Gastric Bypass surgery; It is a morbid obesity surgery and is applied to patients with a body mass index over 40 or over 35 but with concomitant diseases. Different tests are used to make sure that Gastric Bypass surgery is a suitable procedure for the person. Body mass index and personal weight loss goals, as well as a person’s medical history, are important factors in determining whether they are a suitable candidate for Gastric Bypass. Gastric Bypass surgery can also be applied as a revision surgery to patients who have had a previous obesity surgery.

Physiology

Gastric bypass surgery, which is one of the methods that attract attention with its successful results in obesity surgery, is the most preferred obesity surgery after stomach reduction surgery in the world. The method in question helps to lose weight by reducing the size of the stomach by more than 90 percent. A normal stomach can sometimes expand up to 1000 ml. The gastric bypass pouch is 30-40 ml in size. The gastric bypass pouch is usually formed in the least stretchable upper part of the stomach. Increasing the functional capacity of the pouch over time is to maintain the low weight after weight loss.

How Much Weight Loss?

Gastric bypass surgery, which is one of the most effective methods in the treatment of morbid obesity, is one of the most and best weight loss practices among all bariatric surgery. After gastric bypass surgery, weight loss occurs gradually, most rapidly in the first months. It may take 1 and a half to 2 years for maximum weight loss. During this period, approximately 70-80% of excess weight is lost.

Before and After Gastric Bypass Surgery

Many obesity patients consider bariatric surgery as an option when preoperative treatments fail to achieve weight loss. In this context, Gastric Bypass surgery is one of the treatment options.
Patients who are planned to have surgery are first subjected to a detailed evaluation. In addition to physical examinations, every patient is evaluated in detail before the surgery by endocrinology and psychiatry specialists.
Patients usually stay in the hospital for 3-4 days after surgery and are kept under the control of a doctor. At the discharge, the nutrition program until the first control is planned by the dietitian. During the first year, they are followed closely by endocrinology, psychiatry and dietician, apart from the bariatric surgeon.

Gastric Bypass Results

• Hyperlipidemia, popularly known as high cholesterol, improves in more than 70 percent of patients.
• Hypertension improves in more than 70 percent of patients, while the remaining patients need less medication.
• Sleep apnea begins to improve with weight loss.
• Type 2 diabetes resolves in more than 90 percent of patients. Multicenter 10-year data resulted in the same direction. (Rubino F et al. Metabolic surgery versus conventional medical therapy in patients with type 2 diabetes: 10-year follow-up of an open-label, single-centre, randomised controlled trial. Lancet. 2021 Jan 23;397(10271): 293-304).
• Gastroesophageal reflux begins to improve in almost all patients after surgery.
• Symptoms of venous thromboembolic disease, such as swelling in the leg, typically resolve.
• Back and joint pains in patients are eliminated.

Living with Gastric Bypass

Gastric Bypass brings some emotional and psychological burdens to the individual. Most of those who have undergone surgery can become depressed in the months following the operation. This is mostly due to the role of food in making people feel good emotionally. Many morbidly obese patients use food as an emotional escape.
It may take up to 3 months for the emotional level to return to normal.
Muscle weakness is common in the months following surgery. This can be caused by many factors, such as restriction in protein intake, loss of muscle mass and decrease in energy levels. All of these problems disappear with the balancing of food intake.

The entire Gastric Bypass procedure is performed by laparoscopic surgery. Laparoscopic surgery, which is performed by making small incisions, has 2 stages.
In the first stage, a large piece is cut and separated, leaving some stomach in the part of the stomach that connects with the esophagus. Thus, a small stomach bag is created. The remaining stomach volume is approximately 30-50 ml. In this operation, unlike sleeve gastrectomy, no part of the stomach is removed. Through the ports placed through the incisions, the hand tools are provided to reach the abdomen. One of these ports is a surgical telescope that connects to the video camera, and the other is for the entry of specialized surgical instruments. The image obtained by the camera is projected onto a screen and the surgeon can thus follow the surgery without any problems. Since no part is removed from the body, it is possible to restore the digestive system to its original state.
In the second stage of the operation, the small intestines are connected to the small stomach bag with a volume of 30-50 ml by adjusting the length in accordance with the technique, that is, anastomosis is performed.
As a result, the foods we eat provide easy weight loss as a result of both eating less with the volume-restricting effect and less absorption due to this newly created shortcut. However, as a result of reduced absorption, lifelong supplementation may be required as the necessary nutrients and minerals are partially excreted in the body.

As with every surgical procedure, there are potential risks and complications in Gastric Bypass surgeries. For this reason, choosing the right doctor is very important for the post-operative period as well as for the pre-operative period. Some complications are common in all abdominal surgeries, while others are specific to bariatric surgery. Every patient who decides on bariatric surgery should be informed about these risks.

Complications of Abdominal Surgery 

• Infection: Wound infections or intra-abdominal infections can be seen with the release of intestinal bacteria during the surgery.
• Bleeding: Many blood vessels need to be cut to divide the stomach and mobilize the intestine. Any of these may subsequently bleed into the abdomen or intestines. In such a case, blood transfusion or reoperation may be required.
• Abdominal Hernia: A hernia is an abnormal opening in the abdomen or outside of the abdominal muscles. Internal hernia is due to surgery and redesign of the intestines and is very important in terms of causing intestinal obstruction. With laparoscopic surgery, the risk of abdominal wall hernia is minimized.
• Intestinal Obstruction: Abdominal surgery always causes intestinal adhesions. An internal or external hernia can also often cause this.
• Venous Thromboembolism: Any injury, such as a surgical operation, can lead to increased blood clotting. When a clot breaks off and goes to the lung and occludes a vessel there, it brings with it a very dangerous condition called pulmonary embolism. Blood thinners are usually administered before surgery to reduce the likelihood of this type of complication.

Complications of Gastric Bypass

• Anastomotic Leakage: An anastomosis is the surgical connection between the stomach an intestine or two parts of the intestine. The surgeon tries to make a watertight connection between the two organs, using sutures or staples that create holes in the intestinal wall. For some reason, if this lining fails, digestive juices can leak into the abdominal cavity, causing infection and abscess formation.
• Anastomotic Stenosis: As the anastomosis heals, the development of a tissue called scar, which tends to contract naturally, causes narrowing of the passages. This event is called stricture in the medical literature.
• Complicated Marginal Ulcer: Marginal ulcer; It is a peptic ulcer that occurs in the mucosa at the edge of the gastrojejunal anastomosis. It can be seen in the early or late period after gastric bypass. Generally, 50 percent is located in the anastomosis and 40 percent is located in the jejunum.
• Dumping Syndrome: The pyloric valve located at the lower end of the stomach regulates the passage of food into the small intestine. When gastric bypass patients eat sugary food, sugar quickly passes into the intestine, causing a physiological condition called dumping syndrome. Dumping Syndrome is not life threatening.Complications of Gastric Bypass
• Anastomotic Leakage: An anastomosis is the surgical connection between the stomach and intestine or two parts of the intestine. The surgeon tries to make a watertight connection between the two organs, using sutures or staples that create holes in the intestinal wall. For some reason, if this lining fails, digestive juices can leak into the abdominal cavity, causing infection and abscess formation.
• Anastomotic Stenosis: As the anastomosis heals, the development of a tissue called scar, which tends to contract naturally, causes narrowing of the passages. This event is called stricture in the medical literature.
• Complicated Marginal Ulcer: Marginal ulcer; It is a peptic ulcer that occurs in the mucosa at the edge of the gastrojejunal anastomosis. It can be seen in the early or late period after gastric bypass. Generally, 50 percent is located in the anastomosis and 40 percent is located in the jejunum.
• Dumping Syndrome: The pyloric valve located at the lower end of the stomach regulates the passage of food into the small intestine. When gastric bypass patients eat sugary food, sugar quickly passes into the intestine, causing a physiological condition called dumping syndrome. Dumping Syndrome is not a life-threatening picture.

Nutrient Deficiencies

• Hypoparathyroidism: It may occur in a percentage of gastric bypass patients due to insufficient absorption of calcium. Many patients can achieve adequate calcium absorption by taking vitamin D and calcium citrate supplements.
• Iron: It is a serious deficiency especially in menstruating women and must be replaced. Ferrous sulfate can cause significant digestive upset at normal doses.
• Vitamin B-12: Intrinsic factor secreted from the gastric mucosa is required for absorption. In patients with small gastric pouches, it may not be absorbed even if given orally.
• Thiamine Deficiency: It is rarely seen due to bypassing the jejunum, which is the absorption area. It is also known as Beriberi. Deficiency may occur due to insufficient nutritional support after surgery.
• Protein Malnutrition: Some patients cannot get enough nutrition, experiencing severe vomiting after surgery until their digestive systems get used to the situation. Many patients need protein supplementation to prevent excessive loss of muscle mass during these early stages of rapid weight loss.

Nutritional Effects

After the surgery, patients begin to feel satiated with the intake of small volumes of food. After a while, this satiety turns into loss of appetite, and total food intake begins to decrease significantly.

• Proteins: Protein is the most basic food ingredient. Due to the restriction in food intake, patients with gastric bypass should primarily focus on meeting their protein requirements at each meal. If this simple precaution is followed, protein deficiency is rare in proximal gastric bypass.
• Calorie Intake: Profound weight loss after bariatric surgery is taking in much less energy each day than the body needs. To compensate for this deficit, adipose tissue must be burned. This is how weight loss occurs.
• Vitamins: Vitamins are normally found in foods and can be taken as medicine. In GBP, the vitamin content decreases proportionally as food intake decreases significantly. Therefore, vitamin supplements should be taken to meet the daily vitamin and mineral needs. While absorption of many vitamins is not severely affected after proximal GBP, vitamin B12 may not be adequately absorbed in some patients. Since the absorption problem is more in distal GBP, the level of vitamins and trace elements should be monitored and supplemented more carefully.