Robotic Gastric Bypass

Daniel Shouhed, MD
Content Author:
Matthew Zeller DO
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Background Information:

The Roux-en-Y gastric bypass is a weight loss procedure performed on patients for obesity. This procedure causes weight loss through both restrictive and malabsorptive methods. The expected weight loss at 1-year post-op is 70-75% of excess body weight. 


The optimal surgical weight loss procedure depends on individual co-morbidities, goals, and preferences. In general, patients who are candidates for weight loss surgery include those with:

  • BMI ≥40 OR
  • BMI >35 with an underlying health condition related to obesity such as type 2 diabetes, hyperlipidemia, obstructive sleep apnea, among others

These guidelines originated from the NIH Consensus Conference Guidelines in 1991ⁱ for the treatment of morbid obesity and were updated in 2004 by the American Society for Bariatric Surgery².The updates suggested:

  • Patients should have attempted self-directed management of their obesity by non-operative means before surgical consideration
  • Patients with a BMI of 30-34.9 with uncontrolled type 2 diabetes or metabolic syndrome are candidates 
  • Bariatric patients are best cared for by a multidisciplinary team

Procedure Description: The Roux-en-Y procedure decreases the stomach size (restrictive) and bypasses the duodenum and part of the jejunum (malabsorptive) to promote weight loss. The stomach is divided to create a small gastric pouch. The jejunum is then separated 50cm distally from its attachment to the duodenum creating the biliopancreatic (BP) limb. The distal end of the jejunum (roux limb) is then mobilized and brought up to the gastric pouch to create the gastrojejunal (GJ) anastomosis. The roux limb may be brought anterior (antecolic) or posterior (retrocolic) to the transverse colon depending on surgeon preference. The BP limb is then anastomosed 75-150 cm from the GJ anastomosis forming the jejunojejunal (JJ) anastomosis.

Key Anatomy:


  • Esophagus
  • Gastroesophageal junction
  • Stomach
  • ~Cardia
  • ~Fundus
  • ~Body
  • ~Antrum
  • ~Pylorus
  • ~Gastric fat pad
  • ~Angle of His
  • ~Angular incisure
  • Duodenum
  • Jejunum
  • Ligament of Treitz
  • Mesentery of the small intestine


  • Transverse colon
  • Taenia coli


  • Greater omentum
  • Lesser sac

Newly created anatomy:

  • Biliopancreatic limb (duodenum and 50 cm of the jejunum)
  • Roux limb (75-150cm of distal jejunum)
  • Gastric pouch


General surgical risks:

  • Bleeding
  • Infection

Risks of Roux-en-y gastric bypass

  • Anastomotic leak (1.0%³)
  • ~More common at the jejunogastric (JG) anastomosis 
  • Bowel obstruction and internal hernia (4.7%⁴)
  • ~Bowel obstruction commonly from anastomotic stenosis
  • Marginal ulcer (<1%⁵)
  • Cholelithiasis (36% at 6 months post-op⁶)
  • Dumping syndrome (9.4%⁷)

Key Literature:

STAMPEDE Trial (Schauer, et al. 2012)⁸

  • Randomized controlled trial comparing medical therapy and weight loss surgery vs. medical therapy alone in the treatment of uncontrolled diabetes in obese patients
  • Findings showed a significant difference in A1c levels in the medical and surgical treatment group when compared to the medical treatment only at 1 and 3 years follow up

Additional resources:

The American Society for Metabolic and Bariatric Surgery


  • Sabiston Textbook of Surgery: The Biological Basis of Modern Surgical Practice by Courtney M. Townsend Jr. JR. MD
  • Zollinger's Atlas of Surgical Operations, Tenth Edition 10th Edition by Robert Zollinger, E. Ellison 
  • Atlas of General Surgical Techniques: Townsend, Evers
  • Essentials of General Surgery 5th Edition, by Peter F. Lawrence MD, Richard M. Bell MD, Merril T. Dayton MD, James C. Hebert MD FACS

  1. Gastrointestinal surgery for severe obesity. Proceedings of a National Institutes of Health Consensus Development Conference. March 25-27, 1991, Bethesda, MD. Am J Clin Nutr. 1992;55(2 Suppl):487S-619S. doi:10.1093/ajcn/55.2.615s
  2. Buchwald H; Consensus Conference Panel. Bariatric surgery for morbid obesity: health implications for patients, health professionals, and third-party payers. J Am Coll Surg. 2005;200(4):593-604. doi:10.1016/j.jamcollsurg.2004.10.039
  3. Smith MD, Adeniji A, Wahed AS, et al. Technical factors associated with anastomotic leak after Roux-en-Y gastric bypass. Surg Obes Relat Dis. 2015;11(2):313-320. doi:10.1016/j.soard.2014.05.036
  4. Angrisani L, Cutolo PP, Formisano G, Nosso G, Vitolo G. Laparoscopic adjustable gastric banding versus Roux-en-Y gastric bypass: 10-year results of a prospective, randomized trial. Surg Obes Relat Dis. 2013;9(3):405-413. doi:10.1016/j.soard.2012.11.011
  5. Abellán I, López V, Lujan J, et al. Stapling Versus Hand Suture for Gastroenteric Anastomosis in Roux-en-Y Gastric Bypass: a Randomized Clinical Trial. Obes Surg. 2015;25(10):1796-1801. doi:10.1007/s11695-015-1638-2
  6. Shiffman ML, Sugerman HJ, Kellum JM, Brewer WH, Moore EW. Gallstone formation after rapid weight loss: a prospective study in patients undergoing gastric bypass surgery for treatment of morbid obesity. Am J Gastroenterol. 1991;86(8):1000-1005.
  7. Nielsen JB, Pedersen AM, Gribsholt SB, Svensson E, Richelsen B. Prevalence, severity, and predictors of symptoms of dumping and hypoglycemia after Roux-en-Y gastric bypass. Surg Obes Relat Dis. 2016;12(8):1562-1568. doi:10.1016/j.soard.2016.04.017
  8. Schauer PR, Kashyap SR, Wolski K, et al. Bariatric surgery versus intensive medical therapy in obese patients with diabetes. N Engl J Med. 2012;366(17):1567-1576. doi:10.1056/NEJMoa1200225