diving with newly diagnosed brain anurysm

[HBO MD]

Part of the risk in relation to aneurysms are size; Clearly the larger, the greater at risk you are. As highlighted above, sudden elevations in BP, which are often exertional and effort related may place a patient at risk.So another important question, as has already been suggested, is the background upon which this occurs, such as the pre existence of hypertension, diabetes etc.

As to the occurence in a chamber and differentiating between AGE, that can be challenging, however, in the setting of an intracerebral bleed, signs and symptoms would presumably be progressive rather than improve. Alternately in the absence of improvement, or the presentation of NEW signs and symptoms, a CT should clearly demonstrate the presence of a new bleed. This may certainly lead to delay in treatment in the presence of a bleed which is more subtle : say a small sentinel bleed. But I think that any diver who would demonstrate unremitting headache, failure to respond, new signs etc would warrant a CT, especially if the signs are consistent with cerebral or upper motor deficits.

 

[DocVikingo]

I don't see an issue with Valsalva, which will raise intracranial pressure (therefore decreasing the pressure differential across the aneurysm wall) and venous pressures (which you don't really care about).

It certainly would be an issue if it was a venous aneurysm that's involved (admittedly much less common than arterial aneurysm, but they do occur).

And while raising intracranial pressure does decrease rather than increase transmural differential pressure, there still is the mechanical strain of repeated movement of the weakened bulge.

Regards,

DocVikingo

 

[cutlass]

I believe the risk of heavy lifting and Valsalva is mechanical, coming from the flow impulses of rapid BP change. At initiation (Phase I), systolic pressure spikes from compressive forces on the aorta. (Sorry, I don't have any numbers; just trying to recall the physiology.) Then the heart adjusts pulse pressure and output as BP drops and HR increases (Phase II, Frank-Starling mechanism). Also at this time, venous return to the heart falls thereby raising peripheral venous pressure and thus, intracranial pressure. At this point of adaptation, BP should stabilize; transmural pressures should stabilize although perhaps at a higher setpoint. After strain release (Phase III), aortic pressure falls from relief then spikes again as stroke volume climbs with increased venous return and a still-elevated HR; there's a delay before HR returns to baseline (Phase IV). Adding to this complexity is the patient's status in terms of arterial elasticity; e.g. age. Stiffer pipes will better transmit impulse waves than compliant ones which would dampen that energy.

 

[Cruisin Home]

Anuerym risk of bursting is really dominated by three things: size of anneurysm, age, and other risk factors (such as smoking, high BP, etc.) The fact that your doctor, (I assume neurosurgeon0 is leaving it alone is because it is probably small (less than 5mm). The fact that it was found incidentally probalby means that you dont have the other risk factors. I would go on living your life as you would before you noticed it. The bad thing about some of this imaging stuff (some of which I invented) is that when people learn of these little abnormalities they then stress greatly. If you are really worried and it is small speak to an interventional neuroradiologist and talk about endovascular coiling.