Cutoff Values of Plasma D-Dimer Level in Patients with Diagnosis of the Venous Thromboembolism after Elective Spinal Surgery

STUDY DESIGN: A prospective clinical study. PURPOSE: Our objective in the present study was twofold. First, we sought to evaluate the relationship between postoperative venous thromboembolism (VTE) development and concentration of D-dimer to determine the cutoff value in patients who underwent elective spinal surgery. Second, we identified the predictive risk factors for postoperative VTE. OVERVIEW OF LITERATURE: VTE affects the general health of patients and may even cause death. Since the complications of VTE are difficult to predict, the safest and most cost effective diagnostic method should be used in order to confirm a suspected VTE event after spinal surgery. METHODS: This study was performed on 97 patients who underwent elective spinal surgery. The D-dimer assay was carried out on the day before surgery, and on days 1, 3, and 10 following surgery. VTE occurrence and D-dimer levels were compared between the VTE and the control groups. RESULTS: Four patients (4.1%) were diagnosed with deep vein thrombosis and one patient (1%) was diagnosed with a pulmonary embolism. The optimum D-dimer cutoff value on day 3 following surgery in the VTE group was determined to be more than 2.1 microg/mL with a sensitivity of 100% and a specificity of 80.7%. Moreover, the duration of postoperative recumbency was a significant risk factor for the development of VTE in this study. CONCLUSIONS: We have demonstrated that postoperative D-dimer measurements in patients who underwent elective spinal surgery can provide a complementary diagnostic screening for VTE during the first week after surgery.

Incidence of Venous Thromboembolic Complications in Instrumental Spinal Surgeries with Preoperative Chemoprophylaxis

OBJECTIVE: Venous thromboembolism (VTE) after spinal surgery affects a patients' postoperative recovery and also carries a mortality risk. Some studies recommended chemical prophylaxis for high-risk patients and for those after complex spinal surgeries. However, chemoprophylaxis for VTE in spinal surgery is underemployed and there is no agreement on the use of VTE prophylaxis in spinal surgery. The aim of this study was to document the incidence of VTE after an elective instrumental spinal surgery, among those receiving preoperative chemoprophylaxis as compared with patients who did not receive it. METHODS: This study was carried out on eighty-nine patients allocated randomly to receive either low molecular weight heparin (LMWH) or no prophylaxis before elective instrumental spinal surgery. All patients received postoperative compression stockings. A compression Doppler ultrasonography was performed for all patients to detect postoperative deep vein thrombosis. In addition, further imaging studies were performed for patients suspected of VTE. RESULTS: Three (3.3%) patients were diagnosed with VTE. One of them had received preoperative chemoprophylaxis. There were no significant difference in incidence of VTE between the two groups (p>0.95; 95% confidence interval, 0.06-8.7). Laterality of gender and postsurgical recumbence duration were all independent predictors of VTE (p=0.01 and p<0.001, respectively). CONCLUSION: The difference in the incidence of thromboembolic complications between the two groups was not significant. Moreover, we found that preoperative prophylactic LMWH injection has no major bleeding complications altering postoperative course; still, the issue concerning the initiation time of chemoprophylaxis in spinal surgery remains unclear.