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

Abstract

Clinically, the displacement of intravertebral fat into the circulation during vertebroplasty is reported to lead to problems in elderly patients and can represent a serious complication, especially when multiple levels have to be treated. An in vitro study has shown the feasibility of removing intravertebral fat by pulsed jet-lavage prior to vertebroplasty, potentially reducing the embolization of bone marrow fat from the vertebral bodies and alleviating the cardiovascular changes elicited by pulmonary fat embolism. In this in vivo study, percutaneous vertebroplasty using polymethylmethacrylate (PMMA) was performed in three lumbar vertebrae of 11 sheep. In six sheep (lavage group), pulsed jet-lavage was performed prior to injection of PMMA compared to the control group of five sheep receiving only PMMA vertebroplasty. Invasive recording of blood pressures was performed continuously until 60 min after the last injection. Cardiac output and arterial blood gas parameters were measured at selected time points. Post mortem, the injected cement volume was measured using CT and lung biopsies were processed for assessment of intravascular fat. Pulsed jet-lavage was feasible in the in vivo setting. In the control group, the injection of PMMA resulted in pulmonary fat embolism and a sudden and significant increase in mean pulmonary arterial pressure. Pulsed jet-lavage prevented any cardiovascular changes and significantly reduced the severity of bone marrow fat embolization. Even though significantly more cement had been injected into the lavaged vertebral bodies, significantly fewer intravascular fat emboli were identified in the lung tissue. Pulsed jet-lavage prevented the cardiovascular complications after PMMA vertebroplasty in sheep and alleviated the severity of pulmonary fat embolism.

Lavage prior to vertebral augmentation reduces the risk for cement leakage

“…It could be shown that (jet)-lavage does not cause cardiovascular reaction in combination with contralateral application of vacuum and can significantly decrease the embolic load in sheep [30]. Similar results, significant reductions of cement leakage, were found by Mohamed et al [33], using an unipedicular aspiration technique (without lavage) in a vertebroplasty model.…”

“…This lowers potentially the risk of cement leakage and fat embolization and makes vertebral augmentation safer [29]. It could be shown in a sheep model that lavage of the bone marrow prior to VP prevents cardiovascular complications, reduces injection forces and allows a better control of cement distribution pattern with less leakage [30,31]. The advantages of lavage technique were not yet assessed in clinical studies.…”

Percutaneous cement augmentation techniques for osteoporotic spinal fractures

“…To prevent pulmonary symptoms, the number of augmented vertebrae during prophylactic multi-segmental VP should be limited to six levels per session or 25-30 cc of PMMA [36]. In a sheep model, it could be shown that lavage of the bone marrow prior to VP prevents cardiovascular complications, reduces injection pressures and allows a better control of cement distribution, with less leakage [37,38].…”

Acrylic Bone Cements: The Role of Nanotechnology in Improving Osteointegration and Tunable Mechanical Properties

“…[7][8][9] As long term results are highly required it is mandatory to develop new technologies or to improve the existing ones, as they exhibit several disadvantages. [10][11][12][13][14][15][16][17] Poly(methyl methacrylate) (PMMA) and its derivatives have been successfully used in orthopedic surgeries as bone filler in vertebroplasty. 18 19 Also, PMMA is the most common and successful adhesive used to anchor orthopedic implants to bone, as evidenced by data from longterm national joint registries.…”