2 DCS hits and a PFO closure

[Kevrumbo]

Once again, routine screening of divers for PFO is not recommended, especially not with a highly invasive procedure like intracardiac echo.

Best regards,
DDM

Once again, a non-invasive TCD is better than nothing.

Had it done back in April 2009 which turned out negative, free of charge as part of a control group study at UCLA.

. . .Contrast-TCD is a low cost, easy-to-perform, non-invasive method, the results of which are easy to interpret. TCD allows for a semiquantitative estimation of venous-to-arterial circulation shunts which is backed up by a standardized protocol. . . A contrast agent is prepared by mixing in 9 ml of isotonic saline solution to 1 ml of air. The agent is then injected into a cubital vein. The procedure is repeated once. The air-containing echo contrast agent, in the presence of right-to-left shunt, will bypass pulmonary circulation and induces microembolic signals in the basal cerebral arteries. The monitored Doppler spectra are then stored for offline analysis. . .Proper reviewal of time of occurrence and number of microbubbles is carried out in order to assess the size and functional relevance of right-to-left shunt. . .

How to use contrast enhanced transcranial doppler toward detection and follow-up

 

[dmaziuk]

Wouldn't the MRI show it? -- Just curious.

 

[Kevrumbo]

Wouldn't the MRI show it? -- Just curious.

No, you need real time live detection and imaging sonography. . .

 

[Pullnglide]

I don't think it should be recommended for all divers but it's definitely something for someone doing deeper and longer decompression dives to think about. A TEE wasn't that bad but was expensive and a lot of people have insurance with high deductibles and may not have the financial resources to be tested. I'm not a Dr. and not well versed enough to offer any facts. From what I know a lot of it is all hypothesis. All I know is I've had 2 neurological DCS hits so I chose to have it closed. The future will tell the tale for me.

 

[dmaziuk]

No, you need real time live detection and imaging sonography. . .

http://www.ajronline.org/doi/abs/10.2214/ajr.184.1.01840234

 

[Pullnglide]

Interesting but an MRI can be extremely expensive and there are more conventional ways. I had an MRI done after my last DCS occurence and granted it was a brain/ sprine MRI but the cost was over $7k. My TEE was a little over $2k and I can't remember what the TTE was but it was less.

 

[Kevrumbo]

http://www.ajronline.org/doi/abs/10.2214/ajr.184.1.01840234

". . .Until now, the diagnosis of PFO has not been possible using MRI because of insufficient spatial and temporal resolution and the absence of a measurable shunt volume. . ."

It's a 2005 pilot study for non-invasive MRI application vs invasive TEE which is fine -except MRI and the strong magnetic field generated is contraindicated for patients with pacemakers and implanted heart defibrillators. High-quality images are assured only if you are able to remain perfectly still and follow breath-holding instructions while the images are being recorded.

The constant motion of the heart creates challenges in obtaining clear images. These challenges can be overcome by various techniques including synchronizing the imaging with ECG tracing, synchronizing the imaging with breathing, or having you perform repeated short breath holds during imaging.

And finally, a conventional contrast Trans Cranial Doppler (TCD) is still a lot less obtrusive and a quicker initial diagnostic test than lying still inside an enclosing steel cylinder surrounded by a supercooled magnet.

 

[Pullnglide]

I'm bowing out of this conversation, y'all are speaking above my pay grade

 

[Duke Dive Medicine]

Once again, a non-invasive TCD is better than nothing.

Had it done back in April 2009 which turned out negative, free of charge as part of a control group study at UCLA.

. . .Contrast-TCD is a low cost, easy-to-perform, non-invasive method, the results of which are easy to interpret. TCD allows for a semiquantitative estimation of venous-to-arterial circulation shunts which is backed up by a standardized protocol. . . A contrast agent is prepared by mixing in 9 ml of isotonic saline solution to 1 ml of air. The agent is then injected into a cubital vein. The procedure is repeated once. The air-containing echo contrast agent, in the presence of right-to-left shunt, will bypass pulmonary circulation and induces microembolic signals in the basal cerebral arteries. The monitored Doppler spectra are then stored for offline analysis. . .Proper reviewal of time of occurrence and number of microbubbles is carried out in order to assess the size and functional relevance of right-to-left shunt. . .

How to use contrast enhanced transcranial doppler toward detection and follow-up

TCD is a good screening tool in individuals who need to be screened; however, it's not currently a recommendation for divers. Of course divers can feel free to have themselves screened, it's not harmful in and of itself, but the question then becomes what do to with the results. If a TCD is positive, does the previously healthy diver then pursue a more expensive examination to positively diagnose PFO, and then go through an invasive procedure to have it closed, all in anticipation of the unlikely event of a DCS hit? Or does the diver dive conservatively, which is prudent anyway?

@debersole: question, if you have a moment. How effective is TCD in differentiating PFO from other types of ASD?

Best regards,
DDM

 

[Duke Dive Medicine]

I'm bowing out of this conversation, y'all are speaking above my pay grade

Sorry, it got away from your original post. You were (and are) in excellent hands with Dr. Ebersole and I hope that your closure also closes out your series of DCS hits. Happy New Year!

Best regards,
DDM