Hidden blood loss in minimally invasive surgery for osteoporotic vertebral fractures.

Abstract

Purpose Minimally invasive surgery (MIS) of the spine prevents the collapse of osteoporotic vertebral fractures (OVF) with lower complication and bleeding rates than open surgery. However, the possibility of hidden blood loss (HBL) has been recently described. This study aimed to estimate the postoperative impact of HBL in patients undergoing MIS for OVF. Methods This was a retrospective study of a series of patients. Those with pathological fractures, using anticoagulant or antiplatelet therapy, with severe anemia (hemoglobin [Hb] <9 g/dL), who had received a transfusion before surgery, or with hematological disorders were excluded. A descriptive analysis of recorded variables was performed, and total blood volume (TBV), total bleeding (TB), HBL, and Hb drop were calculated. This was followed by a comparative analysis between HBL and the variables of hospital stay and postoperative evolution. Results A total of 40 patients were included, eight men and 32 women, with a mean age of 76.6 years. The mean HBL was 682.5 mL. HBL greater than 500 mL was related to a higher probability of torpid postoperative evolution (p = 0.045) and a longer hospital stay (p = 0.067). A higher HBL was observed in surgeries of greater technical complexity and longer surgical time. Conclusion Although MIS techniques have shown less intraoperative bleeding than open surgery, HBL should be diagnosed because it is associated with a torpid evolution. The use of a diagnostic and therapeutic algorithm may help minimize its impact.