Effect of preoperative weight loss on laparoscopic gastric bypass outcomes

Background: Requiring patients to lose weight before weight reduction surgery is controversial. The goal of this study was to determine whether preoperative weight loss affects laparoscopic Roux-en-Y gastric bypass surgery outcomes. Methods: The medical records of all laparoscopic Roux-en-Y gastric bypass patients from September 1, 2001 to March 31, 2005 were retrospectively reviewed in our prospective database. Depending on their habitus, patients were selectively required to lose >4.54 kg (10 lb) preoperatively (WL group). Their outcomes were compared with those of the patients not required to lose weight preoperatively (no-WL group). Statistical analysis was performed with the chi-square test and Student's t test for demographic data. Student's t test was used to assess the outcome data. P <.05 was considered significant. Results: Of the 353 patients, 74 (21%) were in the WL group. The operative times in the WL group averaged 10 minutes longer than in the no-WL group (P = .022). The mean length of stay was not significantly different between the 2 groups. Of the 353 patients, 262 (74%) completed 1 year of follow-up. The mean net postoperative weight loss was not significantly different between the 2 groups. The no-WL patients had a greater percentage of excess postoperative weight loss than the WL group (74% versus 66%; P = .01). Net complications occurred less frequently in the WL group (P = .035). Conclusion: Preoperative weight loss did not decrease the operative times or the length of stay. Preoperative weight loss increased neither the mean net postoperative weight loss nor the percentage of excess postoperative weight loss at 1-year follow-up. However, the WL group had fewer net complications.