Very good letter! I have two comments:
1) Your medical policy distinguishes between revision (fixing an existing surgery) and conversion (changing to a different procedure) - you are requesting conversion, so make sure you use the right word throughout the letter: “Duodenal Switch is a natural [revision] conversion option ...”
2) Your math is wrong:
“Weight loss is less than 50% of initial procedure pre-operative excess body weight
My pre-procedure weight was 284 lbs. Eighteen monthsafter I had my procedure, I weighed 188 lbs., which is the lowest I weighed after my procedure but is only a 33% weight loss and is less than the 50% weight loss threshold as stated in the BCBS policy. Currently I weigh 303 lbs.”
If your start weight was 284 and your goal weight (normal) was 144, your EXCESS weight was 140 lbs; and you lost 96 lbs, or - at best, your EXCESS weight loss was almost 69%. You initially did reasonably well.
However, your LONG-TERM excess weight loss is a negative number, as you are now heavier than you were prior to your first surgery.