warfarin and Mandibular-Neoplasms

In the setting of acute heparin-induced thrombocytopenia (HIT), argatroban is one of the initial anticoagulants of choice, which is eventually bridged to warfarin over a period of 5 or more days. Argatroban prolongs prothrombin time (PT) and increases international normalized ratio (INR). However, the effects of prolonged argatroban exposure on the PT and INR are not known. We describe an unusual case of prolonged argatroban treatment in a patient with heparin-induced thrombocytopenia with thrombosis syndrome (HITTS) resulting in a minimal elevation of the INR. The patient received a total of 58 days of argatroban and was resistant to warfarin therapy, requiring a 13-day bridge to achieve a therapeutic INR of 2.0 to 3.0. Ultimately, argatroban was successfully transitioned to warfarin therapy when the INR was 2.7 on both agents, producing the confirmatory true INR of 2.4. Argatroban and warfarin cotherapy did not increase the INR beyond 4.0 after prolonged argatroban exposure. Clinicians should consider this unusual response in other cases of prolonged argatroban use, and monitor INR carefully during warfarin and argatroban cotherapy. The use of other methods to monitor anticoagulant therapy, such as chromogenic factor X assay (CFX), may be helpful in this setting.

Topics: Anticoagulants; Antithrombins; Arginine; Carcinoma, Squamous Cell; Drug Substitution; Female; Heparin; Humans; International Normalized Ratio; Mandibular Neoplasms; Middle Aged; Mouth Mucosa; Pipecolic Acids; Prothrombin Time; Sulfonamides; Syndrome; Thrombocytopenia; Thrombosis; Treatment Failure; Warfarin

A 46-year-old male sought periodontal care for a swelling on his right mandibular gingiva. An excisional biopsy revealed a well-differentiated squamous cell carcinoma. Surgical treatment consisted of a right segmental mandibulectomy with ipsilateral right neck dissection and fibular free flap reconstruction. Two days after the surgical procedure, a weakened Doppler signal suggested vascular compromise of the graft. The patient was returned to the operating room where complete thrombosis of the internal jugular vein (recipient vessel) was observed. This event prompted a complete hematological evaluation that disclosed low serum levels of protein S. The patient was started on systemic heparin and local medicinal leeches. A week later, systemic warfarin sodium was added and successfully resolved the vascular compromise of the graft. Two years later, the patient is active and lives a full life with occasional adjustments of warfarin sodium. This case represents the first report on the treatment of gingival carcinoma that led to the serendipitous discovery of an unrelated and unusual systemic condition, protein S deficiency.

Topics: Anticoagulants; Carcinoma, Squamous Cell; Gingival Neoplasms; Humans; Male; Mandibular Neoplasms; Mandibular Prosthesis; Middle Aged; Protein S Deficiency; Ultrasonography, Doppler; Warfarin