Contrast-Enhanced Transcranial Doppler for Detecting Residual Leaks—A Single-Center Study on the Effectiveness of Percutaneous PFO Closure

<b>Background:</b> A persistent connection between the atria, known as a patent foramen ovale (PFO), is present in approximately 25% of the general population. PFO closure is indicated in patients under 60 years of age who have experienced an embolic stroke of undetermined source (ESUS) or transient ischemic attack (TIA) confirmed by neurological imaging, and in selected cases of peripheral embolism. Follow-up after the procedure is indicated to confirm the position of the occluder, assess the effectiveness of the closure, and evaluate any potential thrombus formation on the device. <b>Methods:</b> We analyzed data from 75 consecutive patients who underwent percutaneous PFO closure procedures and were followed up for at least one year. The procedure was performed under fluoroscopy and transesophageal echocardiography (TEE) guidance, and occluder size selection was made using TEE multiplanar imaging (MPR). All patients had standard transthoracic echocardiography (TTE) at 1 and 6-12 months after the procedure. To assess the long-term efficacy, contrast-enhanced transcranial Doppler (ce-TCD) was performed at 12 months to record high-intensity transient signals (HITSs). Cases with positive ce-TCD had TEE performed. <b>Results:</b> During follow-up evaluations after 1 and 6-12 months (TTE), we did not observe any device dislodgements, thrombi, or residual leaks visible in TTE. ce-TCD detected HITSs in eight patients, prompting additional TEE examinations performed in seven cases. In five out of seven patients, a leak around the occluder was identified, including two patients with grade 2 HITSs. <b>Conclusions:</b> Assessing the effectiveness of PFO occluder placement is crucial for the residual embolic risk and thus the necessity of antithrombotic therapy. Even low grades of HITSs observed in ce-TCD help to identify patients with residual leaks confirmed in TEE.