADI-S, similar to gastric bypass, incorporates both restrictive and absorption reducing elements and has proven to be highly effective for weight loss and solving problems such as diabetes. The procedure consists of two stages: first, 85% of the stomach is removed to create a tube-like structure, similar to a sleeve gastrectomy, which restricts food intake. Secondly, part of the duodenum is removed and the gastric outlet is redirected to a segment of the small intestine, effectively reducing the absorption area for fats and calories.The key difference between SADI-S and traditional duodenal switch surgery is the length of the small intestine that is bypassed.

While traditional surgery bypasses approximately 80% of the small intestine, SADI-S leaves sufficient length to mitigate vitamin and mineral deficiencies while maximising weight loss effects.Patients considering SADI-S, especially those with uncontrolled diabetes, should be aware of the need for strict lifelong follow-up schedules and vitamin/mineral supplementation. However, if these requirements are met, SADI-S is considered to be highly effective and safe.