Patterns and Distribution of Deep Vein Thrombus in the Lower Extremity

Introduction Practices vary widely among sonography laboratories in the imaging and evaluation of calf thrombus, contributing to diagnostic and treatment uncertainty. Our goal was to isolate and determine patterns of deep vein thrombus to question the level of sonography required for best diagnosis. Materials and Methods We retrospectively evaluated all patients that had a positive venous duplex exam from 2004 to 2013. Our lab performed 11,503 venous studies during the 8-year period, with 382 showing, via symptom review and reporting, acute first-time thrombus. Results Mean age 62 years 8 months old, 209 females (54.71%), 171 male (44.76%), 221 left sided (57.85%), 161 right sided (42.15%). Percentages for the following segments: above the knee (139, 36.39%), calf (375, 98.17%), superficial (54, 14.14%), IVC (14, 3.66%), iliac (36, 9.42%), CFV (67, 17.54%), PFV (7, 1.83%), FV (114, 29.84%), popliteal AK (123, 32.20%), popliteal fossa (142, 37.17%), popliteal BK (148, 38.74%), gastrocnemius veins (141, 36.91%), peroneal (243, 63.61%), posterior tibial vein (191, 50.00%), soleal (109, 28.53%), anterior tibial veins (3, 0.79%), great saphenous vein (38, 10%), small saphenous vein (18, 5%), and varicosities (8, 2%). Conclusion Calf vein thrombus is found with above the knee thrombus (98.17%). Peroneal (63.61%), posterior tibial (50%), gastrocnemius (36.91%), and soleal (28.53%) veins should be routinely imaged. Binomial logistic regression was conducted with eleven-predictor variables significantly predicted proximal thrombus (above the knee). A test with all eleven-predictor variables, compared with the null model, was significant ( x2 [14] = 288.511, p < 0.001), showing that these variables predict above-the-knee thrombus better than without them (or by chance). We have developed a tool that shows the potential trajectories or tracks of a given patient's DVT (with associated probabilities), based on aggregated patient data.