Aim: The aim of this paper is to summarize the experience and results of deep vein thrombosis prevention after standardized abdominal tumor resection and lymph node dissection, and to investigate standardized treatment methods for postoperative thrombosis prevention. Methods: We performed a retrospective analysis of the clinical data for 548 patients who were given low molecular weight heparin, low molecular weight dextran, or IV salvia to prevent thrombosis development between January 2007 and April 2010 after standardized abdominal tumor resection and lymph node dissection. Patients were divided into the following three groups based on the treatment period and treatment schedule: group 1 included 163 patients who had been treated between January 2007 and March 2008 and received a 7-day course of daily low molecular weight dextran (500 mL) and salvia injection (0.2 g) postoperatively; group 2 included 149 patients who had been treated between April 2008 and March 2009 and received a 7-day course of daily low molecular weight dextran (500 mL), salvia injection (0.2 g), and low molecular weight heparin (40 mg) postoperatively; group 3 included 236 patients who had been treated between April 2009 and April 2010 and postoperatively received a 7-day course of daily low molecular weight dextran (500 mL) and salvia injection (0.2 g), and on postoperative day 3 were started on an additional 7-day course of daily low molecular weight heparin (40 mg). Then, we performed comparative analysis of the treatment efficacy and concomitant symptoms. Results: In group 1, 64 of the 163 cases (39.3%) were positive for D-dimer, and 15 (9.2%) cases were positive for DVT based on Doppler imaging of the lower extremities. In group 2, 38 cases (25.5%) were positive for D-dimer and 3 cases (2.0%) for DVT. In group 3, 62 cases (26.3%) were positive for D-dimer and 6 cases (2.5%) for DVT. In general, the administration of low molecular weight heparin for anticoagulation in groups 2 and 3 led to significant reduction of thromboses when compared to group 1. However, altering the initiation day of low molecular weight heparin administration between groups 2 and 3 did not result in significant differences in the rate of thrombosis formation. Through clinical observation, early administration of low molecular weight heparin may increase adverse effects. Conclusion: We have demonstrated the superior efficacy of postoperative administration of low molecular weight dextran and IV salvia with additional subcutaneous injection of low molecular weight heparin on postoperative day 3 to prevent DVT development after radical resection of abdominal tumors.
 J. A. Heit, D. N. Mohr, M. D. Silverstein, et al., “Predictors of Recurrence after Deep Vein Thrombosis and Pulmonary Embolism: A Population-Based Cohort Study,” Archives of Internal Medicine, Vol. 160, No. 6, 2000, pp. 761-768. http://dx.doi.org/10.1001/archinte.160.6.761
 H. Y. Cheung, C. C. Chung, K. K. Yau, et al., “Risk of Deep Vein Thrombosis Following Laparoscopic Rectosigmoid Cancer Resection in Chinese Patients,” Asian Journal of Surgery, Vol. 31, No. 2, 2008, pp. 63-68.
 R. N. Beck, A. Kuzmin, D. Koren, et al., “Asymptomatic Deep Vein Thrombosis in Advanced Cancer Patients: The Value of Venous Sonography,” Journal of Clinical Ultrasound, Vol. 38, No. 5, 2010, pp. 232-237.
 M. Levine, M. Gent, J. Hirsh, et al., “A Comparison of Low-Molecular-Weight Heparin Administered Primarily at Home with Unfractionated Heparin Administered in the Hospital for Proximal Deep-Vein Thrombosis,” The New England Journal of Medicine, Vol. 334, 1996, pp. 677-681.
 J. Muntz, “Duration of Deep Vein Thrombosis Prophylaxis in the Surgical Patient and Its Relation to Quality Issues,” The American Journal of Surgery, Vol. 200, No. 3, 2010, pp. 413-421.
 D. Malinoski, F. Jafari, T. Ewing, et al., “Standard Prophylactic Enoxaparin Dosing Leads to Inadequate Anti-Xa Levels and Increased Deep Venous Thrombosis Rates in Critically Ill Trauma and Surgical Patients,” Journal of Trauma, Vol. 68, No. 4, 2010, pp. 874-880.