Postoperative efficiency and safety of different regimens of low molecular weight heparin on lumbar posterior decompression and fixation

Objective To explore the postoperative efficiency and safety of different regimens of low molecular weight heparin for anticoagulant therapy on lumbar posterior decompression and fixation. Methods From August 2010 to March 2012, 358 patients with lumbar disc degeneration or lumbar fracture underwent posterior decompression and fixation were divided into three groups: minor bleeding group(72 cases), blood loss ≤ 300 ml, anticoagulant drugs were applied 12 h postoperatively; moderate bleeding group(247 cases), blood loss 300-500 ml, anticoagulant drugs were applied 24 h postoperatively; excessive bleeding group(39 cases), blood loss ≥500 ml, anticoagulant drugs were applied 36 h postoperatively. Low molecular weight heparin(LMWH) was dosed as 0.3ml per day, 7 days consecutively. Smoking history, hypertension and diabetes were recorded, and postoperative deep vein thrombosis(DVT), pulmonary embolism(PE) and hemorrhage-related diseases were collected among the 3 groups, respectively. In addition, the association between the risk factors and occurrence rate of postoperative DVT, PE and hemorrhage-related diseases was analyzed. Results Twenty-seven patients suffered from venous thrombus embolism(VTE), in which 10 patients had smoking history, 12 patients had hypertension history, and 8 patients had diabetes history. The average age was 62 years old; the average body mass index was 26.3 kg/m2. In the minor bleeding group, 1 patient suffered from DVT, and the incidence rate of VTE was 1.39%; in the moderate bleeding group, 19 patients suffered from DVT, 2 patients suffered from PE, and the incidence rate of VTE was 8.50%; in the excessive bleeding group, 4 patients suffered from DVT while 1 patient suffered from PE, so the incidence rate of VTE was 12.82%. There are 12 patients suffered from postoperative hemorrhage-related diseases, including epidural hematoma, hematuria and melena, including 3 patients(4.17%,3/72) in the minor bleeding group; 7 patients(2.83%,7/247) in the moderate bleeding group; 2 patients(5.13%, 2/39) in the excessive bleeding group. Conclusion The initial use of LMWH in 12 h postoperatively could decrease the occurrence rate of VTE while have little influence on the incidence of hemorrhagerelated diseases. Additionally, smoking, hypertension, and diabetes are risk factors for the occurrence of postoperative VTE. Key words: Lumbar vertebrae; Spinal fusion; Venous thrombosis; Heparin, low-molecular-weight; Hemorrhage