Data were collected from the Iranian National Obesity Surgery Database (INOSD)12 and all surgical procedures were performed at a tertiary, academic and accredited IFSO-EC bariatric surgery center.
All the patients who had undergone OAGB from September 2014 to January 2017 were evaluated. During this time, 1356 patients had undergone OAGB, including 73 cases as conversion surgery. A total of 29 patients had undergone conversional OAGB following SG due to weight regain or incomplete weight loss. We only included the 23 patients who had completed their 5-year follow up (Fig. 1).
Prior to the conversional OAGB, all the patients were evaluated by a Multidisciplinary Team (MDT) and an esophagogastroduodenoscopy (EGD) was performed on them.
SG failure was taken as weight loss failure or weight regain and was defined as an unsatisfying weight loss (EWL < 50% in 1 year)13a BMI greater than 35 kg/m2 after reaching the appropriate weight, or 25% EWL increase from the nadir weight14,
The data registered at the time of SG and OAGB included age, gender, weight, height, nadir weight, BMI, percent excess weight loss (%EWL): %EWL =[(Initial Weight) − (Post-Op Weight)],[(Initial Weight) − (Ideal Weight)]14 and conversion indication.
Obesity associated medical problems included type-2 Diabetes Mellitus (DM), arterial Hypertension (HTN), dyslipidemia, Obstructive Sleep Apnea (OSA) and GERD, weight indicators and obesity associated medical problems outcomes were evaluated 1, 2, 3 and 5 years after the conversion to OAGB. The changes in obesity associated medical problems were classified into five categories: no change, remission, improvement, new onset and recurrence, which were assessed according to standardized outcomes reporting in metabolic and bariatric surgery14,
DM remission was defined as HbA1c < 6%, FBG < 100 mg/dl) in the absence of anti-diabetic medications. HTN remission was taken as being normotensive (BP < 120/80) without antihypertensive medications. Dyslipidemia remission was confined to normal lipid profile (LDL, HDL, Cholesterol, TG) without medication usage. GERD remission was defined as the absence of symptoms with no medications14 and the GERD score was assessed using the GERD-Q questionnaire15 in these patients. The patients with GERD score more than eight points were evaluated by EGD. DM improvement was defined as statistically significant reduction inHbA1c and FBG or decrease in antidiabetic medications requirements. HTN improvement was taken as a decrease in dosage or number of antihypertensive medications or decrease in systolic or diastolic blood pressure (BP) on the same medication. Dyslipidemia improvement was confined to decrease in number or dose of lipid-lowering agents with equivalent control of dyslipidemia or improved control of lipids on equivalent medication14,
All of the surgeries were carried out by two senior surgeons of one bariatric surgery team. For these surgeries, the surgeon stands in between the patient’s legs in the French position. OAGB was performed with five trocars laparoscopic technique. The patient was administered general anesthesia. First, the His angle was released and adhesiolysis was performed. Then, the gastric pouch was constructed along the lesser curvature beginning from the distal part of the crow’s foot to the angle of His and if the sleeve tube was dilated, the pouch was trimmed on a 36 Fr calibration tube and the remnant was excised. Then, gastrojejunostomy was carried out with a 30–40 mm anastomosis length in the posterior wall of the pouch side to side with the jejunum with a biliopancreatic limb (BPL) of 180 cm for BMIs under 50 and 200 cm for BMIs of 50 and over by a linear stapler. The enterotomies were closed with one-layer absorbable suture (PDS 2-0). Finally, after obtaining a negative air leak test, a drain was placed for the patient. The average of operation time was 70 min.
On the first postoperative day, after the methylene blue leak test and clear liquid tolerance, the drain was removed and according to Enhanced Recovery after Bariatric Surgery (ERAS) protocol the patient was discharged16,
The research followed the tenets of the Declaration of Helsinki. The Ethics Committee of Iran University of Medical Sciences approved this study (IR.IUMS.REC.1399.801). Accordingly, written informed consent was taken from all participants before any intervention.
The mean, standard deviation (SD), percentage and 95% confidence interval (CI) were reported for the description of the data. Repeated measurements were used to assess the trend of changes in weight, BMI, %TWL and %EWL after conversion surgery. Friedman’s test was used for changes in the pattern of obesity associated medical problems during the time. The level of statistical significance was taken as P-value < 0.05. All the analyses were carried out in SPSS version 25.0 (Chicago, Illinois, USA).