PFO morphology for evaluation of c-TCD and c-TTE RLS grades

PURPOSE: The purpose of this study was to observe the morphologic characteristics of patent foramen ovale (PFO) by transesophageal echocardiography (TEE), and to analyze its correlation with right-to-left shunt (RLS) of contrast-transthoracic echocardiography (c-TTE) and contrast-transcranial Doppler ultrasonography (c-TCD). METHODS: 124 patients with PFO were divided into four groups according to the morphological characteristics of PFO. RLS grade of each group PFO with c-TTE and c-TCD in resting and Valsalva manoeuvre was measured. Anatomical structures influencing RLS grade were analyzed statistically through multivariate logistic analyses and predictive models. RESULTS: The 124 cases of PFO were divided into four groups: 55 cases (44.4%) with smooth uniform tubular tunnel (SUT), 21 cases (16.9%) with granule uniform tubular tunnel (GUT), 23 cases (18.5%) of right funnelform, 25 cases (20.2%) of left funnelform. Between group comparisons and multivariate logistic analyses revealed that PFO morphotype and interatrial septum(IAS) mobility were influencing factors of RLS degree. During Valsalva, the probability of c-TCD RLS ≥ 2 for the right funnelform PFO was 13.428 times that of the GUT, one unit increase in IAS mobility increased the probability of c-TCD RLS ≥ 2 by a factor of 2.029, model predicted c-TCD RLS ≥ 2 with 78.1% sensitivity and 94.7% specificity; During Valsalva, the probability of c-TCD RLS ≥ 2 for the SUT PFO was 4.244 times that of the GUT, one unit increase in IAS mobility increased the probability of c-TTE RLS ≥ 2 by a factor of 2.392, model predicted c-TTE RLS ≥ 2 with 80.2% sensitivity and 87.9% specificity. CONCLUSIONS: Studies have shown that the morphological structure of PFO is an influencing factor of RLS, and TEE can observe the specific morphological characteristics of PFO, which can further predict the level of RLS, help predict the occurrence of Cryptogenic stroke (CS). The above provides more evidences and surgical options for Interventional device closure indications.