Ultrasonic Grading Of Veins Of Lower Extremity From Normal To Thrombosis: A Prospective Preliminary Study.

Objective:To observe the changes in lower extremity venous B-scan and corlor Doppler ultrasound images and laboratory findings in different levels, and evaluate the ultrasonic grading of lower limb vein from normal to thrombosis and the clinical value on diagnosis and treatment of DVT, so as to provide reference for clinicans to manage the DVT-related disease.Methods:A total of 186 in-patient subjects were enrolled in this prospective study. They were aged from 23.0 to 92.0 years old with a mean age of 67.93 years and a standard deviation 13.75 years. The subjects with circulatory disturbance caused by heart disease, or clinical symptoms and signs of DVT in upper extremity or other body part, or cancer,trauma and surgery within six months were excluded from the study, as these parameters have been associated with D-dimer. Ultrasound examinations were performed independently by two experienced sonographers with the same instrument and parameter setting. GE Vivid7, TOSHIBA xario machines with a 5-10 MHz linear-array transducer was used. Recorded the vein diameter and blood flow velocity. All of the subjects were divided prospectivly into four groups: Normal, the veins of lower extremity appeared as a echoless tube or fast axial flow echogenic dots toward heart, and CDFI was good after deep breathing, active toes exercise, or pressing in the distal calf. EPTS, The lumen of vein was filled with dense echogenic dots, and flow to the heart was continuously, slowly, and the vein was variable-deflated with pressurizing probe. In this stage, the vein was not filled before deep breathing, active toes exercise or squeeze the distal calf, but it was filled after those maneuvers; APTS, the vein may be dilated, and filled with dense echogenic dots and the flow was back and forth only with the breath or leg pressurized. The compressibility of the vein was also observed with pressurizing probe. In this stage, the vein was not filled before active toes exercise or squeeze the distal calf, and was filled poorly or not filled after pressurizing; DVT: The vein diameter may be expanded, the lumen was not flattened or partially flattened when pressured probe, the vein was not filled, thinned or "rail sign" was observed in CDFI.The amount of plasma D-dimer and FIB, PLG count, and the time of APTT, PT, TT were also determined by the AMELUNG AMAX 200 automatic blood coagulation analyzer. Statistical analyses were performed by SPSS13.0 software.The chi square test was used to evaluate the differences among the count data. If the measurement data variance was homogenous, evaluated by the LSD examination of the analysis of variance(ANOVA), and the variance was heterogeneous, comparions applied Tamhane's T2 examination. The diagnosis concordance of different method was assessmented with kappa test and Receiver Operating Characteristic(ROC) curve analysis. Ps<0.05 were considered to be statistical significant.Results:1. Among these 186 subjects, 40 of them met the ultrasonic criteria for Normal. In this group, 21 were men and 19 were women with the mean age of 68.1±14.2 years; 41 of them were in the stage of EPTS(25 were men and 16 were women with the mean age of 69.3±11.6 years); 49 of them were in the stage of APTS (34 were men and 15 were women with the mean age of 66.5±13.9 years); Finally, 56 subjects met the criteria for DVT(27 were men and 29 were women with the mean age of 67.2±17.2 years). There was no significant difference in age(P>0.05) among the groups by NAOVA. The analysis of the accompanying diseases was no significant difference among the groups(P>0.05).2. Only 4 out of 186 cases(2%) were not classified in the same group by the physicians. There was no significant difference between the prospective diagnosis of different physician(kappa-test,χ2=452.27, K=0.89).3. Using analysis of variance on the diameter and peak flow velocity of veins of lower extremity.3.1 The posterior tibial vein(PTV) diameter in APTS and EPTS level was widened, and there was significant difference compared with Normal level, and the difference between APTS and EPTS, APTS and DVT level also had significance difference, respectively(P<0.05), however, there was no significant difference between DVT and EPTS level, DVT and Normal level, respectively(P>0.05).3.2 The medial gastrocnemius vein(MGV) diameter increased in APTS level, and there was significant difference compared with the Normal level, while there was no significant difference among other stages with Post-Hoc Comparisons, respectively(P>0.05).3.3 For the diameter of the common femoral vein(CFV), superficial femoral vein (SFV), popliteal vein (POV), none of them has significant difference comparison among groups(P>0.05).3.4 The peak velocity(Vp) of CFV, SFV in the DVT and APTS, POV of the APTS slowed down, respectively, and compared with the Normal, there was significant difference(P<0.05). There has no significant difference between Vp of the CFV, SFV and POV in APTS compared with DVT and EPTS, respectively(P>0.05). There was no significant difference in DVT and Normal about POV peak velocity(P>0.05).4. The concentration of plasma D-dimer among the groups has statistically significant difference(χ~2-test,χ~2=23.80, P=0.00), However, there were no significant difference in concentration of D-dimer between the DVT and the APTS, and between the EPTS and the Normal(χ~2-test,χ~2=0.03, p=0.87;χ~2=3.38, p=0.07, respectively).5. The constituent ratio of the D-dimer-positive rate had no significant difference between the DVT and APTS, EPTS and Normal(kappa-test, P>0.05, respectively). Taking DVT and APTS for the ultrasound-positive, and concentration of plasma D-dimer more than 500μg/L for the positive, there was a good consistency between the two methods(kappa-test,χ~2=48.70, K=0.73, Se, 80%, Sp, 76%).6. The ROC curves plot sensitivity on the ordinate axis and 1- specificity on the abscissa. The area under ROC curve is 0.81, standard error, 0.05. The four levels method of ultrasound imaging has high value. 7. There was significant difference among the groups in the FIB, TT and PLT(P<0.05, respectively), however, there were no significant difference in concentration of FIB between the DVT and APTS level, EPTS and Normal level(P>0.05). The TT was shorten in the APTS and DVT stage, and there has no statistically significant difference between 2 levels at random except the APTS and Normal, DVT and Normal stage(P>0.05, respectively). The PLT increased in EPTS stage compared with others and has significant difference(P<0.05), while there was no significant difference among other stages(P>0.05). There was no statistically significant difference among the groups in the APTT and PT(P>0.05, respectively)。8. There had 18 cases underwent utrasound re-evaluation 1 to 2 weeks later, 2 cases of APTS progressed to LE-DVT who didn't receive the anticoagulants therapy, the EPTS and Normal level subjects had found no DVT. The patients who has treatment of drug therapy or physiotherapy, the speed of echogenic spots flow was increased or they became echo-free lumen, as well as symptomatic was improved. There were no significant changes in B-mode or CDFI for the patients without any treatment in the APTS and EPTS level. No patient with DVT was re-examined.Conclusions:1. In this study, there has good correlation between the changes of the lower extremity vein ultrasonogrames and the concentration of D-dimer, FIB and TT, which were the important biochemical index of the DVT and PTS.2. Based on the changes of the echo and CDFI filling in the vein, the method of lower extremity vein ultrasonograms grading 4 levels from Normal to DVT has a higher accuracy on the diagnosis of lower extremity thrombosis. The vary images could be recognized with the same diagnose standard by different physician.3. In this study, the PTV and MGV diameter were dilatation and Vp was slowed in APTS stage, and the changes of coagulation and fibrinolysis in APTS stage were similar with DVT stage, the APTS stage have high risk in developing thrombosis or have existed micro-thrombosis. The index of coagulation and fibrinolysis in the EPTS is similar to the Normal level, and with no obvious thrombosis tendency. APTS stage is closer to DVT stage than EPTS.4. The ultrasonograms grading method could be of great value in making decision for clinicians managing a patient with a clinical suspicion of DVT.