The proper measurements when performing the Biliopancreatic Diversion with the Duodenal Switch are very important for good long term results. If the common channel is too long or the stomach is too large the patient may not have good sustained weight loss. If the alimentary limb is too short the patient may not be able to absorb adequate protein and may require a revision. The patient must be able to eat, the duodenal stoma should not be small, but wide open, so the patient can take in protein.
We have measured the total small bowel length in more than 1400 patients we have operated and there is a large difference from the shortest (12 feet) to the longest bowel (38 feet). You can see that one size does not fit all! In our experience a common channel of 10% is the best size. We use three sizes: 50 cm, 75 cm, and 100 cm whichever is the closest to the ten percent mark. This way we have three sizes of common channels and we can group them together to evaluate the lengths. The length of the common channel determines the degree of malabsorption of fat. You will, however, absorb enough fat for all the essential fatty acids needed for life.
The alimentary limb (the portion of small bowel which the food passes through) is formed nearest to 40% of the lower part of the small bowel, always in increments of 25 cm (10 inches) from 250 to 350 cm as shown below. The most common size used is 75 cm for the common channel and 275 cm for the alimentary limb. For example: the common channel length is 100 cm in only 7% of our cases, 75 cm in 67 %, and 50 cm in 23 %. From this you can see we feel that using a 100 cm common channel is not correct in most cases.
We believe measuring the total bowel is very important for good long term results (see our ten year graphs). If you don't count you don't know!
Volume of stomach 100 ml (+ or - 15 ml)
Common Channel 10% of total small bowel length, 50, 75, 100 cm
The above chart shows what happens if you use the improper limb lengths.
Example (1): If you always use the 250 cm AL and 100 cm CC on all cases and the total bowel length is 500 cm the percent AL is 50%, this is too long for good weight loss. Also if you have a 100 cm CC there will be 16.7 %, too large an absorption of fat. This patient will not lose weight properly
Example (2): If you use the same parameters and the total small bowel length is 750 cm the AL is only 33.3 % and the CC is 16%; 33.3% alimentary limb is too short and the patient may have difficulty maintaining proper protein since the total alimentary limb is too short. Conversely the common channel is too long for the proper fat malabsorption.
Example (3): If the total small bowel length is 1000 cm as in the third example the common channel is proper, but the alimentary limb is very short and this patient will not be able to absorb adequate protein and will have difficulty. Most likely need to have a revision of the bowel lengths later.
Example (4): These parameters are all proper and will probably not have difficulty and should lose weight and keep it off for years.
The first Biliopancreatic Diversion with the Duodenal Switch (combination surgery for treatment of obesity) was performed on a patient who needed a re-operation procedure. At first we used this operation for only the patients who needed a re-operation for a failed restrictive procedure (Redo). Our results were so much better we begin to use this operation for all our patients. The above graph has the re-operation cases (blue) and the primary (first time surgeries) (red) listed for the first 15 years. You can see how the growth has been steady.