Twenty-eight patients undergoing marrow
transplantation participated in a pilot study to determine the safety of continuous infusion
heparin for the prevention of veno-occlusive disease (VOD) of the liver. Four doses of continuous infusion
heparin were administered, ranging from a dose prolonging the partial thromboplastin time (PTT) to 1.5-2.0 times the patients' baseline value, to a dose prolonging the PTT to less than 1.2 times the patients' baseline value. Seven patients (25%) received a full course of
heparin, beginning from the day the preparative
therapy started through day 14 post-transplant (range 20-26 days on
heparin). In 21 patients infusions were ended before day 14 post-transplant, a median of 16 days on
heparin (range 1-26 days). Of these, 14 patients were withdrawn from
heparin because of
bleeding and seven were withdrawn because of anticipated
bleeding.
Bleeding was observed in 27 patients and was minor in 25. Two patients developed major
bleeding in the gastrointestinal tract which was not fatal. Minor
bleeding was observed in 27 of 28 case control patients who did not receive
heparin. The sites of
bleeding were similar in control and
heparin treated patients. VOD developed in 20 patients (71%) and was sever or fatal in four (14%). The prevalence of VOD was not influenced by the dosage of
heparin or the duration of its administration. We conclude that low dose
heparin resulting in marginal prolongation of the PTT may be infused into patients undergoing marrow
transplantation with a low risk of serious
bleeding. Further studies are needed to evaluate its efficacy.