No abstract

Thrombosis remains a significant complication of microvascular free tissue transfer. Recent discoveries in the field of vascular biology have led to a greater understanding of thrombogenesis and the pivotal role that platelets play in the formation of a clot. However, current antithrombotic strategies in the clinical practice of free tissue transfer have not typically focused on platelet inhibition. Decades of cardiovascular clinical trials have delineated the essential role of platelet inhibitor therapy in patients with acute coronary syndromes and those undergoing percutaneous coronary interventions. Understanding the current treatment guidelines for antiplatelet therapy across the spectrum of patients with coronary heart disease may provide insights into their use in the prevention and treatment of thrombosis in microvascular surgery. In this review, we examine the current antiplatelet agents in clinical use and discuss the potential role of platelet inhibition in free flap surgery, particularly in the setting of repeated microvascular thrombosis.

Therapeutic plasma exchange (TPE) removes coagulation proteins, but its impact on therapeutic anticoagulation is unknown. We performed a systematic review of the literature to determine the coagulation effects of TPE in patients receiving systemic anticoagulation. We searched MEDLINE, CINAHL, EMBASE, and Web of Science until June 2018 for studies combining controlled vocabulary and keywords related to therapeutic plasma exchange, plasmapheresis, anticoagulants, and therapy. The primary outcome was the effect of TPE on anti‐Xa activity, activated partial thromboplastin time (aPTT), or international normalized ratio (INR). The secondary outcome was reports of post‐TPE bleeding or thrombosis. A total of 1830 references were screened and eight studies identified. Our selected studies (five case reports and three case series) involved 23 patients and evaluated the effects of seven anticoagulants. Six studies of unfractionated heparin, low‐molecular‐weight heparins, and direct oral anticoagulants demonstrated an anti‐Xa level decline. Two studies of unfractionated heparin and low‐molecular‐weight heparins showed an aPTT increase. One study of warfarin showed a post‐TPE INR increase. Reports of post‐TPE bleeding occurred in two patients and thrombosis in one. In patients receiving therapeutic anticoagulation, TPE is associated with anti‐Xa activity decline and aPTT and INR increase. These coagulation changes do not appear to significantly increase bleeding or thrombotic risk. Our data suggest the need for prospective studies to investigate the true clinical impact of TPE on therapeutic anticoagulation.