Postoperative Deep Vein Thrombosis

Subcutaneous heparin therapy has been shown in several recent studies to be an effective agent in the prevention of postoperative deep vein thrombosis (DVT). However, DVT has not been abolished by such therapy and an increase in haemorrhagic complications, notably wound haematomata, has been reported after its use.

In an ongoing double blind randomised controlled study the effects of heparin on DVT and postoperative complications have been correlated with blood heparin levels. Thus far some fifty patients have been studied with the following preliminary conclusions :

(I) Subcutaneous heparin administration results in markedly variable blood levels,

being maximal two hours after injection at between 0.01-0.30 I.U./ml. (II) 12-hourly injections of 5000 I.U. heparin did not have a cumulative effect over one week.

(III) Of seven patients with blood heparin levels in excess of 0.2 I.U./ml, four developed a wound haematoma. Of seventeen patients with blood heparin levels of less than 0.2 I.U./ml only two patients developed this complication.

(IV) Thus far ¹²⁵I-Fibrinogen detected DVT has not occurred in the heparin treated patients.