Surgical treatment of obesity is an attractive alternative, mainly due to good results in terms of weight loss, positive impact on the resolution of comorbidities and the durability of achieved results (1-3). The most commonly performed surgeries, at the moment, include – Roux-en-Y gastric bypass (RYGB), sleeve gastrectomy (SG) and adjustable gastric banding (AGB) (4). The ideal bariatric surgery should be associated with a small amount of complications, sustained reduction in body weight and a short learning curve. The method should not cause nutritional deficiencies and, in case they occur, treatment should not be burdensome for the patient (5). One of the methods of surgical treatment of obesity, which can satisfy the above conditions is one-anastomosis gastric bypass (OAGS). In English literature, this operation is also called “single-anastomosis gastric bypass” or “mini-gastric bypass” (6-8). It seems that the term “mini-gastric bypass” should be reserved for the original method presented by Rutledge and other terms may be used successfully in the case of later modifications of this procedure (6). The one-anastomosis gastric bypass is an interesting alternative for RYGB due to less complex surgical technique and comparable results.

The aim of the study was to assess the effectiveness of laparoscopic one-anastomosis gastric bypass within weight loss parameters and the safety of the surgery on the basis of own material.

The paper presents an analysis of prospectively collected data of patients who underwent one-anastomosis gastric bypass. The study included patients with a minimum of 12 months’ follow-up. Surgical treatment qualification included patients with morbid obesity in accordance with generally accepted criteria, i.e. with BMI of 35-39.9 kg/m² and with at least one comorbidity of obesity or with BMI ≥ 40 kg/m². The second group consisted of patients with type 2 diabetes and BMI of 30-35 kg/m². In this group of patients, treatment for diabetes was an indication for the one-anastomosis gastric bypass. Patients in whom one-anastomosis gastric bypass was performed as a second step of bariatric treatment, after sleeve gastrectomy, were excluded. The effect of surgery on body weight change was evaluated on the basis of changes in BMI, percent loss of the excess of BMI – %EBMIL and changes in the baseline body weight as a percentage – %WL. The percentage of weight loss shows a change in body weight at a point of observation in relation to the initial weight. Output data from the surgery day was assumed to calculate the parameters of weight reduction in the postoperative period. Normal BMI of 25 kg/m² was assumed to calculate %EBMIL. The number of early complications to the 30th day after surgery, and late ones, after 30 days, was recorded. The rates of rehospitalization were recorded and their causes were presented.

The surgery was performed in the positioning of the patient with joined or abducted lower limbs. In the first case, the operator stood on the right side of the patient and, in the other, between the lower limbs of the patient. The patient positioning depended on the surgeon preference. The surgery was performed laparoscopically using five trocars. Using a linear stapler, a stomach pouch was created with a capacity of 30-50 ml, and a length of about 7-10 cm. The diameter of the pouch produced was calibrated on a 36Fr bougie. Then, using the LigaSure (Covidien) or a harmonic scalpel (Olympus) the greater omentum was cut slightly to the left of the midline. In the case of patients whose morbid obesity was the indication for the surgery, one-anastomosis gastric bypass with a length of 200 cm was performed. In the case of patients whose indication to surgery was type 2 diabetes, one-anastomosis gastric bypasses of 150 cm was performed. Gastrojejunostomy was performed side-to-side using a linear stapler. The stapler defect was closed using Vicryl 3-0 suture. The afferent loop was fixed to the gastric pouch with interrupted sutures so as the top was a few centimeters above the anastomosis. This maneuver is also recommended by some authors in order to reduce the severity of bile reflux in the postoperative period (11, 12). A methylene blue leak test was performed intraoperatively. Suction drain was left in near the anastomosis. A water-soluble contrast examination was performed on the first postoperative day. The drain was removed on the first postoperative day and clear liquids were administered orally. Liquid diet was recommended on the second day and patients were discharged. The first follow-up visit was done after 10 days (with removing sutures) and next follow-ups were encouraged at 1, 3, 6, 9 and 12 months.

In the period from November 2010 to May 2014, one-anastomosis gastric bypass was performed in 39 patients: 27 women and 12 men. In 21 cases, the indication was type 2 diabetes and morbid obesity in the case of18 patients. The average age of the operated patients was 47.5 ± 9.5 years (range: 29-64). The average weight before surgery was 103.7 ± 17.2 kg (range: 78-161) and the mean BMI 36.7 ± 4.3 kg/m² (range: 29-46). The mean weight 12 months after surgery was 72.3 ± 11.7 kg (range: 58.5-105) and the mean BMI 25.9 ± 3.8 kg/m² (range: 20.7-38.1). The mean %EBMIL for the entire operated group was 100.2 ± 33.2% (range: 34.5-207.2), and the mean %WL was 29.3 ± 8.1% (range: 15.3-49). The results regarding the parameters of weight loss are shown in table 1. Fourteen patients (35.9%) underwent another operation within the abdominal cavity before the one-anastomosis gastric bypass. Only in one case, it was abandoned to continue the procedure because of the numerous adhesions in the peritoneal cavity. After a few months, the patient underwent one-anastomosis gastric bypass with open access. Conversion was recorded in one patient, due to intraoperative bleeding. In the case of the remaining 37 (94.8%) patients, the procedure was finished laparoscopically. There was no leakage and no stenosis within the anastomosis. No postoperative bleeding requiring transfusions or revision surgeries was recorded. One patient (2.6%) had the characteristics of dehydration in the postoperative period. Another patient (2.6%) had iron deficiency anemia requiring erythrocyte mass transfusion and intravenous iron supplementation. In two cases (5.2%), during the 12 months follow-up, marginal ulcer was recorded. None of the patients, 12 months after the surgery, reported diarrhea or discomfort associated with bile reflux, even though the symptoms were reported in some patients during the first months of the follow-up. In 8 cases (20.5%), rehospitalization was necessary. Reasons for readmission with the treatment applied for each complication are shown in table 2.