Project description:Percutaneous vertebroplasty has emerged as an increasingly popular intervention for managing a variety of common spinal conditions. Nevertheless, kyphoplasty cement can accidentally leak into paravertebral venous plexus, then travel to the right heart chambers through the venous system. We report an exceedingly rare case of an intracardiac cement embolism, likely an inadvertent complication of a recent percutaneous lumbar vertebroplasty. A mobile mass was incidentally found during a cardiac catheterization procedure, most likely in right atrium. Subsequent computed tomography angio chest and cardiac imaging confirmed a floating foreign body in the right atrium, which was then retrieved successfully through an endovascular approach. Gross examination of the removed body confirmed a bone cement-like material. Intracardiac cement embolism warrants serious attention as it may result in catastrophic cardiac complications.Learning objectiveIntracardiac cement embolism is an extremely rare, but potentially life-threatening complication after percutaneous vertebroplasty. The bone cement fragments accidentally leak into paravertebral plexus and then via venous system into the right-sided cardiac chambers and pulmonary arteries.
Project description:BackgroundAmong orthopedic surgery materials, poly (methyl methacrylate) (PMMA) is most commonly used for its excellent mechanical properties and rapid self-setting time. However, PMMA bone cement has been reported to cause thermal necrosis and to have poor bioactivity, which must be improved. In contrast, tricalcium silicate (TCS), the most significant component of Portland Cement and the most effective bone cement material, might not always meet the needs of the cement due to its poor mechanical properties and elevated pH levels during hydration. We hypothesize that the benefits of both PMMA and TCS can be harnessed by mixing them together in different proportions. This would represent a better solution for the issues faced when using them alone.MethodsWe, therefore, prepared a novel organic-inorganic PMMA/TCS composite bone cement mixing PMMA and different amounts of TCS and tested its effect on the biophysical properties.ResultsThe addition of 30% TCS reduced the exothermic temperature and pH variation during cement setting and hydration processes. However, the mechanical and handling properties of the bioactive PMMA/TCS composite were not affected. The in vitro study also revealed that the composite materials had higher cell viability than pure PMMA and TCS. Also, the in vivo study on animals indicated that the composite materials were more capable of forming bone, which further reinforced the biocompatibility of the proposed PMMA/TCS bone cement.ConclusionBy combining the advantages of each component, it could be possible to construct a more effective composite bone cement material. This would meet the needs of implantation material for orthopedic surgeries or a possible bone filler.
Project description:BackgroundThree-dimensional intracardiac echocardiography (3D ICE) with wide azimuthal elevation is a novel technique performed for assessment of cardiac anatomy and guidance of intracardiac procedures, being able to provide unique views with good spatial and temporal resolution. Complications arising from this invasive procedure and the value of 3D ICE in the detection and diagnosis of acute cardiovascular pathology are not comprehensively described. This case illustrates a previously unreported iatrogenic complication of clot displacement from the intra-vascular sheath upon insertion of a 3D ICE catheter and the value of 3D ICE in immediate diagnosis of clot in transit through the heart with pulmonary embolism.Case presentationWe conducted a translational study of 3D ICE with wide azimuthal elevation to guide implantation of a left ventricular assist device (Impella CP®) in eight adult sheep. A large-bore 14 Fr central venous sheath was used to enable right atrial and right ventricular access for the intracardiac catheter. Insertion of the 3D ICE catheter was accompanied by a sudden severe cardiorespiratory deterioration in one animal. 3D ICE revealed a large highly mobile mass within the right heart chambers, determined to be a clot-in-transit. The diagnosis of pulmonary clot embolism resulting from the retrograde blood entry into the large-bore sheath introducer, rapid clot formation and consequent displacement into venous circulation by the ICE catheter was made. The sheep survived this life-threatening event following institution of cardiovascular support allowing completion of the primary research protocol.ConclusionThis report serves as a serious warning to the researchers and clinicians utilizing long large-bore sheath introducers for 3D ICE and illustrates the value of 3D ICE in detecting clot-in-transit within right heart chambers.
Project description:BackgroundBone cement embolism is one of major complications of percutaneous kyphoplasty. Although rare, the intracardiac cement embolism is potentially life-threatening, with a documented incidence of 3.9%, and it is even more infrequent if symptomatic (0.3%).Case presentationHerein, we reported an extremely rare case of intracardiac bone cement embolism after percutaneous kyphoplasty causing right ventricle perforation. A 70-year-old woman, experiencing sudden left chest pain with radiation to the shoulder for 9 h, was transferred to our emergency department. Two hours before onset of her symptoms, she underwent percutaneous kyphoplasty at the local hospital. The computed tomography angiography revealed that an intracardiac foreign body penetrated her right ventricle. In light of her surgical history, bone cement embolism was suspected and thus, the patient was transferred to our center. Computed tomography and echocardiography confirmed the presence of intracardiac linear-shaped foreign body perforating the right ventricle. Therefore, the patient underwent open-heart surgery and the bone cement was removed successfully.ConclusionsSymptomatic intracardiac bone cement embolism is potentially fatal, so the rapid diagnosis and prompt treatment measures based on the cement emboli characteristics and the patient's condition are crucial.
Project description:BackgroundPolymethylmethacrylate (PMMA) bone cement loaded with enoxaparin sodium (PMMA@ES) has been increasingly highlighted to affect the bone repair of bone defects, but the molecular mechanisms remain unclear. We addressed this issue by identifying possible molecular mechanisms of PMMA@ES involved in femoral defect regeneration based on bioinformatics analysis and network pharmacology analysis.MethodsThe upregulated genes affecting the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) were selected through bioinformatics analysis, followed by intersection with the genes of ES-induced differentiation of BMSCs identified by network pharmacology analysis. PMMA@ES was constructed. Rat primary BMSCs were isolated and cultured in vitro in the proliferation medium (PM) and osteogenic medium (OM) to measure alkaline phosphatase (ALP) activity, mineralization of the extracellular matrix, and the expression of RUNX2 and OCN using gain- or loss-of-function experiments. A rat femoral bone defect model was constructed to detect the new bone formation in rats.ResultsATF2 may be a key gene in differentiating BMSCs into osteoblasts. In vitro cell assays showed that PMMA@ES promoted the osteogenic differentiation of BMSCs by increasing ALP activity, extracellular matrix mineralization, and RUNX2 and OCN expression in PM and OM. In addition, ATF2 activated the transcription of miR-335-5p to target ERK1/2 and downregulate the expression of ERK1/2. PMMA@ES induced femoral defect regeneration and the repair of femoral defects in rats by regulating the ATF2/miR-335-5p/ERK1/2 axis.ConclusionThe evidence provided by our study highlighted the ATF2-mediated mechanism of PMMA@ES in the facilitation of the osteogenic differentiation of BMSCs and femoral defect regeneration.
Project description:Pulmonary cement embolism is a well-described complication of cement vertebroplasty (1,2). We describe the case of a patient with acute cement embolism during catheter insertion for attempted pulmonary vein isolation 1 month after cement vertebroplasty. We discuss the mechanism of acute cement embolism, possible sequelae, and treatment considerations. (Level of Difficulty: Intermediate.).
Project description:BackgroundThe literature describing the complications following kyphoplasty is limited. This case report is a reminder that novel therapeutic strategies can be associated with unexpected complications.Case summaryA 61-year-old woman with rheumatoid arthritis and degenerative lumbar disc disease underwent open posterior instrumented fusion with bilateral open L2 vertebroplasty elsewhere. A month after discharge, she presented to our institution with acute chest pain and dyspnoea. A subsequent gated cardiac computed tomography (CT) angiogram showed three distinct cardiopulmonary emboli. One of the cement fragments had perforated the inferior wall of the right ventricle close to the base of the posterior tricuspid valve leaflet with a moderate circumferential pericardial effusion. Operative extraction of multiple cement emboli as well as repair of the tricuspid valve was pursued. Postoperative echocardiogram showed trivial tricuspid regurgitation after repair. The patient had an uneventful postoperative course and was discharged from the hospital on postoperative Day 5.DiscussionCement embolization following kyphoplasty can be associated with serious complications such as vascular injury, hypoxaemia, pulmonary artery obstruction, and cardiac perforation. Clinicians must maintain a high index of suspicion as cement embolism may not always present acutely.
Project description:ObjectiveThis research investigated the mechanical properties and bioactivity of polymethylmethacrylate (PMMA) bone cement after addition of the nano-hydroxyapatite(HA) coated bone collagen (mineralized collagen, MC).Materials & methodsThe MC in different proportions were added to the PMMA bone cement to detect the compressive strength, compression modulus, coagulation properties and biosafety. The MC-PMMA was embedded into rabbits and co-cultured with MG 63 cells to exam bone tissue compatibility and gene expression of osteogenesis.Results15.0%(wt) impregnated MC-PMMA significantly lowered compressive modulus while little affected compressive strength and solidification. MC-PMMA bone cement was biologically safe and indicated excellent bone tissue compatibility. The bone-cement interface crosslinking was significantly higher in MC-PMMA than control after 6 months implantation in the femur of rabbits. The genes of osteogenesis exhibited significantly higher expression level in MC-PMMA.ConclusionsMC-PMMA presented perfect mechanical properties, good biosafety and excellent biocompatibility with bone tissues, which has profoundly clinical values.