PFO Diagnosis

[fisherdvm]

If I had my way, I would do a full body MRI

Why am I interested? To be honest, I would spend hours looking at every little detail if I were to get an MRI. I'm no hypochondriac; I'm just really interested in what makes me tick

It would be interesting to see if I have a PFO. If I did, I would probably dive more conservatively.

I know centers around here advertising for a whole body cat scan.... From what I understand, the virtual colonscopy is quite good. Disadvantage is you can't biopsy any lesions you see, but it is non invasive.

I think we grossly under diagnose ovarian cancer, so such a test, if done correctly could pick up those.

But over-diagnosis is not necessary a good thing. I think if every man had a transrectal ultrasound of the prostate, we'd pick up alot more prostate cancer... But the over diagnosis of this type of cancer, I believe, can result in treating some prostate cancer that would never advance, and really, never causes any problem.

We'll see within the next 10 years whether these whole body scan will be a standard of care... Bet cha it will cost a bundle, and insurance will not pay for it.

 

[DandyDon]

We'll see within the next 10 years whether these whole body scan will be a standard of care... Bet cha it will cost a bundle, and insurance will not pay for it.

Even if covered, who pays the costs anyway...?

Ah, the extreme life of the extremist....!

 

[rjack321]

TTE is unreliable for PFO detection, don't bother.

TCD is the latest and greatest non-invasive test with a pretty high sensitivity relative to the "gold standard" of TEE. Without the risks of sedation and the whole gag thing. Cheaper too.

Here's the paper a number of us are using when thinking about methods for PFO detection/analysis:

http://www.ncbi.nlm.nih.gov/entrez/...ve&db=pubmed&dopt=Abstract&list_uids=11020748

Transcranial Doppler ultrasonography as a screening technique for detection of a patent foramen ovale before surgery in the sitting position.Stendel R, Gramm HJ, Schroder K, Lober C, Brock M.
Departments of Neurosurgery, Anesthesiology and Critical Care Medicine, and Cardiology and Pulmonology, Benjamin Franklin Medical Center, Freie Universitat Berlin, Berlin, Germany. stendel@medizin.fuberlin.de

BACKGROUND: Venous air embolism has been reported to occur in 23-45% of patients undergoing neurosurgical procedures in the sitting position. If venous air embolism occurs, a patent foramen ovale (PFO) is a risk factor for paradoxical air embolism and its sequelae. Preoperative screening for a PFO is therefore recommended by some investigators. The reference standard for identifying a PFO is contrast-enhanced transesophageal echocardiography (c-TEE). Contrast-enhanced transcranial Doppler ultrasonography (c-TCD) and contrast-enhanced transthoracic echocardiography (c-TTE) are noninvasive alternative methods, but so far there are no studies as to their diagnostic validity in neurosurgical patients. METHODS: The sensitivity and specificity of c-TCD and c-TTE in detecting a PFO were determined in a prospective study using c-TEE as the reference standard. Preoperative c-TCD, c-TTE, and c-TEE studies were performed during the Valsalva maneuver after intravenous echo-contrast medium (D-Galactose, Echovist-300, Schering AG, Berlin, Germany) was administered in 92 consecutive candidates (47 men and 45 women; mean age, 51 yr; range, 25-72 yr) before neurosurgical procedures in the sitting position. RESULTS: A PFO was detected in 24 of the 92 patients (26.0%) using c-TEE. c-TCD correctly identified 22 patients, whereas c-TTE only correctly identified 10. This corresponds to a sensitivity of 0.92 for c-TCD and 0.42 for c-TTE. The negative predictive value was 0.97 for c-TCD compared with 0.83 for c-TTE. The prevalence of a PFO in patients with a posterior fossa lesion was 27%, and in the group with cervical disc herniation was 24% as detected by c-TEE. The incidence of intraoperative venous air embolism was 35% in cases of cervical foraminotomy and 75% in posterior fossa surgery as detected by c-TEE. CONCLUSIONS: c-TCD is a highly sensitive and highly specific method for detecting a PFO. Because c-TCD is noninvasive, it may be more suitable than c-TEE for routine preoperative screening for a PFO. C-TTE is not reliable in detecting a PFO.

 

[rjack321]

We'll see within the next 10 years whether these whole body scan will be a standard of care... Bet cha it will cost a bundle, and insurance will not pay for it.

Not likely, they increase your risks of lung cancer. Not much radiation there, but some.

PFOs are not evaluated by CT - they don't do flow.

 

[limeyx]

TTE is unreliable for PFO detection, don't bother.

TCD is the latest and greatest non-invasive test with a pretty high sensitivity relative to the "gold standard" of TEE. Without the risks of sedation and the whole gag thing. Cheaper too.
...

do any locations actually perform the TCD? How does it compare $-wise to TEE?

I have Kaiser care right now, so I am guessing I am SOL

 

[Gene_Hobbs]

So why are you guys interested in PFO exams? Any indicators at all....???

This is an older article now but it is a good start...
Patent Foramen Ovale: Background and Impact on Divers by NW Pollock, PhD

From there, the PubMed search engine is a good place to start finding info on the specific exams. There is a continuing flood of literature coming out on the exams as they are important in areas of clinical research (stroke, migraine, etc.).

Several of the Pollock references can be found in the Rubicon Research Repository if you are interested. (18 hits for the term "PFO".)

 

[rjack321]

do any locations actually perform the TCD? How does it compare $-wise to TEE?

I have Kaiser care right now, so I am guessing I am SOL

In Seattle, yes. Try these people down your way:
http://www.surgery.usc.edu/divisions/vas/noninvasivevascularlab.html

Sorry can't help with costs.

 

[Hemlon]

:lol: Well put.

And not something I'd think about doing purely as a precaution. As rare as unexpected hits are, I think I'll wait...

So why are you guys interested in PFO exams? Any indicators at all....???

I was wondering the same thing, Dan.

 

[lamont]

Debersole is the cardiologist, I think.

I believe the gold standard is a TEE with bubble test. The TEE is done with sedation, and the transducer is passed through the mouth into the esophagus. This is not much different from upper endoscopy, a common procedure performed for the diagnosis of ulcers or esophagitis. There is mild discomfort from the gag reflex (which is numbed) as the probe is introduced, and little discomfort thereafter. The procedure is generally not remembered, due to the sedative drugs used.

Transesophageal echocardiography gives a much better picture of the atrial septum, which is why it is preferred to transthoracic echocardiography. It is more expensive, because a technician can do a standard echo, but the TEE requires someone who is trained in the procedure of passing the probe. In addition, the patient has to be monitored during the sedation, the drugs have to be administered, and there is recovery time for the patient to awaken.

I think my cardiologist actually disagrees. Since with a TEE the patient is sedated its harder to find a PFO that only opens under strain. With a conscious patient doing a TTE with bubbles you can have the patient cough or valsalva and see the PFO. He had one patient recently who got a TEE and they didn't see anything but the TTE found the PFO which only opened up under straining.

 

[adjuster-jd]

So if you have PFO which only opens when straining would that be something that needs repaired or would that typically be something to leave alone?