Girth theory: Pumping vs. clamping

… although the nature of the College of Bullshit’s endowment might be of a considerably different character than the kind of endowment that most members here join for …

Yes, it would be a log of a different color.

I hope you don’t mind, but I’m going to correct something you said. As I said in an earlier post, lymph is the fluid in lymph vessels that drain to lymph nodes and ultimately back into the blood circulation. Fluid outside cells is called extracellular fluid (ECF). When ECF increases and causes swelling (aka, fluid build up) it is called edema. This edema fluid will overtime enter the lymph channels and “become” lymph. It may sounds like a case of semantics, but this is the more correct terminology. It’s kinda like capitalizing Kegel, it’s just what it’s called.

In a couple of posts ttt and I talked about the factors that cause fluid to leave the blood vessels (at the capillaries) and become ECF (and if too much, edema). It is a balance between 2 factors. One is the pressure difference between inside of the capillaries (which is 30 - 50 mm Hg) and outside the capillaries (which can be between -3 to 5 mm Hg). This difference would cause the fluid in the blood to exit the vessels and become ECF. The other factor is caused by the differences between the amount of proteins inside (high) and outside (low) the capillaries. Blood proteins do not pass out of the capillary. This difference in proteins tends to draw water back into the blood vessels by osmosis and “holds on” to it; water travels back into the capillary because amount of water is higher outside the vessel and lower inside the blood because of the proteins. (mravg - this is a difference between hydrostatic pressure and oncotic pressure).

The balance between these 2 factors in normal situations keeps fluid inside the blood vessels. There is a small leak normally and this is why there is a lymphatic system in the first place; take ECF back to the blood and keep the space outside of the cells relatively “dry.”

Pumping and clamping alter this balance.

Pumping causes the pressure outside the capillaries to become very negative. This causes the pressure difference between inside and outside to become even larger. This causes fluid to exit and increase ECF. As pumping is sustained, the negative pressure difference remains high and over time fluid builds up (edema).

Clamping increases the pressure in both the arteries and veins so that the pressure difference across the capillaries gets higher and fluid would leave into the the ECF. The difference between clamping and pumping is that the clamps keep the ECF from moving around and leave the penis. Because of this, pressure outside the capillaries rises quickly, balancing the pressure difference and the fluid loss will be small. The other thing is that clamp times are short, so the time for fluid loss is also short.

I think this is the reason for the differences in fluid build up (edema) between pumping and clamping. I hope this is clear.

ttt - Now who’s being too academic? :)

Thanks 3T. I’m not familiar with that equation, but it looks like it is basically saying that volume of fluid filtered is a function of the difference between internal and external pressures. So, You are saying the tissue above the tunica has some tension on it that reduces the effect of the vacuum on the tunica. That may well be at least part of the explanation. But after I typed my question I thought about something else:

A clamp stops the flow of blood into the CC’s as well as into the tissue and skin external to the tunica (and lymph as well?)

On the other hand, inflow and outflow are not effected by vacuum pumping.

Therefore, as you pull a vacuum, you are pulling more lymph into the penis, and more plasma is filtering through the capillary and cell walls into the interstitial spaces. (I am theorizing, not stating this as fact).

I don’t think it matters if you are at full erection or not. If you assume vacuum pumping at full erection, and assume all blood flow out of the CC’s is stopped, there would still be blood and lymph vessels open on the exterior tissues and skin. So, you end up with blood and lymph flowing into the skin as long as you are pulling a vacuum, and more and more of that fluid ends up as edema.

So to summarize my latest theory: Clamping is more effective than vacuum pumping because clamping closes off fluid flow into the superficial tissues of the penis, which prevents the problem of lymphedema. In contrast, vacuum pumping allows blood and lymph to flow into those superficial tissues, causing fluid build up to increase the longer the vacuum is applied.

The net result of this difference is that equivalent stress can not be placed on the tunica with vacuum pumping compared to clamping.

How does that sound?

Pud, I posted my last post before I read yours. I have been basically using lymph, edema, ECF as interchangeable. Thanks for the clarification, but in general, do you agree with the basic idea as I stated it?

Yes, I think what we are saying is similar. I was thinking about clamps stopping fluid from entering the penis, you are pointing out it also prevents it from leaving, and more importantly, that the clamp increases pressure outside to balance the pressure inside the vessels!
both things are true, no?

There is your discoloration.

The Starling equation (that ttt posted) explains the reason why there is a difference in fluid build up (edema) between clamping and pumping. Edema is a side effect and is variable from individual to individual. But I do not believe that edema explains the difference in success between pumping and clamping (if there is one; and you’ll get a lot of debate from both sides on this one).

A basic question from a guy who never pumped: The amount of vacuum used during pumping is relatively small compared to how much vacuum could be pulled (6 inches compared to full vacuum of 29 inches or so.) What is the reason pumpers don’t go to higher vacuums? Is it fluid build up? Pain? Intense pressure inside the penis?

I don’t pump either. But let me take a stab at this one and the pumpers can comment and tell me whether I’m full of it.

The recommended pressure appears by my reading is 6 inches Hg (about 150 mm Hg). This by report causes the penis to become very engorged (and sometimes reaches peak erection; Thunder: see I hedged my bet on this again). If you reach an adequate sustained tunica tension with this level of negative pressure, any increase pressure (more negative) would cause more edema and not necessarily more tension.

Thunder, I am saving my pennies to buy a pump.

I did use higher pressures than we recommend here now. Nothing crazy though. Well maybe a couple times. ;)

It does get uncomfortable. My main reason not to go nuts was I didn’t like looking like the Pillsbury Dough Boy lent me his dick.

Stay tuned and maybe some of these hot shot pumpers will give you their opinions.

Yes, your basic idea is correct. I’m just picky on terminology.

Yes.

Yes Thunder, there is your discoloration. This is a good example to show why that even if the blood flow to the cavernosa ceases at peak erection, skin blood flow continues. That is why the color remains good. When flow ceases, as with clamping, the penis gets that dark dusky color.

So you don’t like it when your penis looks like the Michelin Man. It definitely gives you girth. :)