6.2. Exclusion Criteria Universal exclusion criteria varied with pregnancy, ref 3 previous bariatric or gastric surgery, hiatal hernia, uncontrolled diabetes cardiovascular risks, a history of eating disorders, such as bulimia, medical therapy for weight loss within the previous 2 months, or any other condition that constitutes a significant risk of undergoing the procedure. A BMI > 50 was defined as an exclusion criterion for the Brethauer et al. and Skrekas et al. series. 6.3. Preoperative Preparation In most studies, patients underwent upper GI endoscopy, blood tests, and abdominal ultrasound preoperatively. Anticoagulants were given 12h preoperatively, and chemoprophylaxis with antibiotics was given with the induction of anesthesia [9]. Esophageal pH-metry was also performed in the Khazzaka and Sarkis study of the Obese-GERD group.

6.4. Surgical Technique Patient positioning on the operating table is standard in all cases, in an anti-Trendelenburg position at 30-degree French position (operator between legs) and two assistants on each side of the patient. Trocar placement is also standard in all cases. Closed pneumoperitoneum is achieved using a five-trocar port technique similar to that employed in laparoscopic Nissen fundoplication. Trocar placement is as follows: one 10mm trocar above and slightly to the right of the umbilicus for the 30�� laparoscope; one 10mm trocar in the upper left quadrant (ULQ) for passing the needle, for suturing, and for the surgeon’s right hand; one 5mm trocar also in the upper right quadrant (URQ) below the 10mm trocar at the axillary line for the surgeon’s assistant; one 5mm trocar below the xiphoid process for liver retraction; and one 5mm trocar in the upper left quadrant (ULQ) for the surgeon’s left hand [10].

Ramos et al. preferred dissection of the angle of His as the first step of the operation, whereas in the larger studies of Skrekas et al. and Andraos et al. it was the final step of the dissection of the greater curvature of the stomach. Mobilization of the greater curvature is performed using either a LigaSure Vessel Ligation System (Covidien) or a Harmonic scalpel (Ethicon Endo-Surgery, Inc., Cincinnati, Ohio) initially by opening the greater omentum at the transition between the gastric antrum and gastric body. Once access to the posterior wall is achieved, the greater curvature vessels are dissected distally up to the pylorus and proximally up to the angle of His.

Occasionally, posterior gastric adhesions are also dissected to allow optimal freedom for creating and sizing the invagination properly. The next step is the introduction of a bougie which was of a Brefeldin_A diameter of 36Fr in the Skrekas et al. study with 135 patients, and of 32Fr in the studies of Andraos et al. and Ramos et al. with a total of 166 patients.