Nikki writes:

< My understanding of what happened back in the 1800s is that anatomists
injected liquid wax into the ductwork through the nipple and when the wax
hardened, the shape of what was then called "sinuses" was seen.>


And it is interesting to view the drawing of that exquisite research using
wax (which is still very much in use in histology today) alongside the
artists drawing of the 'new anatomy' in Medela literature. Truly, I see
definite similarities, myself. In fact, not too much real difference.


<To me, the only way to reconcile what I have seen and experienced with
the ancient anatomical work and Ramsey Geddes' new study is that the ducts
near
the areola are capable of swelling temporarily to accomodate an intermittent

filling and emptying. That's why those places could be filled with wax,
that's
why they aren't seen as structures during ultrasound, and that's why I had
little doughnuts around my nipples before feeds.
   A sinus is a pocket, with firm walls. Lactiferous sinuses have flexible
walls, capable of more expansion than the other parts of the duct.

What do you all think?>


You are definitely thinking along some of the same lines I am, Nikki.


There are various definitions of the word 'sinus', depending on the site, a
few of which are:
(American Heritage dictionary)


1. A depression or cavity formed by bending or curving.
2.  Anatomy:
    a. a dilated channel or receptacle containing chiefly venous blood
    b. Any of various air-filled cavities in the bones of the skull,
especially one communicating
        with the nostrils.
3. Pathology-a fistula leading from a pus filled cavity.


In his textbooks, Haagensen, a famous breast surgeon showed a microscopic
view, describiing lactiferous sinuses (in the resting breast) as having a
characteristic, longitudinal accordion-pleated contour.




   1. I invite anyone interested to google "Blue Histology" (which is the
   website of the University of Western Australia.)
   2. Click the second listing "Blue Histology Searchable Large Images".
   3. In the keyword space, type in Lactiferous sinus.
   4. Then click on the square marked "02".



You will get a very clear picture of a microscopic view of a cross section
of the nipple of a resting breast which shows near its base, two lactiferous
sinuses (in cross section). The histology/breast surgery/embryology
specialties have adopted the term 'lactiferous sinus' and determined
this as the official anatomical name of these structures that have been
consistently identified in the resting breasts of not only adult women, but
in children and in men.


In adult women only, they are bounded by a thick wall of elastic tissue in
the resting breast. Notice how much similarity there seems to be in the
shapes on this Blue Histology slide and the outlined illustration of the
duct in Ramsey et al's 2006 article in Pediatrics: "Ultrasound Imaging of
Milk Ejection in the Breast of Lactating Women". The 21 women in these
studies were all exclusively breastfeeding for at least one month, some up
to six months.


My question is "Why would nature have formed a structure found so
consistently in immature and mature resting breasts of both sexes, and then
have caused it to totally cease to exist when the organ was fully at work in
its only known physiological function???"


Could it be that the act of suckling for one month or more brings about
changes in the pliability and thickness of the elastic tissue surrounding
the walls of the sinuses, therefore changing their visibility on ultrasound
to appear much the same as the ducts continuing inward toward the glandular
tissue?? My current thinking is that the structure must be somehow specially
constructed to permit optimum transmission of hydraulic pressures generated
by robust suckling, so as to yield an adequate amount of milk for healthy
infant growth, as well as sufficient removal of FIL to maintain adequate
lactation.


I concede that the MER is a powerful force, but we all know what often
eventually happens to the milk supply when the baby is 'living off the MER'
and not developing efficiency in actual suckling and generating sufficient
additional hydraulic force for milk removal.


I believe the ultimate answer will only be found under the microscope,
by examining the cellular differences of the various ducts in the
nipple-areolar complexes of the breast(s) of women in mid-to-late pregnancy,
during the first month of postpartum, and then of fully breastfeeding women.
Unfortunately, for these to be disease-free breasts, they would have to come
from autopsy specimens, and have willing pathologists in-the-know about this
controversy that has mainly pointed out the inadequacy of previous artists'
conceptions. Such research would involve the ethics of obtaining cadavers of
pregnant and/or lactating women, and this is a tremendous obstacle to
surmount in this day and age, at least in this country.


I have read articles on fairly recent breast research that has been carried
out on cadavers. There is a protocol for obtaining a cadaver, and it is so
formal that the pathologist supplying the cadaverous breast was given
credit in the reference section of the article. Does anyone in our lactation
community have any connections with medical school anatomy departments or
pathologists who would be willing to explore this further under the
microscope?


While I think the redefinition of anatomy regarding the number of
lobes/ducts will be particularly important in decisions on future breast
reduction surgery in women of childbearing age, I found myself bristling at
this statement in the Ramsay et al's 2005 article in the Journal of Anatomy:



"Our failure to observe 'lactiferous sinuses' in the lactating breast
suggests that the current explanation for the importance of positioning and
attachment of the baby to the breast requires revision. In this connection,
further investigation of the importance of positioning the nipple in the
baby's mouth in relation to suck/breathe/swallow reflex would be of
interest."


Fortunately for our profession, there is at least one very experienced
practitioner now involved in conducting such research.


Jean
**************
K. Jean Cotterman RNC, IBCLC
Dayton, OH USA

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