Table 3.

Surgeons’ views about the crucial aspects of bypass

Operative phase	Observation and video findings	Surgeons’ rationale
Gastric pouch formation	All surgeons create a short, thin gastric pouch	‘I think that the most important element is pouch size…I think probably from a hormonal element and also to, um, increase the speed of transit into the small bowel.’ [S3]
	Surgeons in Centre A routinely use a bougie to help size the gastric pouch, whereas surgeons in Centre B do not	‘I, I think the size of the pouch is probably, probably crucial, or at least I know a really small pouch is associated with a good 15-year weight loss.’ [S1]
		‘It depends what you mean by a bigger pouch. Are we, are we talking a difference of a centimetre or a difference of 20 centimetres? I think if you do…a horizontal pouch perhaps the way it was done years ago then that might make a difference. But if you do a vertical pouch, um, I don’t think it matters if it’s 6 centimetres or 10 centimetres or probably even 15 centimetres, as long as it’s a narrow pouch and you’ve excluded the cardia. I know the chaps from [name of country] make long pouches and…they seem to have good results.’ [S5]
		‘I don’t think it is [important]. I mean, it’s done for a number of reasons. You can do it to make sure that your pouch is not too wide. I think more people do it to make sure that they don’t accidentally make the anastomosis too small…But it does…it makes you feel happier.’ [S5]
Roux limb formation	Surgeons in Centre A use the retrocolic route	‘…allows you to make a smaller gastric pouch. If you’re doing an antecolic anastomosis you, you must do a much, probably much longer gastric pouch, um, halfway towards a gastric sleeve almost ….So if you start off with a big pouch you have to think well, the likelihood of it actually getting enlarged over this time is, is going to be there…’ [S1]
	Surgeons in Centre B use the antecolic route	‘…if you go antecolic you don’t get the problem with the mesocolic window…occasionally you have to take a patient back because it’s too tight, um, as you go in the retrocolic tunnel, and it’s one of the more common places for a hernia, in the mesocolic window.’ [S6]
Closure of mesenteric defects	Surgeons in Centre A routinely close the defects	‘Personally I think it’s crazy not to close them…I don’t think you can be too prescriptive because it is a pragmatic trial. Closing an internal defect is preferable but if you don’t do it, it doesn’t mean you can’t be in the study.’ [S1]
	Surgeons in Centre B do not close the defects	‘…the consensus was that medico-legally, regardless of the evidence, it was indefensible not to close the defects.’ [S2]
Testing of the gastrojejunal anastomosis	Performed by all surgeons in Centres A and B	‘Um why – you sleep, it’s probably good for the surgeon. I think, um, yes some sort of leak test is probably a good idea, yes.’ [S3]
		‘…touch wood, I haven’t had a [positive] blue dye test for about 5 years. So is it important? Probably not.’ [S5]