Review of meta-analytic comparisons of bariatric surgery with a focus on laparoscopic adjustable gastric banding.

BACKGROUND: In a prior systematic review and meta-analysis of the large body of literature describing the laparoscopic adjustable gastric band (LAGB), outcomes for the Swedish Adjustable Gastric Band (SAGB) and Lap-Band (LB), in particular, were reviewed. This article summarizes those results and discusses them in relation to the 3 other published bariatric surgery meta-analyses (JAMA 2004;292:1724-37; Ann Intern Med 2005;142:547-59; and Surgery 2007;142:621-32).

METHODS: In the gastric banding meta-analysis, systematic review included screening of 4,594 studies published in any language (Jan 1, 1998-April 30, 2006). Studies with at least 10 SAGB or LB patients reporting > or =30-day efficacy or safety outcomes were eligible for review; data were extracted from accepted studies. Weighted means analysis and random-effects meta-analysis of efficacy outcomes of interest were conducted.

RESULTS: In the gastric banding meta-analysis, 129 studies (patients n = 28,980) were accepted (33 SAGB/104 LB studies). In 4,273 patients (36 treatment groups) in 33 SAGB studies, and in 24,707 patients (111 groups) in 104 LB studies, mean baseline age (39.1-40.2 yrs), body mass index ([BMI] 43.8-45.3 kg/m2), and sex (females 79.2%-82.5%) were similar. Three-year mean SAGB/LB excess weight loss (56.36%/50.20%) was significant, as was resolution of type 2 diabetes (61.45%/60.29%) and hypertension (62.95%/43.58%) (P < .05). Adverse event (AE) rates appeared comparable, and early mortality was equivalent (< or =.1%).

DISCUSSION: In the SAGB and LB meta-analysis at 1, 2, and 3 years, weight loss, resolution of diabetes and hypertension, and adverse events appeared equivalent. All meta-analyses that assessed weight loss found that bariatric surgery produced clinically significant reductions in excess weight across procedures in the short term. One meta-analysis found that bariatric surgery produced significantly more weight loss than medical treatment in patients with BMI >40 kg/m2 in the short term, with malabsorptive procedures producing the greatest weight loss. All studies reporting on comorbidities showed significant resolution or improvement of type 2 diabetes mellitus ([T2DM] > or =60%), hypertension (> or =43%), and dyslipidemia (> or =70%). In one meta-analysis, surgery was found to be superior to medical therapy in resolving T2DM, hypertension, and dyslipidemia. Sleep apnea was significantly resolved/improved in > or =85% across procedures in the one meta-analysis that addressed this comorbidity. One meta-analysis found no differences in AEs between procedures; however, the laparoscopic approach was associated with significantly reduced AEs. In the 4 meta-analyses, mortality was low (.1%-1.11%) for all procedures. Bariatric surgery was observed to be a safe and highly effective therapy for morbid obesity. Heterogeneity in nomenclature, study methods, statistical detail, definitions of weight-loss success and comorbid disease resolution, and completeness of data sets did not allow for comparison of some variables. Initiatives including the Iowa Bariatric Surgery Registry (IBSR), the Longitudinal Assessment of Bariatric Surgery (LABS) consortium, the Surgical Review Corporation (SRC) Center of Excellence initiative, and the Bariatric Outcomes Longitudinal Database [BOLD] are working to improve data standardization, which, in turn, will facilitate summary and comparison of bariatric surgery outcomes.