Anatomical Significance of the Patent Foramen Ovale by Real-Time 3D TEE in Cryptogenic Stroke and Migraine

Background: The transesophageal echocardiogram (TEE) is the standard imaging modality for confirming the presence or absence of patent foramen ovale. PFO is a flap valve depending on the pressure change between the left and right atrium, which can help determine whether to open. 3D-TEE was shown to optimize the visualization of PFO. There is a causal association between PFO and unexplained stroke. It seems that 3D-TEE can present a high-risk PFO morphological feature, which seems to show more than just being easier to open. Methods: In total, 134 consecutive patients with cryptogenic stroke or migraine who had suspected PFO and underwent c-TCD, TTE, and c-TEE were included in this study. TEE confirmed the PFO. The right-to-left shunt (RLS) grade of PFO at rest and abdominal compression Valsalva maneuver was detected by c-TEE. Results: The long diameter of FO (1.74 +/- 0.3 vs. 1.60 +/- 0.4, p = 0.039), the short diameter of FO (1.12 +/- 0.3 vs. 1.00 +/- 0.3, p = 0.036), perimeter of FO (4.62 +/- 0.7 vs. 4.22 +/- 1.0, p = 0.026), and area (1.80 +/- 0.8 vs. 1.35 +/- 0.8, p = 0.05) of the FO were significantly larger in the larger RLS group. In group of CS, a larger proportion of Eustachian valve or a Chiari's network (14.3% vs. 3.5%, p = 0.036), a larger proportion of in the left funnelform (55.1% vs. 16.3%, p < 0.001), a longer length of the PFO tunnel (13.4 +/- 4.4 vs. 7.8 +/- 2.5, p < 0.001), a lower IVC-PFO angle (16.4 +/- 3.4 vs. 20.3 +/- 7.7, p = 0.001), a higher proportion of LA multiple exits of the tunnel (46.9% vs. 14.3%, p < 0.001). Multivariate regression analysis showed that male gender (HR: 4.026, 95% CI: 0.883-18.361, p = 0.072), age (HR: 1.076, 95% CI: 1.002-1.155, p = 0.045), the left funnelform (HR: 7.299, 95% CI: 1.585-33.618, p = 0.011), a longer length of the PFO tunnel (HR: 1.843, 95% CI: 1.404-2.418, p < 0.001) and multiple exits of the tunnel of LA (HR: 8.544, 95% CI: 1.595-45.754, p = 0.012) increased the risk of cerebral infarction. The cut-off value calculated by ROC for the diagnosis of high-risk PFO was that the length of the PFO tunnel was 12 mm and the left funnelform combined with multiple exits of the left atrial (sensitivity was 92%, specificity was 90%). The area under the curve of the combined index versus PoPE score (0.932 vs. 0.736) relative to the RoPE score was statistically significant. Conclusions: TEE has shown outstanding advantages in displaying the specific morphological characteristics of PFO. The left funnelform, a longer length of the PFO tunnel, and multiple exits of the tunnel of LA are associated with an increasing risk of CS in anatomical PFO respect.