The Clinical Study Of Deep Vein Thrombosis In Patients With Thoracolumbar Fractures Caused By High-energy Injuries

Part 1 Prevalence and predictors for preoperative deep vein thrombosis in patients with thoracolumbar fractures caused by high-energy injuriesObjective: The incidence of deep vein thrombosis(DVT)in spinal fractures is underestimated,especially in thoracolumbar fractures caused by high energy-injuries.Researches have focused on postoperative DVT,with few studies on preoperative prevalence.The purpose of this study was to determine the prevalence of DVT and to identify the predictors for preoperative DVT in patients with thoracolumbar fractures caused by high-energy injuries.Methods: There were 429 patients with thoracolumbar fractures caused by high energy-injuries from October 2016 to November 2019 included in this retrospectively study.The patients were examined with ultrasonography before operation and divided into DVT group and non-DVT group.Demographic data and laboratory results were collected.Mechanical and chemical prophylaxis were used for DVT.The incidence of DVT was evaluated and the predictors of preoperative DVT were identified by multivariate logistic regression analysis and receiver operating characteristic curve(ROC)analysis.Results: The overall incidence of preoperative DVT was14.45%(62/429).One patient(0.23%)had proximal DVT and sixty-one(14.22%)patients had distal DVT.The incidence of preoperative DVT in patients with thoracic fractures was 24.59% and 11.04% with lumbar fractures.Multivariate logistic regression identified three predictors:lower extremity motor(P < 0.001),time from injury to operation(P<0.001)and D-dimer(P=0.001).Lower extremity motor<3 score,time from injury to operation>3 days and D-dimer>1.81mg/L showed satisfied accuracy for predicting preoperative DVT.The ROC analysis indicated that the diagnostic value of D-dimer was highest whose AUC(area under the ROC curves)value was 0.769.Conclusion: Despite mechanical and chemical prophylaxis,the incidence of preoperative DVT is still very high,especially in thoracic fractures.Lower extremity motor<3 score,time from injury to operation>3 days and D-dimer>1.81mg/L are predictors for preoperative DVT.More attention should be paid to prevent preoperative DVT when these predictors exist,especially with two or more.Part 2 Diagnostic performance of Caprini risk assessment model combined with D-dimer for preoperative deep vein thrombosis in patients with thoracolumbar fractures caused by high-energy injuriesObjective: The purpose of this study was to assess the validity of Caprini risk assessment model(RAM)in risk stratification for DVT and to investigate the diagnostic value of Caprini score combined with D-dimer in predicting DVT in patients with thoracolumbar fractures caused by high-energy injuries.Methods: This cross-sectional study was conducted in our hospital between October 2016 and November 2019.Demographic and DVT data were collected.Patients were risk-stratified using the 2013 Caprini RAM.Mechanical and chemical prophylaxis were used for DVT.Duplex ultrasound of both lower extremities was performed before surgery.Results: Of the 429 patients,62(14.45%)developed DVT.There were a total of 61 patients with distal DVT,only one patient with proximal DVT.The incidence of preoperative DVT was correlated with Caprini score according to risk stratification(X2=117.4,P<0.001).Based on the original Caprini RAM,all the patients scored in the highest risk category(score ≥ 5).Further substratification showed that the majority(277/429,64.57%)of the patients was in the Caprini score 7-8 and the risk of preoperative DVT was significantly higher among patients with Caprini score>10,as compared with patients with Caprini score of 5 to 6(OR 72.92;95%CI 9.42-564.42),7 to 8(OR 20.98;95%CI 10.36-42.50)and 9 to 10(OR 6.20;95%CI 2.45-15.69).The area under ROC curve of Caprini score and D-dimer was 0.816 and 0.769 when Caprini score>8 or D-dimer>1.81mg/L was considered the criterion of predicting the risk of DVT.When combined the two variables,the area under ROC curve can increase to 0.846.Conclusion: The Caprini RAM is an effective and reliable DVT risk stratified tool for patients caused by high-energy injuries,though the Caprini score was high in this population.Caprini score>8 or D-dimer>1.81mg/L may predict the occurrence of preoperative DVT and the Caprini score combined with D-dimer exhibits better diagnostic performance.These patients need more effective preventive schemes for DVT.Part 3 Incidence and risk factors of postoperative deep vein thrombosis in patients with thoracolumbar fractures caused by high-energy injuriesObjective: To determine the incidence of deep vein thrombosis(DVT)and to evaluate the risk factors of DVT in patients with thoracolumbar fractures caused by high-energy injuries postoperatively.Methods: The study retrospectively analyzed 534 patients with thoracolumbar fractures caused by high-energy injuries who underwent surgical treatment in our hospital from January 2016 to November 2019.Medical record data,including demographic data,perioperative variables,and laboratory results,were collected.Duplex ultrasound of both lower extremities was performed for DVT evaluation after surgery.Mechanical and chemical thromboprophylaxis were used for DVT.The incidence of DVT was determined and risk factors of DVT after surgery were identified by univariate analysis and binary logistic regression analysis.We used receiver operating characteristic(ROC)curve analysis to evaluate the diagnostic value of different factors.Results: The overall incidence of postoperative DVT was18.91%(101/534).Three patients(0.56%)had proximal DVT and ninety-eight(18.35%)patients had distal DVT.The incidence of postoperative DVT in patients with thoracic fractures was 26.80% and 15.50% with lumbar fractures.The multivariate analysis showed that six risk factors increased the incidence of postoperative DVT,including advanced age,decreased lower extremity motor,blood transfusion,duration of bed rests,fibrinogen(FIB),and D-dimer.The ROC analysis of these potential risk factors indicated that the diagnostic value of D-dimer was highest whose AUC(area under the ROC curves)value was 0.754.Conclusion: In patients with thoracolumbar fractures caused by high-energy injuries,despite mechanical and chemical thromboprophylaxis,the risk of postoperative DVT is still very high,especially in thoracic fracture.Advanced age,decreased lower extremity motor,blood transfusion,duration of bed rests,FIB,and D-dimer are risk factors for DVT.Moreover,the diagnostic value of D-dimer is highest among these factors.Part 4 Dynamics of D-dimer in patients with thoracolumbar fractures caused by high-energy injuries and its association with postoperative deep vein thrombosisObjective: The clinical relevance of D-dimer levels when screening for deep vein thrombosis(DVT)in patients with thoracolumbar fractures caused by high-energy injuries has been reported but has not been fully investigated.The purpose of this study was to find the dynamic variation of D-dimer and to evaluate the efficacy and accuracy of D-dimer level as a screening tool in such patients.Methods: A total of 121 patients with thoracolumbar fractures caused by high-energy injuries were retrospectively enrolled in our hospital.The D-dimer levels were measured 1 day before surgery and on the 1st,3rd,and5 th days after surgery.All patients underwent routine ultrasonography preoperatively and postoperatively.The dynamic variation of D-dimer and the effects of risk factors on D-dimer levels were analyzed by statistical analysis.Receiver operating characteristic(ROC)curve analysis was done and the appropriate D-dimer cutoff level was determined for DVT screening.Results: D-dimer levels increased unsustainably after surgery(P < 0.001)due to a trough on the third day,and patients with operation time >120min(P=0.009)and those with ASIA score A-C(P<0.001)had higher D-dimer levels.Area under the curve of D-dimer was greatest on the third day(0.844[P < 0.001,95% CI: 0.767-0.904]).Applying stratified cut-off values did not change the sensitivity,specificity and negative predictive value in the group with an operation time >120 min,and ASIA score A-C group.Conclusion: D-dimer levels elevated with fluctuation in such patients after surgery.Operation time and ASIA score had an impact on D-dimer levels.With regard to DVT diagnosis,the diagnostic value of D-dimer was highest on the third day postoperatively and stratified cutoff values by these two factors didn’t show better diagnostic efficacy compared with a collective one.