Design and demography of the United States Swedish Adjustable Gastric Band trial: a 3-year prospective study

Abstract

Background Laparoscopic adjustable gastric banding (LAGB) provides the least invasive of the bariatric surgical options, and has been shown to be safe, reversible, or convertible to an alternate bariatric procedure. The Swedish Adjustable Gastric Band (SAGB) has been commercially available outside of the United States (U.S.) for treatment of morbid obesity since 1996. A 3-year trial monitored by the Food and Drug Administration (FDA) was initiated in a heterogeneous array of treatment sites to study SAGB outcomes in the U.S. In advance of the availability of these results for publication, the current report presents the design, methodology, and demography of the U.S. SAGB trial. Hypothesis The primary study hypothesis was that percentage of excess weight loss (%EWL) attained in patients at 3 years post-SAGB implantation would not be inferior to the clinically meaningful reduction in weight of 36.2% achieved at 3 years by the first LAGB to receive US FDA approval (the Lap-Band). Design A total of 405 morbidly obese patients were screened from May 29 to November 3, 2003, to participate in a prospective, single-arm, controlled study of the SAGB at 12 bariatric centers across 7 states. Qualified patients were enrolled to undergo device implantation using the pars flaccida laparoscopic technique. Measured outcomes included changes in boby mass index (BMI), excess body weight, incidence and type of complications, quality of life, and laboratory values associated with changes in comorbid disease. Patients were followed for 36 months, with a minimum of 14 postoperative office visits. Statistical Analysis Categorical data measurements included counts and percentages, and, where applicable, 95% confidence intervals. Continuous measures were summarized by presenting the number of patients, mean, median, standard deviation, minimum and maximum, with 95% confidence intervals, as appropriate. The alpha error for all hypotheses was set at .05. Analyses included 2-sided tests and repeated measures ANOVA mixed-model analyses. Demographics A total of 276 patients (mean age 38.6 ± 9.4 yrs [range 18–61], predominantly female [216, 78.3%] white non-Hispanic [169, 61.2%]) qualified for study inclusion and were enrolled. The intent-to-treat population was implanted with the SAGB. Preoperative weight and BMI (means) were 276.5 ± 40.8 lbs, and 44.5 ± 4.7, respectively.