OBJECTIVETo analyze the relation of plasma D-dimer levels and incidence of deep venous thrombosis after spinal surgery.

METHODSThe clinical data of 63 patients underwent spinal surgery from October 2009 to October 2010 were retrospective analyzed. There were 40 males and 23 females with an average age of 48 years old(21 to 76) in operation. Operation levels of 15 cases were in cervical vertebrae, 4 cases were in thoracic vertebrae,and 44 cases were in lumbar vertebrae. Thirty patients with spinal fracture were caused by trauma and 33 patients without trauma, 11 patients combined with nerve injury. The patients were divided into two groups according to plasma D-dimer levels, more than or equal to 500 microg/L was D-dimer positive group and less than 500 microg/L was D-dimer negative group. Venous blood of all patients early morning with empty stomach were testd on admission, and at 2 h, 1 d, 2 d, 3 d, 4 d, 6 d, 8 d, 10 d, 15 d after operation,respectively.

RESULTSThere was no statistically significant differences in sex, operative segments, implants, operative posture, age, bleed volume, body weight, peroperative D-dimer levels between two groups. After operation, plasma D-dimer of 19 patients were more than or equal to 500 microg/L, with persistent or progressive increasing. Two cases occurred deep venous thrombosis in D-dimer positive group, they respectively were found at 3 days and 8 days after operation. Both of them underwent posterior decompression and internal fixation. However,no deep venous thrombosis was found in D-dimer negative group.

CONCLUSIONPostoperative D-dimer assay can effective predict deep venous thrombosis occurrence. D-dimer level more than or equal to 500 microg/L will be considered as a risk factor for deep venous thrombosis after spinal surgery.