Between November 2008 and March 2011 seventy-two patients who matched the inclusion criteria were randomized to either RYGB or LSG treatment groups. The study was approved by the Research and Ethics Committee of the Medical University of Warsaw and was conducted according to the principles of the Declaration of Helsinki. Written informed consent was obtained from all eligible patients before enrolment. All the operations were performed by the same surgical team.
The inclusion criteria for the study were: (1) body mass index (BMI) ≥ 40 kg/m2 or BMI ≥ 35 kg/m2 with at least one comorbidity associated with obesity (type 2 diabetes, hypertension, dyslipidemia, obstructive sleep apnea), (2) age = 18-60 years.
Exclusion criteria included: (1) BMI > 60 kg/m2, (2) poorly controlled significant medical or psychiatric disorders, (3) active alcohol or substance abuse, (4) active duodenal/gastric ulcer disease, (5) difficult to treat gastro-esophageal reflux disease (GERD) with a large hiatal hernia, (6) previous major gastrointestinal surgery, (7) diagnosed or suspected malignancy.
All the patients had a thorough preoperative evaluation by an internal disease specialist, a dietician and a surgeon. A psychiatric evaluation was obtained if considered necessary. Upper gastrointestinal endoscopy, abdominal ultrasound examination, Doppler ultrasound of the veins of the lower extremities and spirometry were performed in all the subjects. Peptic ulcer disease and Helicobacter pylori infection were treated before surgery if diagnosed during the initial assessment. Cholecystectomy was performed at the time of bariatric surgery only if gallstones were symptomatic.
The open RYGB technique included creation of a small (15-20 cc) gastric pouch and an antecolic-antegastric Roux-en-Y reconstruction with routine transection of the greater omentum. The biliopancreatic and alimentary limbs were 100 cm long each. Side-to-side gastrojejunostomy and end-to-side jejunojejunostomy were performed using hand-sewn technique. The resulting mesenteric defects were routinely closed at the time of surgery. No drains were left in the peritoneal cavity.
In LSG a Veress needle is used to establish CO2 pneumoperitoneum of 15 mm Hg and five ports are routinely inserted (). At the beginning the branches of the gastroepiploic artery are divided close to the gastric wall, then the short gastric vessels of the greater curvature and retrogastric attachments are divided with a sealer/divider or ultrasonic shears (LigaSure Atlas™, Covidien or SonoSurg™, Olympus). The dissection extended proximally to the esophagogastric junction and distally toward a point located 5-6 cm from the pylorus. The majority of the antrum was preserved as the resection was initiated 5-6 cm proximal to the pylorus and extended up to the angle of His. Calibration of the gastric sleeve was done with a 36-French gastric bougie inserted into the stomach along the lesser curvature. Continuously applied linear staplers (60 mm and 45 mm long, Endo GIA™ Ultra Universal Stapler with Articulating Medium/Thick Reload, Covidien) were used to transect the stomach. The stapler line was reinforced with a running absorbable braided 2-0 suture using a suturing device (Endo Stitch™ 10 mm, Covidien). The resected stomach was removed through the left flank trocar site. One drain was left in the peritoneal cavity. The use of a 36-Fr bougie corresponds to 50-100 ml volume of a stomach.
Trocar placement for the laparoscopic sleeve gastrectomy
Amoxicillin with clavulanic acid (1.0 g) and metronidazole (0.5 g) at a single preoperative dose were used as an antibiotic prophylaxis. Compression stockings and low molecular weight heparin (40-60 mg s.c. b.i.d.) administered until fully ambulatory were given as an antithrombotic prophylaxis. The upper gastrointestinal (UGI) series were performed during the first or second postoperative day, before commencing oral intake. The patients received a clear liquid diet after correct UGI for 3-6 days. They continued with a pureed diet for the next 2-3 weeks. Roux-en Y gastric bypass patients were usually discharged on day 5-7, and LSG patients on day 4-6 after the procedure. The length of hospitalization after the operation, the minor, major, early (≤ 30 days) and late (> 30 days) complications and mortality were recorded during hospital stay and outpatient visits. A major complication was defined as a complication resulting in death or reoperation, a hospital stay of more than 7 days after the procedure, or a need for blood transfusions of four or more units. All other postoperative complications were considered minor complications.
Vitamin and mineral supplementation was prescribed to both RYGB and LSG patients in a uniform manner to avoid confounding factors related to differences in nutrient supplementation. Postoperatively, one tablet of multivitamin and mineral supplements and sublingual iron at a dose of 0.1 g daily were prescribed. Vitamin B12 supplementation was given sublingually every month at a dose of 1000 µg.
All patients attended the outpatient clinic immediately after discharge to control for early complications and then at 1, 3, 6, 9 and 12 months after the operation. Beginning at the 1 month follow-up visit complete subject evaluation was performed, including anthropometric and clinical parameters, nutritional deficiencies and blood sampling for laboratory tests. Weight loss was assessed using BMI and percent of excess weight loss (%EWL). Excess weight was calculated as the amount of initial body weight in excess of the upper limit of the normal weight range estimated at the BMI of 25 kg/m2 for a given patient height.
Hypertension (HTN) was diagnosed when SBP ≥ 140 mm Hg and/or DBP ≥ 90 mm Hg or on anti-hypertensive therapy; diabetes mellitus (T2DM) when fasting plasma glucose ≥ 126 mg/dl or 2-h plasma glucose ≥ 200 mg/dl or on antidiabetic drug ± insulin therapy; impaired glucose tolerance (IGT) when 2-h plasma glucose ≥ 140 mg/dl and ≤ 200 mg/dl; dyslipidemia (DL): fasting lipid profile, HDL < 40 mg/dl for men, HDL < 50 mg/dl for women and/or triglycerides (TG) > 150 mg/dl and/or LDL > 100 mg/dl or use of lipid-lowering agents. Remission or improvement of comorbidities was assessed according to the clinical, biochemical, hormonal and radiological documentation. The improvement of comorbidity was defined as a reduction of medication taken and improvement of the symptoms or blood investigation specific to the comorbidity. Remission of hypertension was defined as normal systolic and diastolic arterial pressure without active antihypertensive treatment. Remission of type 2 diabetes was defined as normal fasting glucose levels (< 100 mg/dl) and HbA1c < 6.0% in the absence of active antidiabetic treatment. Remission of dyslipidemia was defined as normal levels of total cholesterol (TC), TG, HDL-C and LDL-C in the absence of active lipid-lowering treatment. The other comorbidities were not specifically addressed in the present report.
Simple randomization was used to assign patients to the treatment groups. Categorical variables were presented using absolute values and percentages. Comparisons of categorical variables between groups were done using the χ2 test and for small frequencies Fisher's exact test. Continuous variables were reported as mean ± standard deviation (SD) or median (range) where applicable. Differences between groups in normally distributed continuous variables were tested using the independent samples t test, and for non-normally distributed variables the Mann-Whitney U test was used. Continuous variables were compared within groups with analysis of variance (ANOVA) with post-hoc Tukey HSD test for specific comparisons. In all the tests used p values of less than 0.05 were considered significant. Statistical analyses were performed using Statistica 8.0 (StatSoft Inc., 2008).