Transcranial doppler ultrasonography should it be the first choice for persistent foramen ovale screening?

Abstract

BackgroundPersistent foramen ovale (PFO) is considered a cause of cryptogenic stroke and a risk factor for neurological events in young patients. The reference standard for identifying a PFO is contrast-enhanced transesophageal echocardiography (TEE).The goal of this study was to evaluate the feasibility of transcranial color Doppler (TCD) and its diagnostic sensitivity compared with TEE.MethodsWe investigated 420 patients admitted to our department with cryptogenic stroke, transient ischemic attacks or other neurological symptoms. All patients underwent TCD and TEE evaluation. TCD and TEE examinations were performed according to a standardized procedure: air-mixed saline was injected into the right antecubital vein three times, while the Doppler signal was recorded during the Valsalva maneuver. During TCD the passage of contrast into the right-middle cerebral artery was recorded 25 seconds following the Valsalva maneuver.ResultsWe detected a right-to-left shunt in 220 patients (52.3%) and no-shunts in 159 patients (37.9%) with both TCD and TEE. In 20 (4.8%) patients TEE did not reveal contrast passage which was then detected by TCD. In 21 (5.0%) patients only TEE revealed a PFO. The feasibility of both methods was 100%. TCD had a sensitivity of 95% and a specificity of 92% in the diagnosis of PFO.ConclusionsTCD has a relatively good sensitivity and specificity. TCD and TEE are complementary diagnostic tests for PFO, but TCD should be recommended as the first choice for screening because of its simplicity, non-invasive character, low cost and high feasibility.

The RoPE Score and Right-to-Left Shunt Severity by Transcranial Doppler in the CODICIA Study

“…As previously documented [20,28] we demonstrate moderate agreement between c-TCD and TEE for identifying and grading RLSh. While prior work has suggested that TCD may be a sensitive tool compared to TEE [17,29–33], these prior studies were not performed on large numbers of patients with CS and there is no prior work showing that TCD might be better at distinguishing pathogenically important from less important PFOs.…”

“…[18,19] Although the ability and relevance of RLSh grade evaluated by c-TCD is unknown, some authors have recommended that c-TCD be the first line screening test to detect RLSh for patients with CS. [20] Herein, we investigate whether shunt grade determined by c-TCD is correlated with RoPE score, and also whether c-TCD and TEE agree with respect to shunt identification and grading.…”

Clinical and infarction patterns of PFO‐related cryptogenic strokes and a prediction model

“…Because elderly patients are difficult for TCD, there seemed to be selection bias of patients in this study. However, as a method which could quantify right‐to‐left shunt (RLS) directly, c‐TCD has a class IIa recommendation for RLS detection as well as TEE,41 and have been recommended as the first choice for screening PFO 22. When compared with TEE,42 it has been demonstrated that contrast‐TCD is more feasible in elderly patients.…”

“…As described previously,8, 22 contrast agent was generated by agitating a mixture of 9 mL of isotonic saline solution and 1 mL of air between two 10 mL syringes connected by a three‐way stopcock. A drop of the patient's blood was allowed to mix with the contrast agent, which can slightly increase the detection sensitivity.…”

“…First, we differentiate the cardiac and pulmonary shunt through controlling the time of appearance of microbubbles in the middle cerebral artery, and the signal change after the Valsalva maneuver 22. Second, according to c‐TCD, patients were first divided into five subgroups based on the number of microbubbles (MBs) observed: normal, no MBs; small, 1–9 MBs; moderate, 10–25 MBs; shower, >25 MBs; Curtain: uncountable 24.…”