EAL

NCBS: Weight Loss and Weight Regain Expected After Procedure (2009)

Citation:

Study Design:

Class:

- Click here for explanation of classification scheme.

Quality Rating:

Research Purpose:

Laparoscopic vertical banded gastroplasty (LVBG) remains to be the gold standard for bariatric restrictive surgery
The purpose of this study was to examine the weight loss success and rate of complications from LVBG
Data were collected from a database developed for three French bariatric treatment centers.

Inclusion Criteria:

Patients received LVBG at one of three French bariatric treatment centers between January 1999 and September 2004
The choice between LVBG and LAGB was made by patient or surgeon, based on presence of contraindications
Met 1991 NIH Consensus Conference guidelines
- BMI greater than 40kg per m²
- BMI 35 to 40kg per m² with related co-morbidities
- 18 to 65 years of age
- Failure of medical treatment
- Absence of hormonal dysfunction.

Exclusion Criteria:

Participants who did not meet inclusion criteria
Presence of binge eating and sweet eating disorders.

Description of Study Protocol:

Recruitment: All patients receiving LVBG from the three treatment centers that met the inclusion criteria were used in the analyses
Design: Prospective cohort design
Blinding used: N/A
Intervention: Surgeries were performed by five experiences and trained surgeons used a standardized surgery protocol. "Five trocars were placed in standard positions as per laparoscopic upper gastrointestinal surgery. A vertical gastric pouch (30ml) was created with circular (21 or 25mm) and endolinear stapling techniques, enabling definitive separation of the two parts of the stomach. The gastric outlet was calibrated with either a polypropylene mesh (5.5cm in length and 1cm in width) or a non-adjustable silicone band."
Statistical analysis: Descriptive statistics were used to described the outcomes. Data were presented as proportions of patients exhibiting specified outcome and means of percent changes in weight from pre-surgery state.

Data Collection Summary:

Timing of Measurements

Descriptions of the collection of follow-up data and measurements were not described
Protocols for follow-up assessments of outcomes were not described beyond follow-up time (median 30 months, range one to 72 months)
Follow-up data from patients were collected at subsequent clinic visit or via telephone.

Dependent Variables

Metabolic complications or stability of bands requiring additional surgery
Weight loss as a proportion of pre-operative weight, body weight and BMI post-operatively.

Independent Variables

Patients receiving LVBG (descriptive analyses).

Control Variables

N/A.

Description of Actual Data Sample:

Initial N: 200 patients
Attrition (final N): Not reported
Mean age: 41 years
Ethnicity: Not described
Other relevant demographics: Not described
Anthropometrics: Mean BMI: 43.2kg per m², 25 patients were super-obese (BMI greater than 50kg per m²)
Location: Three bariatric treament clinics in France.

Summary of Results:

Weight Loss Following LVBG by Follow-Up Length

Time	Percent Weight Loss	Body Mass Index (BMI)
Pre-op		43.2kg/m²
6 months	43%	35kg/m²
12 months	57%	32kg/m²
18 months	64%	30.7kg/m²
24 months	68.3%	30.2kg/m²
36 months	65.1%	30.4kg/m²

Excess weight loss was 56.7% at one year, 68.3% at two years and 65.1% at three years
Excess weight loss in the super-obese sample was 52.6% at one year, 66.1% at two years and 66.2% at three years.

Other Findings

Thirty-two patients (16%) had previously undergone another bariatric procedure (LAGB) with good results in the short term, but had re-presented with slippage of the band
Morbidity rate was 24% (12.5% early post-operative morbidity)
Re-operation rate was 11.5% (8% for gastric outlet stenosis)
Staple-line leakage occured in five patients
Mean LOS was 4.8 days.

Author Conclusion:

Laparoscopic vertical banded gastroplasty is a safe and effective means of treatment for morbid obesity, especially in patients with hyperphagia who are unable to manage adjustable gastric banding
The procedure produces relatively minimal complications, which predominately present as gastric outlet stenosis, staple line leakage and gastroesophageal reflux.

Funding Source:

University/Hospital:

University Hospital of Montpellier (France), Imperial College London UK, Clinique Saint Louis (France)

Reviewer Comments:

The authors present a thorough description of the surgical procedures and assessment of complications, but provide little information on the physical assessments used to monitor post-operative changes
It is unclear how post-operative weight data would be collected via a telephone interview for those who missed clinical appointments.

Quality Criteria Checklist: Primary Research
Relevance Questions
	1.	Would implementing the studied intervention or procedure (if found successful) result in improved outcomes for the patients/clients/population group? (Not Applicable for some epidemiological studies)	Yes
	2.	Did the authors study an outcome (dependent variable) or topic that the patients/clients/population group would care about?	Yes
	3.	Is the focus of the intervention or procedure (independent variable) or topic of study a common issue of concern to dieteticspractice?	Yes
	4.	Is the intervention or procedure feasible? (NA for some epidemiological studies)	Yes

Validity Questions
1.	Was the research question clearly stated?		Yes
	1.1.	Was (were) the specific intervention(s) or procedure(s) [independent variable(s)] identified?	Yes
	1.2.	Was (were) the outcome(s) [dependent variable(s)] clearly indicated?	Yes
	1.3.	Were the target population and setting specified?	Yes
2.	Was the selection of study subjects/patients free from bias?		No
	2.1.	Were inclusion/exclusion criteria specified (e.g., risk, point in disease progression, diagnostic or prognosis criteria), and with sufficient detail and without omitting criteria critical to the study?	Yes
	2.2.	Were criteria applied equally to all study groups?	Yes
	2.3.	Were health, demographics, and other characteristics of subjects described?	No
	2.4.	Were the subjects/patients a representative sample of the relevant population?	No
3.	Were study groups comparable?		N/A
	3.1.	Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT)	N/A
	3.2.	Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline?	N/A
	3.3.	Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.)	N/A
	3.4.	If cohort study or cross-sectional study, were groups comparable on important confounding factors and/or were preexisting differences accounted for by using appropriate adjustments in statistical analysis?	N/A
	3.5.	If case control study, were potential confounding factors comparable for cases and controls? (If case series or trial with subjects serving as own control, this criterion is not applicable.)	N/A
	3.6.	If diagnostic test, was there an independent blind comparison with an appropriate reference standard (e.g., "gold standard")?	N/A
4.	Was method of handling withdrawals described?		???
	4.1.	Were follow-up methods described and the same for all groups?	???
	4.2.	Was the number, characteristics of withdrawals (i.e., dropouts, lost to follow up, attrition rate) and/or response rate (cross-sectional studies) described for each group? (Follow up goal for a strong study is 80%.)	N/A
	4.3.	Were all enrolled subjects/patients (in the original sample) accounted for?	???
	4.4.	Were reasons for withdrawals similar across groups?	???
	4.5.	If diagnostic test, was decision to perform reference test not dependent on results of test under study?	N/A
5.	Was blinding used to prevent introduction of bias?		N/A
	5.1.	In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate?	N/A
	5.2.	Were data collectors blinded for outcomes assessment? (If outcome is measured using an objective test, such as a lab value, this criterion is assumed to be met.)	N/A
	5.3.	In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded?	N/A
	5.4.	In case control study, was case definition explicit and case ascertainment not influenced by exposure status?	N/A
	5.5.	In diagnostic study, were test results blinded to patient history and other test results?	N/A
6.	Were intervention/therapeutic regimens/exposure factor or procedure and any comparison(s) described in detail? Were interveningfactors described?		Yes
	6.1.	In RCT or other intervention trial, were protocols described for all regimens studied?	N/A
	6.2.	In observational study, were interventions, study settings, and clinicians/provider described?	Yes
	6.3.	Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect?	???
	6.4.	Was the amount of exposure and, if relevant, subject/patient compliance measured?	No
	6.5.	Were co-interventions (e.g., ancillary treatments, other therapies) described?	Yes
	6.6.	Were extra or unplanned treatments described?	Yes
	6.7.	Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups?	N/A
	6.8.	In diagnostic study, were details of test administration and replication sufficient?	Yes
7.	Were outcomes clearly defined and the measurements valid and reliable?		No
	7.1.	Were primary and secondary endpoints described and relevant to the question?	???
	7.2.	Were nutrition measures appropriate to question and outcomes of concern?	N/A
	7.3.	Was the period of follow-up long enough for important outcome(s) to occur?	???
	7.4.	Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures?	???
	7.5.	Was the measurement of effect at an appropriate level of precision?	???
	7.6.	Were other factors accounted for (measured) that could affect outcomes?	Yes
	7.7.	Were the measurements conducted consistently across groups?	???
8.	Was the statistical analysis appropriate for the study design and type of outcome indicators?		???
	8.1.	Were statistical analyses adequately described and the results reported appropriately?	No
	8.2.	Were correct statistical tests used and assumptions of test not violated?	???
	8.3.	Were statistics reported with levels of significance and/or confidence intervals?	No
	8.4.	Was "intent to treat" analysis of outcomes done (and as appropriate, was there an analysis of outcomes for those maximally exposed or a dose-response analysis)?	N/A
	8.5.	Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)?	No
	8.6.	Was clinical significance as well as statistical significance reported?	Yes
	8.7.	If negative findings, was a power calculation reported to address type 2 error?	N/A
9.	Are conclusions supported by results with biases and limitations taken into consideration?		Yes
	9.1.	Is there a discussion of findings?	Yes
	9.2.	Are biases and study limitations identified and discussed?	No
10.	Is bias due to study's funding or sponsorship unlikely?		???
	10.1.	Were sources of funding and investigators' affiliations described?	No
	10.2.	Was the study free from apparent conflict of interest?	???