TEC Assessment Index
Laparoscopic Adjustable Gastric Banding for Morbid Obesity
Assessment Program
Volume 21, No. 13
February 2007
EXECUTIVE SUMMARY
Background: Bariatric surgery leads to substantial amounts of weight loss in morbidly obese patients, and this weight loss leads to net improvements in health outcomes. Among different surgical procedures, gastric bypass is the most common procedure performed in the U.S., and offers the most favorable benefit/risk ratio among established procedures. Laparoscopic adjustable gastric banding (LAGB) is an alternative technique that has the potential advantages of being less invasive and reversible. Prior TEC Assessments have concluded that LAGB does not meet the TEC criteria.
Objective: To review the available evidence on whether LAGB results in similar improvements in health outcomes as does open or laparoscopic gastric bypass (GBY).
Search strategy: MEDLINE search for the period of 1980 through September 2006, supplemented by hand search of bibliographies and search of Cochrane database.
Selection criteria: Comparative studies of LAGB vs. GBY (open or laparoscopic) were included in the Assessment that had at least 25 patients per treatment arm, reported on the outcomes of weight loss and/or adverse events, and had at least 1 year of follow-up (for weight loss outcomes). Single-arm studies with the same characteristics were included, except that the minimum number of enrolled patients was 100 or more. Single-arm studies that reported on longer-term outcomes (i.e., 3 years or longer) and that had the most complete follow-up at 2 and 3 years were highlighted.
Main results: Eight comparative trials of LAGB vs. GBY, enrolling 4,191 patients, and 57 single-arm series met the inclusion criteria for this Assessment. A total of 9 single-arm series met the additional follow-up criteria of at least 50% of enrolled patients available at 2 years' follow-up.
Weight loss outcomes from these studies confirm the conclusions of previous TEC Assessments. Substantial weight loss does occur following LAGB; however, the amount of weight loss at 1 year is less than that seen following GBY. The percent excess weight lost (%EWL) at 1 year is approximately 40%, compared to 60% or higher for GBY. At time points longer than 1 year, some of the comparative studies report that the difference in weight loss between LAGB and GBY lessens; however, other studies do not. Weight loss outcomes from the 9 single-arm series with the most complete follow-up do not support the hypothesis that weight loss continues to increase after 1–2 years of follow-up.
These studies also confirm that short-term (perioperative) complications are very low with LAGB, and lower than either open or laparoscopic GBY. Death is extremely rare, and serious perioperative complications probably occur at rates of less than 1%.
The reported rates of long-term adverse events vary considerably. In the comparative trials, reoperations are reported in approximately 25% of patients, while in the single-arm studies the composite rate for reoperations is approximately half of this value (11.9%). The rates of other long-term complications are also highly variable; for example, the reported range of rates for band slippage is 1–36% and the range for port access problems is 2–20%.
Author's conclusions and comments: Conclusions regarding the comparative efficacy of different bariatric surgery techniques on weight loss are best made from comparative trials, particularly trials with concurrent control groups that demonstrate baseline comparability of groups on important clinical and demographic variables. This is best achieved through randomized, controlled trials, although other well-controlled designs may also be acceptable. The current body of literature lacks high-quality clinical trials that directly compare outcomes between LAGB and GBY. Therefore, the conclusions in this Assessment are derived from other types of evidence, primarily comparisons of clinical series with or without matching.
Weight loss at 1 year is less for LAGB compared with GBY, and conclusions on the comparative weight loss at longer time periods are not possible from these data. Some studies report that the difference in weight loss between these procedures diminishes, or disappears, with longer follow-up. However, the present data are mixed, and overall, do not confirm this hypothesis. It appears more likely from the current data that attrition bias may account for the diminution of the difference in weight loss over time, particularly when patients who have their band removed or deflated are excluded from analysis.
The data on long-term complications remain suboptimal. The reporting of long-term complications in these trials is not systematic or consistent. As a result, highly variable rates of long-term outcomes are reported. It is not possible to determine the precise rates of long-term complications from these data, but it is likely that complications are under-reported in many studies due to incomplete follow-up and a lack of systematic surveillance. The high rates of long-term complications reported in some studies raise concern for the impact of these events on the overall benefit/risk ratio for LAGB.
In comparing LAGB with GBY, there is a tradeoff in terms of risks and benefits. LAGB offers a less-invasive procedure that is associated with fewer procedural complications, a decreased hospital stay and earlier return to usual activities. However, the amount of weight loss will also be less for LAGB. The patterns of long-term complications also differ between the two procedures. For LAGB, longer-term adverse events related to the presence of a foreign body in the abdomen will occur, and will result in reoperations and removal of the band in a minority of patients. Patients who have their bands removed can later be offered an alternative bariatric surgery procedure, such as gastric bypass.
For patients considering bariatric surgery, there is sufficient evidence to allow an informed choice to be made between gastric bypass and LAGB. An informed patient may reasonably choose either GBY or LAGB as the preferred procedure. Preoperative counseling should include education on the comparative risks and benefits of the two procedures in order to allow the optimal choice to be made based on patient and surgeon preferences.
Based on the available evidence, the Blue Cross and Blue Shield Medical Advisory Panel made the following judgments about whether laparoscopic adjustable gastric banding (LAGB) meets the Blue Cross and Blue Shield Association Technology Evaluation Center (TEC) criteria.
1. The technology must have final approval from the appropriate governmental regulatory bodies.
Bariatric surgery itself is a procedure and is not subject to U.S. Food and Drug Administration (FDA) regulations. However, certain devices that may be used as part of the procedure may be subject to FDA approval. The Lap-Band® system received premarket application (PMA) approval by the FDA in June 2001 for use in morbidly obese patients.
2. The scientific evidence must permit conclusions concerning the effect of the technology on health outcomes.
The evidence is sufficient to permit conclusions concerning the short-term safety and efficacy of LAGB in comparison with GBY. Weight loss at 1 year following LAGB is substantial, in the range of 40% EWL, although less than that seen following GBY. The short-term complications of LAGB are very low, with serious short-term complications being uncommon, and mortality exceedingly rare. Rates of short-term adverse events, including serious procedural complications and mortality, are lower for LAGB compared with GBY.
Conclusions concerning longer-term weight loss following LAGB are less definitive. Some studies report that the difference in weight loss between LAGB and GBY diminishes over longer time periods, but other studies do not. Studies that report longer-term outcomes do not generally have complete follow-up, and therefore it is not possible to determine whether continued increases in % EWL are due to further weight loss or attrition bias.
The evidence on the rates of long-term complications is also not robust. The precise rates of long-term complications cannot be determined from the data due to inadequacy of long-term follow-up in the available studies. However, the data does define a range of complications that permits decision-making on the overall benefit/risk ratio of this procedure. A considerable minority of patients who undergo LAGB may require reoperations for long-term complications, and/or removal of the band.
3. The technology must improve the net health outcome.
The amount of weight loss following LAGB is substantial, in the range of 40% EWL at 1 year.
This amount of weight loss is equal to or greater than the amount of weight loss that has been associated with health outcome benefits, such as a reduction in the incidence of diabetes. There is a low rate of serious procedural complications, and therefore the weight loss benefit outweighs the short-term risks. Longer-term risks may be more frequent and are less well-defined, but are unlikely to outweigh the benefits of the procedure. Longer-term complications may result in reoperations and/or removal of the band. The reversibility of the procedure makes it unlikely that long term complications will outweigh the benefits of this procedure.
4. The technology must be as beneficial as any established alternatives.
The main established alternative to LAGB is open or laparoscopic GBY. Both procedures are effective in producing weight loss; the comparison of LAGB with GBY offers a tradeoff in terms of safety and efficacy. LAGB is a safer procedure in the short term, and is reversible. However, LAGB results in lower amounts of weight loss at 1 year compared with GBY. The longer-term complications of LAGB are more common than short-term complications, and are different than those seen with GBY.
While it is not possible to say with confidence whether LAGB or GBY is the "better" procedure, either one might be a reasonable choice for a patient considering bariatric surgery. Numerous factors may play a role in decision-making including baseline BMI, surgical risk, comorbidities, and tolerance for repeat procedures.
5. The improvement must be attainable outside the investigational settings.
Training on insertion of LAGB is widely available and expertise for inserting the devices is common among bariatric surgeons in the U.S. As a result, the use of LAGB has been widely disseminated among bariatric surgery centers, both in the academic and community settings.
Based on the above, laparoscopic adjustable gastric banding meets the TEC criteria when performed in appropriately selected patients, by surgeons who are adequately trained and experienced in the specific techniques used, and in institutions that support a comprehensive bariatric surgery program, including a long-term monitoring and follow-up post-surgery.
TEC Assessment Index
NOTICE OF PURPOSE:TEC Assessments are scientific opinions, provided solely for informational purposes. TEC Assessments should not be construed to suggest that the Blue Cross Blue Shield Association, Kaiser Permanente Medical Care Program or the TEC Program recommends, advocates, requires, encourages, or discourages any particular treatment, procedure, or service; any particular course of treatment, procedure, or service; or the payment or non-payment of the technology or technologies evaluated.
Gastroenterology (category); Surgery/Surgical Alternatives/Interventional Radiology (category); adjustable gastric band; bariatric surgery; BMI; body mass index; diabetes; diabetes mellitus; erosion; gastric band; gastric banding; gastric bypass; HGP; gastroesophageal reflux disease; GERD; hypocalcemia; iron deficiency anemia; laparoscopic banding; laparoscopic gastric band; hypertension; intraperitoneal surgery; LAGB; laparoscopic gastric bypass; laparoscopic bypass; laparoscopic surgery; Lap-Band; LGBY; malabsorptive procedures; morbid obesity; morbidly obese; nonsurgical treatments; obese; obesity; obesity surgery; open gastric banding; open gastric bypass; peritonitis; restrictive procedures; roux-en-y; roux-en-y anastomosis; SAGB; silastic ring gastroplasty; SRGP; severe obesity; super-obesity; surgery; Swedish adjustable gastric band; Type II diabetes; Type II DM; vitamin deficiency; weight loss
