Ja. Caprini et al., The influence of oral anticoagulation therapy on deep vein thrombosis rates four weeks after total hip replacement, J VASC SURG, 30(5), 1999, pp. 813-820
Citations number
44
Categorie Soggetti
Cardiovascular & Respiratory Systems","Cardiovascular & Hematology Research
Purpose: The purpose of this study was to assess the rate of postoperative
deep vein thrombosis (DVT) as a function of oral anticoagulation therapy af
ter total hip replacement surgery.
Methods: A total of 125 patients completed the study. All the patients rece
ived sequential gradient pneumatic compression over elastic stockings until
hospital discharge. In addition, all the patients underwent postoperative
heparin therapy followed by oral warfarin therapy, adjusted in dose to main
tain a goal international normalized ratio (INR) level of 2.0 to 3.0. Warfa
rin therapy and compression stockings were continued for 1 month after surg
ery. Bilateral duplex scanning was performed 1 and 4 weeks after surgery to
assess the rate of DVT.
Results: Nineteen of the 125 patients had DVT develop (15.2%). Of those thr
omboses, six (31.6%) and 13 (68%) were detected 1 week and 1 month after su
rgery, respectively. The rate of proximal DVT was 2.4% (3 of 125) 1 week af
ter surgery and rose to 8.2% (10 of 122) 1 month after surgery. Most DVT ca
ses (64%; 12 of 19) were asymptomatic. The patients in whom DVT developed h
ad significantly lower INR values during the second to fourth postoperative
weeks than did those patients without thrombosis, and no differences in IN
R values were found during the first postoperative week.
Conclusion: The risk of the development of DVT extends beyond hospital disc
harge in patients who undergo total hip replacement, despite a regimen of p
rolonged oral anticoagulation therapy. This is particularly true in patient
s whose INR values did not reach therapeutic range during the first postope
rative month. Therefore, thrombosis prophylaxis regimens on the basis of th
e administration of warfarin should try to maintain INR values within thera
peutic range during the entire first postoperative month to minimize the in
cidence of DVT.