Table 1.

Summary of studies on the frequency of DVT/PE in patients with CS linked to PFO.

References	Patient with CS linked to PFO: % of the whole cohort (n)	Work-up for VTE	Days between Index stroke and VTE work-up	Frequency of DVT/PE in patients with CS linked to PFO
Lethen et al. (15)	23% (n = 53)	Venography	8 ± 3	DVT: 9.5% (5/53) PE: N/A
Cramer et al. (16)	100% (n = 37)	VenographyMRV	8	DVT: 27% (10/37) PE: N/A
Lapergue et al. (17)	100% (n = 114)	Combined CT-Venography and pulmonary angiography	4–9	VTE: 10.5% (12/114) DVT: 8.8% (10/114) Silent PE: 4.4% (5/114)
Osgood at al. (18)	100% (n = 50)	MRV	4 ± 3	DVT: 8% (n = 4) May Thurner Syndrom*: 10% (n = 5) PE: N/A
Tanislav et al. (19)	100% (n = 151)	Ventilation perfusion scintigraphy	N/A	DVT: 7% (n = 11) Silent PE: 37% (n = 56)
Ranoux et al. (20)	19.1% (n = 13)	Venography	0–38	DVT: 8% (n = 1) in a plegic leg 14 days after index stroke PE: N/A

PFO, patent foramen ovale; CS, cryptogenic stroke; PE, pulmonary embolism; DVT, deep vein thrombosis; VTE, venous thromboembolism; MRV, magnetic resonance venography; N/A, not available. *May Thurner Syndrome indicates an anatomical variation, in which the origin of left V. iliaca communis is being anatomically narrowed by the right A. iliaca communis. This reduces venous blood flow, increasing the risk of DVT (21).