ABSTRACT
BACKGROUND: The association between a patent foramen ovale (PFO) and cryptogenic stroke (CS) is well established, and the benefits of PFO closure are clearly recognized. This study aimed to investigate the presence of a residual shunt in patients who have experienced cryptogenic cerebrovascular events following a PFO closure. METHODS: Two researchers systematically searched the PubMed and Embase online database for pertinent clinical studies published between January 2000 and July 2021 concerning the recurrence of cerebrovascular events after PFO closures. RESULTS: Upon screening an initial list of 2,342 articles, six studies were identified, involving 2,083 patients. Overall, the analysis indicated a marked difference in the recurrence of cerebrovascular events in 8.89% of residual shunt (RS) cases compared to only 2.90% of non-RS cases. The summary odds ratio was 3.484 (95% confidence interval, 2.169-5.596), which suggested that RS may be a risk factor for recurrent cerebrovascular events in patients that experienced PFO-related cerebrovascular events within 6 months after PFO closure surgery. CONCLUSIONS: The presence of RS significantly increases the risk of recurrent cerebrovascular events in patients with clinical PFO closure.