Weight Loss Percentile Charts of Large Representative Series: a Benchmark Defining Sufficient Weight Loss Challenging Current Criteria for Success of Bariatric Surgery

Background

The frequently used 35 kg/m² body mass index (BMI) and 50 % excess weight loss (%EWL) criteria are no longer adequate for defining the success of a bariatric or metabolic surgery. It is not clear whether they are still useful to simply determine the sufficiency of a patient’s postoperative weight loss. An alternative way of defining sufficient weight loss is presented, using weight loss percentile charts of large representative series as a benchmark.

Methods

Gastric bypass weight loss results from the Bariatric Outcomes Longitudinal Database (BOLD) with ≥2 years of follow-up are presented with percentiles in function of postoperative time and their nadir results in function of initial BMI using different outcome metrics. These percentiles are compared with the BMI35 and 50 %EWL criteria.

Results

Of 49,098 patients eligible for ≥2 years of follow-up, 8,945 had reported weight loss at ≥2 years (20.0 % male, mean initial BMI 47.7 kg/m²). They reached nadir BMI at a mean of 603 days. Their 50th percentiles surpassed both 50 %EWL and BMI35 after 135 days. More than 95 % achieved 50 %EWL; more than 75 % achieved BMI35. BMI and %EWL results are influenced more by initial BMI than total weight loss (%TWL) results.

Conclusions

BOLD gastric bypass weight loss data are presented with percentile curves. BMI and %EWL are clearly not suited for this purpose. Provided that follow-up data are solid, %TWL-based percentile charts can constitute neutral benchmarks for defining sufficient postoperative weight loss over time. Criteria for overall success, however, should consider clear goals of health improvement, including metabolic aspects. Frequently used criteria 50 %EWL and BMI35 are inadequate for both. Their static weight loss components do not match the found percentiles and their health improvement components do not match known metabolic criteria.     

Weight Loss Prior to Bariatric Surgery Is Not a Pre-requisite of Excess Weight Loss Outcomes in Obese Patients

Background  

Although weight loss before bariatric surgery may carry advantages during the surgical procedure (decreased liver volume, operation duration, and blood loss), it is still debated whether it induces a greater long-term weight loss.     

Revisional Bariatric Surgery for Unsuccessful Weight Loss and Complications

Background

There are growing numbers of patients who require revisional bariatric surgery due to the undesirable results of their primary procedures. The aim of this study was to review our experience with bariatric patients undergoing revisional surgery.

Methods

We conducted a retrospective analysis to review the indications for revisional bariatric procedures and assess their postoperative outcomes.

Results

From 04/04 to 01/11, 2,918 patients underwent bariatric surgery at our institution. A total of 154 patients (5.3 %) of these cases were coded as revisional procedures. The mean age at revision was 49.1?±?11.3 and the mean BMI was 44.0?±?13.7 kg/m². Revisional surgery was performed laparoscopically in 121 patients (78.6 %). Laparoscopic revisions had less blood loss, shorter length of hospital stay, and fewer complications compared to open revisions. Two groups (A and B) were defined by the indication for revision: patients with unsuccessful weight loss (group A, n?=?106) and patients with complications of their primary procedures (group B, n?=?48). In group A, 74.5 % of the patients were revised to a bypass procedure and 25.5 % to a restrictive procedure. Mean excess weight loss was 53.7?±?29.3 % after revision of primary restrictive procedures and 37.6?±?35.1 % after revision of bypass procedures at >1-year follow-up (p?<?0.05). In group B, the complications prompting revision were effectively treated by revisional surgery.

Conclusions

Revisional bariatric surgery effectively treated the undesirable results from primary bariatric surgery. Laparoscopic revisional surgery can be performed after both failed open and laparoscopic bariatric procedures without a prohibitive complication rate. Carefully selected patients undergoing revision for weight regain have satisfactory additional weight loss.     

Relative Outcome Measures for Bariatric Surgery. Evidence Against Excess Weight Loss and Excess Body Mass Index Loss from a Series of Laparoscopic Roux-en-Y Gastric Bypass Patients

Background  

Bariatric results expressed in the relative measure excess weight loss (%EWL) vary significantly by initial body mass index (BMI): the heavier the patient, the lower the %EWL. We examine if this variation is caused by using a wrong outcome measure and argue that no relative weight loss measure can express bariatric or metabolic goals unequivocally.     

Bariatric Surgery: 1-Year Weight Loss Outcomes in Patients with Bipolar and Other Psychiatric Disorders

Background  

Bariatric surgery is the most effective obesity treatment in terms of weight loss and resolution of comorbidities. Roux-en-Y bypass surgery achieves weight loss of 60% to 70% excess body weight in most morbidly obese individuals. Patients with psychological disorders are reported to have less optimal results and those with bipolar, possibly worse.     

Outcomes of a Third Bariatric Procedure for Inadequate Weight Loss

Background and Objectives:

The robust volume of bariatric surgical procedures has led to significant numbers of patients requiring reoperative surgery because of undesirable results from primary operations. The aim of this study was to assess the feasibility, safety, and outcomes of the third bariatric procedure after previous attempts resulted in inadequate results.

Methods:

We retrospectively identified patients who underwent a third bariatric procedure for inadequate weight loss or significant weight regain after the second operation. Data were analyzed to establish patient demographic characteristics, perioperative parameters, and postoperative outcomes.

Results:

A total of 12 patients were identified. Before the first, second, and third procedures, patients had a mean body mass index of 67.1 ± 29.3 kg/m², 60.9 ± 28.3 kg/m², and 49.4 ± 19.8 kg/m², respectively. The third operations (laparoscopic in 10 and open in 2) included Roux-en-Y gastric bypass (n = 5), revision of pouch and/or stoma of Roux-en-Y gastric bypass (n = 3), limb lengthening after Roux-en-Y gastric bypass (n = 3), and sleeve gastrectomy (n = 1). We encountered 5 early complications in 4 patients, and early reoperative intervention was needed in 2 patients. At 1-year follow-up, the excess weight loss of the cohort was 49.4% ± 33.8%. After a mean follow-up time of 43.0 ± 28.6 months, the body mass index of the cohort reached 39.9 ± 20.8 kg/m², which corresponded to a mean excess weight loss of 54.4% ± 44.0% from the third operation. At the latest follow-up, 64% of patients had excess weight loss >50% and 45% had excess weight loss >80%.

Conclusion:

Reoperative bariatric surgery can be carried out successfully (often laparoscopically), even after 2 previous weight loss procedures.     

Understanding Patients' Value of Weight Loss and Expectations for Bariatric Surgery

Background: Few studies examine patients' expectations for bariatric surgery or the value patients place on weight loss. Methods: 44 patients planning to undergo bariatric surgery were surveyed to examine patients' expectations and motivations for surgery. We also quantified how much patients valued different health and weight loss states using the standard gamble, an approach that estimates an outcome's value based on a patient's willingness to risk death to achieve the outcome. Utilities ranging from 0 to 1.00 were calculated where 1.00 represented the most desired state. Results: Mean age of the patients was 42.6 years, and mean body mass index was 47.1 kg/m². The majority were women (n=42) and white (n=29), and reported poor quality of life. Most patients considered surgery for health reasons. Patients expected to lose 38% of their total body weight and would be disappointed if they did not lose at least 24% of their body weight. Significantly more patients were willing to risk death to achieve their "dream" weight (n=40) than to lose 20% (n=32) or 10% (n=17) of their total body weight. The respective utilities for these weight states were 0.98, 0.94, and 0.92. More patients were willing to risk death to undergo surgery (n=42) than to achieve a permanent weight loss of 20% (n=32), P<0.004. Conclusion: Patients appeared to value weight loss highly but had unrealistic expectations for bariatric surgery. Future studies should examine whether patient expectations, motivations, and value for realistic weight losses might predict outcomes and satisfaction after surgery.     

Bariatric Surgeon Perspective on Revisional Bariatric Surgery (RBS) for Weight Recurrence

BackgroundWeight recurrence (WR) after bariatric surgery occurs in nearly 20% of patients. Revisional bariatric surgery (RBS) may benefit this population but remains controversial among surgeons.ObjectivesExplore surgeon perspectives and practices for patients with WR after primary bariatric surgery (PBS).SettingWeb-based survey of bariatric surgeons.MethodsA 21-item survey was piloted and posted on social media closed groups (Facebook) utilized by bariatric surgeons. Survey items included demographic information, questions pertaining to the definition of suboptimal and satisfactory response to bariatric surgery, and general questions related to different WR management options.ResultsOne hundred ten surgeons from 19 countries responded to the survey. Ninety-eight percent responded that WR was multifactorial, including behavioral and biological factors. Failure of PBS was defined as excess weight loss < 50% by 31.4%, as excess weight loss <25% by 12.8%, and as comorbidity recurrence by 17.4%. Surgeon responses differed significantly by gender (P = .036). 29.4% believed RBS was not successful, while 14.1% were unsure. Nevertheless, 73% reported that they would perform RBS if sufficient evidence of benefit existed. Most frequently performed revisional procedures included conversion of sleeve gastrectomy to Roux-en-Y gastric bypass (RYGB), adjustable gastric band to RYGB, and RYGB revision (21.9% versus 18.2% versus 15.3%, respectively).ConclusionsThis survey demonstrates significant variability in surgeon perception regarding causes and the effectiveness of RBS. Moreover, they disagree on what constitutes a nonsatisfactory response to PBS and to whom they offer RBS. These findings may relate to limited available clinical evidence on best management options for this patient population. Clinical trials investigating the comparative effectiveness of various treatment options are needed.     

The Role of Attachment in Body Weight and Weight Loss in Bariatric Patients

Purpose

The aim of this study is to explore the role of attachment styles in obesity.

Material and Methods

The present study explored differences in insecure attachment styles between an obese sample waiting for bariatric surgery (n = 195) and an age, sex and height matched normal weight control group (n = 195). It then explored the role of attachment styles in predicting change in BMI 1 year post bariatric surgery (n = 143).

Results

The bariatric group reported significantly higher levels of anxious attachment and lower levels of avoidant attachment than the control non-obese group. Baseline attachment styles did not, however, predict change in BMI post surgery.

Conclusion

Attachment style is different in those that are already obese from those who are not. Attachment was not related to weight loss post surgery.

     

Body Composition and Source of Weight Loss After Bariatric Surgery

Background: Little is known about the composition and source of weight loss after bariatric surgery for morbid obesity. Purpose: This study was undertaken to determine changes in weight, body mass index (BMI), lean body weight (LBW), fat weight (FW) and left ventricular cardiac mass (LVM) following vertical banded gastroplasty (VBG). Methods: After VBG for morbid obesity, 26 women and four men (mean age = 39.1 years) were weighed and had body composition analysis undertaken at intervals. Thirteen patients underwent echocardiography preoperatively and 1 year postoperatively to determine change in LVM and LVM index. Results: Over 12 months there was significant weight loss for all weight parameters examined (p < 0.05). Fat weight loss was most significant; total weight loss and reduction of BMI were significant but less so than fat loss (Wilcoxon's signed ranks test). LBW loss had the smallest contribution to weight loss (p < 0.0001). There was a significant loss of LVM and posterior cardiac wall thickness (p < 0.05). Conclusions: VBG can lead to loss of lean body weight and left ventricular mass, and more dramatically, fat weight, body weight, and BMI. Cardiac mass and lean body mass are preferentially conserved relative to body fat with weight loss after VBG.     

The Effect of Loss of Excess Weight on the Metabolic Risk Factors after Bariatric Surgery in Morbidly and Super-Obese Patients

BACKGROUND: Changes in metabolic risk factors such as dyslipidemia and hyperinsulinemia as well as levels of sex hormones and leptin were studied in morbidly obese (MO) and super-obese (SO) patients during excess weight loss (EWL), separately in males and females. METHODS: In this prospective clinical intervention study, 431 patients were included (361 females and 70 males). There were 217 patients with MO (BMI 40-49.9 kg/m2) and 214 patients with SO (BMI > or =50 kg/m2). All patients underwent restrictive bariatric operations. Metabolic parameters (lipids, insulin, leptin, hepatic transaminases, uric acid, and sex hormones) were measured before obesity surgery and at defined postoperative points of EWL (25%, 50%, 75% and 100%). RESULTS: Successful weight reduction of 25% EWL was achieved by 94% of patients at 2 months. With this moderate EWL, most of the patients already improved their risk profile considerably, including normalization of insulin levels. Additional EWL led to a further amelioration of risk profile in all patients, including normalization of triglyceride levels. Male MO and SO patients had a worse metabolic situation preoperatively and a greater benefit after weight loss. Even though SO patients did not lose as much excess weight as MO patients, they did profit comparably. CONCLUSION: Bariatric surgery is a valuable tool not only to reduce excess weight in severely obese patients but also to improve the metabolic risk profile within a short time-frame. This benefit is most pronounced in high-risk males.     

Psychosocial Factors and 2-Year Outcome Following Bariatric Surgery for Weight Loss

Background: How psychosocial factors may impact on weight loss after bariatric surgery is not well understood. This lack of knowledge is problematic, because there is a high prevalence of psychosocial distress in patients seeking treatment for obesity in hospital-based programs. The purpose of this study was to examine the relationship between preoperative psychosocial factors and eventual weight loss. Method: Between 1987 and 1998, all individuals undergoing Roux-en-Y gastric bypass for weight loss in our institution had psychologic preoperative evaluations. Patients who were followed prospectively were studied. The relation of having received mental health treatment to percentage of excess weight loss at 2 years is examined using t-tests. Results: 62 women and 18 men completed a 2-year follow-up. Patients who had received treatment for either substance abuse (n=10) or psychiatric co-morbidity (n=39) lost more weight compared with those without such histories (P<0.05, P <0.001 respectively). Conclusion: Given these results, it is plausible that a history of having received either psychiatric treatment for a disorder or counseling for substance abuse should not be a contraindication to bariatric surgery, and, in fact, may be prognostic of favorable outcome. Further research examining psychosocial factors and outcome from bariatric surgery is clearly warranted.     

Continuous Positive Airway Pressure (CPAP) Changes in Bariatric Surgery Patients Undergoing Rapid Weight Loss

Background: Obstructive sleep apnea (OSA) is a common condition in morbidly obese patients, with the reported prevalence ranging from 12-78%. There is increasing recognition of the need to diagnose and treat/manage OSA both preoperatively and postoperatively. Nasal CPAP is the preferred treatment of OSA; however, weight loss is associated with a reduction in required pressures. We evaluated the CPAP pressure requirements in a group of patients undergoing rapid weight loss following Roux-en-Y gastric bypass . Methods: 15 patients who had been diagnosed with OSA before surgery were retrospectively evaluated. All patients had demonstrated compliance on home CPAP therapy, were minimally 3 months post-surgery and had follow-up reports that their CPAP was less effective. We obtained data on age, sex, weight, BMI, and apnea/hypopnea index (AHI). Optimal CPAP pressure was obtained initially through attended in-laboratory complex polysomnography. Follow-up CPAP pressure was obtained using an auto-titrating PAP device at home. These data were used to evaluate the pressure changes that accompanied weight loss. Results: This group of patients had lost an average of 44.5 ± 19.4 kg. Four patients had achieved their goal weight. Their starting CPAP pressures averaged 11 ± 3.0 cm H₂O, with a range of 7-18 cm H₂O. Follow-up CPAP pressures averaged 9 ± 2.7 cm H₂O, with a range of 4-12 cm H₂O, representing an overall reduction of 18%. The subgroup of patients who had achieved goal weight had a pressure reduction of 22% (9 ± 2.0 to 7 ± 1.0 cm H₂O). Conclusion: CPAP pressure requirements change considerably in bariatric surgery patients undergoing rapid weight loss. Auto-titrating PAP devices have promise for facilitating the management of CPAP therapy during this time. Consideration should also be given to the use of autotitrating PAP units as the treatment of choice in these patients.     

Effect of Revisional Bariatric Surgery on Weight Loss and Frequency of Complications

Background: The relative risks and effectiveness of primary and revision operations done to produce weight loss are of interest both from a patient care and an economic perspective. The possibility that patients requiring revision surgery comprise a treatment resistant subgroup who are more likely to have post-operative complications is a valid concern. Methods: The records of all patients having bariatric procedures since January of 1970 were evaluated for weight loss and complications. Results: Most revisions were from jejunoileal bypass or a gastric restrictive procedure. Early complications were significantly more common following revision surgery (19%) than after primary procedures (6%), although late and combined early and late complication rates were similar. Operative mortality was lower following primary procedures (2/382) than revisions (1/75). Cholecystectomy was a common sequela following primary procedures but did not occur after revision procedures. Regardless of surgical category, weight loss after revision was equivalent to weight loss after primary procedures. Conclusions: Weight loss following revisional bariatric surgery is equivalent to weight loss following a primary operation of the same type. Although mortality and early complications are more common after revisional bariatric surgery, the frequency of late complications is not different. In all groups wound infections and hernias were relatively common complications and cholecystectomies are rare after revisional bariatric operations.     

Efficacy of a Required Preoperative Weight Loss Program for Patients Undergoing Bariatric Surgery

The efficacy of mandatory medically supervised preoperative weight loss (MPWL) prior to bariatric surgery continues to be a controversial topic. The purpose of this observational study was to assess the efficacy of a MPWL program in a single institution, which mandated at least 10 % excess body weight loss before surgery, by comparing outcomes of patients undergoing primary bariatric surgery with and without a compulsory preoperative weight loss regimen. We analyzed our database of 757 patients who underwent primary bariatric surgery between March 2008 and January 2015. Patients were placed into two cohorts based on their participation in a MPWL program requiring at least 10 % excess weight loss (EWL) prior to surgery. Patients were evaluated at 3, 6, 12, and 24 months after surgery for weight loss, comorbidity resolution, and the occurrences of hospital readmissions. A total of 717 patients met the inclusion criteria of whom 465 underwent surgery without a preoperative weight loss requirement and 252 participated in the MPWL program. One year after surgery, 67.1 % of non-participants and 62.5 % of MPWL participants showed a resolution of at least one of five associated comorbidities (p?=?0.45). Non-participants showed an average of 58.6 % EWL, while MPWL participants showed 59.1 % EWL at 1 year postoperatively (p?=?0.84). Readmission rates, excluding those which were ulcer-related, at 30 days (3.4 vs. 6.40 %, p?=?0.11) and 90 days (9.9 vs. 7.5 %, p?=?0.29) postoperatively were not significantly different between the non-participants and MPWL patients, respectively. A mandatory preoperative weight loss program prior to bariatric surgery did not result in significantly greater %EWL or comorbidity resolution 1 year after surgery compared to patients not required to lose weight preoperatively. Additionally, the program did not result in significantly lower 30- or 90-day readmission rates for these patients. The value of a MPWL program must be weighed against the potential loss of bariatric surgery candidates. Patients who fail to lose 10 % excess weight preoperatively are thus ineligible for a procedure from which they would otherwise benefit. Our data suggest these patients will have similar positive outcomes.     

Daily High Doses of Fluoxetine for Weight Loss and Improvement in Lifestyle before Bariatric Surgery

Background: The number of gastric restrictive bariatric operations is increasing each year, but about one-fifth of patients will become disappointed due to unsatisfactory weight reduction or annoying complications. We questioned whether weight reduction by taking high doses of fluoxetine improves lifestyle before surgery. Methods: 84 severely obese subjects were referred by one bariatric surgeon for medical weight reduction and dietary counseling, before bariatric surgery. Subjects were voluntarily treated with fluoxetine, 60 mg per day, and followed-up at 1, 3, 6 and 12 months. Surgery was scheduled between 6 to 12 months after subjects started to take fluoxetine. Endpoints of this study were body weight reductions, the number of individuals who decided for themselves to postpone surgery for at least 6 months, and side-effects of fluoxetine therapy. Results: 84 severely obese subjects consisting of 28 men (group 1) and 41 women (group 2) consented to take fluoxetine for its anorectic effects, whereas 12 men and 3 women who did not want to take fluoxetine served as the control group (group 3). Weight in these 3 groups at baseline was 149±26, 124±17, and 132±23 (controls) (P<0.05) with BMI 46±3, 44±3, and 45±2 (controls) kg/m² (NS). Maximum weight reduction before surgery in male and female fluoxetine users occurred at 3 and 6 months, respectively. At 6 months, men had achieved a weight reduction (kg) of -8.3 (95% CI: -9.3 to -5.9), women of -13.3 (95% CI: -16.3 to -8.8), sex difference P<0.001, and controls of -1.6 (95% CI: -3.8 to -2.5) kg, group difference P<0.0001. Only 2 men stopped fluoxetine because of annoying sexual side-effects. At 6 months, 25 fluoxetine users (29.7%) and none of the controls consented to postpone the time of surgery for at least another 6 months. Conclusion: Fluoxetine is effective to reduce weight in severely obese men and women who originally had requested to undergo bariatric surgery. One-third of subjects who consented to take fluoxetine as an anorectic drug agreed to delay surgery for at least 6 months later than scheduled.