Radiation-Free Thoracic Endovascular Aneurysm Repair with Fiberoptic and Electromagnetic Guidance: A Phantom Study

PurposeTo evaluate the feasibility and accuracy of a radiation-free implantation of a thoracic aortic stent graft employing fiberoptic and electromagnetic tracking in an anthropomorphic phantom.Materials and MethodsAn anthropomorphic phantom was manufactured based on computed tomography (CT) angiography data from a patient. An aortic stent graft application system was equipped with a fiber Bragg gratings and 3 electromagnetic sensors. The stent graft was navigated in the phantom by 3 interventionalists using the tracking data generated by both technologies. One implantation procedure was performed. The technical success of the procedure was evaluated using digital subtraction angiography and CT angiography (before and after the intervention). Tracking accuracy was determined at various anatomical landmarks based on separately acquired fluoroscopic images. The mean/maximum errors were measured for the stent graft application system and the tip/end of the stent graft.ResultsThe procedure resulted in technical success with a mean error below 3 mm for the entire application system and <2 mm for the position of the tip of the stent graft. Navigation/implantation and handling of the device were rated sufficiently accurate and on par with comparable, routinely used stent graft application systems.ConclusionsThe study demonstrates successful stent graft implantation during a thoracic endovascular aortic repair procedure employing advanced guidance techniques and avoiding fluoroscopic imaging. This is an essential step in facilitating the implantation of stent grafts and reducing the health risks associated with ionizing radiation during endovascular procedures.     

全身振动训练联合正弦交变电磁场对去卵巢骨质疏松大鼠骨密度、骨代谢指标的影响研究

目的探讨全身振动训练联合正弦交变电磁场对去卵巢骨质疏松大鼠骨密度、骨代谢、骨生物力学性能的影响。方法将100只大鼠随机分为切除卵巢组和对照组,分别进行卵巢切除术和假手术,大鼠进行6周恢复,恢复后将造模成功的切除卵巢大鼠随机分为模型组(MO组)、全身振动训练组(W组)、正弦交变电磁场组(S组)、全身振动训练+正弦交变电磁场组(WS组),对照组列为假手术组(SO组),进行为期16周干预,干预结束后对大鼠进行骨密度、骨代谢、骨生物力学性质的检测。结果16周干预完成后,MO组、S组大鼠体质量显著高于SO组、W组、WS组大鼠(P0. 05); W组、WS组、SO组大鼠骨密度指标、血清雌二醇浓度指标明显高于大鼠MO组(P0. 05); SO组大鼠血清雌二醇浓度指标明显高于S组、W组、WS组(P0. 05); M组大鼠血清OC、ALP浓度明显高于SO组、W组、S组、WS组大鼠(P0. 05);尿液DPD/Cre、Ca/Cre、P/Cre浓度方面,M组大鼠明显高于SO组、W组、S组、WS组大鼠(P0. 05)。SO组、W组、S组、WS组大鼠股骨最大载荷和弹性模型明显高于MO组大鼠(P0. 05)。SO组、W组、S组、WS组大鼠股骨断裂载荷组间无明显差异(P0. 05); SO组、W组、S组、WS组大鼠股骨弹性模量明显高于MO组大鼠(P0. 05)。SO组大鼠股骨弹性模量明显高于S组大鼠(P0. 05),但与W组、WS组大鼠没有明显差异(P0. 05)。L4椎体压缩试验,SO组、W组、S组、WS组大鼠股骨最大载荷和弹性模型明显高于MO组大鼠(P0. 05)。SO组大鼠高于S组、W组,差异有统计学意义(P0. 05),但与WS组大鼠没有明显差异(P0. 05)。结论全身振动训练、正弦交变电磁场、全身振动训练联合正弦交变电磁场3种干预方式施用于去卵巢骨质疏松大鼠均能提升骨密度、抑制骨吸收、平衡骨代谢、改善骨骼结构力学和材料力学性能。而全身振动训练联合正弦交变电磁场能的治疗效果优于单纯使用全身振动训练或正弦交变电磁场,在临床应用中有一定推广价值。     

手术动力设备电磁兼容测试中工况选取的探索

目的介绍手术动力设备的电磁兼容测试方法,为多功能手术动力设备测试提供指引。方法通过对常见手术动力设备的不同功能逐一测试得出的结果进行比对,分析不同功能在同一检测项目中的差异。结果传导发射(Conduction Emission,CE)与负载引起的功率变化有关,辐射发射(Radiation Ernission,RE)与负载引起的功率变化无必然联系。静电放电(Electrostatic Discharge,ESD)与负载刀头到设备输入插口的插入损耗有关。结论可选择输入功率较大的负载进行CD和RE测试;电路原理不明确时,还可通过频谱仪预测判断后,选择出现最大幅值的负载进行RE测试;ESD测试选择插入损耗最小的负载测试;其余抗扰度项目可选取任一负载测试。     

Combined magnetic field results in higher fusion rates than pulsed electromagnetic field bone stimulation after thoracolumbar fusion surgery

BackgroundBone growth stimulators have been used as an adjunct to spinal fusion surgery in efforts to increase fusion rates.MethodsThe authors retrospectively reviewed the medical records of patients who underwent thoracolumbar fusion surgeries by a single surgeon. Patients were then separated into three groups; pulsed electromagnetic field stimulation (PEMF), combined magnetic field stimulation (CMF) or no stimulation (NS), and computed tomography radiographic results at least 1 year after surgery were compared (solid fusion, stable nonunion, and pseudarthrosis).ResultsA total of 60 patients were included; 16 (26.7%) used PEMF, 24 (40.0%) used CMF, and 20 (33.3%) had NS. There were no significant differences in patient demographics. There was no difference in the mean fusion levels (p = 0. 477). Solid fusion was achieved in 11/16 (68.8%) PEMF, 21/24 (87.5%) CMF, and 20/20 (100.0%) NS patients. Stable nonunion was displayed in 2/24 (8.3%) CMF, and zero PEMF and NS patients. There were 5/16 (31.3%) PEMF, 1/24 (4.2%) CMF, and zero NS patients demonstrating radiologic pseudarthrosis. There was a statistically significant difference between PEMF and CMF (p = 0.017) and between PEMF and NS (p = 0.006) groups. No statistical difference was found between CMF and NS (p = 1.000).ConclusionThis is the first study to compare PEMF and CMF bone growth stimulators in patients with degenerative pathologies who underwent thoracolumbar spinal fusions. Overall, the addition of these bone growth stimulators does not improve fusion outcomes, although CMF appears superior to PEMF.     

电磁导航系统与徒手锁定在胫骨髓内钉远端锁定应用中的对比研究

目的对比研究电磁导航系统与徒手锁定在胫骨髓内钉远端锁定中的临床应用。方法将2013年1月~2014年12月需要行髓内钉固定的40例胫骨骨折患者平均分为两组(各20例),电磁导航组:男性11例,女性9例;年龄20~65岁,平均(44.3±1.8)岁;徒手锁定组:男性12例,女性8例;年龄18~66岁,平均(42.5±2.0)岁。比较电磁导航与徒手锁定组间远端锁定总耗时与术中放射线暴露时间。结果电磁导航组平均远端锁定耗时(668.2±195.0)s,徒手锁定组平均远端锁定耗时(1431.1±501.3)s。电磁导航组平均放射线暴露时间(3.1±2.2)s,徒手锁定组平均放射线暴露时间(18.3±6.9)s。结论电磁导航系统能显著缩短远端锁定时间,减少放射线暴露,值得推广。     

In vitro chondrogenic differentiation of human articular cartilage derived chondroprogenitors using pulsed electromagnetic field

BackgroundThe ability to grow new cartilage remains the standard goal of any treatment strategy directed at cartilage repair. Chondroprogenitors have garnered interest due to their applicability in cell therapy. Pulsed electromagnetic field (PEMF) favors chondrogenesis by possible upregulation of genes belonging to TGFβ superfamily. Since TGFβ is implicated in chondrogenic signalling, the aim of the study was to evaluate the ability of PEMF to induce chondrogenesis via endogenous TGFβ production in chondroprogenitors vs differentiation using chondrogenic medium inclusive of TGFβ.MethodsChondroprogenitors were harvested from three non-diseased human knee joints via fibronectin assay. Passage 3 pellets were subjected to four different culture conditions: a) negative control contained chondrogenic medium without TGFβ2, b) positive control contained medium with TGFβ2, c) PEMF 1 contained medium of negative control plus single exposure to PEMF and d) PEMF 2 contained medium of negative control plus multiple exposures to PEMF. Following differentiation (day 21), pellets were assessed for gene expression of ACAN, SOX9, COL2A1, TGFβ1, TGFβ2, and TGFβ3. Alcian blue staining to detect glycosaminoglycan deposition was also performed. Medium supernatant was used to detect endogenous latent TGF-β1 levels using ELISA.ResultsAll study arms exhibited comparable gene expression without any significant difference. Although positive control and PEMF study arms demonstrated notably better staining than negative control, the level of latent TGF-β1 was seen to be significantly high in supernatant from positive control (P < 0.05) when compared to other groups.ConclusionOur results indicate that PEMF induced chondrogenesis might involve other signalling molecules, which require further evaluation.     

Role of pulsed electromagnetic fields after joint replacements

Although the rate of patients reporting satisfaction is generally high after joint replacement surgery, up to 23% after total hip replacement and 34% after total knee arthroplasty of treated subjects report discomfort or pain 1 year after surgery. Moreover, chronic or subacute inflammation is reported in some cases even a long time after surgery. Another open and debated issue in prosthetic surgery is implant survivorship, especially when related to good prosthesis bone ingrowth. Pulsed Electro Magnetic Fields(PEMFs) treatment, although initially recommended after total joint replacement to promote bone ingrowth and to reduce inflammation and pain, is not currently part of usual clinical practice. The purpose of this review was to analyze existing literature on PEMFs effects in joint replacement surgery and to report results of clinical studies and current indications. We selected all currently available prospective studies or RCT on the use of PEMFs in total joint replacement with the purpose of investigating effects of PEMFs on recovery, pain relief and patients' satisfaction following hip, knee or shoulder arthroplasty. All the studies analyzed reported no adverse effects, and good patient compliance to the treatment. The available literature shows that early control of joint inflammation process in the first days after surgery through the use of PEMFs should be considered an effective completion of the surgical procedure to improve the patient's functional recovery.