Correlation Factors Analysis For Early Deep Venous Thrombosis After Spine Surgery

Background: Deep venous throbosis(DVT) is one of the most serious conplications in orthopedics.It has a high morbidity and mortality,so how to prevent it effectively and safely is one of the central issues through worldwide. The studies about DVT after spine surgery is increasing overseas, but the internal report of the incidence and correlation factors about this kind of disease is seldom. Whether it is necessary for preoperative anticoagulation remains discussion.Objective: This article explore the rate and correlation factors of early deep venous thrombosis(DVT) on posterior of spine surgery, aim to give some clinial advice of analysing the risk of the getting DVT and protecting the patients from thrombosis.Method: A total of 231 consecutive and independent samples of spinal surgery patients in the Third Hospital of Peking University from April 2009～March 2010. Type-B ultrasonic were examined in lower extremities preoperative and early postoperative patients when the drainage tubes were removed.Classify these cases into two groups, group complicated with DVT and group without DVT .according to age,gender,weight,peripheral surgical complications,smoking and drinking,blood clotting function,preoperative type-B ultrasonic,operating time,blood loss,blood transfusion, post-operative bed time,physical anticoagulation and dehydration drug.All factors were analyzed by Logistic multi-factor regression analysis using SPSS 17.0 statistics software.All the patients that had abnormal results of preoperative ultrasonic were over 50, then use the Chi-square test to analysis this factor for the patients over 50 years old,. Result: There were 231 patients who developed DVT after surgery, including 115 males and 116 females. Age 14~81, 55.6 in average. Preoperative type-B ultrasonic show that 17 patients(7.36%) complicated with chronic DVT or vascular abnormalities. The group without DVT include 190 patient post operation. 41 (17.75%) patients were complicated with early deep venous thrombosis(DVT),in which 5 (2.16%) patients had symptoms. All the patients leave hospital in 6~53 days without death. Advanced age, high blood coagulation status and blood transfusion were associated with occurrunce of DVT postoperatively, with the P value of 0.003, 0.001 and 0.007 respectively(P<0.05).Active exercise of lower extremeties and physical anticoagulation early postoperative can lower the risk of DVT,with the P value of 0.022 and 0.031(P<0.05). The other factors, including gender, body mass index, hypertension, cardiovascular and encephalasthenia disease, diabetes, smoking, drinking, operating time, blood loss and dehydration drug, can not compose as risk factors and protective factors. Their Chi-square values are 0.069, 0.370, 0.499, 0.165, 0.474, 0.119, 0.094, 0.450, 0.089 and 0.997 respectively(P>0.05). In Logistic anylasis the P value of"abnormal results of preoperative ultrasonic"is 0.172(P>0.05), but in Chi-square test, Chi-square value of this factor is 6.88(P<0.05). So abnormal results of preoperative ultrasonic maybe an other correlation factor for the DVT after spine surgery.Conclusion:Patients complicated with deep venous thrombosis after spine surgery can have these characters:①7.36% patients complicated with chronic DVT or vascular abnormalities preoperation;②The incidence of DVT after spine surgery is high,up to 17.75%;③Most of the thrombosis post operation is asymptomatic and easy to misdiagnosis;④Advanced age, high blood coagulation status, abnormal results of preoperative ultrasonic and blood transfusion were associated with occurrunce of DVT postoperatively, active exercise of lower extremeties and physical anticoagulation early postoperative can lower the incidence of DVT;⑤Imaging examination can help to reduce the rate of misdiagnosis of DVT after spine surgery.