Weight Loss Outcomes in Laparoscopic Vertical Sleeve Gastrectomy (LVSG) Versus Laparoscopic Roux-en-Y Gastric Bypass (LRYGB) Procedures: A Meta-Analysis and Systematic Review of Randomized Controlled Trials.

TLDR: LRYGB and LVSG are comparable with regards to the weight loss outcomes in the short term, with LRYGB achieving slightly greater weight loss.

Abstract: Purpose: Laparoscopic Roux-en-Y gastric bypass (LRYGB) and laparoscopic vertical sleeve gastrectomy (LVSG), have been proposed as cost effective strategies to manage morbid obesity. This aim of this meta-analysis was to compared the postoperative weight loss outcomes reported in randomised control trials (RCTs) for LVSG versus LRYGB procedures. Material and Methods: RCTs comparing the weight loss outcomes following LVSG and LRYGB in adult population between January 2000 and November 2015 were selected from PubMed, Medline, Embase, Science Citation Index, Current Contents, and the Cochrane database. The review was prepared in accordance with Preferred Reporting of Systematic Reviews and Meta-Analyses (PRISMA). Results: Nine unique RCTs described over 10 publications involving a total of 865 patients (LVSG n=437, LRYGB n=428) were analyzed. Postoperative follow up ranged from 3 months to 5 years. Twelve-month excess weight loss for LVSG ranged from 69.7% to 83%, and for LRYGB, ranged from 60.5% to 86.4%. A number of studies reported slow weight gain between the 2nd and 3rd years of postoperative follow-up ranging from 1.4 to 4.2% EWL. This trend was seen to continue to 5 years postoperatively (8% to 10% EWL) for both procedures. Conclusions: In conclusion, LRYGB and LVSG are comparable with regards to the weight loss outcomes in the short term, with LRYGB appearing achieving slightly greater weight loss. Slow weight recidivism is observed after the first postoperative year following both procedures. Long-term reporting of outcomes obtained from well-designed studies using ITT analyses are identified as a major gap in the literature at present.

Full text

TITLE
Weight loss outcomes in laparoscopic vertical sleeve gastrectomy (LVSG) versus laparoscopic
Roux-en-Y gastric bypass (LRYGB) procedures: A meta-analysis and systematic review of
randomized controlled trials
AUTHORS (EMAILS)
Emma Osland, BHSc (Nutr & Diet) MPhil
1,2
(Emma.Osland@health.qld.gov.au)
Rossita Mohamad Yunus, PhD
3
(rossita@um.edu.my)
Shahjahan Khan, PhD
4
(Shahjahan.Khan@usq.edu.au)
Breda Memon, RN, LLB, PGCEd, DipPractMan
5
(bmemon@yahoo.com)
Muhammed Ashraf Memon, MBBS, MA, DCH, FACS, FRACS, FRCSI, FRCSEd,
FRCSEng
4,5,6,7,8
(mmemon@yahoo.com)
DEPARTMENTS AND INSTITUTIONS
1
Department of Nutrition and Dietetics, Royal Brisbane and Women’s Hospital, Herston, Qld,
4019 Australia.
2
Department of Human Movements and Nutrition, University of Queensland, Brisbane,
Queensland, Australia
3
Institute of Mathematical Sciences, University of Malaya, Kuala Lumpur, Malaysia
4
School of Agricultural, Computational and Environmental Sciences, International Centre for
Applied Climate Sciences and Centre for Health Sciences Research, University of Southern
Queensland, Toowoomba, Queensland, Australia
5
Sunnybank Obesity Centre
South & East Queensland Surgery (SEQS), Suite 9, McCullough
Centre, 259 McCullough Street, Sunnybank, Queensland, Australia
6
Mayne Medical School, School of Medicine, University of Queensland, Brisbane, Queensland,
Australia

7
Faculty of Health Sciences and Medicine, Bond University, Gold Coast, Queensland, Australia
8
Faculty of Health and Social Science, Bolton University, Bolton, Lancashire, UK
REPRINTS/CORRESPONDENCE
Professor M. A. Memon, FACS, FRACS, FRCS, Sunnybank Obesity Centre, Suite 9,
McCullough Centre, 259 McCullough Street, Sunnybank, QLD 4109, Australia
Tel: +61 7 3345 6667 Fax: +61 7 3344 1752 Mobile: +61 448614170
Email: mmemon@yahoo.com
SECTION OF THE JOURNAL
Meta-analysis/Systematic Reviews
KEY WORDS
Bariatric Surgery; Laparoscopic; Sleeve Gastrectomy; Roux-en-Y Gastric Bypass; Weight Loss;
Longitudinal Study; Meta-analysis; Systematic review

ABSTRACT
Purpose: Laparoscopic Roux-en-Y gastric bypass (LRYGB) and laparoscopic vertical sleeve
gastrectomy (LVSG), have been proposed as cost effective strategies to manage morbid obesity.
This aim of this meta-analysis was to compared the postoperative weight loss outcomes reported
in randomised control trials (RCTs) for LVSG versus LRYGB procedures.
Material and Methods: RCTs comparing the weight loss outcomes following LVSG and
LRYGB in adult population between January 2000 and November 2015 were selected from
PubMed, Medline, Embase, Science Citation Index, Current Contents, and the Cochrane
database. The review was prepared in accordance with Preferred Reporting of Systematic
Reviews and Meta-Analyses (PRISMA).
Results: Nine unique RCTs described over 10 publications involving a total of 865 patients
(LVSG n=437, LRYGB n=428) were analyzed. Postoperative follow up ranged from 3 months to
5 years. Twelve-month excess weight loss for LVSG ranged from 69.7% to 83%, and for
LRYGB, ranged from 60.5% to 86.4%. A number of studies reported slow weight gain between
the 2nd and 3rd years of postoperative follow-up ranging from 1.4 to 4.2% EWL. This trend was
seen to continue to 5 years postoperatively (8% to 10% EWL) for both procedures.
Conclusions: In conclusion, LRYGB and LVSG are comparable with regards to the weight loss
outcomes in the short term, with LRYGB appearing achieving slightly greater weight loss. Slow
weight recidivism is observed after the first postoperative year following both procedures. Long-

term reporting of outcomes obtained from well-designed studies using ITT analyses are
identified as a major gap in the literature at present.

INTRODUCTION
Obesity is fast becoming the one of the most significant health problems facing the modern
world, representing a major cause of morbidity, disability and early mortality. According to the
World Obesity Federation adult obesity is now more common than under-nutrition with 670
million of the world’s population now considered obese (BMI >30kg/m
2
) and a further 98
million severely obese (>35kg/m
2
)[1]. In countries such as the United States, Mexico, Australia
and New Zealand between a quarter and a third of their population are now considered to be
obese[2].
Obesity is associated with development of chronic health conditions such as Type 2 Diabetes,
cardiovascular disease and some forms of cancer[1]. In addition to the health burden to the
individual, there is a significant and growing economic burden associated with obesity. It is
therefore essential that effective population-based prevention strategies along with sustainable
individual management approaches are being urgently sought to reduce the burden of disease and
economic demands caused by widespread obesity. Bariatric surgical procedures, such as
laparoscopic Roux-en-Y gastric bypass (LRYGB) and laparoscopic vertical sleeve gastrectomy
(LVSG), are increasingly being utilized as cost-effective and efficacious strategies to manage
obesity related chronic disease and metabolic conditions in the moderately to severely obese
individuals[2-5].
This aim of this systematic review and meta-analysis is to study the peer review literature
regarding postoperative weight loss outcomes reported from randomised control trials (RCTs)
comparing LVSG and LRYGB bariatric procedures.

Frequently asked questions

Q1. What have the authors contributed in "Weight loss outcomes in laparoscopic vertical sleeve gastrectomy (lvsg) versus laparoscopic roux-en-y gastric bypass (lrygb) procedures: a meta-analysis and systematic review of randomized controlled trials authors (emails)" ?

This aim of this meta-analysis was to compared the postoperative weight loss outcomes reported in randomised control trials ( RCTs ) for LVSG versus LRYGB procedures. Material and Methods: RCTs comparing the weight loss outcomes following LVSG and LRYGB in adult population between January 2000 and November 2015 were selected from PubMed, Medline, Embase, Science Citation Index, Current 

Q2. What are the future works in "Weight loss outcomes in laparoscopic vertical sleeve gastrectomy (lvsg) versus laparoscopic roux-en-y gastric bypass (lrygb) procedures: a meta-analysis and systematic review of randomized controlled trials authors (emails)" ?

Similar mechanisms are hypothesized to occur post LVSG, however conflicting research presently exists and further studies are required [ 38, 41-43 ]. Another issue that requires further description in the literature is attrition from longer term studies investigating weight loss outcomes in bariatric patients. A further physiological mechanism currently being investigated is the role bile acid signalling that occurs following LVSG and its potential role in facilitating weight loss and metabolic improvements, particularly around fatty liver [ 43-45 ]. Their review, along with much of the literature in this area, suggests LRYGB may provide a comparatively greater degree of weight loss than LVSG in the long term. 

Q3. What are the main factors in sustained weight loss after bariatric surgery?

ongoing postoperative psychological support to facilitate lifetime behaviour change along with the management of concurrent psychological issues such as depression have been identified as important factors in sustained weight loss post bariatric surgery[37]. 

Q4. What was the common weight loss outcome reported in the Chinese study?

Systematic Review%EWL was the most commonly reported weight loss outcome, being reported in seven studies[19-22, 24, 25, 27, 28]. 

Q5. What are the main reasons for the lack of weight loss after bariatric surgery?

Structured postoperative programs providing psychological and combined pharmacological and lifestyle change interventions have been shown to be effective at reducing postoperative weight regain following a range of bariatric procedures[48-50]. 

Q6. What is the main issue in the literature regarding weight loss after bariatric surgery?

Loss to follow up creates major issues in accurately describing long term weight loss outcomes following bariatric procedures, and is an issue that needs innovative measures to address, both to improve the quality of research in this area and to achieve optimal clinical practice, as sustained follow up appears to be related to improved weight outcomes postoperatively[51]. 

Q7. What is the main reason why patients are gaining weight after a bariatric procedure?

Failure to adhere to appropriate dietary behaviours post-surgery is also a significant contributor to weight regain in both procedures. 

Q8. What is the purpose of this systematic review and meta-analysis?

This aim of this systematic review and meta-analysis is to study the peer review literature regarding postoperative weight loss outcomes reported from randomised control trials (RCTs) comparing LVSG and LRYGB bariatric procedures. 

Q9. What is the importance of long-term postoperative outcomes?

In seeking long-term solutions for obesity management, it is essential that longterm postoperative outcomes be reported for sufficient durations in sufficient number of patients to allow informed decisions about to be made. 

Q10. What is the need for longer term studies to understand this trend?

Longer term studies are required to better understand this trend, along with improved surveillance and reporting on the number of patients who go on to have further bariatric procedures to manage weight recidivismto allow an accurate assessment of the cost-effectiveness of bariatric surgery as a strategy in the battle against obesity. 

Q11. How many studies reported weight loss at 3 years postoperatively?

Systematic ReviewBMI was reported in seven[19-26, 28] of the eight eligible studies at a range of time points between 1 month and 5 years postoperatively. 

Q12. What are the other studies reporting weight loss outcomes?

Other systematic reviews and meta-analyses reporting weight loss outcomes at 2 year follow-up post-surgery[31] and for non-specified follow up time periods[32, 33] also report that greater weight loss outcomes were achieved with LRYGB compared to LVSG. 

Q13. How did Yang et al weight loss at 3 months post LVSG?

The average weight of subjects at the end of the 12 month follow up period was around 85-90 kg irrespective of which procedure was performed, and no procedure demonstrated superior weight loss outcomes to the other. 

Q14. How many years of follow up have there been a decline in the number of patients having ?

It is interesting to note in the present work that of the four studies[19, 20, 23, 25] that report outcomes at 3 to 5 years postoperatively there is an obvious decline in number with each year of follow-up, ranging from 32 to 95%.