Predictive factors of outcome after gastric banding - A nationwide survey on the role of center activity and patients' behavior

Background: Systematic studies of postoperative outcome of bariatric surgery provide information on the predictors of success. Surgeon's and institution experience and patient's behavior after surgery are key determinant of success or failure. Data on clinical trials generally reflect the experience of skilled obesity surgery centers. Little is known about the current practice at a nationwide level. The present study was realized in the frame of a national survey on medical and surgical practices conducted by the public health insurance system. The objective was to analyze systematically and prospectively the outcome of all bariatric surgery procedures consecutively performed in a given period, as registered by the French National Medical Insurance Service. This study at a nationwide level focused on predictive factors of success and analyzed how the experience of the centers relates to the patients' outcomes at I and 2 years after surgery. Methods: This study examined prospectively the 2-year predictors of success of all consecutive 1236 bariatric operations performed at a nationwide level. Most (87.3%) were laparoscopic adjustable gastric banding (LAGB), so that the non-LAGB were eliminated from the study. Data were collected independently by consultants of the French National Medical Insurance Service: characteristics of the patients, evolution of body mass index (BMI), physical activity and comorbidities, changes in behavior, complications, reoperations. Information was available on the activity of the surgical teams. Excess weight loss (EWL) >50% was considered a "success," and EWL <50% "not a success." A backstep, logistic regression (likelihood ratio test) was used to determine predictive factors. Results: Statistical analysis showed significant differences in EWL with the following data: age <40 years (P < 0.01), initial BMI <50 kg/m(2) (p < 0.001), experience of the surgeon(s) >2 procedures per week (P < 0.01), recovery of physical activity (P < 0.001), and change in eating habits (P < 0.001). Compared with 15- to 39-year-old patients, 40- to 49-year-old patients have a 1.5 higher risk not to have a success after surgery and over 50-year-old patients a 1.8 higher risk. Morbidly obese patients (40 < BMI < 49) had a 2.6 times higher risk not to have a success than patients with severe obesity (35 < BMI < 39). Superobese patients (BMI >50) had a 5.4 times higher risk not to succeed than patients with severe obesity. Being operated by a team with a surgical activity over 15 bariatric procedures/2 months doubles the chance of a successful operation when compared with patients operated by surgical teams having only performed I or 2 bariatric procedures. Patients who had not recovered or increased their physical activity after operation had a 2.3 times higher risk not to have a success than those who did. Patients who had not changed their eating habits had a 2.2 times higher risk not to have a success than those who did. Conclusions: This nationwide survey shows that the best profile for a success after gastric banding is a patient <40 years, with an initial BMI <50 kg/m(2), willing to change his eating habits and to recover or increase his physical activity after surgery and who has been operated by a team usually performing >2 bariatric procedures per week. This study emphasizes that obesity surgery requires a significant experience of the surgical team and a multidisciplinary approach to improve behavioral changes.