Polymethylmethacrylate causes prolonged pulmo-nary hypertension during fat embolism: A study in sheep

Abstract

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.

Cardiovascular changes after PMMA vertebroplasty in sheep: the effect of bone marrow removal using pulsed jet-lavage

“…pulmonary bone marrow fat embolization, was characterized by a sudden (within 60 s after injection) and considerable ([50%) increase in pulmonary arterial pressure which is in accordance with previous investigations [13,17]. Pulmonary hypertension lasted for 9 min.…”

“…There were significantly (P = 0.022) more fat droplets present in the control lung tissue requires an animal model suited to inject a similar quantity of bone cement and thus forcing a similar quantity of bone marrow into the circulation as in the clinical situation. Previous studies have shown that the sheep model is suitable to elicit reproducible and well-defined fat embolism and subsequent cardiovascular changes [13,14,20]. The sheep was therefore chosen to investigate cardiovascular changes during percutaneous vertebroplasty, even though the sheep's vertebral bodies have a higher bone mineral density and therefore a lower quantity of bone marrow fat content compared to-especially osteoporotic-human patients (Benneker, Gisep, Krebs et al Percutaneous vertebroplasty in sheep; development of an animal model.…”

“…Cardiovascular changes resulting from fat embolism are often transient, but may be fulminant, resulting in cardiac arrest and even death [10][11][12]. Aebli et al [13] have demonstrated the embolization of bone marrow fat and the associated cardiovascular changes during vertebroplasty in a sheep model. There was a cumulative increase of fat emboli in lung biopsies of sheep after multiple level augmentations [14].…”

Influence of Bone Marrow Fat Embolism on Coagulation Activation in an Ovine Model of Vertebroplasty

“…Cement was injected into three lumbar vertebrae (L2-L4) after a twenty-minute time-interval between injections. The duration of the time-intervals was sufficient for stabilization of cardiovascular parameters to a new steady state 10,11 . Postinjection evaluation of cardiac output and blood gas parameters was carried out one minute and ten minutes after having started the first injection; ten minutes after having started the second injection; and ten minutes, thirty minutes, and sixty minutes after having started the third injection.…”

“…Aebli et al 10 demonstrated the embolization of bone marrow fat during vertebroplasty in an animal model, using transesophageal echocardiography and histopathology of the lungs. Associated cardiovascular deterioration was characterized by transient but severe pulmonary hypertension, arterial hypotension, decreased cardiac output, and respiratory acidosis in this animal model 11 . Fat embolism is a well-known complication during total hip and knee arthroplasty [12][13][14][15] , intramedullary reaming 16,17 , and Disclosure: In support of their research for or preparation of this work, one or more of the authors received, in any one year, outside funding or grants in excess of $10,000 from the Wesley Foundation, Brisbane, Australia; the AO Foundation, Davos, Switzerland; and AOSpine, Dübendorf, Switzerland (SRN 02/105).…”