What Causes Weight Gain After Gastric Bypass?

A surgical complication, rather than eating habits, can cause patients to regain lost weight after gastric bypass surgery, reports Barham K. Abu Dayyeh et al. in the March issue of Clinical Gastroenterology and Hepatology. The authors correlated increased diameter of the gastrojejunal stoma with long-term weight gain after this common weight-loss surgery.

Of weight-loss strategies, bariatric surgery leads to the most significant and sustained loss, as well as resolution of associated metabolic disorders. Roux-en-Y gastric bypass (RYGB) is the most commonly used weight-loss surgery—patients typically lose 62% of excess body weight and 84% resolve their diabetes. However, regaining lost weight after this surgery can cause significant complications. 

To investigate factors that contribute to weight loss after bypass surgery, Dayyeh et al. collected 4 years of data from 165 patients that received upper endoscopies after RYGB. They found that 59% of the patients regained 20% or more of the weight they lost after RYGB surgery, and that gastrojejunal stoma diameter correlated with weight regain (see below figure).

Predicted percentage of maximal weight lost after RYGB that was regained within 5 years for different diameters of gastrojejunal stoma, based on a linear-regression model.

Although many factors are likely to contribute to weight regain after bypass surgery (preoperative body mass index, nutritional habits, self-esteem, mental health, socioeconomic status, and fistula formation), bariatric surgeons have believed that progressive dilatation of the gastrojejunal stoma after RYGB is also a cause. The study by Dayyeh et al. is the first to establish this association.

An estimated 220,000 bariatric surgeries were performed in the United States and Canada in 2008, and numbers are predicted to increase, so it is important to identify patients at risk for weight regain. Based on their findings, Dayyeh et al. developed a prediction rule based on clinical and endoscopic variables.

Dayyeh et al. proposed that a dilated gastrojejunal stoma causes early emptying of a gastric pouch and loss of post-prandial satiety. However, the combination of a patient’s anatomy and physiological and psychosocial factors that regulate their eating behavior are likely to determine weight loss after surgery.

The authors conclude that stoma dilation should be treated with as much caution as gastrogastric fistulae or other post-surgical anatomic complications. Interventions designed to reduce gastrojejunal anastomosis aperture might prevent weight regain, such as endoluminal suturing devices, tissue plication platforms and sclerotherapy techniques—these have shown promise in managing weight regain after RYGB but need to be tested in randomized, controlled trials.

Read the article online:
Dayyeh BKA, Lautz DB, and Thompson CC. Gastrojejunal stoma diameter predicts weight regain after roux-en-y gastric bypass. Clin Gastroenterol and Hepatol 2011;9:228–233.