Polymethylmethacrylate causes prolonged pulmonary hypertension during fat embolism - A study in sheep

Background Fat embolism (FE), the release of bone marrow contents into the circulation and the subsequent cardiovascular changes, is still a potentially fatal complication during orthopedic surgery. Different causative factors have been suggested, but the exact pathomechanism of FE still remains unclear. We investigated the role of polymethylmethacrylate (PMMA) in FE during vertebroplasty in sheep. Methods In 8 sheep, two vertebral bodies were augmented alternatively with PMMA or bone wax. Pulmonary and cardiovascular parameters were monitored during the procedure. Results The peak response was similar for both groups and characterized by hypotension, a drop in cardiac output and pulmonary hypertension. However, the recovery in pulmonary arterial pressure and pulmonary vascular resistance was quicker in the wax group. Interpretation The injection of PMMA may cause prolonged pulmonary hypertension during vertebroplasty and also arthroplasty. Surgeons should be aware of this potential cardiovascular complication, especially in patients with impaired pulmonary and cardiovascular function.