WHY WE NEED VALVES

[CindyCB]

I gave birth three times (no caesareans) but still had 99% and 80% blocked jugulars due to valves. It didn't pop them open in my case!

Ha, yeah, no such luck, eh? Perhaps that's the difference between MS and ME (or numerous other neuro conditions).

MS valves are persistent little *ahem* things!

[1eye]

In my steady-state drawing of venous stenosis I omitted the fact that the heart's pressure is not steady but repetitive, and sometimes may go negative, reversing flow. Being sometimes negative or even just going down to zero pressure makes it sensitive to events like coughing, desalva, breath holding, or a punch in the chest. In a mathematical description, having a fundamental frequency means the system the heart beats into may add to its harmonics, affecting the pulse's waveshape, occasionally or even continuously. That is what Dr. Tucker describes in his YouTube animations.

The valve is supposed to prevent these excursions into negative territory by closing at the right time. That will work if its flap(s) remain free, and it does not become too sticky. It can also fail by being too loose, allowing pressure to overcome it's shut-off, or it's timing. It can also fail altogether by being 'blown through', rendering it of no further use. That is more likely in a leg vein, but gravity is a continuous stress on all veins, as we age.

How do people who have no jugular valves avoid the problem? Well, gravity is a significant component when we are upright, and the likelihood of strong standing-wave-type effects when we are supine is less, so unless a strong disturbance happens like a cough, valsalva, or a blow, there may be no problem when the heart is not beating hard. These events may cause jugular reflex when supine, if absent valves allow it in.

If we are vertical those who don't have valves may have learned that being upside down can make them very ill. This same problem can happen to those who have a stenosis, and significant collateral drainage, because the new growth will not develop new valves. My brother has only one original jugular, and he gets very very dizzy and sick on swings and rides, car-sick, etc. It is usually a good thing to have valves because they do protect the brain, and in the case of the legs, make sure all the blood stays in circulation.

What if the system were steady-state? If the heart were more like a rotary motor-driven pump? Could there still be steady-state reflux? I think evolution would have made sure it didn't happen, or that it had seldom had ill effects. But evolution can not protect individuals from late-onset problems because it only works to make the average person reach breeding age. So I think a) there can be occasional reflux and b) reflux can become pulsatile in older individuals. Keep your valves as long as you can, and when you are old, Father William, pray, don't stand on your head.

[CindyCB]

Keep your valves as long as you can, and when you are old, Father William, pray, don't stand on your head.

Ha, oh you reminded me that I used to stand on my head a LOT when I was a child. Loved doing it. The thought of it now makes me feel queasy, I can't even lean forward without feeling dizzy with a thumping headache.

Why does your brother only have one IJV ? Born that way or as a result of treatment?

[1eye]

Why does your brother only have one IJV ? Born that way or as a result of treatment?

Hydrocephalus shunt inserted into jugular with only CSF flow instead of blood, as a baby (1964). He still has it, but no more excess CSF in it.

[Jugular]

I think you make an excellent point 1eye that collaterals don't have valves.

[1eye]

I pondered something again today at the gym. When doing a workout, even weights, my heart rate and BP are elevated some. So, when I'm breathing and my heart is beating, a little more than normal, I get sick on my back. I am not sure of how I am on my side, but I get nauseous just leaning back for a sit-up or crunch.

Also, I have a hard time getting to sleep at night once I am flat on my back in bed. No reading, no noise, no lights, even with eye-mask and earplugs. Stopped using CPAP mostly because of the noise. Awake with eyes closed in the dark.

I think you make an excellent point 1eye that collaterals don't have valves.

That might be what Drs. Zamboni and Freedman are on about with "collateral circles".

[drsclafani]

I am not sure whether those of who have valve problems can ever have working valves. Mine were ballooned, not disrupted or torn. Based on my improvements in health, I am better off without the valves as obstructions, although maybe not as well off as I'd be if I had normal, functional valves. But normal functional valves may never have been an option for me! I agree that the disruption or tearing of valves does not have science to support it, nor to my knowledge is anyone who is doing this gathering data on outcomes. My biggest concern with it is that other doctors have said they have seen more complications in patients who have had their valves torn, compared to those who have had their valves ballooned. If there was anything that frightened me when going in for CCSVI treatment, it was the possibility of complications. You all had convinced me of the importance of jugulars and azygous veins and I did not want any damage done to them.

15 % of humans o not have valves in the their jugular veins.
Ricci had aneurysms of his jugular vein

i think that the vast majority of stenoses of the jugular veins are valvular stenoses.

I am not sure there is good evidence that disruption of the valves is harmful

[CindyCB]

Dr Sclafani,
Do you ever consider the use of cutting balloons?

[1eye]

Strange to see one guy arguing that reflux is normal and to think the only reason for a valve there is to prevent reflux. Is this a timing thing? Is it OK to have no valves, and to have reflux, as long as it doesn't come under the amount of pressure that would close a valve, if you had one, or as long as there is enough downward flow at that time to act as a damper and slow it to a non-damaging rate?

Are we seeing reflux that is a result of the stenosis itself, as Dr. Tucker is saying, and is a backward deflection of normal flow by the stenosis, at such a timing that it causes constructive interference and strengthens itself?

[DrCumming]

Just too clarify, when the valves are ballooned, they are essentially disrupted. In most instances they are no longer functional afterwords. In the majority of patients, IVUS has shown that narrowings are related to incompletely opening valve leaflets. So, treatment is aimed at opening the valves. This usually results in tearing or disruption of the leaflets and they no longer can close.

[Cece]

thanks, I'd misused the word 'disruption,' thinking it was the tearing of the annulus of the valve, not just the valves' leaflets.

[DrCumming]

In some instances we are also disrupting the annulus. That used to be the 'goal' of the procedure.

[cheerleader]

New research.
Valves were found in 97% of people in cadaver studies.

http://www.ispub.com/journal/the_intern ... valve.html

The competence of the IJV valve is crucial in maintaining the transcranial blood pressure gradient during cardiopulmonary resuscitation with closed-chest compression.(7) This valve also prevents a sudden increase in the IJV pressure during coughing or during positive pressure ventilation and may thus protect the brain from acute increases in intrathoracic pressure.(8,9) This feature is unimportant in neurologically normal patients, but may be important in patients with compromised cerebral perfusion (e.g.,after head trauma or neurosurgery).(10) At the same time the functional or morphological incompetence or absence of the IJV valves may cause cough headache, cerebral morbidity after positive end-expiratory pressure ventilation and some types of cerebrovascular diseases.(6) Transient mesiotemporal ischemia induced by venous congestion may be a potential cause of transient global amnesia (TGA).(11) In 1998, Lewis originally proposed the venous congestion hypothesis for TGA.(11) which is primarily based on the observation that the onset of symptoms is often correlated with prior Valsalva-like activities, which in turn may lead to venous reflux through the IJV. In anatomical studies, aplasia is reportedly present in as many as 16% of non-selected patients but in these studies valve competence was not assessed.(12) In humans approximately 90% of internal jugular veins have a valve. (13,14) In a preclinical study, Imai et al. reported that competent IJV valves became incompetent after being punctured with a 14-gauge needle.(9) As the IJV valve may be situated slightly above the clavicle at the base of the neck, Imai et al. raised the concern that the valve may be injured in clinical situations when the IJV is cannulated at the lower neck for the insertion of a central venous catheter.(8,9) In our study valves were bilaterally present in 96.7% of the subjects but the clinical importance of such an abnormality is not yet clear. Venous back pressure due to incompetence or absence of the IJV valves may give rise to transient blood flow disturbances in the brain. Incompetence of these valves may be associated with respiratory brain syndrome.(6,11,15,16) Positive end-expiratory pressures for long periods of time may induce incompetence of the IJV valves with subsequent cerebral venous back flow which would contribute to the venous engorgement noted in patients undergoing this form of treatment. The presence and competence of the IJV valves may prevent respiratory brain syndrome. However, a thrombus may easily develop from venous congestion and blood coagulation resulting from IJV catheterization.

Please discuss this research with doctors before having working valves removed. I remain concerned that we still do not understand how valve disruption will affect patients as they age...I still recommend caution going forward. Obviously, if valves are not functioning prior to treatment, this is a non-issue.
cheer

[Cece]

The article that Cheer posted mentions this:

The competence of the IJV valve is crucial in maintaining the transcranial blood pressure gradient during cardiopulmonary resuscitation with closed-chest compression.(7) This valve also prevents a sudden increase in the IJV pressure during coughing or during positive pressure ventilation and may thus protect the brain from acute increases in intrathoracic pressure.(8,9) This feature is unimportant in neurologically normal patients, but may be important in patients with compromised cerebral perfusion (e.g.,after head trauma or neurosurgery).(10)

If we do not have IJV valves, is CPR ineffective and/or dangerous for us?
If post-CCSVI procedure we are "neurologically normal" at least in regards to cerebral perfusion, then the function of the valve as a preventer of sudden pressure increases is unimportant?

[daniel]

New research.
Valves were found in 97% of people in cadaver studies.

...This valve also prevents a sudden increase in the IJV pressure during coughing or during positive pressure ventilation and may thus protect the brain from acute increases in intrathoracic pressure.(8,9) This feature is unimportant in neurologically normal patients, but may be important in patients with compromised cerebral perfusion (e.g.,after head trauma or neurosurgery).(10) At the same time the functional or morphological incompetence or absence of the IJV valves may cause cough headache, cerebral morbidity after positive end-expiratory pressure ventilation and some types of cerebrovascular diseases.(6) Transient mesiotemporal ischemia induced by venous congestion may be a potential cause of transient global amnesia (TGA).(11) ...

...cheer

What are the implications of this? If we've had our jugulars ballooned, should we be avoiding coughing and 'acute increases in intrathoracic pressure' (whatever that means)?