Laparoscopic Revisional Surgery: Adding Malabsorption for Failed Gastric Bypass

Since 1998, there has been a substantially progressive increase in bariatric surgery. In 2005, the American Society of Metabolic and Bariatric Surgery (ASMBS) reported that 81% of bariatric procedures were approached laparoscopically. 205,000 people, in 2007, had bariatric surgery in the United States from which approximately 80% of these were Gastric Bypass. Moreover, there is a mismatch between eligibility and receipt of bariatric surgery with just less than 1% of the eligible population being treated for morbid obesity through bariatric surgery. Along with the increasing number of elective primary weight loss procedures, up to 20% of post RYGB patients cannot sustain their weight loss beyond 2 to 3 years after the primary bariatric procedure11. Thus, revisional surgery for poor weight loss and re-operations for technical or mechanical complications will rise in a parallel manner. RYGB is consistently considered the revisional procedure of choice for failed restrictive procedures.

At present there are three broad categories of bariatric procedures according to its mechanism of action: 1) purely restrictive, 2) primarily restrictive with some malabsorption, and 3) primarily malabsorptive with some restriction. Modern standard bariatric procedures recognized by the American Society for Metabolic and Bariatric Surgery "ASMBS" include the following 1) adjustable gastric band, 2) sleeve gastrectomy, 3) gastric bypass, 4) biliopancreatic diversion, and 5) duodenal switch.

In general, there is a lack of long-term (5-10 years) and very long-term (> 10 years) outcome studies for modern bariatric surgery that would allow us to better define the role of each one of these procedures, especially after the advent of the laparoscopic approach.

In an animal model, diet induced obese animals exhibiting metabolic syndrome underwent Roux-en-Y gastric bypass with highly reproducible surgical outcomes as well as biochemical and energetic homeostatic abnormalities similar to post-RYGB findings in humans. Weight regain occurs in approximately 20% of patients after two to three years after RYGB. It seems that the weight-loss-promoting effects of chronically elevated plasma PYY concentrations dominate the weight-gain-promoting effects of lowered plasma leptin concentrations, with the relative plasma PYY: leptin concentration ratio determining whether weight loss will be sustained or regained.

Several studies have compared different Roux limb lengths in primary bariatric surgery. It seems to be that long limb RYGB (150cm), especially in patients with BMI > 50 kg/m2, confers at least better short-term weight loss without nutritional consequences. Conversely, other investigators have not found any clinically significant difference in weight loss with increasing Roux limb lengths, especially in patients with BMI < 50 kg/m2 23-26. The following are the main investigators that have increased the malabsorptive component of the failed proximal gastric bypass as a revisional strategy: