Length of Small Bowel
2012
2011
2010
2009
Stontium
Biphosphonates 9/21
Hair loss after weight loss surgery! 5/18
Drug interactions with herbal remedies 5/4
Exercise habit
Pregnancy after duodenal switch 4/27
Calorie calculation 4/13
Cells found in bones 3/11
Calorie predictive relations in energy regulation by rats3/9
2/2
Am I going Bald
Trans Fatty Acids 1/7
2008
Olive oil 12/30
Bariatric surgery before pregnancy 12/5
Antioxidant effects of almonds 10/20
Moderate Exercise Yields Big Benefits 6/1
It appears that there are series of questions and concerns that are not completely resolved, and they resurface every so frequently. Length of the small bowel for the Common Channel and the Alimentary limb in the Duodenal Switch operation is one of those topics.
The Questions that I am asked:
- How long is my common Channel?
- Another patient had the same length, but they are loosing more (or less) as the case may be.
- I was told by another surgeon that they would give me a certain length of common channel, what do you think?
The common problem is that
there is no accurate and practical
way to measure the length of the
bowel. There is also two schools of
though, with very little objective
research to support one or the other.
There is no published data that I
could find that answers this question
head on. There are number of other
articles, and presentations that
touch on this topic.
The best reference that I think is worth looking over is an editorial by Dr. Hess. The link is provided below.
I would like to discuss this in an organized way.
The artistic work is done by
yours truly!
First a Brief over view of our GI
track:
Our GI track starts at the mouth
and ends in the rectum (figure 1). It
is a long tube that has a very few
side branches. These include the
opening of the salivary glands in the
mouth, the opening of the biliary (from the liver) and the pancreatic
(from the pancreas) plumbing to in
the first part of the small bowel
(duodenum) and the Appendix (at
the junction of the small bowel and
the large bowel).
Related Link:
http://www.springerlink.com/content/qn23527k0nkh682n/fulltext.pdf
The small bowel is the part that
causes all this confusion. The small
bowel is a long pliable, elastic tube
that can be stretched (figure 2).
Depending on how much force is
applied to it, it can be of different
lengths. A similar analogy is the
phone cord to head set of a
conventional phone. The spiral cord
placed on a table will coil up to a
certain length. If one then pulls on
two ends it will
measure longer. And
if more pull is exerted,
then it will easure
even longer. This
demonstrates that the
absolute measured
length of the small
bowel, is directly
related to the force
with which it is pulled.
What this means is
that if two individuals
measure the length of
the headset cord, or
the bowel, they will
get two different
lengths, both correct
but not the same. The
length is directly
proportional to the
pull force applied to
both ends.
Furthermore; the length of the small bowel is determinant of the absorptive capacity (amongst other factors). The longer the small bowel the more absorption, and the shorter the small bowel, the less absorption. There is a general-trauma surgical problem knows as short gut syndrome, where the length of the bowel is so short that it cannot support maintenance of the electrolytes and minerals, in additions to the required absorption of the calories. Short gut syndrome is a very difficult surgical problem to solve.
Getting back to our
discussion however, we can
now appreciate how two
surgeons can measure the
same amount of small bowel
(the same absorptive capacity)
but end of with different lengths
of small bowel. Same amount
of bowel, same absorptive
capacity, different lengths.
This is why comparing lengths of
small bowel is probably not the most
accurate way to. Two patients, both
with 75 cm common channels may
have very different absorptive
capacity, unless the bowel was
measured by the same surgeon, and both patients had the same amount
of total bowel length.
We should next consider a
possible alternative. Consider the
drawing on (figure 3) and (figure 4). 
The
distance between C and B is 25%
(quarter) of the total length between
A and B. This represents a segment
of bowel that was measured and
marked
Now lets take the same amount
of bowel and apply a little more pull
force to the ends while measuring it.
We will have a total length of 80 cm,
between A and B (figure 5). The
distance between A and C will be 60
cm and the distance between C and
B will be 40 cm (figure 6). The
absolute lengths then are double of
the first case. Same amount of
bowel, same absorptive capacity yet
double the length. Does this mean
that the second patient with distance between C and B at 20 cm will absorb twice as much as the first patient? The answer is no, since it was the same amount of bowel that was measured with different technique.
Lets now however look at this from another perspective. In both cases the distance between C and B was only 25% of the total length.
| Distances | Figures 3 & 4 | Figures 5 & 6 |
| Total length A-B | 40 cm | 80 cm |
| A-C | 30 cm | 60 cm |
| % of total | 25% | 25% |
The table above shows why lengths of bowel discussed in-terms of percentage of total may be a more standardized than the absolute numbers.
In this example both patient will have same absorptive capacity (25%) yet will have much longer absolute lengths. In our practice, we measure the total length and the common channel and the alimentary lengths are based on the patient BMI, comorbidities, age, sex, and activity level.
Please remember that this is only my opinion, different surgeons do it differently.