A Cochrane review included 2 studies with a total of 79 subjects. One trial (n=20) examined the efficacy of intravenous (iv.) unfractionated heparin. The other trial (n=59) examined high dose, subcutaneous, low-molecular weight heparin (nadroparin). Anticoagulant therapy was associated with a pooled relative risk of death of 0.33 (95 % CI 0.08 to 1.21) and of death or dependency of 0.46 (95 % CI 0.16 to 1.31). No new symptomatic intracerebral haemorrhages were observed. One major gastro-intestinal haemorrhage occurred after anticoagulant treatment. Two control patients (placebo) had a diagnosis of probable pulmonary embolism (one fatal).
Comment: The quality of evidence was downgraded by inconsistency (heterogeneity in treatments) and imprecise results (limited study size for each comparison) and upgraded by large magnitude of effect. The statistically non-significant benefit observed would be clinically highly significant.
A large prospective international study recruited 624 patients with sinus thrombosis. In acute phase 83% were anticoagulated with iv. heparin or subcutaneous low-molecular-weight heparin (LMWH) in therapeutic dosages. A total of 79% had full recovery, 8% had minor handicaps, 5% were severely handicapped, and 8% died.