Transcranial Doppler as a Screening Tool for High-Risk Patent Foramen Ovale in Cryptogenic Stroke

Effects of morphological characteristics of patent foramen ovale by transesophageal echocardiography on minimalist transcatheter closure in southern China

OBJECTIVES

Transcatheter closure has become one of the main treatment methods for patent foramen ovale (PFO). However, the population in southern China is generally thin and the size of PFO is small, so the application of minimalist surgery is challenging. This study aimed to analyze the morphological characteristics of PFOs in southern China by transesophageal echocardiography (TEE), and to explore the influence on minimalist transcatheter closure.

METHODS

About 110 patients with PFO closure in our hospital were selected. All cases were examined by TEE including the PFO size, length, septum secundum thickness, color characteristic and surrounding structures, and morphologically classified. During the operation, the procedure time, number of times for the guidewire attempting to pass the interatrial septum and the success rate of simply using J guidewire to cross the interatrial septum were recorded.

RESULTS

About 110 cases of PFO were classified into two categories and four subtypes, including 55 cases with Uniform Channel Type (UCT, 50.0%), 16 cases with Irregular Channel Type (ICT, 14.6%), 15 cases with Right Funnel Type (RFT, 13.6%), and 24 cases with Left Funnel Type (LFT, 21.8%). According to the complexity of the procedure, they were divided into simple procedure (n = 73) and complex procedure (n = 37). Multivariate logistic regression showed that the anatomical types of PFO, the tunnel entrance size, and the tunnel entrance size <2 mm were independent factors affecting the complexity of procedure [OR = 2.819, 95% CI (1.124, 7.066), p = .027; OR = .027, 95% CI (.004, .208), p = .001; OR = 4.715, 95% CI (1.028, 21.619), p = .046]. With ICT and LFT groups, the procedure duration was relatively long (p < .001), number of times for the guidewire attempting to pass the interatrial septum was significantly increased (p < .001), and the success rate of simply using J guidewire to cross the interatrial septum was relatively low (p < .001).

CONCLUSIONS

The PFO size in southern China was relatively small and characterized by large tunnel tension. It was concluded that TEE could clearly show the morphological characteristics of PFO, which could provide guidance for making more reasonable surgical plans in clinical practice, shorten the procedure time and improve the success rate of PFO closure.

Differences in clinical and biological factors between patients with PFO-related stroke and patients with PFO and no cerebral vascular events

Background

While stroke is one of the most dissected topics in neurology, the primary prevention of PFO-related stroke in young patients is still an unaddressed subject. We present a study concerning clinical, demographic, and laboratory factors associated with stroke and transient ischemic attack in patients with patent foramen ovale (PFO), as well as comparing PFO-patients with and without cerebrovascular ischemic events (CVEs).

Patients and methods

Consecutive patients with PFO-associated CVEs were included in the study; control group was selected from patients with a PFO and no history of stroke. All participants underwent peripheral routine blood analyses, as well as, on treating physician's recommendations, screening for thrombophilia.

Results

Ninety-five patients with CVEs and 41 controls were included. Females had a significantly lower risk of CVEs than males (p = 0.04). PFO size was similar between patients and controls. Patients with CVEs had more often hypertension (n = 33, 34.7%), p = 0.007. No significant differences were found between the two groups with regard to routine laboratory tests and thrombophilia status. Hypertension and gender were identified in a binomial logistic regression model as independent predictors for CVEs, but with an area under the ROC curve of 0.531, suggesting a very poor level of discrimination between the two groups.

Discussion and conclusions

There is little difference between patients with PFO with and without CVEs in terms of PFO size and routine laboratory analyses. While still a controversial topic in the specialty literature, classic first-level thrombophilic mutations are not a risk factor for stroke in patients with PFO. Hypertension and male gender were identified as factors associated with a higher risk of stroke in the setting of PFO.

Residual Right-to-Left-Shunt Following Transcatheter Patent Foramen Ovale Closure: The Role of Antithrombotic Treatment

BACKGROUND

Transcatheter closure of patent foramen ovale (PFO) is a highly effective therapy for patients with left circulation thromboembolism, not attributable to other conditions.

OBJECTIVES

This retrospective cohort study investigates the impact of baseline foramen ovale anatomy on the severity of the postclosure shunt.

METHODS

Patients with PFO, who underwent percutaneous closure, were followed up for at least 5 years postimplantation. Patients were classified into two groups based on the presence of high-risk features of the baseline PFO anatomy. At the follow-up follow-up, residual right-to-left shunt was assessed for the high and non-highrisk anatomy groups, via transcranial Doppler at rest and after performing the Valsalva maneuver, with the injection of agitated saline.

RESULTS

38 patients were examined after a mean follow-up period of 9 ± 3 years after implantation. After retrospective evaluation of the baseline transthoracic and transesophageal echo studies, 14 patients with high-risk PFO anatomy were identified. The degree of the residual right-to-left shunt, as assessed by the number of microbubbles was higher in the high-risk PFO anatomy group compared to the non-high-risk group, both at rest [1.50 (IQR: 0.00-3.25) vs. 0.00 (IQR: 0.00-0.00), p < 0.001] and post-Valsalva maneuver [7.50 (IQR: 1.50- 10.25) vs. 0.00 (IQR: 0.00-3.75), p = 0.003]. Furthermore, in the high-risk group, more microbubbles were detected at rest (p = 0.008) and post-Valsalva (p = 0.002) in subjects without antiplatelet treatment compared to subjects on prolonged antiplatelet therapy.

CONCLUSION

Baseline PFO anatomy affects the severity of the residual right-to-left shunt. Prolonged antiplatelet therapy may benefit patients with high-risk anatomical features.

Point-of-Care Ultrasound in Neurology - Report of the EAN SPN/ESNCH/ERcNsono Neuro-POCUS Working Group

In the last decade, ultrasound examination in neurology has been undergoing a significant expansion of its modalities. In parallel, there is an increasing demand for rapid and high-quality diagnostics in various acute diseases in the prehospital setting, the emergency room, intensive care unit, and during surgical or interventional procedures. Due to the growing need for rapid answers to clinical questions, there is particular demand for diagnostic ultrasound imaging. The Neuro-POCUS working group, a joint project by the European Academy of Neurology Scientific Panel Neurosonology, the European Society of Neurosonology and Cerebral Hemodynamics, and the European Reference Centers in Neurosonology (EAN SPN/ESNCH/ERcNsono Neuro-POCUS working group), was given the task of creating a concept for point-of-care ultrasound in neurology called "Neuro-POCUS". We introduce here a new ultrasound examination concept called point-of-care ultrasound in neurology (Neuro-POCUS) designed to streamline conclusive imaging outside of the ultrasound center, directly at the bedside. The aim of this study is to encourage neurologists to add quick and disease-oriented Neuro-POCUS to accompany the patient in the critical phase as an adjunct not a substitution for computed tomography, magnetic resonance imaging, or standard comprehensive neurosonology examination. Another goal is to avoid unwanted complications during imaging-free periods, ultimately resulting in advantages for the patient.

Estimation of patent foramen ovale size using transcranial Doppler ultrasound in patients with ischemic stroke

BACKGROUND AND PURPOSE

Patent foramen ovale (PFO)is associated with cryptogenic stroke, especially in young adults. Transcranial Doppler (TCD) ultrasound is used as a screening tool before transesophageal echocardiography (TEE). However, the use of Valsalva maneuver (VM) to identify a right-to-left-shunt underlies interindividual variability. Here, we aimed to assess whether a pressure-controlled standardization of VM is useful to estimate PFO size.

METHODS

We included patients aged 18-80 years with a PFO according to TEE. Subjects underwent TCD with microembolic signals (MES) counted under four pressure conditions (i.e., at rest, 15 mbar, 40 mbar, and maximum expiratory pressure). Findings were correlated with TEE-based PFO size. The predictive value of TCD at rest and VM-based TCD for PFO size estimation was assessed by stepwise multivariate linear regression models and multiple cross-tab-analyses.

RESULTS

We screened 203 subjects after a cerebrovascular event, of which 78 (48 males [61.5%], median age 55 years [22-80]) with PFO were included. We found an association between MES count and expiratory pressure (p < .001). Predefined MES count categories at TCD pressure conditions correlated significantly with PFO size measured by TEE. We propose a PFO size estimation model based on TCD at rest and under VM, which classified PFO size correctly in 64.1% with the highest accuracy for small PFOs.

CONCLUSION

Our data provide evidence that TCD with step-wise barometric standardization allows an estimation of PFO size with good accuracy. Though TCD will not replace TEE in future, this might be of clinical value in circumstances where TEE cannot be easily performed.