Does preoperative weight loss predict success following surgery for morbid obesity?

Preoperative Weight Gain Is Not Related to Lower Postoperative Weight Loss, But to Lower Total Weight Loss up to 3 Years After Bariatric-Metabolic Surgery

INTRODUCTION

Weight loss prior to bariatric-metabolic surgery (BMS) is recommended in most bariatric centers. However, there is limited high-quality evidence to support mandatory preoperative weight loss. In this study, we will evaluate whether weight gain prior to primary BMS is related to lower postoperative weight loss.

METHODS

A retrospective analysis of prospectively collected data was performed. Preoperative weight loss (weight loss from start of program to day of surgery), postoperative weight loss (weight loss from day of surgery to follow-up), and total weight loss (weight loss from start of program to follow-up) were calculated. Five groups were defined based on patients' preoperative weight change: preoperative weight loss of >5 kg (group I), 3-5 kg (group II), 1-3 kg (group III), preoperative stable weight (group IV), and preoperative weight gain >1 kg (group V). Linear mixed models were used to compare the postoperative weight loss between group V and the other four groups (I-IV).

RESULTS

A total of 1928 patients were included. Mean age was 44 years, 78.6% were female, and preoperative BMI was 43.7 kg/m2. Analysis showed significantly higher postoperative weight loss in group V, compared to all other groups at 12, 24, and 36 months follow-up. Up to three years follow-up, highest total weight loss was observed in group I.

CONCLUSION

Weight gain before surgery should not be a reason to withhold a bariatric-metabolic operation. However, patients with higher preoperative weight loss have higher total weight loss. Therefore, preoperative weight loss should be encouraged prior to bariatric surgery.

Systematic Review and Meta-Analysis of the Effectiveness of Insurance Requirements for Supervised Weight Loss Prior to Bariatric Surgery

Many insurance plans impose strict criteria mandating preoperative weight loss attempts to limit patient's access to surgery. Preoperative acute weight loss has been hypothesized to reduce perioperative risk and to identify compliant patients who may have improved long-term weight loss. In this review, the evidence from studies examining clinical and weight loss outcomes both with and without preoperative weight loss are summarized. Although preoperative weight loss may have modest impact on some factors related to perioperative conduct, the evidence does not support these programs' effectiveness at promoting long-term weight loss. Provision of weight loss surgery should not be contingent on completion of insurance-mandated weight loss goals preoperatively, and these programs may, through patient attrition, actually do more harm than good.

Preoperative weight loss is linked to improved mortality and leaks following elective bariatric surgery: an analysis of 548,597 patients from 2015-2018

BACKGROUND

The effects of preoperative weight loss on bariatric surgery outcomes are still unclear, despite the practice being adopted by bariatric centers worldwide. Ongoing studies are needed for routine adoption of this practice given the multiple issues patients face with following difficult preoperative weight loss protocols.

OBJECTIVES

The aim of this study was to characterize the prevalence of preoperative weight loss and evaluate its impact on outcomes following elective bariatric surgery.

SETTING

This retrospective study was conducted using the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP) data registry from 2015-2018.

METHODS

All primary Roux-en-Y (RYGB) and sleeve gastrectomy (SG) procedures were included, whereas prior revisional surgeries and emergency surgeries were excluded. Cases were then divided into preoperative weight loss (PWL) and control cohorts. PWL was defined categorically if the highest 30-day preoperative weight was greater than the closest recorded weight before surgery. Primary outcomes included identifying the impact of PWL on postoperative complications. Multivariable logistic regression modelling was used to examine the influence of PWL on serious complications and mortality after adjusting for patient co-morbidities and procedure type.

RESULTS

A total of 548,597 patients were identified with the majority experiencing preoperative weight loss (n= 459,500; 83.8%). The PWL cohort was older (44.8 ± 12.0 versus 43.2 ± 11.9 yr), had a reduced body mass index (BMI) (45.0 ± 7.4 versus 46.1 ± 7.6 kg/m²), and was more likely to be male (20.3% versus 18.7%). Patients with preoperative weight loss also were more likely to have metabolic co-morbidities including medication and insulin-dependent diabetes (27.0% versus 23.2%), hypertension (HTN) (48.9% versus 44.7%), dyslipidemia (DLP ) (24.6% versus 21.0%), and sleep apnea (39.6% versus 32.3%). No clinically significant differences were observed for operative length between cohorts (85.3 ± 46.9 min PWL versus 83.9 ± 46.2 min control). The protective benefit was found to be most significant for patients experiencing greatest weight loss with those experiencing a >10% PWL showing 30% decreased odds of leak (OR .68%; 95% CI [confidence interval] .56-.84; P < .0001) and a 40% decrease in odds of mortality versus those with no PWL (OR .60; 95% CI .39-.92; P = .02).

CONCLUSION

Preoperative weight loss before bariatric surgery is common, occurring in >80% of elective cases. Our findings suggest that preoperative weight loss is associated with improved odds of 30-day mortality and leaks but no differences in bleeds or overall serious complications. Additional prospective trials are needed to further evaluate the role of routine PWL in addition to ongoing development of tolerable preoperative weight-loss protocols.

Weight loss in adults following bariatric surgery, a systematic review of preoperative behavioural predictors

Bariatric surgery is effective in treating obesity in many cases, yet as many as 50% of patients may not achieve the desired weight reduction. Preoperative modifiable behavioural factors could help patient selection and intervention design to improve outcomes. Medline, EMBASE, Cochrane Library and PsychINFO were searched to identify studies published between 1 January 2008 and 14 February 2019 reporting on preoperative modifiable behavioural factors associated with postoperative weight loss, with minimum 2 years follow-up. A total of 6888 articles were screened, 34 met the inclusion criteria. Maladaptive eating behaviours (MEB), preoperative weight loss (PWL), and tobacco use were reported 21, 18, and 3 times respectively. Physical activity and substance abuse were each reported once. Most articles on PWL (72.2%) and MEB (52.4%) reported no association. Positive associations were reported in 22.2% and 14.3% of articles for PWL and MEB respectively. Negative associations were reported in 5.6% and 33.3% of articles for PWL and MEB, respectively. Marked heterogeneity in outcome reporting hindered quantitative synthesis. The current paucity of evidence amenable to synthesis leads to ongoing uncertainty regarding the size and direction of association between PWL and MEB with outcomes following bariatric surgery. Long-term studies with common reporting of outcomes are needed.

Preoperative change in 6-minute walk distance correlates with early weight loss after sleeve gastrectomy

Introduction:

The 6-minute walk test (6MWT) is an objective preoperative measure of functional capacity and response to intervention in patients with heart or lung disease. In bariatric surgery, there has been no reliable preoperative measure predictive of postoperative success. Here we investigated the impact of bariatric surgery on changes in distance traveled in the 6MWT (the 6MWD) and whether preoperative changes in 6MWD correlated with weight change after surgery.

Methods:

This is a retrospective study of consecutive patients in which the 6MWT was performed before and after laparoscopic sleeve gastrectomy for weight loss. 6MWD and total weight were measured. Pearson correlation was used to determine association between variables.

Results:

Of 100 patients who underwent laparoscopic sleeve gastrectomy, 31 patients had a preoperative 6MWT. Thirty patients (97%) were available for follow-up after surgery. Percentage of excess weight loss was 45.7% over an average of 7 months after surgery. There was a weak correlation between the postoperative weight loss and the change in preoperative and postoperative 6MWD (r = 0.28; P = .13). In a subset of patients who demonstrated a change in distance traveled in 2 separate preoperative 6MWD measurements (average 18.5% increase in distance), there was a strong correlation with postoperative weight loss (r = 0.82; P = .02).

Conclusions:

A demonstrated increase in 6MWD before surgery correlates strongly with early postoperative weight loss after laparoscopic sleeve gastrectomy. A multidisciplinary team that includes a physical therapist is useful in preparing bariatric patients for surgery.

Pre-operative weight loss does not predict weight loss following laparoscopic adjustable gastric banding

BACKGROUND

This study aimed to test the hypothesis that the amount of weight lost on a mandatory 2-week pre-operative very-low-calorie diet (VLCD) would predict the longer-term outcomes of laparoscopic adjustable gastric banding (LAGB).

METHODS

All patients treated with a primary LAGB from 21 October 2008 until 30 June 2010, who were prescribed a 2-week pre-operative VLCD, have been included in the study. Patient age, weight, BMI and excess weight (defined as weight above a BMI of 25) were extracted on the day of first visit, day of surgery and at the post-operative visits at 3, 12 and 24 months. From these data, percent excess weight loss (EWL) was calculated and compared at all time points.

RESULTS

The weight loss achieved on a mandatory 2-week pre-operative diet did not predict weight outcomes at 2 years (r = -0.008; p = 0.931). Using multivariate analysis, the best predictor of 24-month percent EWL was percent EWL at 3 months post operation (sr(2) = 0.34; p = 0.003).

CONCLUSIONS

Results from a pre-operative diet should not be used to predict the ultimate outcome of bariatric surgery. The weight loss at 3 months following LAGB was a strong predictor of longer-term outcomes. There may be potential for improving longer-term results with LAGB by better supporting patients who are not achieving good weight loss at this early time point.

Preoperative nutritional interventions in morbid obesity: impact on body weight, energy intake, and eating quality

BACKGROUND

Although the benefits of preoperative weight loss and adequacy of dietary patterns in bariatric surgery is well-recognized, the nutritional strategies in the preoperative period have been scarcely investigated. We aimed to evaluate the impact of intensive and standard nutritional interventions on body weight, energy intake, and eating quality.

METHODS

This is a retrospective study in which 32 patients undergoing intensive nutritional intervention, with low-calorie diet (10 kcal/kg) and biweekly visits, were pair-matched by age, sex, and body mass index with 32 patients under a standard nutritional intervention, based on a general dietary counseling. Twenty-four-hour food recall was used to assess energy intake and to derive healthy eating index (HEI). The follow-up preoperative period varied from 8 to 16 weeks.

RESULTS

Weight loss was observed in 72% of the patients from the intensive intervention group and 75% of the patients from the standard intervention group. According to the mixed model analysis, time effect on weight loss in both groups was significant (P = 0.0002); however, no difference was found between the intervention groups (P = 0.71). The time effect was significant in both groups for energy intake reduction as well (P < 0.0001), but no difference was found between the intervention groups (P = 0.25). Improvement of eating quality was expressed by the nutrient score of the HEI that increased significantly overtime (P = 0.02), also without distinction between the groups (P = 0.61).

CONCLUSION

Both intensive and standard nutritional interventions promoted weight loss, energy intake reduction, and improvement of eating quality in morbidly obese patients during preoperative period.

Preoperative predictors of weight loss following bariatric surgery: systematic review

BACKGROUND

Obesity affects 32% of adults in the USA. Surgery generates substantial weight loss, but 20-30% fails to achieve successful weight loss. Our objective was to identify preoperative psychosocial factors associated with weight loss following bariatric surgery.

METHODS

We performed a literature search of PubMed® and the Cochrane Database of Reviews of Effectiveness between 1988 and April 2010. Articles were screened for bariatric surgery and weight loss if they included a preoperative predictor of weight loss: body mass index (BMI), preoperative weight loss, eating disorders, or psychiatric disorder/substance abuse. One thousand seven titles were reviewed, 534 articles screened, and 115 included in the review.

RESULTS

Factors that may be positively associated with weight loss after surgery include mandatory preoperative weight loss (7 of 14 studies with positive association). Factors that may be negatively associated with weight loss include preoperative BMI (37 out of 62 studies with negative association), super-obesity (24 out of 33 studies), and personality disorders (7 out of 14 studies). Meta-analysis revealed a decrease of 10.1% excess weight loss (EWL) for super-obese patients (95% confidence interval (CI) [3.7-16.5%]), though there was significant heterogeneity in the meta-analysis, and an increase of 5.9% EWL for patients with binge eating at 12 months after surgery (95% CI [1.9-9.8%]).

CONCLUSIONS

Further studies are necessary to investigate whether preoperative factors can predict a clinically meaningful difference in weight loss after bariatric surgery. The identification of predictive factors may improve patient selection and help develop interventions targeting specific needs of patients.

Pre-bariatric surgery weight loss requirements and the effect of preoperative weight loss on postoperative outcome

Pre-bariatric surgery requirements vary between surgeons and surgical centers, with standards of practice not yet established. The goal of this systematic review was to summarize and evaluate the available literature on pre-bariatric surgery weight loss requirements and the relation between preoperative weight loss and postoperative outcome. Major databases, including Medline, PubMed and PsychINFO were searched for relevant articles. Case studies, studies>20 years old and studies that utilized self-reported body weight data were excluded. Data on the effect of the following was summarized: (1) preoperative requirements on preoperative weight loss; (2) insurance-mandated preoperative requirements; (3) the contingency of receipt of surgery; (4) preoperative weight loss on postoperative weight loss and (5) preoperative weight loss on perioperative and postoperative complication and comorbidity rates. The majority of studies suggest that: (1) current preoperative requirements held by the majority of third party payer organizations in the United States are ineffective in fostering preoperative weight loss; (2) making receipt of surgery contingent upon achieving preoperative weight loss, and meal-replacement diets, may be particularly effective in fostering preoperative weight loss and (3) preoperative weight loss may lead to improvements in at least some relevant postoperative outcomes. However, a preoperative weight loss mandate may lead to the denial of surgery and subsequent health benefits to individuals who are unable to achieve a prespecified amount of weight. Overall, the limited number and quality of prospective studies in this area prohibits the much-needed establishment of standards of practice for pre-bariatric requirements.

Food aversions in women during the 2 years after Roux-en-Y gastric bypass

The anatomical and physiological changes of the gastrointestinal tract after Roux-en-Y gastric bypass lead to changes in dietary patterns and their effects are still little known. Hence, the objective of this work was to characterize the prevalence, the associated factors and the list of food aversions with the effect of surgery on the body weight of women in the first two years after Roux-en-Y gastric bypass. A total of 141 women were studied. Their food aversions were assessed with a short food frequency questionnaire (FFQ-S) containing 26 items before and 6, 12 and 24 months after surgery. The FFQ-S was filled out during individual interviews and referenced in the medical records. The association between total aversion score and body weight variables and general characteristics of the group was analyzed. Variation of food aversions over time was assessed for 26 foods individually and grouped. Of all the studied variables, a weak but significant negative correlation (rs = -0.1944; p = 0.0208) was found between total aversion score and shorter postoperative period and a weak but significant positive correlation was found between total aversion score and percentage of weight regained (rs = -0.1759; p = 0.0369). Food aversions were more common in the first six months after surgery, especially to red meats, rice, chicken, eggs, pasta, milk and others. Food aversions in the early postoperative period are associated with weight variations in the first two years after surgery and subside significantly over time, probably because of a physiological and cognitive adaptation of the individual to the surgical procedure.

[Preoperative weight loss in bariatric surgery candidate patients. evidence-based recommendations]

INTRODUCTION

Bariatric surgery is becoming increasingly more common in the treatment of morbid obesity in our hospitals. One of the measures being used to optimise the results of this surgery seems to be the standardising the preoperative weight loss. As there are no universal recommendations for carrying out this weight loss, a review of this topic is presented.

OBJECTIVES

To analyse whether sufficient scientific evidence exists to recommend preoperative weight loss in candidate patients for bariatric surgery. What would be the best options to carry out this weight loss is also analysed, as well as making some recommendations based on the scientific evidence.

RESULTS

There is great heterogeneity in the designs of the different studies, with different guidelines for weight loss and various surgical techniques. However, preoperative weight loss leads to a decrease in the size of the liver and intra-abdominal fat, which improves the surgical field and intra-operative view, which in turn helps during the surgical act, both in open as well as laparoscopic surgery. There is no consensus on the effect of preoperative weight loss has in predicting the medium or long term results after bariatric surgery.

CONCLUSION

The current scientific evidence makes preoperative weight loss recommendable in candidate patients for bariatric surgery. However, there is no consensus on what is the best procedure to achieve this preoperative weight loss.

Effect of preoperative weight loss in bariatric surgical patients: a systematic review

BACKGROUND

The potential benefit of preoperative weight loss in patients undergoing bariatric surgery has led many bariatric surgeons to recommend an aggressive weight reduction regimen to their patients. Some surgeons might withhold bariatric procedures if a certain threshold of preoperative weight loss is not achieved. It is unclear whether this practice has any scientific evidence supporting it. Our study aimed to examine the current evidence surrounding this issue in a systematic review. The setting was a university hospital.

METHODS

A systematic search of multiple databases, including MEDLINE, Google Scholar, EMBASE, the Cochrane Library, and conference proceedings were reviewed, yielding a final total of 27 studies. Of the 27 studies, 7 were prospective studies (2 randomized controlled trials from the same patient population), 14 were retrospective studies (2 chart reviews from the same patient population), 1 was an editorial, and a number were conference presentations.

RESULTS

A total of 17 trials, including approximately 4611 patients, deemed preoperative weight loss beneficial, and 10 studies, including 2075 patients, deemed preoperative weight loss to be of no benefit. The operative time was 12.5 minutes shorter for the preoperative weight loss patients undergoing laparoscopic Roux-en-Y gastric bypass. With regard to the effects of preoperative weight loss on postoperative weight loss, 9 studies (39%) reported a positive correlation, and 15 (62.5%) reported no benefit. Nine studies reporting perioperative complications (852 patients) revealed no difference in the complication rates, and 2 studies (1234 patients) suggested a significant decrease was associated with preoperative weight loss.

CONCLUSION

This systematic review suggests little evidence is available to support or refute the routine use of preoperative weight reduction in bariatric surgery. Clearly, a large-scale, multicenter, randomized, controlled trial with sufficient power is necessary to clarify this significant aspect of preoperative care.

Office and hospital needs

Obesity is a national phenomenon that affects every facet of the delivery and the reception of health care. Orthopedic surgeons are not immune to these influences. This article discusses the social and physical environment in which orthopedic surgeons evaluate obese patients. Special attention should be paid in both the inpatient and outpatient arenas to the different emotional and physical needs with which obese patients present in contrast to their lean counterparts.

Evolução e classificação do peso corporal em relação aos resultados da cirurgia bariátrica: derivação gástrica em Y de Roux

OBJETIVO: Avaliar a evolução e a classificação do peso corporal em relação aos resultados da cirurgia bariátrica em mulheres submetidas ao procedimento cirúrgico há mais de dois anos. SUJEITOS E MÉTODO: Foram avaliadas 141 mulheres submetidas à derivação gástrica em Y de Roux (DGYR) com anel de contenção. As participantes foram divididas de acordo com o tempo de pós-operatório e conforme o percentual da perda do excesso de peso (%PEP): < 50; 50 ┤ 75; e, > 75. RESULTADOS: As mulheres do grupo com %PEP < 50 (15,6%) se mantiveram obesas, enquanto aquelas que apresentaram %PEP > 75 (36,2%) situaram-se entre a eutrofia e préobesidade e tiveram menor índice de recuperação tardia de peso em relação aos demais grupos. CONCLUSÃO: A evolução de peso após dois ou mais anos da cirurgia mostrou sua esperada redução com variados graus de resposta, apontando a necessidade de monitoramento, investigação e intervenção para obtenção dos resultados esperados.

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.

METHODS

We conducted a retrospective analysis over 539 patients operated by the same surgeon until September 2008. Five hundred seven primary bariatric surgical procedures were performed: gastric bypass in 381, gastric banding in 97, and sleeve gastrectomy in 29. Preoperative multidisciplinary care was similar for all the patients over a period of 12 months. Relationship between weight changes during this period and the percentage of excess weight loss (%EWL) over the 48 month after surgery was analyzed by logistic regression.

RESULTS

No relationship could be evidenced between pre- and postoperative weight loss, regardless of the surgical technique performed. Whether patients were male or female, and whether they had an initial BMI greater or lower than 50 kg/m(2), did not make a difference in the relationship between EWL at any point and weight loss prior to surgery. Despite a large range of weight changes before surgery, there was no trend for a relationship.

CONCLUSIONS

This study suggests that weight loss before surgery should not be considered a pre-requisite. Although it can reduce the difficulties of the surgical procedure, advantages for long-term weight loss are not validated.

Effectiveness of a prebariatric surgery insurance-required weight loss regimen and relation to postsurgical weight loss

Most US insurance companies require patients to participate in a medically supervised weight loss regimen prior to bariatric surgery. However, the utility of this requirement has not been documented. Data was collected from 94 bariatric surgery patients who were required, and 59 patients who were not required, by their insurance company to participate in a presurgical weight loss regimen. Weight change in the required group, as well as group differences in weight change, was examined from 3 and 6 months presurgery to 1 week presurgery, and from 1 week presurgery to 3 months postsurgery. Weight change presurgery was then used to predict weight loss postsurgery. In the 6 months prior to surgery, required patients gained 3.7 kg +/- 5.9 (s.d.) (P < 0.0005), which did not differ from nonrequired patients. From surgery to 3 months postsurgery, required patients lost 23.6 +/- 8 kg (P < 0.0005), also without differing from nonrequired patients. Patients who gained more weight prior to surgery, lost more weight postsurgery (P = 0.001), while controlling for initial weight. Findings suggest that the common weight loss regimen requirements of US insurance carriers were ineffective in producing presurgical weight loss in this sample. Most patients (>70%) in this sample gained weight prior to surgery, potentially taking advantage of final opportunities to overindulge in preferred foods. Required patients fared no better in terms of weight change postsurgically and, surprisingly, presurgical weight gain predicted better postsurgical weight loss outcome. Several potential explanations for this finding are offered.

Does weight loss immediately before bariatric surgery improve outcomes: a systematic review

BACKGROUND

Preoperative weight loss before bariatric surgery has been proposed as a predictive factor for improved patient compliance and the degree of excess weight loss achieved after surgery. In the present study, we sought to determine the effect of preoperative weight loss on postoperative outcomes.

METHODS

A search of MEDLINE was completed to identify the patient factors associated with weight loss after bariatric surgery. Of the 909 screened reports, 15 had reported on preoperative weight loss and the degree of postoperative weight loss achieved. A meta-analysis was performed that compared the postoperative weight loss and perioperative outcomes in patients who had lost weight preoperatively compared to those who had not.

RESULTS

Of the 15 articles (n = 3404 patients) identified, 5 found a positive effect of preoperative weight loss on postoperative weight loss, 2 found a positive short-term effect that was not sustained long term, 5 did not find an effect difference, and 1 found a negative effect. A meta-analysis revealed a significant increase in the 1-year postoperative weight loss (mean difference of 5% EWL, 95% confidence interval 2.68-7.32) for patients who had lost weight preoperatively. A meta-analysis of other outcomes revealed a decreased operative time for patients who had lost weight preoperatively (mean difference 23.3 minutes, 95% confidence interval 13.8-32.8).

CONCLUSION

Preoperative weight loss before bariatric surgery appears to be associated with greater weight loss postoperatively and might help to identify patients who would have better compliance after surgery.