ANTECOLIC LRYGB

Peterson’s defect: 

The sub-colic space behind the alimentary limb, exposed when the transverse colon is lifted up (1)

Jejunal mesenteric defect:

Exposed by lifting to the side the JJ-anastomosis to show the mesenteric defect under the free edge of the biliopancreatic limb (2)

This is the commonest site

Video of closure using Clips:

RETROCOLIC