Paul E. O'Brien

Systematic Review of Medium-Term Weight Loss after Bariatric Operations

Background: Although bariatric surgery is known to be effective in the short term, the durability of that effect has not been convincingly demonstrated over the medium term (>3 years) and the long term (>10 years). The authors studied the durability of weight loss after bariatric surgery based on a systematic review of the published literature. Methods: All reports published up to September, 2005 were included if they were full papers in refereed journals published in English, of outcomes after Roux-en-Y gastric bypass (RYGBP), and its hybrid procedures of banded bypass (Banded RYGBP) and longlimb bypass (LL-RYGBP), biliopancreatic diversion with or without duodenal switch (BPD±DS) or laparoscopic adjustable gastric banding (LAGB). All reports that had at least 100 patients at commencement, and provided ≥3 years of follow-up data were included. Results: From a total of 1,703 reports extracted, 43 reports fulfilled the entry criteria (18 RYGBP; 18 LAGB; 7 BPD). Pooled data from all the bariatric operations showed effective and durable weight loss to 10 years. Mean %EWL for standard RYGBP was higher than for LAGB at years 1 and 2 (67 vs 42; 67 vs 53) but not different at 3, 4, 5, 6 or 7 years (62 vs 55; 58 vs 55; 58 vs 55; 53 vs 50; and 55 vs 51). There was 59 %EWL for LAGB at 8 years, and 52 %EWL for RYGBP at 10 years. Both the BPD±DS and the Banded RYGBP appeared to show better weight loss than standard RYGBP and LAGB, but with statistically significant differences present at year 5 alone. The LL-RYGBP was not associated with improved %EWL. Important limitations include lack of data on loss to follow-up, failure to identify numbers of patients measured at each data point and lack of data beyond 10 years. Conclusions: All current bariatric operations lead to major weight loss in the medium term. BPD and Banded RYGBP appear to be more effective than both RYGBP and LAGB which are equal in the medium term.

The Laparoscopic Adjustable Gastric Band (Lap-Band®): A Prospective Study of Medium-Term Effects on Weight, Health and Quality of Life

Background: Obesity is now one of our major public health problems. Effective and acceptable treatment options are needed.The Lap-Band® system is placed laparoscopically and allows adjustment of the level of gastric restriction. Methods: A prospective study of 709 severely obese patients was conducted over a 6-year period at a university-based multidisciplinary referral center. After extensive preoperative evaluation, patients with a body mass index >35 were treated by LapBand® placement. Close follow-up with progressive adjustment of gastric restriction continued permanently. Medical co-morbidities were monitored as part of comprehensive prospective data collection. Results: There have been no deaths perioperatively or during follow-up. Significant perioperative adverse events occurred in 1.2% only. Reoperation has been needed for prolapse (slippage) in 12.5%, erosion of the band into the stomach in 2.8% and for tubing breaks in 3.6%. A steady progression of weight loss has occurred through the duration of the study with 52 ± 19 %EWL at 24 months (n=333), 53±22 %EWL at 36 months (n=264), 52 ± 24 %EWL at 48 months (n=108), 54 ± 24 %EWL at 60 months (n=30), and 57 ± 15% EWL at 72 months (n=10). Major improvements have occurred in diabetes, asthma, gastroesophageal reflux, dyslipidemia, sleep apnea and depression. Quality of life as measured by Rand SF-36 shows highly significant improvement. Conclusions: Placement of the Lap-Band® system provides safe and effective control of severe obesity. The effect on weight loss is durable and is associated with major improvement in health and quality of life. It has the potential to provide a broadly acceptable option for this common and serious disease.

Long-term outcomes after bariatric surgery : fifteen-year follow-up of adjustable gastric banding and a systematic review of the bariatric surgical literature

Objective:To describe the long-term outcomes after laparoscopic adjustable gastric banding (LAGB) and compare these with the published literature on bariatric surgery. Background:Because obesity is a chronic disease, any proposed obesity treatment should be expected to demonstrate long-term durability to be considered effective. Yet for bariatric surgery, few long-term weight loss data are available. We report our 15-year follow-up data after LAGB and provide a systematic review of the peer-reviewed literature for weight loss at 10 years or more after bariatric surgical procedures. Methods:We performed a prospective longitudinal cohort study of LAGB patients using an electronic database system (LapBase) to track progress, measure weight changes, and document revisional procedures. The evolution of the LAGB procedure was recognized, and revisional rates for 3 separate periods between September 1994 and December 2011 were described. In addition, we performed a systematic review of the peer-reviewed published literature collecting all reports that included weight loss data at or beyond 10 years. Results:A total of 3227 patients, with a mean age of 47 years and a mean body mass index of 43.8 kg/m2, were treated by laparoscopic adjustable gastric band placement between September 1994 and December 2011. Seven hundred fourteen patients had completed at least 10 years of follow-up. Follow-up was intact in 81% of patients overall and 78% of those beyond 10 years. There was no perioperative mortality for the primary placement or for any revisional procedures. There was 47.1% of excess weight loss (% EWL) at 15 years [n = 54; 95% confidence interval (CI) = 8.3] and 62% EWL at 16 years (n = 14; 95% CI = 13.6). There was a mean of 47.0% EWL (n = 714; 95% CI = 1.3) for all patients who were at or beyond 10 years follow-up. Revisional procedures were performed for proximal enlargement (26%), erosion (3.4%), and port and tubing problems (21%). The band was explanted in 5.6%. The need for revision decreased as the technique evolved, with 40% revision rate for proximal gastric enlargements in the first 10 years, reducing to 6.4% in the past 5 years. The revision group showed a similar weight loss to the overall group beyond 10 years. The systematic review of all bariatric procedures with 10 or more years of follow-up showed greater than 50% EWL for all current procedures. The weighted mean at maximum follow-up for LAGB was 54.2% EWL and for Roux-en-Y gastric bypass was 54.0% EWL. Conclusions:The LAGB study from 1 center demonstrates a durable weight loss with 47% EWL maintained to 15 years. This weight loss occurred regardless of whether any revisional procedures were needed. A systematic review shows substantial and similar long-term weight losses for LAGB and other bariatric procedures.

Pro-Inflammatory CD11c+CD206+ Adipose Tissue Macrophages Are Associated With Insulin Resistance in Human Obesity

OBJECTIVE Insulin resistance and other features of the metabolic syndrome have been causally linked to adipose tissue macrophages (ATMs) in mice with diet-induced obesity. We aimed to characterize macrophage phenotype and function in human subcutaneous and omental adipose tissue in relation to insulin resistance in obesity. RESEARCH DESIGN AND METHODS Adipose tissue was obtained from lean and obese women undergoing bariatric surgery. Metabolic markers were measured in fasting serum and ATMs characterized by immunohistology, flow cytometry, and tissue culture studies. RESULTS ATMs comprised CD11c+CD206+ cells in “crown” aggregates and solitary CD11c−CD206+ cells at adipocyte junctions. In obese women, CD11c+ ATM density was greater in subcutaneous than omental adipose tissue and correlated with markers of insulin resistance. CD11c+ ATMs were distinguished by high expression of integrins and antigen presentation molecules; interleukin (IL)-1β, -6, -8, and -10; tumor necrosis factor-α; and CC chemokine ligand-3, indicative of an activated, proinflammatory state. In addition, CD11c+ ATMs were enriched for mitochondria and for RNA transcripts encoding mitochondrial, proteasomal, and lysosomal proteins, fatty acid metabolism enzymes, and T-cell chemoattractants, whereas CD11c− ATMs were enriched for transcripts involved in tissue maintenance and repair. Tissue culture medium conditioned by CD11c+ ATMs, but not CD11c− ATMs or other stromovascular cells, impaired insulin-stimulated glucose uptake by human adipocytes. CONCLUSIONS These findings identify proinflammatory CD11c+ ATMs as markers of insulin resistance in human obesity. In addition, the machinery of CD11c+ ATMs indicates they metabolize lipid and may initiate adaptive immune responses.

Laparoscopic Adjustable Gastric Banding in Severely Obese Adolescents: A Randomized Trial

CONTEXT Adolescent obesity is a common and serious health problem affecting more than 5 million young people in the United States alone. Bariatric surgery is being evaluated as a possible treatment option. Laparoscopic adjustable gastric banding (gastric banding) has the potential to provide a safe and effective treatment. OBJECTIVE To compare the outcomes of gastric banding with an optimal lifestyle program on adolescent obesity. DESIGN, SETTING, AND PATIENTS A prospective, randomized controlled trial of 50 adolescents between 14 and 18 years with a body mass index (BMI) higher than 35, recruited from the Melbourne, Australia, community, assigned either to a supervised lifestyle intervention or to undergo gastric banding, and followed up for 2 years. The study was performed between May 2005 and September 2008. MAIN OUTCOME MEASURES Weight loss. Secondary outcomes included change in metabolic syndrome, insulin resistance, quality of life, and adverse outcomes. RESULTS Twenty-four of 25 patients in the gastric banding group and 18 of 25 in lifestyle group completed the study. Twenty-one (84%) in the gastric banding and 3 (12%) in the lifestyle groups lost more than 50% of excess weight, corrected for age. Overall, the mean changes in the gastric banding group were a weight loss of 34.6 kg (95% CI, 30.2-39.0), representing an excess weight loss of 78.8% (95% CI, 66.6%-91.0%), 12.7 BMI units (95% CI, 11.3-14.2), and a BMI z score change from 2.39 (95% CI, 2.05-2.73) to 1.32 (95% CI, 0.98-1.66). The mean losses in the lifestyle group were 3.0 kg (95% CI, 2.1-8.1), representing excess weight loss of 13.2% (95% CI, 2.6%-21.0%), 1.3 BMI units (95% CI, 0.4-2.9), and a BMI z score change from 2.41 (95% CI, 2.21-2.66) to 2.26 (95% CI, 1.91-2.43). At entry, 9 participants (36%) in the gastric banding group and 10 (40%) in the lifestyle group had the metabolic syndrome. At 24 months, none of the gastric banding group had the metabolic syndrome (P = .008; McNemar chi(2)) compared with 4 of the 18 completers (22%) in the lifestyle group (P = .13). The gastric banding group experienced improved quality of life with no perioperative adverse events. However, 8 operations (33%) were required in 7 patients for revisional procedures either for proximal pouch dilatation or tubing injury during follow-up. CONCLUSIONS Among obese adolescent participants, use of gastric banding compared with lifestyle intervention resulted in a greater percentage achieving a loss of 50% of excess weight, corrected for age. There were associated benefits to health and quality of life. TRIAL REGISTRATION ANZCTR Identifier: 12605000160639.

Grazing and Loss of Control Related to Eating: Two High‐risk Factors Following Bariatric Surgery

Background: Gastric restrictive surgery induces a marked change in eating behavior. However, the relationship between preoperative and postoperative eating behavior and weight loss outcome has received limited attention.

Changes in fat-free mass during significant weight loss: a systematic review

Objective:To identify the proportion of weight lost as fat-free mass (FFM) by various weight loss interventions.Methods:Medline and Embase were systematically searched for reliable measurements of FFM before and after weight loss of >10 kg and eligible data were pooled. In a fixed effect model of % FFM loss/weight loss (%FFML), linear regression analysis was used to determine the influence of degree of caloric restriction, exercise, magnitude of weight loss, initial body mass index (BMI) and type of surgery.Results:Data were included from 26 cohorts treated with dietary and behavioral interventions and 29 cohorts of bariatric surgery patients. The degree of caloric restriction was positively associated with %FFML (r 2=0.31, P=0.006) and in three randomized controlled trials exercise was shown to decrease %FFML. Compared with laparoscopic adjustable gastric banding (LAGB), biliopancreatic diversion (BPD) and roux en Y gastric bypass (RYGB) caused greater loge (natural log) %FFML (r 2=0.453, P<0.001). Differences in loge %FFML between surgical procedures were independent of initial BMI and magnitude of weight loss.Conclusions:The degree of caloric restriction, exercise and rate of weight loss influence the proportion of weight lost as FFM after non-surgical interventions. For surgical interventions, BPD and RYGB result in greater %FFML than LAGB.

Preoperative weight loss with a very-low-energy diet: quantitation of changes in liver and abdominal fat by serial imaging

BACKGROUND A very-low-energy diet (VLED) can result in substantial, rapid weight loss and is increasingly prescribed before obesity surgery to minimize risk and difficulty by reducing liver size and abdominal adiposity. Despite its growing popularity, a VLED in this setting has received little attention. OBJECTIVE The aim of this study was to investigate the efficacy and acceptability of a preoperative VLED. DESIGN In a prospective observational study, 32 subjects (n = 19 men and 13 women) with a mean (+/-SD) age of 47.5 +/- 8.3 y and a body mass index (in kg/m(2)) of 47.3 +/- 5.3 consumed a VLED for 12 wk. Primary outcomes included changes in liver volume (LV) and in visceral and subcutaneous adipose tissue (VAT/SAT). Changes in body weight, anthropometric measures, and biochemical variables were also recorded, and compliance with, acceptability of, and side effects of treatment were assessed. Changes in LV and VAT/SAT area were measured by computed tomography and magnetic resonance imaging at baseline and weeks 2, 4, 8, and 12. RESULTS Mean (+/-SD) LV, VAT/SAT, and body weight decreased significantly (P < 0.001 for all). The degree of LV reduction was directly related to the reduction in relative body weight (r = 0.54, P = 0.001) and initial LV (r = 0.43, P = 0.015). Eighty percent of the reduction in LV occurred between weeks 0 and 2 (P < 0.001). Reductions in body weight and VAT were uniform over the 12-wk period. Attrition was 14%. Acceptability was adequate but waned over time, and mild transitory side effects occurred. CONCLUSIONS Given the observed early reduction in LV and the progressive reduction in VAT, we suggest that the minimum duration for a preoperative VLED be 2 wk. Ideally, the duration should be 6 wk to achieve maximal LV reduction and significant reductions in VAT and body weight without compromising compliance and acceptability.

A Prospective Randomized Trial of Placement of the Laparoscopic Adjustable Gastric Band: Comparison of the Perigastric and Pars Flaccida Pathways

Background: Laparoscopic adjustable gastric banding (LAGB) is a safe and effective method for the treatment of obesity. The most common problem after LAGB has been the occurrence of prolapse (slippage) of the stomach through the band. It has been proposed that the pars flaccida (PF) pathway (dissection from the base of the right crus, along the left crus to the angle of His) is less likely to be associated with prolapse than the traditional perigastric (PG) pathway (dissection between the lesser curvature of stomach and lesser omentum, across the apex of the lesser sac, to the angle of His). We have tested this hypothesis using a randomized controlled trial format. Methods: We have performed a randomized controlled trial to compare the outcomes after LAGB using PF and PG pathways. 202 patients (mean age 40 years, mean weight 123 kg, mean BMI 45) were randomly allocated to the PF or PG pathway and followed for 2 years. Results: At 24 months, there have been 16 revisional procedures for prolapse, 4 in the PF group (all anterior prolapse) and 15 in the PG group (12 posterior and 3 anterior). This difference is significant (P<0.001). The mean % excess weight lost was 53% for the PF group and 46% for the PG group. There was equally significant improvements in the metabolic syndrome in both groups (59% preoperatively and 19% at 2 years). All 8 paired domain scores of the SF-36 measures of quality of life were improved significantly in both group (P<0.001). Conclusions: The PF pathway is as effective as the PG pathway in generating substantial weight loss, improved health and improved quality of life and is significantly less likely to be associated with prolapse (slippage). It is recommended as the primary dissection pathway.

Predictors of dropout in weight loss interventions: a systematic review of the literature

Attendance and completion of weight loss intervention is associated with better weight loss outcomes; however, attrition is neither consistently reported nor comprehensively explored in the weight loss literature. A systematic review was undertaken to identify factors associated with attrition in weight loss interventions involving overweight or obese (body mass index ≥ 25) adults (18–65 years). Sixty‐one studies published before May 2011 and addressing factors associated with weight loss programme attrition were identified. Conclusions were limited by the large number of variables explored, the small number of studies exploring each variable, the large variety of study settings and methodologies used, the inconsistent reporting of results, and the conflicting findings across studies. A consistent set of predictors has not yet been identified. The majority of studies relied on pre‐treatment routinely collected data rather than variables selected because of their theoretical and/or empirical relationship with attrition. However, psychological and behavioural patient factors and processes associated with the treatment were more commonly associated with attrition than patient background characteristics. Future research should consider theoretically grounded social–psychological and behavioural processes as potential predictors of dropout. Identification of patients at risk of dropout will contribute to both the effectiveness and the cost‐effectiveness of weight loss interventions.