Failure of adjustable gastric banding: starting BMI of 46 kg is a fulcrum of success/failure

Here is abstract fyi (I do have full article as well in PDF)

Surgery for Obesity and Related Diseases
Volume 5, Issue 3, Pages 310-316 (May 2009)

Failure of adjustable gastric banding: starting BMI of 46 kg/m2 is a fulcrum of success and failure

Brad Snyder, M.D., Terry Scarborough, M.D., Sherman Yu, M.D., Erik Wilson, M.D.

Abstract
Background
To determine the body mass index (BMI) located at the fulcrum of success and failure in a prospective study conducted at the University of Texas Health Science Center at Houston. On average, our patients whose percentage of excess weight loss (%EWL) was >50% at 1 year had a significantly lower BMI than those with <30% EWL.

Methods
We prospectively collected the weight loss data for 430 patients who had had an adjustable gastric band placed. We stratified the %EWL within 1 year for patients with a BMI of 30-59 kg/m2. A line was generated for the %EWL over time for BMI groups of 30-39, 40-49, and 50-59 kg/m2 and compared with the average %EWL over time. The y-intercepts of the resulting four lines were graphed against the average BMI for each group.

Results
The generated y-intercept line had an R2 of .9237. Using the equation of this line and the known y-intercept for the average, we solved for x, resulting in a BMI of 46 kg/m2. Patients with a BMI <46 kg/m2 had a 50% EWL at 1 year, and those with a BMI >46 kg/m2 had only a 33% EWL at 1 year. The %EWL between the groups was significantly different at all measured intervals (P <.0001).

Conclusion
A BMI of 46 kg/m2 identifies those at high risk of failure to lose a significant percentage of excess weight after adjustable gastric banding and *****quire closer follow-up. Furthermore, patients who have a BMI >46 kg/m2 should be advised that their weight loss might be suboptimal at 1 year.