Laparoscopic Gastric Bypass Technique

Updated: Apr 26, 2023
  • Author: Subhashini Ayloo, MD; Chief Editor: Kurt E Roberts, MD  more...
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Laparoscopic Roux-en-Y Gastric Bypass

Before the gastric bypass (GBP) procedure is started, the monitors should be adjusted so that they can be viewed at eye level. The trocars should be positioned at least a fist-length apart. This allows the surgeon to use both hands comfortably. A preoperative liquid diet seems to help decrease the size of the liver.

The operation is initiated by placing a total of six trocars, of which four are 10 mm and two are 5 mm.

Some of the gastrophrenic ligaments are taken down at the angle of His. A small gastric pouch is created by creating a window in the lesser sac. A stapler is used to staple and transect the stomach first horizontally and then vertically to the angle of His. A Maloney dilator is used to guide in creating the pouch (see the video below).

Laparoscopic gastric bypass: part 1.

The omentum and the transverse colon are retracted cranially, and the ligament of Treitz is thereby exposed. The small bowel and its mesentery are stapled and transected at the jejunum. A Roux limb of 150 cm is bypassed.

A jejunojejunal anastomosis is performed. The common enterotomy of the jejunojejunal anastomosis is sewn by hand in a double-layered fashion. The mesenteric defect is closed (see the video below) so as to prevent internal hernias. [21]

Laparoscopic gastric bypass: part 2.

The Roux limb is brought out in an antecolic and antegastric manner. A gastrojejunal anastomosis between the pouch and the Roux limb is performed in a double-layered fashion as well. [22] A gastrotomy and an enterotomy are created. An orogastric tube is advanced through the gastrojejunal anastomosis.The anterior layer of the gastrojejunal anastomosis is closed in a double-layered technique. The gastrojejunal anastomosis is tested for air leak by submerging the anastomosis with irrigation fluid and inflating the orogastric tube with air (see the video below).

Laparoscopic gastric bypass: part 3.

The anastomosis (gastrojejunal or jejunojejunal) can be either handsewn or stapled. Using the staple line reinforcer (eg, Seamguard, Peristrips) appears to reinforce the staple line.

Recommendations vary with respect to when patients should be discharged after the procedure. A 2014 study from the United Kingdom found a 23-hour postprocedure stay to be safe and cost-effective. [23] Same-day discharge has been tried, but some have found it to be associated with increased morbidity and mortality. [24]  A 2021 single-center study from The Netherlands found same-day discharge after laparoscopic Roux-en-Y GBP to be feasible in selected patients with the use of remote monitoring. [25]



Laparoscopic Roux-en-Y GBP is a major elective surgical procedure. Risks include the following:

  • Mortality (1-2%), mainly due to pulmonary embolism or gastrointestinal leak
  • Wound infections (possibly more common with the use of tissue adhesive for wound closure [26] )
  • Gastrojejunal stomal stricture
  • Marginal ulcers (possibly more common with an antecolic approach than with a retrocolic approach [27] )
  • Internal hernia [21]
  • Roux limb ischemia
  • Blowout of the stomach remnant
  • Long-term deficiencies of micronutrients (eg, vitamin B12, folate, iron)

Bleeding from the staple line, though rare, can be a serious problem after laparoscopic GBP. It may be controlled by means of clipping or monopolar cauterization. [28]

In a large study (N = 42,345) that included a substantial population of older adults, Yu et al found that Roux-en-Y GBP (n = 29,624) was associated with a 73% increased risk of nonvertebral (eg, hip, wrist, and pelvis) fracture after the procedure as compared with adjustable gastric banding (n = 12,721). [29] The difference in postoperative fracture risk between the two procedures was consistent across different subgroups and occurred to a similar degree among older and younger adults.