Surgical or medical treatment for thrombus straddling the patent foramen ovale: impending paradoxical embolism? Report of four clinical cases and literature review.

Background: Thrombus straddling the patent foramen ovale (TSFO) is a rare event. It occurs in the presence of pulmonary embolism and can be responsible for paradoxical embolism. The aim of this report is to guide the optimal choice of treatment for TSFO in different clinical contexts.

Methods: A PubMed search was conducted of articles published between 1985, when the first TSFO was reported, and 2007. We identified 93 cases of TSFO diagnosed by echocardiography, nine of which were excluded because of lack of information. We analysed data from these 84 patients plus a further four seen at three French cardiology departments.

Results: The patients' mean age was 58 years. Pulmonary embolism was present in 94% of cases, and was severe in 34%. Paradoxical embolism, before or after treatment, was found in 44% of cases. Fifty-five patients were treated surgically, 21 were treated with heparin, and 11 received thrombolysis. The mortality rates for the treatments were 13, 14 and 36%, respectively. Patients who received heparin were older (60+/-17 years) and had more strokes (11/21) than the surgical group (56+/-15 years, 14/55). The group that received thrombolysis was more likely to have haemodynamic compromise.

Conclusion: Medical treatment with heparin tends to be used as a second option in patients with more frequent comorbidities and strokes but the mortality rate is similar to that in the surgical group. Surgery seems to be justified in the prevention of paradoxical embolism. Thrombolysis is more frequently chosen in the higher risk group and is associated with the greatest mortality.