Roux-en-Y gastric bypass (synonyms: Roux-en-Y gastric bypass, RYGB, gastric bypass) is a surgical procedure in bariatric surgery. Gastric bypass may be offered for obesity with a BMI ≥ 35 kg/m2 or greater with one or more obesity-associated comorbidities when conservative therapy has been exhausted. Two different effects serve to reduce weight in Roux-en-Y gastric bypass: an increased feeling of satiety occurs after surgery, on the one hand, through a therapeutic malabsorption effect (reduced absorption of food components from the gastrointestinal tract into the blood) and, on the other hand, through the formation of a gastric pouch (artificially reduced stomach size). The procedure is associated with a significant reduction in body weight, diabetes rates (remission rate of approximately 62%), and other cardiovascular risk factors.With the loss of body weight due to gastric bypass, patients with a follow-up period of approximately four years had a relatively 46% lower risk of being diagnosed with heart failure (heart failure) for the first time. Among adolescents, the proportion of type 2 diabetics decreased from 14% to 2, 4% after gastric bypass (relative decrease 86%). 5 years after surgery, the proportion among adolescents with hypertension had fallen from 57% before surgery to 11% after surgery. Gastric bypass and mortality after a mean of 4, 9 years: Patients aged ≥ 55 years benefited most, in whom mortality decreased from 6.1% (without surgery) to 2.8% (with surgery); overall collective: surgery group 1.4%, in a control group 2.5%. Cardiovascular mortality decreased relatively by 47%, and cancer mortality by 46%.
Indications (areas of application) for bariatric surgery [according to S3 guideline: Surgery for Obesity and Metabolic Diseases, see below]
- In patients with a BMI ≥ 40 kg/m2 without concomitant diseases and without contraindications, bariatric surgery is indicated after exhaustion of conservative therapy after comprehensive education.
- Patients with a BMI ≥ 35 kg/m2 with one or more obesity-associated comorbidities such as type 2 diabetes mellitus, heart failure, hyperlipidemia, arterial hypertension, coronary artery disease (CAD), Nephropathy, obstructive sleep apnea syndrome (OSAS), obesity hypoventilation syndrome, Pickwick syndrome, nonalcoholic fatty liver (NAFLD), or nonalcoholic fatty liver hepatitis (NASH), Pseudotumor cerebri, gastroesophageal reflux disease (GERD), bronchial asthma, chronic venous insufficiency (CVI), urinary incontinence, immobilizing joint disease, fertility limitations, or polycystic ovary syndrome (PCO syndromeM) should be offered bariatric surgery when conservative therapy is exhausted.
- In certain circumstances, a primary indication for bariatric surgery may be made without a prior attempt at conservative therapy. The primary indication may be given when any of the following conditions exist: in patients.
- With a BMI ≥ 50 kg/m2.
- In whom a conservative therapy attempt was classified by the multidisciplinary team as not promising or hopeless.
- With particular severity of concomitant and secondary diseases that do not allow postponement of a surgical intervention.
Contraindications
- Unstable psychopathological conditions
- Untreated bulimia nervosa
- Active substance dependence
- Poor general health
- Lack of indication – should obesity be caused by a disease (e.g., hypothyroidism, Conn syndrome (primary hyperaldosteronism, PH), Cushing’s disease, pheochromocytoma)
Before surgery
Before surgery, a detailed basic screening must be performed to accurately evaluate possible pre-existing conditions and to assess the effect of surgery before the procedure. Based on this, it is necessary to perform a determination of the fasting blood glucose level (fasting glucose), as this is an important indicator of diabetes mellitus and usually also of metabolic syndrome. In addition, concomitant diseases such as sleep apnea syndrome, hypoventilation (inadequate breathing), pulmonary arterial hypertension (increased blood pressure in the pulmonary vessels), coronary heart disease (CHD), and cor pulmonale (heart disease resulting from lung disease) must be addressed.In order to avoid intraoperative and postoperative complications, existing diseases usually have to be optimally controlled with medication before the intervention. Furthermore, it is indispensable that the gastrointestinal tract (gastrointestinal tract) is also subjected to a detailed examination. Among other things, this serves to diagnose gastroesophageal reflux disease (heartburn) or a gastric ulcer. In such cases, preoperative therapy with proton pump inhibitors (PPI; acid blockers), for example, is necessary.
The surgical procedure
The basic principles of Roux-en-Y gastric bypass are the separation of the small forestomach from the larger remnant stomach and the connection between the forestomach (gastric pouch; artificially miniaturized stomach) and the small intestine. This transports the ingested food from the esophagus (food pipe) into the forestomach. Subsequently, the food is transported into the anastomized (surgical connection of two parts of the gastrointestinal tract) small intestine, bypassing both the residual stomach and the duodenum and the upper part of the jejunum (empty intestine). By bypassing the different portions of the gastrointestinal tract, digestion is delayed because the food pulp is transported late along with the digestive enzymes. The surgical procedure leads to reduced food intake both through an increased feeling of satiety and through the targeted surgical elimination of the residual stomach, the duodenum and the upper parts of the small intestine. This, of course, also results in the risk of early dumping syndrome, in which undiluted osmotically active food pulp shifts fluid toward the intestinal lumen, causing loss of plasma and kinin release (regulation of vascular width). With additional mechanical stretching of the intestinal loops, the combination of factors can result in a lack of volume, which can lead to shock status. Tachycardia (heartbeat too fast: >100 beats per minute) and nausea (nausea) may also occur as weaker symptoms.
After surgery
Following surgery, intensive monitoring of the patient is necessary. For this purpose, the patient should be transferred to an “intermediate care” unit postoperatively. On the day of surgery or on the first postoperative day, careful mobilization of the patient should already be performed. On the second postoperative day, an X-ray examination with gastrographin (sip of radiopaque contrast medium) should be performed to detect possible insufficiencies or stenoses (narrowing). A slow and gentle diet buildup over several weeks should be aimed for.
Possible complications
- Early dumping syndrome (see above) resulting in volume deficiency shock.
- Volume deficiency shock – as a result of surgery, it is possible that hyperosmolar food mush fluid is displaced from the tissue into the intestinal lumen. Depending on the severity, shock may follow, which may require treatment in the intensive care unit.
- Malabsorption (“poor absorption“) – in the context of the operation, a targeted malabsorption is induced, which reduces the absorption of food components such as fats and carbohydrates. However, due to the lack of selectivity, this can also lead to deficiency symptoms, which must be prevented at all costs. As preventive measures, sufficient protein intake (protein intake) and additional calcium and iron intake must be taken. Furthermore, intrinsic factor must be supplied, among other things, since this is produced by the gastric mucosa. Without the intrinsic factor, vitamin B12 can not be absorbed in the ileum (ileum).
- Pulmonary embolism
- Wound healing disorders
- Gastric perforation (stomach rupture)
- Insufficiency of the anastomosis, i.e., an insufficient connection between the operated parts of the organ
- Thrombosis
- Reoperation (reoperation) – was required in 20% of adolescents vs. 16% of adults (19 vs. 10 reoperations per 500 person-years, respectively.
Further notes
- Alcohol intolerance: after bariatric surgery with installation of a Roux-en-Y gastric bypass (RYGB), it resulted that blood alcohol levels rose more rapidly after a strong alcoholic test drink than in a control group of obese women in whom the RYGB surgery had not yet been performed (operated women: after 5 minutes, 1.1 per mille alcohol in the blood; not yet operated women: Peak only after 20 minutes at 0.80 per mille).
- Immunological changes favoring food allergy; accompanied by symptoms of food intolerance such as abdominal pain, nausea and vomiting, flatulence (flatulence), constipation (constipation) and diarrhea (diarrhea).
- In a study from central Denmark, 2,238 severely obese patients underwent Roux-en-Y gastric bypass between 2006 and 2011. Approximately 8% of patients experienced a subjective worsening of health after this procedure. The most common symptoms were fatigue, abdominal pain, and a dumping syndrome. The lassitude, which 40% of patients complained of, was probably the result of anemia (anemia) due to insufficient absorption of iron, folic acid, or vitamin B12. Other late effects included nephrolithiasis (kidney stones; 21%), cholelithiasis (gallstones; 31%), and hypoglycemia (low blood sugar; 38%).
- Gastric bypass in adolescents: Adolescents have poorer compliance regarding necessary substitution of trace elements and vitamins: 48% of adolescents had iron deficiency (low ferritin) at 2 years versus only 24% of adults; vitamin D deficiency 38% versus 24%; vitamin B12 deficiency 4% in both groups.
