Randomized Comparison of Laparoscopic Sleeve Gastrectomy and Gastric Bypass for Morbid Obesity

Randomized Clinical Trial Comparing Laparoscopic Sleeve Gastrectomy and Gastric Bypass for Morbid Obesity and Underlying Metabolic and Hormonal Abnormalities

Bariatric surgery is the most effective treatment for morbid obesity. Roux-en-Y gastric bypass (RYGB) is a bariatric procedure with known safety and effectiveness. Laparoscopic sleeve gastrectomy (LSG) is a newer procedure gaining popularity. The aim of the study is to compare outcomes of these two surgical methods in terms of weight loss, improvement of common comorbidities of obesity and influence on metabolic and hormonal status.

Authors of the study believe that a more detailed head-to-head comparison of RYGB and LSG is necessary. The former method is the established "gold standard" procedure with good outcomes reported in many studies. However it is much more complex and the learning curve is longer. The latter method was introduced as an initial procedure in superobese patients because of its relative simplicity. It produced good outcomes in this population of superobese patients and surgeons in some centers started to use it as a primary bariatric procedure. RYGB is a restrictive and partially malabsorptive procedure and it is believed to have additional benefits in patients with metabolic disorders such as type 2 diabetes and dyslipidemia. Purely restrictive procedures such as LSG are theoretically less beneficial in this group of patients. In the present study authors will look at weight loss as well as improvement in comorbidities and several biochemical parameters and indices to assess also metabolic action of these two procedures.

Bariatric surgery, Gastric bypass, Sleeve gastrectomy, Weight loss, Lipoproteins, Insulin resistance, Incretins, Quality of life

Laparoscopic sleeve gastrectomy (LSG) is a restrictive bariatric procedure. LSG involves resection of a large part of the body and fundus of the stomach starting from the antrum up to the angle of His. The remaining part of the stomach (the gastric sleeve) is calibrated with a 36 French bougie.

Roux-en-Y gastric bypass (RYGB) is an intermediate (restrictive and malabsorptive) operation. RYGB involves creation of a 15-20 mL gastric pouch that is anastomosed to a 100cm Roux limb created at 100cm from the ligament of Treitz.

Weight loss measured as a percentage of excess weight lost is one of the most commonly used and accepted outcome measure in clinical trials evaluating bariatric surgery.

Complications are defined as any negative deviation from the normal postoperative course. Complications of bariatric surgery include but are not limited to: gastrointestinal leak, intrabdominal bleeding, gastrointestinal bleeding, gastrointestinal stricture, gastrointestinal fistula, marginal ulceration, internal hernia, bowel obstruction, deep vein thrombosis, pulmonary embolism, wound infection, seroma, fascial dehiscence, abdominal hernia, gallstone formation, dehydration, nutritional deficiencies

Number of patients with comorbidities such as: type 2 diabetes mellitus, arterial hypertension, dyslipidemia, obstructive sleep apnea, degenerative arthritis, gallbladder disease, gastro-esophageal reflux disease.

Absolute weight loss (in kilograms) is evaluated. It is one of the most commonly used and accepted outcome measures in clinical trials evaluating bariatric surgery. It is more dependent on the initial weight of a study participant.

Fasting plasma high density lipoprotein (HDL) cholesterol concentration in patients 12 months after surgery.

Fasting plasma low density lipoprotein (LDL) cholesterol concentration in patients 12 months after surgery.

Insulin resistance (IR) measured with the homeostatic model assessment (HOMA) method. In the published studies the HOMA model correlated with estimates using the reference euglycemic clamp method. The following equation is used: HOMA-IR = (fasting plasma glucose concentration [mmol/L] x fasting plasma insulin concentration [miliunits/L])/22.5

The proportion of glycosylated hemoglobin (HbA1c) [%] is measured to assesses the average plasma glucose concentration and regulation.

C-reactive protein (CRP) is used as a marker of inflammation. It may be also used in the assessment of heart disease risk.

Ghrelin is an appetite-stimulating hormone produced in the fundus of the stomach. Its concentration may change after some bariatric procedures.

Leptin is one of the adipose-derived hormones that causes inhibition of appetite. Elevated leptin levels are associated with obesity, inflammation, metabolic syndrome and cardiovascular disease. Weight loss leads to a decline in leptin concentrations.

Glucagon is synthesized and secreted from alpha cells of the pancreas. It leads to elevation of the plasma glucose.

Insulin like growth factor 1 (IGF-1) is similar in structure to insulin. It has anabolic effects. Its levels may be related to BMI and level of nutrition.

Spirometry and plethysmography results are used to assess pulmonary function before and after surgery.

Inclusion Criteria: BMI≥40 kg/m2 BMI≥35 kg/m2 with at least one comorbidity associated with obesity Exclusion Criteria: BMI > 60 kg/m2 poorly controlled significant medical or psychiatric disorders active alcohol or substance abuse active duodenal/gastric ulcer disease difficult to treat gastro-esophageal reflux disease with a large hiatal hernia previous major gastrointestinal surgery diagnosed or suspected malignancy

Department of General, Transplant and Liver Surgery, Public Central Teaching Hospital, Medical University of Warsaaw

Kalinowski P, Paluszkiewicz R, Ziarkiewicz-Wroblewska B, Wroblewski T, Remiszewski P, Grodzicki M, Krawczyk M. Liver Function in Patients With Nonalcoholic Fatty Liver Disease Randomized to Roux-en-Y Gastric Bypass Versus Sleeve Gastrectomy: A Secondary Analysis of a Randomized Clinical Trial. Ann Surg. 2017 Nov;266(5):738-745. doi: 10.1097/SLA.0000000000002397.