Discussion Of The Risk Factors Of The Lower Limbs Deep Vein Thrombosis And Its Clinical Quantitative Evaluation

Objective：1、 To summarize risk factors associated with lower limbs deep venous thrombosis(LDVT), and analysis its common clinical manifestations, locations and high riskindicators in laboratory test.2、To analysis risk factors associated with LDVT, and try to establish the clinical riskscoring system of LDVT.Methods：Part1：607cases examined by ultrasound examination and diagnosed by clinical asLDVT in our hospital were chosen, and578cases had no thrombosis and thrombosishistory in the same period were selected randomly as control group.Analysis risk factors associated LDVT retrospectively, and record clinicalmanifestations of thrombosis patients by initial visit， positions of blood clots tested byColor Doppler ultrasound and negative laboratory test results.Part2：677cases suspected as LDVT in our hospital were selected continually. Assesseach case’ risk factors associated LDVT，and calculate each indicator’s OR values.According to the epidemiology, OR≤0.3means strong correlation, OR between0.3to3.0means no obvious correlation, OR≥3.0means strong correlation, and OR≥10.0means extremely strong correlation., the assignment is0,1,2,3respectively. Toestablishing quantitative grading system, we quantitative evaluated every researchobject’ risk factors of LDVT, drew ROC curve, got the cut-off point between LDVTand no LDVT, and made the dividing level according to it.Results：Part1：In607cases of thrombosis patients,414cases (68.2%of the total) occurredLDVT in the left leg, compared to193cases(31.8%of the total) occurred in the right. 94.6%(574/607) patients had symptoms,83.7%patients complained of pain, and85.0%patient complained of swelling of lower limbs.98.2%(599/607) patients’ bloodD-dimmer (DD) were more than0.5mg/l,33.8%(206/607) patients’ fibrinogen (FG)were more than4g/l, and30.0%(183/607) patients’ International normalized ratio(INR) were abnormal (normal for2-3). The proportion of patients whose age weregreater than40, or had a surgery history of joint or pelvic recently, or had limitedactivities, or had thrombosis history in three years recently, or had pelvic, pulmonaryand other parts’ malignant tumor, or had heart diseases, diabetes, fracture, soft tissueinjury, joint inflammation, kidney diseases (acute or chronic nephritis, nephriticsyndrome), or had a history of varicose veins more than3years in LDVT patients issignificantly higher than the control group. The difference was statistically significant(P <0.05).Part2：In677cases of the research object,226patients were diagnosed as LDVT bycolor Doppler ultrasound and clinical methods, compared to451patients who were notappearing LDVT. Every patients in research were scored according to OR. In the casesscored2,3,4,5,6,7,8,9,10,11,12points,the constituent ratio of the lower limb DVT was11.34%,12.63%,18.18%,26.23%,30.65%,36.84%,40.31%,52.08%,57.78%,64.44%,81.58%respectively. Through the ROC curves, the Best critical point distinguished theoccurrence of thrombosis is7. LDVT dangerous degree classification：Level1:≤3(thrombosis incidence≤11.98%); Level2:4-6(thrombosis incidence is18.18%-30.65%);Level3:7-9(thrombosis incidence is36.84%to52.08%); Level4:≥10(thrombosisincidence≥57.78%).Conclusion：1、LDVT is associated with disease histories and clinical manifestations, and most ofLDVT patients exist risk factors. Whether the thrombosis is formed is associated withthe degree of risk factors, and it is worth to assess in clinics;2、D-dimmer, fibrinogen, and international normalized ratio can be used as screeningindicators, and the value of D–dimmer is more effective;3、Establishing the clinical risk scoring system of LDVT can forecast LDVT patients with no symptoms conveniently, and improve the ability of early diagnosis;4、LDVT risk scoring system can provide preliminary and reliable basis for clinicalDVT danger level evaluating.