Transcranial Doppler quantification of residual shunt after percutaneous patent foramen ovale closure. Comparison of two devices.

BACKGROUND: Recurrent paradoxical embolism after catheter-based closure of right-to-left shunt (RLS) can be related to residual RLS. To improve closure success, we need a better understanding of the anatomic and device-related factors associated with closure efficacy. METHODS: Patients with cryptogenic neurologic events and severe RLS (Valsalva Spencer transcranial Doppler [TCD] grade 5/5+) who underwent patent foramen ovale (PFO) closure by either central pin (Amplatzer(®) PFO [A-PFO]) or central occluding (Amplatzer(®) SO [A-SO]) devices were evaluated for residual shunt by quantitative TCD evaluation at 3 months. The findings were correlated with atrial septal aneurysm (ASA), device type, and device size. RESULTS: We closed 628 consecutive patients with either the A-PFO (n = 327) or A-SO (n = 301) device. The frequency of large defects, small defects, and ASA was 12%, 88%, and 44% of cases, respectively. Severe residual shunt was detected in 13% of A-PFO and 7% of A-SO recipients (P = 0.005). This difference was attributable to a much higher frequency of severe residual shunt among patients with large defects closed with the A-PFO compared to the A-SO device (12 out of 29 [41%] vs. 3 out of 42 [7%], respectively; P < 0.001). There was no significant difference in device failure frequency for small defects. The presence of ASA increased the frequency of severe residual shunt compared to those without this feature (36 out of 275 [13%] vs. 28 out of 353 [8%], respectively; P = 0.046) but did not influence device-related differences. CONCLUSIONS: (1) Both noncentering and central occluding closure devices effectively reduce RLS after PFO closure. (2) Large PFO defects with or without ASA have lower residual shunt grades at 3 months when closed by central occluding devices.

Transient neurological symptoms during contrast transcranial Doppler right-to-left shunt testing in patients with cryptogenic neurological disease.

BACKGROUND: Paradoxical embolization from right-to-left shunt (RLS) resulting in neurological events is well described and patients with cryptogenic neurological disease are commonly evaluated for this condition. In the course of testing for RLS by bubble contrast transcranial Doppler (TCD), we observed that some patients developed transient neurological symptoms. This report describes our findings. METHODS: We performed diagnostic TCD on 445 consecutive patients with cryptogenic neurological disease (cerebral vascular accident, 21%; transient ischemic attack, 30%; migraine, 48%; and abnormal magnetic resonance brain imaging, 68%). Immediately following the procedure, patients were questioned about neurological symptoms. RESULTS: One hundred and sixty-three (37%) of the 445 patients had absent or minimal shunting (Spencer grades 0-1) and 233 of 445 (52%) had severe RLS (Spencer grades 4-5+). One or more TCD-associated neurological symptoms (TCD-SX) developed in 95 of 445 (21%) of the patients. Compared to patients with absent or minimal shunting, patients with shunt grades 2-5+ were two and one half times more likely to develop TCD-SX (18/164 [11%] vs. 77/283 [27%], P < 0.001). TCD-SX were fourfold more common among patients with a history of migraine compared to history-negative subjects (35 vs. 8.7%, P < 0.0001). CONCLUSIONS: Diagnostic bubble-contrast TCD provoked transient neurological symptoms. The symptoms correlated with the severity of RLS and were more common in migraine patients, suggesting that migraine patients are sensitized to chemical and/or microembolic shunt factors. There was no significant residual morbidity, and bubble-contrast echocardiograph continues to be a safe and valuable diagnostic procedure.