Retrospective study on clinical features and interventional therapy of acute deep venous thrombosis of lower extremity combined with type Ⅱ heparin-induced thrombocytopenia / 中华放射学杂志

ABSTRACT

Objective To explore the clinical features, diagnosis and interventional management of acute deep venous thrombosis of lower extremity (LEDVT)combined with type Ⅱ heparin-induced thrombocytopenia (HITⅡ) and to improve the knowledge of this disease. Methods A retrospective review and analysis of the clinical data of the patients with acute LEDVT combined with HIT Ⅱ enrolled from January 2010 to June 2014. All of them underwent anticoagulation with low molecular weight heparin (LMWH) and the comprehensive interventional therapy at the beginning of treatment.When HIT Ⅱ was identified, all forms of heparin and LMWH were avoided . Alternative anticoagulation was commenced with argatrobam. Adjustments in interventional therapy were taken while the short-term low-dose glucocorticoid treatment were used.The clinical manifestations, changes of PLT, 4Ts score (Warkentin 4T scoring system, 4Ts) , HIT antibody assay (ELISA) and response to therapy of the patients were analyzed and the treatment effect was observed . The efficacy of interventional therapy was evaluated according to the improvement clinical symptoms and venography. Results The incidence of acute LEDVT combined with HIT Ⅱ was 1.9%(8/416). There were 4 males and 4 females with a median age of 24 years in this study. The median time between their initiation exposure to heparin and onset of thrombocytopenia was 5 days (range,3 to 8 days). The median platelet counts prior to HIT Ⅱ was 218 × 109/L( range,122 × 109/L to 254 × 109/L ). Platelet counts decreased to the lowest level range from 20 × 109/L to 51 × 109/L(median 32 × 109/L). After alternative anticoagulation, the interval period which PLT recovered to the basic level was range from 3 to 7 days (median 3.5 days) . According to the score of 4Ts , there were 2 cases score 6 and 6 cases score 8. HIT antibody assay (ELISA) was detected in 6 patients which the results were positive. During heparin anticoagulation treatment, the LEDVT condition of all patients continued to deteriorate. Vein thrombosis extended in 7 patients. Among them, 5 patients occurred new thrombosis in the inferior vena cava and(or) at the vessel of catheter insertion. Another 2 patients complicated with pulmonary embolism. After underwent anticoagulation with argatrobam , with the increased of PLT the treatment efficacy of thrombolysis therapy was ameliorated. At the endpoint of interventional therapy, the curative effect evaluation was excellent in 3 cases, good in 3 cases and medium in 2 cases respectively. All patients were followed up for 12 to 20 months (median 15.5 months) with no evidence of recurrence .Conclusions The study showed that acute LEDVT combined with HITⅡdisplayed the following features(1)an absolute drop in platelet count below the normal range (PLT ≤100 × 109/L) or as a relative decrease of 30% to 50% from baseline counts. (2) refractory venous thrombosis,during the interventional treatment of acute LEDVT, platelets counts should be monitored regularly in patients who receiving heparin anticoagulation. For patients with strongly suspected HIT Ⅱ, withdrawal of all forms of heparin and early introduction of alternative anticoagulant therapy can improve the effect of interventional therapy.