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:

To study the early results (adverse events) of laparoscopic gastric banding surgery in the morbidly obese.

Inclusion Criteria:

The following inclusion criteria were stated:

Indications for surgery were based on the National Institutes of Health standard recommendations for bariatric surgery
BMI more than 40 or BMI more than 35 in association with a comorbidity
Patients were educated and screened for pre-operative psychological, nutritional and medical evaluations
Assessment for motivation and commitment to long-term follow-up.

Exclusion Criteria:

Patients were denied surgery if they did not meet the criteria established by NIH; if their BMIs were inappropriate (too thin); and if they did not pass their medical, psychological or nutritional screening assessments.

Description of Study Protocol:

Recruitment

The patients were recruited from two locations:

NY University School of Medicine, New York
University of Louisville School of Medicine, Louisville, KY.

Design

Prospective of case studies of 445 morbidly obese patients.

Intervention

Laparoscopic adjustable banding (LAGB) surgery.

Statistical Analysis

Percentages, means, ranges.

Data Collection Summary:

Timing of Measurements

May, 2001 to December, 2002.

Dependent Variables

Variable One: Post-surgical monitoring for adverse events
Variable Two: Post-surgical weight loss.

Independent Variables

Laparoscopic adjustable gastric banding surgery.

Control Variables

All the patients were evaluated post-surgery for complications, as well as for documentation of band position and devise-related concerns. All the patients followed a post- surgery progression diet of clear liquid to pureed food to solid food.

Description of Actual Data Sample:

Initial N

445 (103 males, 341 females).

Attrition (Final N)

Data exist for only 99 of the 445 patients at the one-year anniversary date; however, the purpose of this study was to examine the early results of the surgical procedure, not the long-term results of the surgery.

Age

Mean age of 42.1 years and a range of 17 to 72 years.

Anthropometrics

Mean BMI was 49.6 with a range of 35.3 to 92.2, and average body weight was 299.4 pounds with a range of 160 to 565 pounds.

Location

All the patients were gleaned from university hospital patients in Louisville, KY or New York City, NY.

Summary of Results:

Perioperative Complications

There was one death, post-surgery (sudden cardiac arrhythmia). This death was unrelated to the surgery.

One patient had complications of hyperthermia, which required five days of intensive care and respiratory support.

Acute post-operative stoma obstructions, secondary to peri-band edema, occurred in 12 patients (2.7% of the patient population).

One patient required a splenectomy. None of the patients experienced a thromboembolism, micardial infarction or sepsis.

Devise-related Complications

There were 13 port-related complications. Five were the result of port infections and eventually these ports had to be removed, but they were replaced within three to six months. There were four port migrations and four tubing problems that required correction.

Delayed Complications

Gastric prolapse or band slippage occurred in 14 patients. All of these patients were treated with repositioning or replacement procedures. One patient experienced erosion and four patients had their devices removed (explanations).

Weight Loss

The average excess weight loss at the 12-month mark after the surgery was 44.3%, with a range of 6.5% to 92% excess weight loss. The average BMI decreased to 39.3 with a range of 22 to 72.

Author Conclusion:

The Lap-band system has considerable merit for the morbidly obese. It is a safe, effective, adjustable device for the treatment of morbid obesity. The weight loss is excellent and the post-surgical complication rates are reasonably low.

Funding Source:

University/Hospital:

New York University School of Medicine, University of Saint Louis School of Medicine

Reviewer Comments:

This study was an honest evaluation of LAP-band surgery as experienced in two university hospitals. The post-surgical complications were rare and treatable. The procedure seems to be effective for treating patients with massive amounts of weight to lose.

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?	N/A
	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?		Yes
	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?	Yes
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?	Yes
	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?		Yes
	4.1.	Were follow-up methods described and the same for all groups?	Yes
	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%.)	Yes
	4.3.	Were all enrolled subjects/patients (in the original sample) accounted for?	Yes
	4.4.	Were reasons for withdrawals similar across groups?	Yes
	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?		No
	5.1.	In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate?	No
	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.)	No
	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?	Yes
	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?	Yes
	6.4.	Was the amount of exposure and, if relevant, subject/patient compliance measured?	Yes
	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?	Yes
	6.8.	In diagnostic study, were details of test administration and replication sufficient?	N/A
7.	Were outcomes clearly defined and the measurements valid and reliable?		Yes
	7.1.	Were primary and secondary endpoints described and relevant to the question?	Yes
	7.2.	Were nutrition measures appropriate to question and outcomes of concern?	Yes
	7.3.	Was the period of follow-up long enough for important outcome(s) to occur?	Yes
	7.4.	Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures?	Yes
	7.5.	Was the measurement of effect at an appropriate level of precision?	Yes
	7.6.	Were other factors accounted for (measured) that could affect outcomes?	Yes
	7.7.	Were the measurements conducted consistently across groups?	Yes
8.	Was the statistical analysis appropriate for the study design and type of outcome indicators?		Yes
	8.1.	Were statistical analyses adequately described and the results reported appropriately?	Yes
	8.2.	Were correct statistical tests used and assumptions of test not violated?	Yes
	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)?	???
	8.5.	Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)?	N/A
	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?	Yes
10.	Is bias due to study's funding or sponsorship unlikely?		Yes
	10.1.	Were sources of funding and investigators' affiliations described?	No
	10.2.	Was the study free from apparent conflict of interest?	Yes