Does Preoperative Weight Change Predict Postoperative Weight Loss After Laparoscopic Sleeve Gastrectomy?

William E Sherman, MD, Aaron E Lane, MD, Christopher W Mangieri, MD, Yong U Choi, MD, Byron J Faler, MD. Dwight D. Eisenhower Army Medical Center

INTRODUCTION: Some institutions and insurance providers mandate preoperative weight loss prior to bariatric surgery. Previous studies of patients who have undergone laparoscopic Roux-en-Y gastric bypass suggest little to no correlation between preoperative weight loss and postoperative weight loss. A literature search found no studies investigating this question in patients who have undergone laparoscopic sleeve gastrectomy. Therefore, the objectives of this study were to examine the impact of preoperative weight loss on postoperative weight loss in these patients as well as any effect on length of surgery.

METHODS AND PROCEDURES: After obtaining institution review board approval, a retrospective analysis was performed on patients undergoing laparoscopic sleeve gastrectomy at our institution between 2010 and 2012. Patients were grouped based on preoperative weight gain or loss. Preoperative weight change was defined as the difference in weight upon entering our multidisciplinary bariatric surgery pathway and weight at the time of surgery. Analysis of Variance (ANOVA) and linear regression analysis were used to study the correlation between preoperative BMI change and amount of postoperative BMI change in these groups. The operative times for each group were also examined.

RESULTS: Of 141 patients with at least one year follow-up, 72 lost weight preoperatively (mean BMI decrease of 2.8%), 6 maintained weight, and 64 gained weight preoperatively (mean BMI increase of 1.8%). Comparison between the two groups showed no statistical difference in initial BMI, BMI at time of surgery, or length of time from initial weigh-in to time of surgery (duration of bariatric pathway). Percentage of excess BMI loss (%EBMIL) at 1 year was not statistically different between those who lost weight and those who gained weight preoperatively (74.2% vs 73.4%, respectively, p=0.42). A linear regression analysis demonstrated that percent change in BMI from initial visit to surgery does not correlate with change in BMI at 1 year postoperatively (p=0.77). Mean operative times were 96.9 minutes and 95.6 minutes for those who lost weight and those who gained weight, respectively. Preoperative BMI change did not correlate with length of surgery (p=0.87).

CONCLUSION: The results of this study demonstrate that preoperative weight loss is not a reliable predictor of postoperative weight loss after laparoscopic sleeve gastrectomy. Losing weight preoperatively also did not predict shorter operative time. Thus, potential patients who otherwise meet indications for bariatric surgery should not be denied this procedure based on inability to lose weight preoperatively.

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