Common Channel length for the DS?
Mine is 75cm. You will have a hard time finding anything shorter than 100.
A lot of those long CCs are not traditional DS surgeries. They are a newer procedure known as SIPS/Loop/SADI. Procedures that are similar to the DS but with only one intestinal anastomosis instead of 2. So it's not just CC. Know, for sure, what surgery you are getting.
100 is the classic baseline for the BPD/DS, with 80 being about as short as we typically see from the legit surgeons (though I wouldn't argue about Patty's 75 - not enough difference to argue about.) The old Scopanaro procedure (the origins of the BPD part) was, (IIRC) typically around 50cm and that caused enough problems to get that rejected for normal use in the US. I sometimes see 120 used for less needy patients. The SIPS/SADI, from what I have seen, frequently uses much longer CCs - 2-300 cm.
You should certainly discuss this with your prospective surgeon(s), but also listen to what they say and what their experience is - back when my wife had her DS, 15-16 years ago, the need for revised CC length was fairly evenly split between those needing it shortened and those needing it lengthened. I expect that they have learned more since then on how to predict who needs what (at least the more experienced DS guys have - how well that filters down to the less experienced DS docs I can't say. The last revision that I have seen in our support group was a guy who needed it lengthened as he was having problems keeping his weight up, after several years post op.
There are many factors that go into successful weight loss and maintenance with any of these procedures - when I was new with my VSG there were some on these boards that were insisting the you absolutely needed a certain size bougie sleeve to be successful, though there were (and are) many who were successful with a variety of sizes; likewise with the DS, there is more to it than just the CC length - it's how it all plays together (also the split of the rest of the intestines, and how big or small your sleeve it. It's still as much art as science, so I wouldn't necessarily go shopping for a surgeon that prefers one particular parameter over another. How many other patients like you has he done and how are they doing, and what has he/she learned from them and other patients?
1st support group/seminar - 8/03 (has it been that long?)
Wife's DS - 5/05 w Dr. Robert Rabkin VSG on 5/9/11 by Dr. John Rabkin
Size doesn't matter, it's your specific body with a combo cc and stomach pouch that works for you.
With a Sadi DS, I'm about 300cm. At 7 years out, I'm 160lbs at 6'1. The vsg part also matters and needs the right balance. You gain more weight with a shorter cc if the whole package doesn't work for your body.
Find a great surgeon and do your research. The rest will fall into line.
Just under 300.
A lot of things aren't as obvious as they seem. Usually wls patients gain weight (good weight) with exercise, the longer common channel does not mean a worse weight loss outcome, and slower weight loss often means longer term.
There is a reason smart surgeons are going for a longer cc.