Correlation Between The Pulmonary Embolism And Above-knee Deep Vein Thrombosis And Below Knee Deep Vein Thrombosis

ObjectiveTo evaluate the correlation between the pulmonary embolism(PE)and above-knee deep vein thrombosis(AKDVT)and below-knee deep vein thrombosis(BKDVT).MethodsWe retrospectively reevaluated CTPA and color Doppler ultrasound data sets for 910 patients with DVT of lower extremity during hospitalization in The Affiliated Hospital of Taishan Medical College from January 2016 to December 2017.DVT were divided into Above-knee deep vein thrombosis(AKDVT)and Below-knee deep vein thrombosis(BKDVT).BKDVT was defined as any thrombus involving the peroneal vein,tibial vein or Calf muscle vein.AKDVT was defined as any thrombus involving the popliteal vein,femoral vein or external iliac vein.Those patients found to have both a BKDVT and an AKDVT on first positive ultrasound finding were divided into the AKDVT group.The incidence of deep venous thrombosis in lower extremities was compared between the two groups and the incidence of pulmonary embolism(PE)of lower extremity deep venous thrombosis in the two groups were compared respectively.The PE were divided into massive pulmonary embolism(MPE)and non-massive pulmonary embolism.MPE was defined as central pulmonary artery involvement or pulmonary artery obstruction with more than 2 lobes or 7 segments arteries(the lungs are counted according to 20 segments).Beyond the PE above were placed in the non-massive pulmonary embolism group.The incidence of massive pulmonary embolism of lower extremity deep venous thrombosis in the two groups were compared respectively.The difference in occurring PE and MPE between BKDVT and AKDVT groups was analyzed and compared by chi-squared tests.ResultsOf 910 DVTs,188 cases were in the AKDVT group,722 cases were in the BKDVT group,587 cases of isolated calf muscle vein thrombosis in the BKDVT group.There were36 cases of pulmonary embolism in AKDVT patients,and the incidence of PE in AKDVT group was 19.1%.There were 72 cases of pulmonary embolism in BKDVT patients,and the incidence of PE in BKDVT group was 10.0%.The incidence of PE was significantly higher in patients with AKDVT than with BKDVT.The difference in occurring PE between those two groups were statistically significant(P<0.05).There were 31 cases of MPE and 5 cases of non-massive pulmonary embolism in AKDVT patients,and the incidence of MPE in AKDVT group was 16.5%.There were 35 cases of MPE and 37 cases of non-massive pulmonary embolism in BKDVT patients,and the incidence of MPE in BKDVT group was 4.8%.The incidence of MPE was significantly higher in patients with AKDVT than with BKDVT.The difference in occurring MPE between those two groups were statistically significant(P<0.05).Among 587 cases of isolated calf muscle venous thrombosis,64 cases had PE and the incidence of PE in isolated calf muscle venous thrombosis was 10.9%.23 cases had MPE,and the incidence of MPE in isolated calf muscle vein thrombosis was 3.9%.1 case of isolated calf muscle vein thrombosis had fatal pulmonary embolism,and the incidence of fatal pulmonary embolism in isolated calf muscle vein thrombosis was 0.1%.Isolated calf muscle vein thrombosis can also lead to fatal pulmonary embolism.Conclusions1.In addition to the central,peripheral,mixed,proximal or distal thrombosis grouping method according to position,DVT can also be divided into AKDVT and BKDVT according to the risk of pulmonary embolism.2.The incidence of deep venous thrombosis in patients with BKDVT is higher than that with AKDVT,and the isolated calf muscle vein thrombosis was the most common type in BKDVT group.3.The incidence of PE or MPE(imaging classification)in patients with AKDVT is higher than that with BKDVT.The number of PE or MPE(imaging classification)in patients with BKDVT is higher than that with AKDVT.the isolated calf muscle vein thrombosis can also lead to fatal pulmonary embolism.