Gastric Bypass Surgery – Specialists and Information on the Treatment of Obesity

According to studies, many comorbidities of obesity can be improved or even prevented through a gastric bypass.

In particular, diabetes mellitus improves in more than 80 percent of cases following surgery, and in the case of type 2 diabetes, it may even go into remission. Weight loss also helps minimize other consequences such as joint degeneration or vascular disease.

When is gastric bypass surgery performed?

Severe obesity (adipositas permagna) or morbid obesity (BMI over 40) can lead to significant health problems. Many patients have already made several unsuccessful attempts to lose weight.

Comorbidities or severe impairments of general health often occur in such cases. In these situations, gastric bypass surgery may be considered.

The choice of procedure is always made on an individual basis and depends on the following conditions:

• Presence or risk of a serious comorbidity or condition with a body mass index of 35 or higher
• Completion of conservative therapy: Gastric bypass is considered a treatment option in bariatric surgery once all conservative measures have been exhausted.
• Motivation and cooperation of the patient: The success of the surgery depends directly on the patient’s motivation and willingness to comply. A well-founded doubt about this is a direct exclusion criterion.
• Appropriate age: Gastric bypass surgery is generally performed between the ages of 18 and 65.

On the other hand, physicians advise against this procedure in the presence of the following factors:

• Poor general health
• Presence of a malignant disease (cancerous tumor)
• Substance use disorder
• Unstable psychiatric illness
• Untreated eating disorder
• Severe hypertension
• Various physical and psychiatric conditions
• Severe liver disease

Illustration of a Roux-en-Y gastric bypass © bilderzwerg | AdobeStock

Surgical procedure of a Roux-en-Y gastric bypass

Almost 99 percent of gastric bypass procedures are performed laparoscopically (minimally invasive). Only small incisions are required, through which the surgeon inserts tiny instruments. The wounds heal faster than in an open surgery and leave only very small scars.

The laparoscopic gastric bypass is performed under general anesthesia and usually takes about 60 to 90 minutes.

The standardized so-called Roux-en-Y technique proceeds as follows:

1. The surgeon makes several incisions of about two centimeters in the abdominal wall. Through these, a camera with a light source and the necessary instruments are inserted. By introducing gas (usually CO₂) into the abdominal cavity, the abdominal wall lifts slightly, giving the surgeon better visibility and access to the organs.

2. With the help of a stapling device, the stomach is divided into a small functional pouch and a larger, bypassed section.

3. The small intestine is then divided, creating two free ends. This results in a Y-shaped configuration of the small intestine. The method was developed by Swiss surgeon César Roux and is medically referred to as Roux-en-Y gastric bypass.
4. The lower free loop of the small intestine is pulled upward and sewn to the outlet of the small gastric pouch.
5. The upper end, which is connected to the bypassed part of the stomach, is reattached to the small intestine, typically about 100 centimeters further downstream.

Surgeons distinguish between two types of gastric bypass:

• proximal gastric bypass, and
• distal gastric bypass.

The main difference is the length of the small intestine available for digestion — the segment between the outlet of the gastric pouch and the transition to the large intestine.

The standard procedure is the proximal gastric bypass with about 2.5 meters of small intestine remaining. The more extreme distal gastric bypass, leaving only about one meter, is less commonly performed.

After the procedure

After a Roux-en-Y procedure, intensive monitoring is required, which is why patients are initially cared for in the intensive care unit.

On the first day after surgery, patients should already begin to move to prevent pneumonia and dangerous blood clots. In addition, they are given a daily blood-thinning medication (heparin).

On the second day after surgery, the first follow-up evaluation is performed to identify possible weak points or narrowing. This involves an X-ray examination with Gastrografin swallow (contrast medium).

If there are no complications or medical concerns, patients can usually leave the hospital after 4 to 5 days.

A medical certificate of work incapacity is usually issued for a total of 4 weeks.

Risks and complications

Gastric bypass is a major procedure and, particularly due to excess weight and comorbidities, carries a higher risk of complications.

To assess the individual risk, a comprehensive preoperative screening is carried out.

Nevertheless, as with any abdominal surgery, complications may occur, such as:

• Adhesions in the abdominal cavity
• Infections
• Blood clots
• Bleeding or postoperative hemorrhage

Risks specifically associated with gastric bypass include:

• Anastomotic leakage
• Stenosis (narrowing)
• Injury to adjacent structures such as the esophagus, liver, spleen, or stomach
• Allergic reactions
• Perforation of the stomach
• Poor connection between the operated organs

Because several organs are completely or partially bypassed, such as:

• the remaining stomach
• the duodenum
• the upper sections of the small intestine

This carries the risk of a so-called early dumping syndrome, in which food passes too quickly from the stomach into the small intestine.

In dumping, there is a kind of rapid emptying of undigested, osmotically active food mass into the small intestine. This leads to fluid loss, as water is drawn from surrounding tissue into the intestine.

This results in a so-called volume deficiency, which can manifest as:

• Nausea and vomiting
• Sweating
• Drop in blood pressure
• Rapid heartbeat
• Sensation of fullness

What can be done against dumping syndrome?

In addition to early dumping, which occurs about 30 minutes after a meal, late dumping is also possible, when large amounts of glucose are transported too quickly. In such cases, symptoms usually occur 1 to 3 hours after eating and may include:

• Low blood sugar
• Cold sweats
• Weakness
• Dizziness
• Changes in pulse

If you experience dumping after bypass surgery, consult your treating physician. They will examine you thoroughly to rule out other causes and provide important guidance on how to avoid such rapid emptying in the future. In some cases, medication may be prescribed to help relieve symptoms.

Prevention is best achieved through an adapted diet, for example high in fiber and protein. Avoid simple carbohydrates and sugar. Experience has shown that some patients also no longer tolerate dairy products.

It is not only about the type of food, but also about portion size and eating slowly. Do not consume liquids and solid food at the same time, but at separate intervals.

In addition, long-term complications after surgery may include:

• Alcohol intolerance
• Gallstones and kidney stones
• Peritonitis (inflammation of the abdominal lining)
• Deficiency syndromes such as iron and vitamin B12 deficiency

Gradual diet progression after bypass surgery

During the first 48 hours after surgery, the focus is on healing the sutures. Therefore, the patient is only allowed to drink still water or other clear fluids.

Afterward, a gradual and gentle diet progression takes place over several weeks in four phases:

1. First phase (first two weeks) with low-fat milk and dairy products, yogurt, or fine vegetable soups.
2. Second phase (two to three weeks) with pureed foods low in fat and sugar.
3. Third phase (if phase 2 is well tolerated) with protein-rich foods while limiting sugar and fat intake.
4. Fourth phase (if phase 3 is well tolerated) with primarily protein-rich foods and a gradual transition from soft to solid food. Patients should avoid sugar- and fat-rich foods.

Dairy products are used in Phase 1 of diet progression © beats_ | AdobeStock

This occurs as part of an outpatient or inpatient rehabilitation program. Patients learn to adjust their diet in such a way that deficiencies do not occur.

The gastric bypass deliberately leads to a reduced absorption of fats and carbohydrates. Because of the shortened intestinal passage, nutrient deficiencies can occur due to early excretion. To prevent this, patients must consume enough protein.

The so-called intrinsic factor, produced by the stomach lining and necessary for vitamin B12 absorption, can no longer be formed after a gastric bypass. Patients therefore need to supplement it for life.

After surgery, the following values should be regularly monitored:

• Iron
• Vitamin B12
• Folic acid

Supplementation may be necessary if deficiencies are found.

The Omega-loop bypass

Another procedure is the mini-gastric bypass, in which only one connection is made between the remaining gastric pouch and the small intestine. It is a variation of the Roux-en-Y method and is also called the Omega-loop bypass.

Procedure

In an Omega-loop gastric bypass, surgeons reshape the stomach into a long, narrow tube. They remove large parts of the stomach as well as sections of the adjacent small intestine.

This significantly reduces stomach volume. The patient can consume less food and absorb fewer nutrients from the food mass in the intestine.

As a result, hormonal changes occur: patients feel less hungry and thus eat less. The feeling of satiety also sets in relatively quickly. Bariatric surgery also appears to have a positive effect on diabetes.

Complications of the loop procedure

Due to the altered digestive physiology (shortened stomach and intestinal passage), nutrient deficiencies can occur. Essential nutrients, such as vitamin B12, may no longer be sufficiently absorbed.

In addition, an Omega-loop bypass can lead to a disturbed water balance in the intestine. Patients may suffer more frequently from constipation or persistent diarrhea.

Swallowing difficulties, peritonitis, osteoporosis, and hair loss may also occur.

Another complication is the reflux of bile into the remaining stomach. The long-term effects of such reflux are not yet fully understood.

Observations suggest that bile acids, when refluxing over a period of about 10 to 15 years, may trigger gastric cancer.

For this reason, physicians advise patients with bile reflux to undergo another surgery, replacing the Omega-loop variant with a Roux-en-Y bypass.

Cosmetic consequences after surgery

As a result of rapid weight loss within a short period after surgery, the skin often does not shrink back quickly enough. It may therefore sag in various areas, leading to abdominal overhangs and sagging breasts.

In many cases, plastic surgery can help. Until then, proper skin care is especially important in areas with large skin folds. Contacts with experts in plastic surgery can also be found on our pages.

Costs of gastric bypass surgery

Statutory health insurance providers do not automatically cover the costs of this surgery. However, if the necessary requirements are met, coverage can be approved.

These requirements include a BMI of at least 40, or a BMI between 35 and 40 with an additional condition such as type 2 diabetes.

Which doctors perform gastric bypass surgery?

Specialists in bariatric surgery are board-certified visceral surgeons who specialize in the surgical treatment of patients with obesity.

Gastric surgery experts may also focus their practice on gastric bypass procedures.

Alternative surgical methods include, for example, a gastric band or a sleeve gastrectomy.