Probable dalteparin-induced thrombocytopenia with cerebral venous sinus thrombosis following replantation of severed fingers: a case report and literature review

Heparin-induced thrombocytopenia (HIT) is an uncommon but potentially serious adverse effect of heparin therapy and is associated with an increased risk of thrombosis. This case report describes a rare case of probable HIT complicated by cerebral venous sinus thrombosis (CVST) following exposure to low-molecular-weight heparin (LMWH). A 46-year-old man developed severe thrombocytopenia, hypofibrinogenemia, and markedly elevated D-dimer levels nine days after the initiation of prophylactic dalteparin following finger replantation surgery, which ultimately progressed to dry gangrene of the replanted fingers. After discontinuation of argatroban, the patient subsequently developed a severe headache, and neuroimaging revealed sigmoid sinus thrombosis. Confirmatory HIT antibody testing was unavailable in this case. The clinical diagnosis and therapeutic strategy were therefore guided by the 4T score, dynamic laboratory trends, and exclusion of alternative diagnoses rather than serological confirmation of HIT. All heparin products were immediately discontinued, and anticoagulation with the non-heparin agent argatroban was initiated. Because of a temporarily high bleeding risk, anticoagulation was briefly withheld to permit blood product support before transitioning to long-term oral anticoagulation with rivaroxaban. This management strategy resulted in normalization of the platelet count, correction of the coagulopathy, and substantial improvement in CVST on follow-up imaging. This case underscores the importance of considering probable HIT even in patients receiving LMWH, demonstrates the effective sequential use of argatroban followed by a direct oral anticoagulant, and highlights the need for prompt neuroimaging when neurological symptoms develop in patients with probable HIT.