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http://www.ncbi.nlm.nih.gov/pubmed/23845008

BMC Neurol. 2013 Jul 11;13(1):81.

An ultrasound model to calculate the brain blood outflow through collateral vessels: a pilot study.
Zamboni P, Sisini F, Menegatti E, Taibi A, Malagoni AM, Morovic S, Gambaccini M.

Abstract
BACKGROUND:
The quantification of the flow returning from the head through the cervical veins and the collaterals of the internal jugular vein (IJV), is becoming of prominent interest in clinical practice. We developed a novel model to calculate the cerebral venous return, normalized to the arterial inflow, in the different segments of the IJV.

METHODS:
We assessed, by established Echo Colour Doppler (ECD) methodology, the head inflow (HBinF) defined as the sum of common carotids and vertebral arteries, as well as the cerebral flow (CBF) defined as the sum of internal carotid and vertebral arteries. We also assessed the head outflow (HBoutF) defined as the sum of the measurements at the junction of the IJV and the vertebral veins. In addition, we also calculated the collateral flow index (CFI) by estimating the flow which re-enters directly into the superior vena cava as the amount of blood extrapolated by the difference between the HBinF and the HBoutF. We preliminarily tested the model by comparing ten healthy controls (HC) with ten patients affected by chronic cerebral spinal venous insufficiency (CCSVI), a condition characterized by some blockages in the IJV which are bypassed by collateral circulation.

RESULTS:
In HC the HBinF was 1040+/-125 ml/min, whereas the HBoutF was > 90% of the HBinF, leading to a final CFI value of 1%. The last result shows that a very small amount of blood is drained by the collaterals. In upright we confirmed a reduction of the outflow through the IJV which increased CFI to 9%. When we applied the model to CCSVI, the HBinF was not significantly different from controls. In supine, the flow of CCSVI patients in the IJV junction was significantly lower (p < 0.001) while the correspondent CFI value significantly increased (61%, p < 0.0002).

CONCLUSIONS:
Our preliminary application of the novel model in the clinical setting suggests the pivotal role of the collateral network in draining the blood into the superior vena cava under CCSVI condition.

sent PM fyi

OK. Dr. Zamboni has measured the difference in collateral capacity between
healthy controls and CCSVI. This cerebral flow index goes from 1% in HC to
60% (!) in pwCCSVI. That's a big difference.

Since there are more major veins than arteries in the neck (jugulars +others), there
are at least 4 important numbers:

1. Jugular flow when upright. (JFu)
2. Jugular flow when supine. (JFs)
3. Other flows when supine. (OFs)
4. Other flows when upright. (OFu)

What goes in, must come out --> (Jugular + other veins) = (carotid + other arteries), in volume or mass (CBF).

-----------------------------------------------digression---------------------
The total flow when upright (TFu) does not have to be = total flow when
supine (TFs), because flow is rate, not volume. Flow is determined by heart
rate and the heart does not pump as fast when supine (if we are resting when
supine). The reason it's not as fast is probably twofold:

(1.) We primarily rest when supine.
(2.) Gravity affects the total flow rate when supine, making it (normally) less.

Examining this, we find that (2.) can be true, since the total mass of the
moving blood has not changed, and the acceleration due to gravity is a
constant 1 G (9.8 m/s^2). What has changed is the vertical distance (against
1 G) that the total mass of blood must travel from one end of the body to the
other. It is less, when supine, by an amount equal to the difference between
our vertical height when standing (say 5.5 feet) and when supine (say 1 foot).
Regardless of metabolism changes when upright versus standing, due to a usual
difference in work output (which cannot be dismissed, either, because we do
far less work when asleep, unless we are comatose), when lying down the heart
does intrinsically less work.

That might be another reason why we sleep lying down. The difference in work
output is less significant for four-legged animals than for primates. We
might say they have less difference in aspect ratios (width versus height),
when supine versus standing. In humans, that difference is related to our
body fat. It affects us more the rounder we are, and the more time we spend
sleeping in the average day.
---------------------------------------------end of digression------------

So Dr. Zamboni has enough data to fill out the table of flows (and probably
has done that already), for both healthy controls and CCSVI patients :

JFu || JFs || OFu || OFs
-------------------------------------

"Other" seems to be the total venous flow measured at the vena cava minus the jugular venous flow.

RESULTS:
In HC the HBinF was 1040+/-125 ml/min, whereas the HBoutF was > 90% of the
HBinF, leading to a final CFI value of 1%. The last result shows that a very
small amount of blood is drained by the collaterals. In upright we confirmed a
reduction of the outflow through the IJV which increased CFI to 9%. When we
applied the model to CCSVI, the HBinF was not significantly different from
controls. In supine, the flow of CCSVI patients in the IJV junction was
significantly lower (p < 0.001) while the correspondent CFI value
significantly increased (61%, p < 0.0002).

In normals, there is more vein capacity when jugulars are in service.
Collaterals are draining a much bigger share when supine, in CCSVI.
Therefore there is reduced jugular capacity in CCSVI.

Don't know exactly how CFI was calculated, but Dr. Zamboni found that the
cerebral blood flow index was much higher in people with CCSVI, and that
collaterals were both more prevalent and more used in supine position, leading
to the conclusion jugular capacity is reduced. How much more evidence do we
need? Does every investigation of Dr. Zamboni's have to be reproduced before
we start thinking there might be something to them?

It shows that the flow is different in people with CCSVI but it does not establish if this difference (collaterals used instead of jugulars) is abnormal or a normal variant.

I like that they establish the concept of HBoutF and HBinF. Seems like this should have all been researched years ago.

I am extremely pleased to read that Dr.Zamboni and his team continue to explore and provide questions and answers in all things CCSVI.

I doubt collateral blood pathways .... are normal.

This document is current. 2013.

The precise measurement of bloodflow is elusive. Dr.Zamboni has and will continue to attract medical professionals that can perform this task , to his team.

What a remarkable man.


MrSuccess

If this ultrasound model holds up, then the next step would be showing the difference in individuals from before to after angioplasty? Quantification....

With a few more measurements, the model could include Pressure Drops. See http://sullivanweb.me/pdfdocs/Calculati ... ts9%20.pdf

I wrote it and all mistakes are mine.