Use of Bemiparine as a Prophylactic Antithrombotic Agent, in Patients Undergoing Microsurgery for Head and Neck Reconstruction

Inclusion Criteria: * Patients that will undergo reconstructive surgery for defects in any part of the body, especially in head and neck, after cancer, traumatic or infectious pathology, which will require the use of techniques of microsurgery. * Patients who have given their informed consent * Patients in which it has been decided to use thromboprophylaxis with bemiparina before proposing them to participate in the study. Exclusion Criteria: * Patients not eligible for repair through the use of free flaps, and therefore the use of Microsurgical techniques for vascular anastomosis * Patients with an underlying pathology that may interfere to a clinically significant or contraindicated the use of Bemiparina, such as: serious hepatic or renal insufficiency, uncontrolled arterial hypertension, history of gastroduodenal, thrombocytopenia, nephrolithiasis or uretrolitiasis and vascular disease ulcer of choroid and retina. * Refusal of the patient or their family members to participate in the study. * Pregnancy and breastfeeding * Known hypersensitivity to study drugs or any of its components