Objective:
The World Health Organization approved the use of ChAdOx1 nCoV-19 (Astra Zeneca) vaccine since the outbreak of the COVID-19 pandemic in 2019. It has proven beneficial but in a limited number of the general population was found to be associated with vaccine induced immune thrombotic thrombocytopenia (VITT). Currently, there has been no reports of this complication occurring in a microsurgical free tissue transfer.
Material and Methods:
A case report reviewed at Dalin Tzu Chi Hospital in 2021.
Results:
A 49-year-old man with history of hypertension, diabetes mellitus and end stage renal disease on hemodialysis received his first dose of ChAdOx1 nCoV-19 in June 2021. He went on to develop an acute myocardial infarction 3 weeks after that. Cardiac catheterization revealed triple-vessel disease and coronary artery bypass surgery was performed. He recovered without further complications. Three months later, he presented with right third toe wet gangrene with extension into the plantar foot nine days after receiving his second ChAdOx1 nCoV-19 vaccine. Work-up showed his platelet count to be 140 x 103/ul, D-dimer was 4916 ng/ml and anti–platelet factor 4 (PF4) antibodies was 83.77 ng/ml. VITT was diagnosed. Due to the large soft tissue defect with bone exposure, a free vastus lateralis muscle flap was performed for limb salvage. The flap was complicated by persistent partial necrosis of superficial portion of the flap without vascular pedicle compromise. Repeated debridement of the superficial necrosis was done. Three months after the development of VITT, no further new superficial necrosis was seen. The flap was skin grafted for final coverage. A well contoured flap was seen 5 months after the initial surgery.
Conclusions:
We believe this is the first case describing microthrombi in the free flap due to VITT after microsurgical reconstruction. Patients and surgeons should be advised of this possible risk when contemplating microsurgery once VITT has developed after ChAdOx1 nCoV-19 administration.
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