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Updated: Jul 16, 2026
Roux-en-Y Gastric Bypass Operation in Rats
Published on: June 11, 2012
Is there a benefit to preoperative weight loss in gastric bypass patients? A prospective randomized trial
Ramzi S Alami1, John M Morton, Rob Schuster
1Department of Surgery, Stanford University School of Medicine, Stanford, California 94305, USA.
Background:
Roux-en-Y gastric bypass surgery is the leading surgical treatment of morbid obesity in the United States. The role of preoperative weight loss in gastric bypass surgery remains controversial. We performed a prospective randomized trial to determine whether preoperative weight loss results in better outcomes after laparoscopic gastric bypass.
Methods:
A total of 100 patients undergoing laparoscopic gastric bypass surgery from May 2004 to October 2005 were randomized preoperatively to either a weight loss group with a 10% weight loss requirement or a group that had no weight loss requirements. The patients were followed prospectively. The variables analyzed included perioperative complications, operative time, postoperative weight loss, and resolution of co-morbidities.
Results:
Data were available for 26 patients in the weight loss group and 35 in the nonweight loss group. The 2 groups had similar preoperative characteristics, conversion and complication rates, and resolution of co-morbidities. The initial body mass index was 48.7 kg/m(2) and 49.3 kg/m(2) for the weight loss group and nonweight loss group, respectively (P = NS). The preoperative body mass index was 44.5 kg/m(2) and 50.7 kg/m(2) for the weight loss group and nonweight loss group, respectively (P = 0.0027). The operative time was 220.2 and 257.6 minutes for the 2 groups (P = 0.0084). The percentage of excess weight loss at 3 and 6 months for the weight loss group and nonweight loss group was 44.1% and 33.1% (P = 0.0267) and 53.9% and 50.9% (P = NS), respectively. The interval to surgery from the initial consultation was 5.4 months and 5.2 months for the 2 groups (P = NS).
Conclusions:
Preoperative weight loss before laparoscopic Roux-en-Y gastric bypass was associated with a decrease in the operating room time and an improved percentage of excess weight loss in the short term. Preoperative weight loss, however, did not affect the major complication or conversion rates, and its long-term effects were not apparent through this study. Also, preoperative weight loss did not have any bearing on the resolution of co-morbidities.
