The original 2008 Guidelines:
www.aace.com/files/bariatric.pdf
The update:
www.aace.com/files/publish-ahead-of-print-final-version.pdf
The part I think is interesting (sorta) - but the superiority of the DS at durably curing comorbidities and maintaining EWL seems to be disregarded again:
Q1. Which patients should be offered bariatric surgery?
R1(1).The evidence base for recommending bariatric surgery for patients with BMI ≥40 kg/m2 without coexisting medical problems is enriched with recent EL 1-3 studies demonstrating benefit: mortality (31 [EL 1, MRCT]; 32 [EL 1, RCT]), weight loss (33 [EL 1, MRCT]; 34 [EL 1, MRCT]; 35 [EL 2, PCS]; 36 [EL 2, PCS]), diabetes remission (37 [EL 1, MRCT]; 38 [EL 1, RCT]; 39 [EL 1, RCT]; 40 [EL 1, RCT]); improved beta-cell function (41 [EL1; RCT]); and improved pulmonary function (42 [EL 3; PCS]). Currently, the WHO classification scheme for obesity, based on BMI, determines diagnostic and therapeutic management. However, BMI is confounded by ethnic differences (43 [EL 2, MNRCT]; 44 [EL 4, NE]) and body composition (44 [EL 4, NE]); (45 [EL 2, CSS], and future improved risk stratification strategies may incorporate other anthropometric measurements, such as waist circumference (46 [EL 3, SS]) or waist-to-hip ratio (43 [EL 2, MNRCT]), co-morbidity and functional status assessments (47 [EL 4 NE]), and body composition technologies (45 [EL 3, CSS]). Factors found to be associated with poor outcome include open procedures, male gender, older age, congestive heart failure, peripheral vascular disease, deep venous thrombosis, PE, obstructive sleep apnea, impaired functional status, and chronic kidney disease (48 [EL 2, PCS]; 49 [EL 3, SS]). Therefore, further studies are needed that utilize new clinical risk-stratification systems to optimize patient selection criteria and consequently, patient outcomes.
R2(2/3). Many recent studies demonstrate benefit for bariatric surgery patients with BMI <35 kg/m2 in terms of weight loss (10 [EL 1, RCT]; 12 [EL 2, PCS]), diabetes remission, and cardiovascular risk reduction (50 [EL 2, RCT]; 51 [EL 1, RCT]; 52 [EL 2, PCS]; 53 [EL 2, PCS]).
This evidence base is supported by additional, though not as strong, studies and post hoc analyses from diverse ethnicities on weight loss (54 [EL 2, PCS]) and T2D improvement (11 [EL 2; PCS]; 55 [EL 3, SS]; 56 [EL 4, NE review and analysis]; 57 [EL 2, PCS]; 58 [EL 3, SS]; 59 [EL 2; PCS]; 60 [EL 2, NRCT]; 61 [EL 2, PCS]; 62 [EL 2; MNRCT]; 63 [EL 2, PCS]; 64 [EL 2, PCS]). As a result, the United States Food and Drug Administration (FDA) approved the LAP-BAND for patients with a BMI of 30-34.9 kg/m2 with an obesity-related co-morbidity. Moreover, the recent comparative effectiveness, randomized, nonblinded, single-center trial, with 34% of patients with BMI <35 kg/m2, represents a highly relevant study, even though it cannot yet be generalizable (39 [EL 2, RCT]). A companion paper by Mingrone et al. (40 [EL 2, RCT]) randomized patients with BMI ≥35 kg/m2 and does not apply to this CPG recommendation. Future, well-designed clinical trials that incorporate longer follow-up periods with demonstration of safety in the surgical group, relevant CVD outcomes, and an intensive medical therapy comparator group associated with weight loss, will clarify this CPG recommendation for patients with BMI <35 kg/m2.
R3(4). There are no compelling studies to date that support recommending a bariatric surgical procedure for the management of T2D alone, in the absence of obesity (BMI <30 kg/m2).
Q2. Which bariatric surgical procedure should be offered?
R4(5/6/7). Two principal determinants since publication of the 2008 AACE-TOS-ASMBS CPG (7 [EL 4; CPG]) have impacted clinical decision making regarding the choice of a specific bariatric surgery procedure (see Fig. 1 for depictions of the 4 common bariatric surgery procedures). First, the emphasis has shifted from weight-loss outcomes to the metabolic effects of bariatric surgery procedures, and second, sufficient data regarding the safety, efficacy, and durability of various procedures, especially the LSG, have been published. The advent of personalized medicine and applicability to obesity genetics and medicine is reviewed by Blakemore and Froguel (65 [EL 4]). Additionally, new procedures have emerged that are still considered investigational but will clearly impact future decision making. The superiority of laparoscopic bariatric surgical procedures, versus open procedures, was further demonstrated by the meta-analysis of Reoch et al. (66 [EL 1, MRCT]).
As the metabolic effects of various bariatric operations become better understood, the traditional classifications of procedures as “restrictive,” “malabsorptive,” or “combination” procedures have become less functional and less widely accepted. Adjustable gastric banding has clearly been shown to result in improvement or remission of diabetes and metabolic syndrome (50 [EL 2, RCT]), but it appears that these effects may not be related to changes in gut hormones (67 [EL 2, PCS]). The early, weight-independent effects of RYGB, BPD/BPDDS, and LSG on T2D improvement have led many to refer to these procedures as “metabolic” operations (68 [EL 2, NRCT]; 69 [EL 2, PCS]; 70 [EL 2, NRCT]; 71 [EL 4, NE]). In a 2-year period, RYGB was associated with increased achievement of American Diabetes Association (ADA) composite endpoints (38.2% versus 10.5% with routine medical management; P<.001; A1c <7.0% + LDL-cholesterol <100 mg/dL, and systolic blood pressure [BP] <130 mm Hg) (72 [EL 3, SS]). In recent follow-up reports of the Swedish Obese Subjects (SOS) study at median follow-up of 14.7 years, bariatric surgery was associated with improved T2D prevention and reduced cardiovascular deaths; these results extend the bariatric surgery benefits on surrogate markers to relevant clinical outcomes (26 [EL 2, PCS]; 73 [EL 2, PCS]). Nevertheless, the durability issue of T2D resolution remains at issue since approximately one third of RYGB patients experience relapse (74 [EL 3, SS]). Elevated
GLP-1 levels and various other gut hormone changes favoring satiety and glucose metabolism have been demonstrated after RYGB (75 [EL 2, NRCT]; 76 [EL 2, NRCT], 77 [EL 4, NE]; 78 [EL 1, RCT]), BPD (79 [EL 4, NE]; 80 [EL 2, PCS]; 81 [EL 2, PCS]), and LSG (82 [EL 1, RCT]; 83 [EL 2, PCS]; 84 [EL 2, NRCT]). Exclusion of nutrient flow through the duodenum and proximal bowel (RYGB, BPD, BPD/DS) may also play a role in diabetes remission after these procedures, although the precise mechanism for this effect has not been established and requires further study (85 [EL 4, NE]; 86 [EL 4, NE]). Future therapeutic targets based on the various mechanisms of action of these operations are likely as they become more clearly defined (86 [EL 4, NE]; 87 [EL 4, NE]).
The LSG has become widely accepted as a primary bariatric operation and is no longer considered investigational (see ASMBS statement at
s3.amazonaws.com/publicASMBS/GuidelinesStatements/PositionStatement/ASMBS-SLEEVE-STATEMENT-2011_10_28.pdf [accessed on May 22, 2012]). The LSG is seldom used as part of a 2-stage risk management strategy for highrisk patients. Because nearly 80% of the stomach is transected and nutrients rapidly pass through a gastric conduit, increased GLP-1 and PYY 3-36 and decreased ghrelin levels result, producing key metabolic effects (78 [EL 1, RCT]; 82 [EL 1, RCT]; 83 [EL 2, PCS]; 84 [EL 2, NRCT]; 88 [EL 1, RCT]). In addition to many recently published case series reporting the short- and medium- term safety and efficacy (weight loss and glycemic status) of the SG, the majority of which were performed laparoscopically (89 [EL 3, SS]; 90 [EL 3, SS]; 91 [EL 2, PCS]; 92 [EL 3, SS]; 93 [EL 3, SS]; 94 [EL 3, SS]; 95 [EL 2, PCS]; 96 [EL 3, SS]; 97 [EL 2, PCS]; 98 [EL 2, PCS]; 99 [EL 3, SS]; 100 [EL 3, SS]; 101 [EL 3, SS]; 102 [EL 2, PCS]), there are now several comparative studies (103 [EL ]; 104 [EL ]; 105 [EL ]; 106 [EL ]; 107 [EL ]; 108 [EL ]; 109 [EL ]; 110 [EL ]; 111 [EL ]; 112 [EL ]; 113 [EL ]; 114 [EL ]; 115 [EL ]), 6 randomized controlled trials (78 [EL 1, RCT]; 82 [EL 1, RCT]; 116 [EL 1, RCT]; 117 [EL 1, RCT]; 118 [EL 1, RCT]; 119 [EL 1, RCT]), and meta-analyses (120 [EL 2, MNRCT]; 121 [EL 2, MNRCT]) demonstrating equivalency or superiority to other accepted procedures (RYGB and LAGB). Analyses of outcomes from large prospective databases have revealed a risk/benefit profile for LSG that is positioned between the LAGB and RYGB (122 [EL 3, SS]; 123 [EL 3, SS]). There is also data demonstrating the durability of LSG at 5 to 9 years with acceptable long-term weight loss in the range of 50%-55% EWL (124 [EL 2, PCS]; 125 [EL 3, SS]; 126 [EL 3, SS]; 127 [EL 3, SS]; 128 [EL 2, PCS]). However, there are still concerns about the overall durability of the LSG procedure in light of a paucity of long-term (>5-10 year) data, major complication rates (approximately 12.1% on average), mortality (up to 3.3% in some studies), and costs (129 [EL 2, MNRCT]).
Gastric plication is an investigational procedure designed to create gastric restriction without the placement of a device or resection of tissue. This procedure is performed laparoscopically and involves infolding the greater curvature of the stomach to tubularize the stomach and create an intraluminal fold. This technique has also been used in combination with a LAGB to help augment early weight loss. There are several short-term studies demonstrating relative safety and effectiveness of greater curvature plication with outcomes intermediate between LAGB and SG (130 [EL 2, PCS]; 131 [EL 2, PCS]; 132 [EL 2, PCS]; 133 [EL 2, PCS]). Notwithstanding the above EL 2 studies, more robust comparative data and conclusive data evaluating the durability of this procedure will be needed before specific recommendations can be made. As new procedures (both surgical and endoscopic) continue to emerge within the field of bariatric surgery, it is important to balance innovation and patient choice with patient safety and demonstrated effectiveness based on clear benchmarks. For now, investigational bariatric procedures should only be recommended within the framework of an institutional review board (IRB), or equivalent, approved clinical research study.
