| Ruud, 2007 | No prophylaxis (n=33) | warfarin (n=29) | 14/29 (48%) | 12/33 (36%) | p=0.44 | Most thrombi were transient | yes (n=11) | >6 mos | 1,3,6 mos |
| Elhasid, 2001 | Matched historical controls (n=50) | LMWH (n=27) | 1/41 (2.4%) | 2/50 (10%) | p<0.05 | 1 patient LMWH had brain infarct | no | 6 mos | 1,3,6 mos |
| Massicottea, 2003 | No prophylaxis (n=80) | LMWH (n=92) | 11/78 (14.1%) | 10/80 (12.5%) | p=0.41 | Bleeding, 2 deaths in control | no; 15%(n=28) were not evaluable | 30 days | 2 weeks |
| Meister, 2008 | Historical controls who got Antithrombin only (n=71) | LMWH and Antithrombin (n=41) | 0/41 (0%) | 9/71 (12.7%) | p=0.02 | no | no | 45 days | 240 days |