Power m-mode transcranial Doppler for diagnosis of patent foramen ovale and assessing transcatheter closure.
OBJECTIVE
Transcatheter closure of patent foramen ovale (PFO) can benefit from a less invasive diagnostic method than transesophageal echocardiography (TEE). Thirty-three gate power m-mode transcranial Doppler (pmTCD) was evaluated for its accuracy in diagnosis of PFO and utility in evaluating residual intracardiac right-to-left shunt (RLS) following transcatheter closure.


METHODS
The sensitivity of pmTCD and single-gate TCD (sgTCD) to detect contrast bubble emboli through RLS was compared during transcatheter PFO closure. During 100 preclosure diagnostic evaluations and in 81 postclosure assessments, embolic tracks on pmTCD were counted following intravenous contrast injections and were graded using a 6-level logarithmic scale. The accuracy of TEE and pmTCD was separately compared to PFO anatomical findings during transcatheter closures.


RESULTS
There were significantly more microemboli detectable on pmTCD (322 +/- 166; 95% confidence interval [CI], 388-257) than on sgTCD (186 +/- 109; 95% CI, 229-143; P < .001). McNemar change tests suggest that the diagnostic capabilities of pmTCD and TEE for detecting PFO are comparable and correspond to the anatomical findings determined during cardiac catheterization (P = .69 and .45, respectively). During 6-month postclosure evaluation (mean = 185 days), 66% of the patients demonstrated successful closure without significant RLS (ie, grades 0, I, or II), and 34% were found to have incomplete closure with significant RLS (ie, grades III, IV, or V).


CONCLUSIONS
pmTCD provides greater sensitivity to contrast bubble emboli than does sgTCD. Among candidates for transcatheter closure, pmTCD provides an improved noninvasive method for diagnosing PFO and evaluating transcatheter closure.
Spencer
Merrill P
MP
Spencer Vascular Laboratories, Seattle, Washington 98104, USA. merrill@spencervascular.com
Moehring
Mark A
MA
Jesurum
Jill
J
Gray
William A
WA
Olsen
John V
JV
Reisman
Mark
M
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D006328:Cardiac Catheterization; D004617:Embolism / Q000000981:diagnostic imaging / Q000209:etiology; D005260:Female; D006344:Heart Septal Defects, Atrial / Q000000981:diagnostic imaging* / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D017585:Ultrasonography, Doppler, Transcranial / Q000379:methods*