Ninh T. Nguyen

Meta-analysis: surgical treatment of obesity.

Context The effectiveness of surgical therapy in the treatment of obesity is unclear. Contribution Many published studies of obesity surgery have significant limitations, and case series make up much of the evidence. Evidence is complicated by the heterogeneity of procedures studied. However, surgery can result in substantial amounts of weight loss (20 to 30 kg) for markedly obese individuals. One cohort study documented weight loss for 8 years with associated improvements in comorbid conditions, such as diabetes. Complications of surgery appear to occur in about 20% of patients. Implications Those considering surgical treatment for obesity should understand that, although patients who have surgery can lose substantial amounts of weight, the evidence base for these treatments is limited. The Editors The prevalence of obesity in the United States is reaching epidemic proportions. An estimated 30% of individuals met the criteria for obesity in 19992002 (1, 2), and many industrialized countries have seen similar increases. The health consequences of obesity include heart disease, diabetes, hypertension, hyperlipidemia, osteoarthritis, and sleep apnea (3-7). Weight loss of 5% to 10% has been associated with marked reductions in the risk for these chronic diseases and with reducing the incidence of diabetes (8-14). The increasing numbers of obese individuals have led to intensified interest in surgical treatments to achieve weight loss, and a variety of surgical procedures have been used (Figure 1). Bariatric surgery was first performed in 1954 with the introduction of the jejunoileal bypass, which bypasses a large segment of small intestine by connecting proximal small intestine to distal small intestine. With this procedure, weight loss occurs secondary to malabsorption from reduction of upstream pancreatic and biliary contents. However, diarrhea and nutritional deficiencies were common, and this procedure was discontinued because of the complication of irreversible hepatic cirrhosis. With the development of surgical staplers came the introduction of gastroplasty procedures by Gomez in 1981 (15) and Mason in 1982 (16). In these early procedures, the upper portion of the stomach was stapled into a small gastric pouch with an outlet (that is, a stoma) to the remaining distal stomach, which limited the size of the meal and induced early satiety. These procedures were prone to staple-line breakdown or stoma enlargement and were modified in turn by the placement of a band around the stoma (vertical banded gastroplasty). Figure 1. Surgical procedures. The first gastric bypass was reported in 1967 by Mason and Ito (17). It combined the creation of a small gastric pouch with bypassing a portion of the upper small intestine. Additional modifications resulted in the Roux-en-Y gastric bypass (RYGB), a now common operation that involves stapling the upper stomach into a 30-mL pouch and creating an outlet to the downstream small intestine. The new food limb joins with the biliopancreatic intestine after a short distance. This procedure, performed laparoscopically or by using an open approach, generates weight loss by limiting gastric capacity, causing mild malabsorption, and inducing hormonal changes. A second common technique, particularly outside of the United States, is the laparoscopic adjustable gastric band. This device is positioned around the uppermost portion of the stomach and can be adjusted to allow tailoring of the stoma outlet, which controls the rate of emptying of the pouch and meal capacity. Another procedure, preferred by a number of surgeons, is the biliopancreatic bypass, which combines a limited gastrectomy with a long Roux limb intestinal bypass that creates a small common channel (that is, an intestine where food and biliopancreatic contents mix). This procedure can be combined with a duodenal switch, which maintains continuity of the proximal duodenum with the stomach and uses a long limb Roux-en-Y bypass to create a short common distal channel. These latter 2 procedures generate weight loss primarily through malabsorption. Recent worldwide survey data from 2002 and 2003 show that gastric bypass is the most commonly performed weight loss procedure (65.1%) (18). Slightly more than half of gastric bypasses are done laparoscopically. Overall, 24% of cases are laparoscopic adjustable band procedures; 5.4% are vertical banded gastroplasties; and 4.9% are biliopancreatic diversion, with or without the duodenal switch. In California, the number of bariatric cases increased 6-fold between 1996 and 2000 (19), from 1131 cases to 6304; an estimated 140000 procedures were performed in the United States in 2004. With this escalation in the number of procedures, there have been reports of high postoperative complication rates (20-24). Because of these reports and the increasing use of obesity surgery, we were asked to review the literature to estimate the effectiveness of bariatric surgery relative to nonsurgical therapy for weight loss and reduction in preoperative obesity-related comorbid conditions. We were also asked to compare outcomes of surgical techniques. This paper is part of a larger evidence report titled Pharmacological and Surgical Treatment of Obesity, which was prepared for the Agency for Healthcare Research and Quality and is available at www.ncbi.nlm.nih.gov/books/bv.fcgi?rid=hstat1a.chapter.19289. Methods Literature Search and Selection We began with an electronic search of MEDLINE on 16 October 2002, followed by a search of EMBASE and subsequent periodic search updates (on 22 May, 2 June, 12 June, and 3 July 2003). We also assessed existing reviews of surgical therapy for obesity (10, 25, 26). Three reviewers independently reviewed the studies, abstracted data, and resolved disagreements by consensus (2 reviewers per study). The principal investigator settled any unresolved disagreements. We focused on studies that assessed surgery and used a concurrent comparison group. This category includes randomized, controlled trials (RCTs); controlled clinical trials; and cohort studies. A brief scan of the literature showed that these types of studies were rare. Therefore, we also elected to include case series with 10 or more patients, since these studies can be used to assess adverse events and could potentially augment the efficacy data from comparative studies. Publication bias is one potential limitation of analyzing the available literature because poor or negative results are not as likely to be reported as are successes or positive results. Extraction of Study-Level Variables We abstracted data from the articles, including number of patients and comorbid conditions, adverse events, types of outcome measures, and time from intervention until outcome. Detailed data were also collected on characteristics of the study samples, including median age, percentage of women, median baseline weight (in kilograms or body mass index [BMI]), percentage of patients with comorbid conditions at baseline (diabetes, hypertension, dyslipidemia, and sleep apnea), percentage of improvement or resolution of preexisting comorbid conditions, and median follow-up time. We also recorded whether the case series studies reported on consecutive patients. Choice of Outcomes The main outcomes of interest were weight loss, mortality, complication rates, and control of obesity-related comorbid conditions. We used the most commonly reported measurement of weight loss, that is, kilograms, which allowed us to include the greatest number of studies. Among 111 surgical studies reporting weight loss, 43 reported weight loss in kilograms or pounds, 17 reported excess weight loss or some variant, 46 reported both of these outcomes, and 5 reported neither. A total of 89 studies had sufficient data to be included in the weight loss analysis. Because weight loss achieves health benefits primarily by reducing the incidence or severity of weight-related comorbid conditions, we also compared the effects on these outcomes. Quality of life, an important outcome in assessing tradeoffs between benefits and risks, was reported infrequently. Statistical Analyses Because we included both comparative studies and case series, we conducted several types of analyses. The vast number of types of surgical procedures and technical variations required that we aggregate those that were clinically similar and identify the comparisons that were of most interest to the clinical audience. On the basis of discussions with bariatric surgeons, we categorized obesity surgery procedures by procedure type (for example, gastric bypass, vertical banded gastroplasty), laparoscopic or open approach, and specific surgical details such as length of Roux limb (see the larger evidence report for details). Analysis of the Efficacy of Surgical Weight Loss We extracted the mean weight loss and standard deviation at 12 postoperative months and at the maximum follow-up time (36 months). These times were chosen because they are clinically relevant and are most commonly reported. Of the 89 weight loss studies, 71 reported baseline BMI (average, 47.1 kg/m2), 16 reported baseline weight in kilograms or pounds (average, 123.3 kg), and 2 did not report either. The average age of patients was 38 years, and more than three quarters were women. For comparative studies that reported a within-study comparison of 2 procedures, a mean difference was calculated. Mean differences were pooled by using a random-effects model, and 95% CIs were estimated; the same method was used to determine a pooled mean weight loss for each group considering all studies combined. However, mean difference in weight loss was not calculated. Analysis of Surgery Mortality We recorded the number of deaths observed and the total number of patients in each procedure group. If the study self-identified the deaths as early or postoperative or as occurring within 30 days of the surgery, we termed these early deaths. If the

Laparoscopic Versus Open Gastric Bypass: A Randomized Study of Outcomes, Quality of Life, and Costs

ObjectiveTo compare outcomes, quality of life (QOL), and costs of laparoscopic and open gastric bypass (GBP). Summary Background DataLaparoscopic GBP has been reported to be a safe and effective approach for the treatment of morbid obesity. The authors performed a prospective randomized trial to compare outcomes, QOL, and costs of laparoscopic GBP with those of open GBP. MethodsFrom May 1999 to March 2001, 155 patients with a body mass index (BMI) of 40 to 60 kg/m2 were randomly assigned to undergo laparoscopic (n = 79) or open (n = 76) GBP. The two groups were similar in age, sex ratio, mean BMI, and comorbidities. Main outcome measures included operative time, estimated blood loss, length of hospital stay, operative complications, percentage of excess body weight loss, and time to return to activities of daily living and work. Changes in QOL were assessed using the SF-36 Health Survey and the bariatric analysis of reporting outcome system (BAROS). Operative and hospital costs of the two operations were also compared. ResultsThere were no deaths in either group. Mean operative time was longer for laparoscopic GBP than for open GBP, but operative blood loss was less. Two (2.5%) of the 79 patients in the laparoscopic group required conversion to laparotomy. Median length of hospital stay was shorter for laparoscopic GBP patients (3 vs 4 days). The rate of postoperative anastomotic leak was similar between groups. Wound-related complications such as infection (10.5 vs 1.3%) and incisional hernia (7.9 vs 0%) were more common after open GBP; late anastomotic stricture was less frequent after open GBP (2.6 vs 11.4%). Time to return to activities of daily living and work were shorter after laparoscopic GBP than after open GBP. Weight loss at 1 year was similar between groups. Preoperative SF-36 scores were similar between groups; however, at 1 month after surgery, laparoscopic patients had better physical conditioning, social functioning, general health, and less body pain than open GBP patients. At 6 months, the BAROS outcome was classified as good or better in 97% of laparoscopic GBP patients compared with 82% of open GBP patients. Operative costs were higher for laparoscopic GBP patients, but hospital costs were lower. ConclusionsLaparoscopic GBP is a safe and cost-effective alternative to open GBP. Despite a longer operative time, patients undergoing laparoscopic GBP benefited from less blood loss, a shorter hospital stay, and faster convalescence. Laparoscopic GBP patients had comparable weight loss at 1 year but a more rapid improvement in QOL than open GBP patients. The higher initial operative costs for laparoscopic GBP were adequately offset by the lower hospital costs.

First Report from the American College of Surgeons -- Bariatric Surgery Center Network: Laparoscopic Sleeve Gastrectomy has Morbidity and Effectiveness Positioned Between the Band and the Bypass

Objective:To assess the safety and effectiveness of the laparoscopic sleeve gastrectomy (LSG) as compared to the laparoscopic adjustable gastric band (LAGB), the laparoscopic Roux-en-Y gastric bypass (LRYGB) and the open Roux-en-Y gastric bypass (ORYGB) for the treatment of obesity and obesity-related diseases. Background:LSG is a newer procedure being done with increasing frequency. However, limited data are currently available comparing LSG to the other established procedures. We present the first prospective, multiinstitutional, nationwide, clinically rich, bariatric-specific data comparing sleeve gastrectomy to the adjustable gastric band, and the gastric bypass. Methods:This is the initial report analyzing data from the American College of Surgeons—Bariatric Surgery Center Network accreditation program, and its prospective, longitudinal, data collection system based on standardized definitions and collected by trained data reviewers. Univariate and multivariate analyses compare 30-day, 6-month, and 1-year outcomes including morbidity and mortality, readmissions, and reoperations as well as reduction in body mass index (BMI) and weight-related comorbidities. Results:One hundred nine hospitals submitted data for 28,616 patients, from July, 2007 to September, 2010. The LSG has higher risk-adjusted morbidity, readmission and reoperation/intervention rates compared to the LAGB, but lower reoperation/intervention rates compared to the LRYGB and ORYGB. There were no differences in mortality. Reduction in BMI and most of the weight-related comorbidities after the LSG also lies between those of the LAGB and the LRYGB/ORYGB. Conclusion:LSG has morbidity and effectiveness positioned between the LAGB and the LRYGB/ORYGB for data up to 1 year. As obesity is a lifelong disease, longer term comparative effectiveness data are most critical, and are yet to be determined.

Association of Hypertension, Diabetes, Dyslipidemia, and Metabolic Syndrome with Obesity: Findings from the National Health and Nutrition Examination Survey, 1999 to 2004

BACKGROUND Hypertension, diabetes, and dyslipidemia are common conditions associated with obesity. This study provides current estimates of the prevalence of hypertension, diabetes, dyslipidemia, and metabolic syndrome according to the severity of obesity in men and women participating in the 1999 to 2004 National Health and Nutrition Examination Survey (NHANES). STUDY DESIGN Data from a representative sample of 13,745 US men and women who participated in the NHANES between 1999 and 2004 were reviewed. Overweight and obesity classes 1, 2, and 3 were defined as a body mass index of 25.0 to 29.9, 30.0 to 34.9, 35.0 to 39.9, and> or =40.0 kg/m(2), respectively. Metabolic syndrome was defined according to the 2004 National Heart, Lung and Blood Institute/American Heart Association conference proceedings. RESULTS With increasing overweight and obesity class, there is an increase in the prevalence of hypertension (18.1% for normal weight to 52.3% for obesity class 3), diabetes (2.4% for normal weight to 14.2% for obesity class 3), dyslipidemia (8.9% for normal weight to 19.0% for obesity class 3), and metabolic syndrome (13.6% for normal weight to 39.2% for obesity class 3). With normal weight individuals as a reference, individuals with obesity class 3 had an adjusted odds ratio of 4.8 (95% CI 3.8 to 5.9) for hypertension, 5.1 (95% CI 3.7 to 7.0) for diabetes, 2.2 (95% CI 1.7 to 2.4) for dyslipidemia, and 2.0 (95% CI 1.4 to 2.8) for metabolic syndrome. CONCLUSIONS The prevalence of hypertension, diabetes, dyslipidemia, and metabolic syndrome substantially increases with increasing body mass index. These findings have important public health implications for the prevention and treatments (surgical and nonsurgical) of obesity.

The Relationship Between Hospital Volume and Outcome in Bariatric Surgery at Academic Medical Centers

Objective:To examine the effect of hospital volume of bariatric surgery on morbidity, mortality, and costs at academic centers. Summary Background Data:The American Society for Bariatric Surgery recently proposed categorization of certain bariatric surgery centers as “Centers of Excellence.” Some of the proposed inclusion criteria were hospital volume and operative outcomes. The volume–outcome relationship has been well established in several complex abdominal operations; however, few studies have examined this relationship in patients undergoing bariatric surgery. Methods:Using the International Classification of Diseases, 9th edition, diagnosis and procedure codes, we obtained data from the University HealthSystem Consortium Clinical Data Base for all patients who underwent Roux-en-Y gastric bypass for the treatment of morbid obesity between 1999 and 2002 (n = 24,166). Outcomes of bariatric surgery, including length of hospital stay, 30-day readmission, morbidity, observed and expected (risk-adjusted) mortality, and costs were compared between high-volume (>100 cases/year), medium-volume (50–100 cases/year), and low-volume hospitals (<50 cases/year). Results:There were 22 high-volume (n = 13,810), 27 medium-volume (n = 7634), and 44 low-volume (n = 2722) hospitals included in our study. Compared with low-volume hospitals, patients who underwent gastric bypass at high-volume hospitals had a shorter length of hospital stay (3.8 versus 5.1 days, P < 0.01), lower overall complications (10.2% versus 14.5%, P < 0.01), lower complications of medical care (7.8% versus 10.8%, P < 0.01), and lower costs (

Comparison of pulmonary function and postoperative pain after laparoscopic versus open gastric bypass: A randomized trial

10,292 versus

Minimally invasive esophagectomy.

13,908, P < 0.01). The expected mortality rate was similar between high- and low-volume hospitals (0.6% versus 0.6%), demonstrating similarities in characteristics and severity of illness between groups. The observed mortality, however, was significantly lower at high-volume hospitals (0.3% versus 1.2%, P < 0.01). In a subset of patients older than 55 years, the observed mortality was 0.9% at high-volume centers compared with 3.1% at low-volume centers (P < 0.01). Conclusions:Bariatric surgery performed at hospitals with more than 100 cases annually is associated with a shorter length of stay, lower morbidity and mortality, and decreased costs. This volume–outcome relationship is even more pronounced for a subset of patients older than 55 years, for whom in-hospital mortality was 3-fold higher at low-volume compared with high-volume hospitals. High-volume hospitals also have a lower rate of overall postoperative and medical care complications, which may be related in part to formalization of the structures and processes of care.

A prospective randomized trial of laparoscopic gastric bypass versus laparoscopic adjustable gastric banding for the treatment of morbid obesity: outcomes, quality of life, and costs.

BACKGROUND Impairment of pulmonary function is common after upper abdominal operations. The purpose of this study was to compare postoperative pulmonary function and analgesic requirements in patients undergoing either laparoscopic or open Roux-en-Y gastric bypass (GBP). STUDY DESIGN Seventy patients with a body mass index of 40 to 60 kg/m2 were randomly assigned to undergo laparoscopic (n = 36) or open (n = 34) GBP. The two groups were similar in age, gender, body mass index, pulmonary history, and baseline pulmonary function. Pulmonary function studies were performed preoperatively and on postoperative days 1, 2, 3, and 7. Oxygen saturation and chest radiographs were performed on both groups preoperatively and on postoperative day 1. Postoperative pain was evaluated using a visual analog scale and the amount of narcotic consumed was recorded. Data are presented as mean +/- standard deviation. RESULTS Laparoscopic GBP patients had significantly less impairment of pulmonary function than open GBP patients on the first three postoperative days (p < 0.05). By the 7th postoperative day, all pulmonary function parameters in the laparoscopic GBP group had returned to within preoperative levels, but only one parameter (peak expiratory flow) had returned to preoperative levels in the open GBP group. On the first postoperative day, laparoscopic GBP patients used less morphine than open GBP patients (46 +/- 31 mg versus 76 +/- 39 mg, respectively, p < 0.001), and visual analog scale pain scores at rest and during mobilization were lower after laparoscopic GBP than after open GBP (p < 0.05). Fewer patients after laparoscopic GBP than after open GBP developed hypoxemia (31% versus 76%, p < 0.001) and segmental atelectasis (6% versus 55%, p = 0.003). CONCLUSION Laparoscopic gastric bypass resulted in less postoperative suppression of pulmonary function, decreased pain, improved oxygenation, and less atelectasis than open gastric bypass.

Trends in Use of Bariatric Surgery, 2003−2008

BACKGROUND Open esophagectomy can be associated with significant morbidity and delay return to routine activities. Minimally invasive surgery may lower the morbidity of esophagectomy but only a few small series have been published. METHODS From August 1996 to September 1999, 77 patients underwent minimally invasive esophagectomy. Initially, esophagectomy was approached totally laparoscopically or with mini-thoracotomy; thoracoscopy subsequently replaced thoracotomy. RESULTS Indications included esophageal carcinoma (n = 54), Barretts high-grade dysplasia or carcinoma in situ (n = 17), and benign miscellaneous (n = 6). There were 50 men and 27 women with an average age of 66 years (range 30 to 94 years). Median operative time was 7.5 hours (4.5 hours with > 20 case experience). Median intensive care unit stay was 1 day (range 0 to 60 days); median length of stay was 7 days (range 4 to 73 days) with no operative or hospital mortalities. There were four nonemergent conversions to open esophagectomy; major and minor complication rates were 27% and 55%, respectively. CONCLUSIONS Minimally invasive esophagectomy is technically feasible and safe in our center, which has extensive minimally invasive and open esophageal experience. Open surgery should remain the standard until future studies conclusively demonstrate advantages of minimally invasive approaches.

A comparison study of laparoscopic versus open gastric bypass for morbid obesity

Background:Gastric bypass and adjustable gastric banding are the 2 most commonly performed bariatric procedures for the treatment of morbid obesity. The aim of this study was to compare the outcomes, quality of life, and costs of laparoscopic gastric bypass versus laparoscopic gastric banding. Study Design:Between 2002 and 2007, 250 patients with a body mass index of 35 to 60 kg/m2 were randomly assigned to gastric bypass or gastric banding. After exclusion, 111 patients underwent gastric bypass and 86 patients underwent gastric banding. Outcome measures included demographic data, operative time, blood loss, length of hospital stay, morbidity, mortality, early and late reoperation rate, weight loss, changes in quality of life, and cost. Treatment failure was defined as losing less than 20% of excess weight or conversion to another bariatric operation for failure of weight loss. Results:There were no deaths at 90 days in either group. The mean body mass index was higher in the gastric bypass group (47.5 vs. 45.5 kg/m2, respectively, P < 0.01) while the mean age was higher in the gastric band group (45 vs. 41 years, respectively, P < 0.01). Compared with gastric banding, operative blood loss was higher and the mean operative time and length of stay were longer in the gastric bypass group. The 30-day complication rate was higher after gastric bypass (21.6% vs. 7.0% for gastric band); however, there were no life-threatening complications such as leaks or sepsis. The most frequent late complication in the gastric bypass group was stricture (14.3%). The 1-year mortality was 0.9% for the gastric bypass group and 0% for the gastric band group. The percent of excess weight loss at 4 years was higher in the gastric bypass group (68 ± 19% vs. 45 ± 28%, respectively, P < 0.05). Treatment failure occurred in 16.7% of the patients who underwent gastric banding and in 0% of those who underwent gastric bypass, with male gender being a predictive factor for poor weight loss after gastric banding. At 1-year postsurgery, quality of life improved in both groups to that of US norms. The total cost was higher for gastric bypass as compared with gastric banding procedure (