Bariatric Surgery–How Much Malabsorption Do We Need?—A Review of Various Limb Lengths in Different Gastric Bypass Procedures

Abstract

The number of obese individuals worldwide continues to increase every year, thus, the number of bariatric/metabolic operations performed is on a constant rise as well. Beside exclusively restrictive procedures, most of the bariatric operations have a more or less malabsorptive component. Several different bypass procedures exist alongside each other today and each type of bypass is performed using a distinct technique. Furthermore, the length of the bypassed intestine may differ as well. One might add that the operations are performed differently in different parts of the world and have been changing and evolving over time. This review evaluates the most frequently performed bariatric bypass procedures (and their variations) worldwide: Roux-en-Y Gastric Bypass, One-Anastomosis Gastric Bypass, Single-Anastomosis Duodeno-Ileal Bypass + Sleeve Gastrectomy, Biliopancreatic Diversion + Duodenal Switch and operations due to weight regain. The evaluation of the procedures and different limb lengths focusses on weight loss, remission of comorbidities and the risk of malnutrition and deficiencies. This narrative review does not aim at synthesizing quantitative data. Rather, it provides a summary of carefully selected, high-quality studies to serve as examples and to draw tentative conclusions on the effects of the bypass procedures mentioned above. In conclusion, it is important to carefully choose the procedure and small bowel length excluded from the food passage suited best to each individual patient. A balance has to be achieved between sufficient weight loss and remission of comorbidities, as well as a low risk of deficiencies and malnutrition. In any case, at least 300 cm of small bowel should always remain in the food stream to prevent the development of deficiencies and malnutrition.

Outcome of Sleeve Gastrectomy Converted to Roux-en-Y Gastric Bypass and One-Anastomosis Gastric Bypass

“…Thus, major points when talking about revisional procedures are the length of the biliopancreatic and the common limb but also the question whether a re-shaping of the sleeve/pouch is done [22]. These potential differences make the studies and procedures in the literature hard to compare in terms of weight loss.…”

Feasibility of a new bariatric fully endoscopic duodenal-jejunal bypass: a pilot study in adult obese pigs

“… The exceptionally long bypass limb in Pig Green was attributed to difficulty with the light beacon. Some human studies suggest that longer bypassed limb lengths are associated with greater weight loss 15 , which is inconsistent with Pig Green’s minimal amount of weight loss despite a very long limb. Based on studies supporting that a 100–200 cm combined length of biliopancreatic and alimentary limb gives optimum results with Roux-en-Y gastric bypass in most patients 16 , we will continue to aim for a total limb length in this range in future studies.…”

Exocrine pancreatic insufficiency and pancreatic exocrine replacement therapy in clinical practice

“…8,9,24 Certain bariatric surgery procedures are engineered to be malabsorptive to aid in weight loss. 10 RYGB, oneanastomosis gastric bypass, single-anastomosis duodenoileal bypass, sleeve gastrectomy, and biliopancreatic diversion with duodenal switch (BPD-DS) are malabsorptive procedures, with BPD-DS having the most pronounced malabsorptive component. 10 In RYGB, food enters the alimentary limb, evading digestive secretions located in the biliopancreatic limb.…”

“…8,9 This asynchrony of nutrients and digestive secretions can be found in patients with altered GI anatomy, such as with total gastrectomy, esophagectomy, and bariatric weight loss surgery, including Roux-en-Y gastric bypass (RYGB) and duodenal switch. 10 Other clinical diagnoses within which EPI may occur include trauma, critical illness, celiac disease, gastroparesis, human immunodeficiency virus, and inflammatory bowel disease. 11 The prevalence of EPI in those with diabetes mellitus (DM) has also been documented.…”