Borow M, Goldson H.
Postoperative venous thrombosis. Evaluation of five methods of treatment.
Am J Surg 1981 Feb;141(2):245-51

Five methods for preventing deep venous thrombosis in postoperative patients were
evaluated and compared with a control group. Five hundred patients from five
surgical specialties were studied. The incidence of deep venous thrombosis was
37.3 percent in the control group but significantly less within all treatment
groups. The minidose heparin group had the highest incidence (26.9 percent)
because there were a large number of bilateral thromboses. The antistasis
modalities did slightly better than the drugs; the intermittent pneumatic
compression group had the fewest thromboses (11.9 percent). The significant risk
factors for postoperative deep venous thrombosis are (1) obesity, (2) malignancy,
(3) a history of venous disease, major surgery or major fracture, (4) length of
surgery greater than 1 hour, and (5) increasing age. Four nonfatal pulmonary
emboli occurred in 500 patients. Two were in women with hysterectomies in whom
thrombosis had never been detected in an extremity; it is presumed that these
clots arose from pelvic veins. It is thus recommended that patients in these high
risk groups be treated prophylactically with one of the aforementioned modalities
to decrease the risk of postoperative deep venous thrombosis. Of the different
methods used to detect deep venous thrombosis, iodine-125 fibrinogen scanning was
superior to both impedance plethysmography and venous Doppler ultrasound. One
hundred percent of the thrombi were identified with scanning, whereas far fewer
were detected with the latter methods. It is recommended that fibrinogen scanning
be used clinically in patients in high risk categories who are undergoing major
operative procedures.