Bariatric Surgery

Obesity and Bariatric Surgery

Obesity is a chronic condition that is often difficult to treat with a simple diet combined with regular exercise. In these cases, bariatric surgery is a valid therapeutic option, especially for severely obese people who suffer from serious health problems exacerbated by excess weight.

Bariatric surgery includes a variety of procedures that promote weight loss by reducing food intake and / or absorption. Weight loss can be achieved by reducing the size of the stomach with a gastric bandage, by surgical resection (partial vertical gastrectomy or biliopancreatic diversion with duodenal switch) or by creating a small gastric pouch connected directly to a section of the small intestine ( gastric bypass and variants). The best outcome is obtained when the patient who undergoes surgery is strongly determined to adhere to strict dietary guidelines and to perform regular physical activity after the operation. In addition, the subject must agree to commit to long-term follow-up and post-operative medical treatment. These behaviors are essential to maintain the results obtained with bariatric surgery.

Indications

Currently, bariatric surgery is a suitable option for patients who:

• They present a serious obesity;
• They failed to achieve effective results with a controlled food program (with or without pharmacological support);
• They present associated pathologies, such as hypertension, reduced glucose tolerance, diabetes mellitus, hyperlipidemia and obstructive sleep apnea.

The body mass index ( BMI ) is used to define the levels of obesity, an indicator of the weight state of an individual who compares height and weight. A subject with BMI ≥ 30 is considered obese .

Bariatric surgery is recommended only for people with at least one of the following characteristics:

• BMI> 40 (obesity of IIIa class / very serious);
• BMI> 35 (2nd / 2nd class obesity), associated with at least one pathological condition linked to obesity that can improve with weight loss.

However, recent research suggests that bariatric surgery may also be appropriate for people with a BMI of 35-40 with no associated disease or a BMI of 30-35 and significant comorbidities.

Anyone considering the possibility of undergoing bariatric surgery to achieve significant weight loss should be aware of the risks and benefits of the treatment.

The patient can be considered suitable for a bariatric surgery if:

• It fails to reach or maintain a beneficial level of weight loss (for at least six months) by adopting appropriate non-surgical solutions, such as diet, drugs and exercise.
• He agrees to commit himself long term, after the operation, to adopt a healthy diet and to follow a regular physical activity; it is therefore aware of the limits it will have to face to its future food choices and the need to undergo regular follow-ups.
• It does not present any medical or psychological obstacles to surgery or to the use of anesthesia, it does not abuse alcohol and / or drugs.
• He is motivated to improve his health and is aware of how life can change after surgery (for example, patients must adapt to side effects, such as the need to chew food well or the impossibility of eating large quantities of food).

There is no absolutely safe method, including surgery, to produce significant weight loss and maintain it over time. Some subjects who undergo a bariatric surgery procedure may experience a lower weight loss than expected; others may regain part of the weight lost over time. This recovery can vary depending on the degree of obesity and the type of surgery. Even some bad habits, such as lack of exercise or frequent consumption of high-calorie snacks can affect the long-term outcome of the treatment.

Classification

Bariatric procedures can be grouped into three main categories:

• Malabsorption interventions. Malabsorbent surgical procedures reduce the absorption of food. They lead to an irreversible reduction in the size of the stomach and their effectiveness derives mainly from the creation of a physiological condition: the gastric cavity is connected to the terminal part of the small intestine, with consequent limitation of the absorption of calories and nutrients. They belong to this type:
  • Biliopancreatic diversion (wider form of gastric bypass, with the gastric pouch attached to the ileum. It produces the most extreme malabsorption);
  • Jejuno-ileal by-pass;
• Restrictive procedures. Gastro-destructive interventions limit the introduction of food through a prevailing mechanical action. They are based on the formation of a small gastric pouch in the upper part of the stomach, which limits the gastric volume and leaves the alimentary canal in continuity through a narrow and non-dilatable orifice. Restrictive procedures act to reduce the amount of food taken orally. They belong to this type:
  • Adjustable gastric banding;
  • Vertical gastroplasty;
  • Sleeve gastrectomy (partial vertical gastrectomy);
  • Intragastric balloon (transient non-surgical treatment).
• Mixed interventions. Mixed bariatric procedures apply both techniques simultaneously, as in the case of gastric bypass or sleeve gastrectomy with duodenal switch .

The type of surgery that more than any other can help an obese person depends on a number of factors. Patients should discuss with the reference surgeon which option is best suited to their needs.

Bariatric surgery can be performed through standard "open " approaches, which include laparotomy with incision of the abdominal wall, or by laparoscopy . With the second technique, doctors insert surgical instruments through small cuts made on the abdomen, guided by a small camera that transmits the images to a monitor. Currently, in most cases, laparoscopic bariatric procedures are performed, because they are minimally invasive, require smaller incisions, create less tissue damage and are associated with fewer post-operative problems. However, not all patients are suitable for laparoscopy. Extremely obese patients (eg> 350kg) who have undergone previous stomach surgery or who have complex health problems (severe heart and lung disease) may require an open approach.

Surgical options

There are four types of operations most commonly practiced: adjustable gastric banding (AGB), Roux-en-Y gastric bypass (RYGB), biliopancreatic diversion with duodenal switch (BPD-DS) and vertical sleeve gastrectomy (or sleeve gastrectomy, VSG) .

• Adjustable gastric banding (AGB) : gastro-destructive intervention that reduces food intake by placing an elastic silicone band around the upper portion of the stomach. This allows you to create a small gastric pouch that communicates with the rest of the stomach through a narrow unbleachable emptying orifice. The containment capacity of the gastric pouch can be adjusted according to the patient's needs without resorting to further surgery; in fact the bandage houses a saline solution that can be increased or decreased, varying the constrictive effect, by means of a thin catheter connecting it to a tank placed just below the skin.

  Weight loss is mainly due to the limited amount of food that can be ingested in a single meal (early satiety) and the increase in the time needed to digest introduced foods. It is often performed by laparoscopy (LAGB) and represents a reversible intervention: the gastric cavity is not sectioned and the bandage can be removed. Weight loss: about 50% of excess weight.

• Roux-en-Y gastric bypass ( RYGB): it is a mixed intervention, which limits both the intake and absorption of food. The amount of food eaten is limited by reducing (by surgical resection) the stomach to a small bag, similar in size to the pocket created with the gastric band. Furthermore, this small sac is connected, through a jejunal loop, directly to the small intestine (at the jejunum), excluding the digestive tract responsible for absorbing nutrients (part of the stomach, duodenum and biliary tract). The RYGB is considered an irreversible intervention, but, in some cases, the procedure can be partially reversed. Weight loss: around 60-70% of the excess weight
• Biliopancreatic diversion with duodenal switch ( BPD-DS ) : usually referred to as "duodenal switch" (duodenal inversion), it is a complex bariatric surgery with three peculiarities: 1) eliminates a large portion of the stomach (vertical resection), making the patients sated early, who are "obliged" to eat less; 2) is a malabsorption intervention, where food is diverted and limited in its absorption: the surgeon realizes a new alimentary canal, creating an anastomosis between the residual gastric cavity and a tract of the small intestine (ileum); 3) the functionality of bile, pancreatic juice and enteric juices is modified, influencing the body's ability to digest the elements and absorb calories. This operation leaves a small part of the duodenum available, necessary to absorb food, vitamins and minerals. However, when the patient ingests a meal, most of the intestine is bypassed (it is a more "drastic than the previous" procedure). The distance between the stomach and the colon becomes much shorter after this operation, thus limiting the normal way in which food is absorbed. BPD-DS produces significant weight loss (approximately 65-75% of excess weight). However, a decrease in the amount of nutrients, vitamins and minerals absorbed entails a high risk of long-term complications (anemia, osteoporosis, etc.). For this reason, bilopancreatic diversion is generally recommended only when it is believed that rapid weight loss is essential to avoid a serious health condition, such as heart disease.
• Partial vertical gastrectomy (VSG, vertical sleeve gastrectomy): it belongs to the gastrorecticive interventions, because it limits food intake by reducing the size of the stomach
  This form of bariatric surgery is used to treat severely obese people (BMI ≥ 60), for which performing a bandage or gastric bypass is not advisable. In such circumstances, in fact, both procedures would involve a very high risk of causing complications. The aim of the procedure is to induce an early sense of satiety. To pursue it, a partial vertical resection is performed during the surgery which affects 80-90% of the stomach. Weight loss should be around 60%. Once this has been achieved, it should be possible to perform a bandage or gastric bypass safely.

The patient and the competent surgeon must confront themselves to choose the best surgical option, evaluating the long-term effects and any complications that may arise during and after the operation (such as problems related to malabsorption, vomiting and esophageal reflux, the impossibility of consuming large meals, the need to limit certain foods, etc.). Other factors to consider are the patient's BMI, his eating habits, the repercussions of obesity on his health and any previous stomach surgeries.

Effectiveness

The purpose of bariatric surgery is to reduce the risk of disease or death associated with obesity. In general, malabsorptive procedures induce greater weight loss than restrictive procedures, but they have a higher risk profile.

Recovery after bariatric surgery

Immediately after bariatric surgery, the patient is limited to a liquid diet, which includes foods such as broth or diluted fruit juices. This line is adopted until the complete recovery of the gastrointestinal tract from the operation. In the later stages, the patient is "forced" to take only modest quantities of food, because if he exceeds the containment capacity of the stomach he may experience nausea, headache, vomiting, diarrhea, dysphagia and so on. Dietary restrictions depend in part on the type of surgery. Many patients, for example, will need to take a multivitamin daily for life, to compensate for the reduced absorption of essential nutrients.

Side effects

A variety of complications can be associated with bariatric surgery procedures. The risks depend on the type of intervention and any other health problems present before the operation. Postoperatively, some short-term complications (within 1-6 weeks after surgery) may include bleeding, surgical wound infection, bowel obstruction, nausea and vomiting (due to overeating or stenosis in the surgical site). Other problems that can occur are related to nutrient deficiencies, typical of individuals subjected to malabsorbent bariatric procedures that do not take vitamins and minerals; in extreme cases, if patients do not face the problem, diseases such as pellagra (caused by deficiencies of vitamin B3, niacin), pernicious anemia (lack of vit. B12) and beriberi (caused by the lack of vitamin B1 thiamine) can occur. After bariatric surgery, other important medical complications may include: venous thromboembolism (deep vein thrombosis in the legs and pulmonary embolism), heart attack, pneumonia, urinary tract infections, gastrointestinal ulcers, gastric and / or intestinal fistula, stenoses and hernias internal hernia).