Postoperative Versus Preoperative Initiation of Deep-Vein Thrombosis Prophylaxis with a Low-Molecular-Weight Heparin (Nadroparin) in Elective Hip Replacement

Abstract

The aim of this multicenter, randomized, double-blind study performed in patients undergoing elective hip surgery was to compare the efficacy and safety of prophylaxis with low-molecular-weight heparin (LMWH) (Nadroparin, 7,500 anti-Xa IC units for the first 3 days and 10,000 from the fourth day on, s.c. o.i.d.) begun in one group shortly after surgery and in the other 12 h before operation, as is usually recommended. Preoperative administration (drug or placebo) was the only difference between the two groups. Deep vein thrombosis (DVT) was detected by bilateral venography 10-15 days after surgery. The study investigated 179 patients (55 men), 40-80 years old, in seven Italian orthopedic centers. In 131 patients efficacy analysis was possible because of adequate bilateral venography. All 179 patients were evaluated for bleeding complications. The prevalence of thrombotic complications was similar in the two groups. Proximal DVT was found in 8.4% of patients (10.8% and 6.1% in the preop and postop groups, respectively ; difference not statistically significant). Distal DVT was recorded in 30.5% of patients (30.8% and 30.3% in the pre-and postop groups, respectively). DVTs were more common in patients &ge;65 years old (54.2% versus 28.4%, p < 0.05); no significant differences were detected in terms of other characteristics. No significant differences were recorded in the number or type of bleeding complications: major (nonfatal) bleeding episodes were reported in five patients (2.8%, two and three in the preand postop groups); minor bleeding was noted in 25 (13.9%, 14 and 11 in the pre-and postop groups). In conclusion, the present study suggests that a LMWH regimen started postoperatively is no less effective in preventing DVT in elective hip replacement than the classical regimen started preoperatively. Surprisingly, postoperative commencement offered no significant advantage in terms of bleeding complications.

Prevention of Venous Thromboembolism in High-Risk Surgical and Medical Patients

“…The two reviews yielded to discordant results, as Kearon and Hirsh failed to show a difference in efficacy between preoperative and postoperative-initiated LMWH prophylaxis for THR patients, 35 whereas Hull et al concluded that preoperative initiated LMWH was significantly more effective when compared with postoperative-initiated LMWH. 36 Three studies have directly compared preand postoperative commencement of LMWH prophylaxis, the first two in patients undergoing elective hip surgery, 16,37 and the last one in patients undergoing surgery for hip fracture. 38 As shown in Table 7, the first study did not show appreciable differences between the two strategies, 37 the second showed a higher risk of major bleeding in case of a early initiation, 16 and the third study (although conducted in fewer patients) showed an impressive superiority of the preoperative initiation in case of hip fracture.…”

“…36 Three studies have directly compared preand postoperative commencement of LMWH prophylaxis, the first two in patients undergoing elective hip surgery, 16,37 and the last one in patients undergoing surgery for hip fracture. 38 As shown in Table 7, the first study did not show appreciable differences between the two strategies, 37 the second showed a higher risk of major bleeding in case of a early initiation, 16 and the third study (although conducted in fewer patients) showed an impressive superiority of the preoperative initiation in case of hip fracture. 38 The comparability between these studies is problematic because of different study designs, patient population, and drug utilized.…”

Heparins and Venous Thromboembolism: Current Practice and Future Directions

“…The two reviews yielded discordant results, as Kearon and Hirsh failed to show a difference in efficacy between preoperative and postoperativeinitiated LMWH prophylaxis for THR patients (84), whereas Hull et al concluded that pre-operative initiated LMWH was significantly more effective when compared with postoperative-initiated LMWH (85). Three studies have directly compared pre-and postoperative start of LMWH prophylaxis, the first two in patients undergoing elective hip surgery (82,86), and the third in patients undergoing surgery for hip fracture (87). The first study did not show appreciable differences between the two strategies (86), the second showed a higher risk of major bleeding with early initiation (82), and the third (although conducted in fewer patients) showed an impressive superiority of the preoperative initiation in patients with hip fracture (87) ( Table 11).…”

“…Three studies have directly compared pre-and postoperative start of LMWH prophylaxis, the first two in patients undergoing elective hip surgery (82,86), and the third in patients undergoing surgery for hip fracture (87). The first study did not show appreciable differences between the two strategies (86), the second showed a higher risk of major bleeding with early initiation (82), and the third (although conducted in fewer patients) showed an impressive superiority of the preoperative initiation in patients with hip fracture (87) ( Table 11). As the comparabil-ity between these studies is problematic due to different study designs, patient population and drug utilized, the problem remains open.…”

Optimal Timing of Perioperative Chemical Thromboprophylaxis in Elective Major Abdominal Surgery

“…Consequently, chemoprophylaxis timing is frequently based on personal experience and surgical dogma, leading to significant and often irrational variability in practice 5. Notably, evidence in other fields, such as orthopedic surgery, suggests that preoperative initiation of chemoprophylaxis confers no additional benefit for reducing VTE risk compared with postoperative 6. In addition, in several general surgery cohorts, initiation before skin closure increased the risk of postoperative bleeding 7.…”