Thrombocytopenia and Neurosurgery: A Literature Review.

INTRODUCTION: The absence of evidence-based guidelines for platelet transfusion surrounding invasive neurosurgical procedures leads to uncertainty in management. Multiple studies have illuminated this lack of high quality data, and subsequent reliance on expert opinion. The generally accepted threshold for platelet transfusion has hovered around 100,000/µL. METHODS: We have conducted a review of available clinical literature to identify any evidence that may support or refute these general guidelines, in an attempt to clarify the need for platelet transfusion in the patient requiring neurosurgical intervention. RESULTS: The available evidence is sparse and of low quality, but suggests that a platelet count <100,000/µL is associated with increased risk of hemorrhagic complications. In addition, the acuity of thrombocytopenia, magnitude of decrease in platelet count, and responsiveness to platelet transfusions impact the risk of neurosurgical intervention, and should be taken into account when evaluating a patient's surgical candidacy. Higher quality, prospective studies on the subject are unlikely, given a general lack of clinical equipoise on the subject, and the ethical concerns such a study would present.

The gracilis myocutaneous free flap in swine: an advantageous preclinical model for vascularized composite allograft transplantation research.

Vascularized composite allotransplantation (VCA) has become a clinical reality, prompting research aimed at improving the risk-benefit ratio of such transplants. Here, we report our experience with a gracilis myocutaneous free flap in Massachusetts General Hospital miniature swine as a preclinical VCA model. Fourteen animals underwent free transfer of a gracilis myocutaneous flap comprised of the gracilis muscle and overlying skin, each tissue supplied by independent branches of the femoral vessels. End-to-end anastomoses were performed to the common carotid artery and internal jugular vein, or to the femoral vessels of the recipients. Thirteen of fourteen flaps were successful. A single flap was lost due to compromise of venous outflow. This model allows transplantation of a substantial volume of skin, subcutaneous tissue, and muscle. The anatomy is reliable and easily identified and harvest incurs minimal donor morbidity. We find this gracilis myocutaneous flap an excellent pre-clinical model for the study of vascularized composite allotransplantation.