Inferior Vena Cava Filters: Aligning Practice With Evidence to Improve Patient Outcomes

BackgroundDespite indications for the removal of temporary inferior vena cava (IVC) filters, many filters are unintentionally left in place, predisposing patients to adverse outcomes.ObjectiveThis quality improvement study set out to determine the impact of an IVC filter retrieval protocol on filter retrieval rates and patients lost to follow-up for patients who had undergone placement of a temporary IVC filter.MethodsFollowing a quasi-experimental design, data of all consecutive patients who underwent insertion of a temporary IVC filter for a period of 24-month preprotocol and 12-month postprotocol were compared.ResultsFilter retrieval rates of eligible filters increased from 64.2% to 100%; patients lost to follow-up decreased from 35.9% to 0% (p < .01, both outcomes).ConclusionAdoption of a comprehensive IVC filter protocol by the service that implants these devices can improve filter retrieval rates and decrease patients being lost to follow-up.     

Radiation-Shielding Devices: The Best Combination for Spine Interventional Procedures

PurposeAlthough many studies have examined the efficiency of various protective devices for reducing the dose of radiation exposure to physicians during interventional pain procedures, no study has compared the protective effect of these devices when they are used in combination. The purpose of this prospective experimental study was to determine the best combination of radiation-shielding devices.Materials and MethodsUsing anthropomorphic phantoms of a physician and patient, we measured the radiation protection efficiency (RPE) of each of the following protection methods and in combination during C-arm–guided simulated lumbar epidural injection: (a) personal protective equipment (PPE), (b) bedside curtain shield (Curtain), (c) x-ray tube filter (Filter), and (d) fluoroscopic collimation method (Collimation). We measured exposure doses using personal electronic dosimeters at the eye, thyroid, and gonad levels for 1 minute. Each experiment was repeated 15 times.ResultsThe radiation exposure dose and RPE with the best single-, double-, and triple-protection methods were as follows: PPE for the single-protection method (11.82 μSv/min, 80.04%), PPE + Collimation for the double-combination method (4.68 μSv/min, 92.09%), and PPE + Collimation + Curtain for the triple-combination method (3.08 μSv/min, 93.39%). Additionally, PPE + Collimation + Curtain + Filter for the quadruple-combination method resulted in a radiation exposure and RPE of 2.91 μSv/min and 93.61%, respectively, compared with nonprotection.ConclusionsThe best single-, double-, and triple-protection method was PPE, PPE + Collimation, and PPE + Collimation + Curtain, respectively. While preparing protective equipment, we recommend prioritizing equipment in this order.     

The impact of canister geometry on chemical biological radiological and nuclear filter performance: A computational fluid dynamics analysis

Steady-state axisymmetric simulations using the Reynolds-Averaged Navier-Stokes equations have been carried out in order to optimize the performance of a Chemical, Biological, Radiological, and Nuclear (CBRN) canister filter for its use in a powered air-purifying respirator (PAPR). Alterations have been made to the shape of the canister, the spacing of the rear wall of the canister with regard to the carbon filter, and the bracketing between (i) the particulate filter and the carbon bed and (ii) the carbon bed and the canister wall. The pressure drops across the canister and the residence time distribution at the rear of the carbon bed have been analyzed in detail based on an extensive parametric analysis involving the aforementioned variations. It has been demonstrated that the non-uniform porosity profile of the carbon bed resulted in alternating regions of high and low velocity close to the canister wall, providing a possible route for breakthrough. Designs, which included a bracket at the rear of the carbon bed, blocked this route and consequently had a longer minimum mean residence time than those, which did not. It has also been shown that the spacing between the carbon bed and the canister rear wall had a large impact on both residence time and pressure drop. In cases where the carbon backed directly onto the canister rear wall flow in the axial direction from the outside wall toward the canister axis resulted in far greater pressure drop and a reduction in minimum mean residence time within the carbon bed.     

Extracellular vesicles transmitted miR-31-5p promotes sorafenib resistance by targeting MLH1 in renal cell carcinoma

Sorafenib provides survival benefits in patients with advanced renal cell carcinoma (RCC), but its use is hampered by acquired drug resistance. It is important to fully clarify the molecular mechanisms of sorafenib resistance, which can help to avoid, delay or reverse drug resistance. Extracellular vesicles (EVs) can mediate intercellular communication by delivering effector molecules between cells. Here, we studied whether EVs are involved in sorafenib resistance of RCC and its possible molecular mechanisms. Using differential centrifugation, EVs were isolated from established sorafenib-resistant RCC cells (786-0 and ACHN), and EVs derived from sorafenib-resistant cells were uptaken by sensitive parental RCC cells and thus promoted drug resistance. Elevated exogenous miR-31-5p within EVs effectively downregulated MutL homolog 1 (MLH1) expression and thus promoted sorafenib resistance in vitro. Mice experiments also confirmed that miR-31-5p could mediate drug sensitivity in vivo. In addition, low expression of MLH1 was observed in sorafenib-resistant RCC cells and upregulation of MLH1 expression restored the sensitivity of resistant cell lines to sorafenib. Finally, miR-31-5p level in circulating EVs of RCC patients with progressive disease (PD) during sorafenib therapy was higher when compared to that in the pretherapy status. In conclusion, EVs shuttled miR-31-5p can transfer resistance information from sorafenib-resistant cells to sensitive cells by directly targeting MLH1, and thus magnify the drug resistance information to the whole tumor. Furthermore, miR-31-5p and MLH1 could be promising predictive biomarkers and therapeutic targets to prevent sorafenib resistance.     

彩超引导下床旁下腔静脉滤网置入术的临床应用

目的 探讨彩超引导下床旁下腔静脉滤网置入术在住院患者下肢深静脉血栓后肺栓塞预防中的临床应用。方法 2016年10月～2018年10月，我院血管外科对28例确诊为下肢深静脉血栓的患者行彩超引导下下腔静脉滤网置入术，所有手术均在ICU或病房床旁进行。结果 28例手术均顺利完成，成功率达100%，手术时间约 20～35分钟 ，平均时间30分钟，手术全程由彩超实时引导，术前精准定位，术中清晰显示穿刺、置入导管和释放滤器全过程，术后观察滤网位置和通畅性，无1例并发症发生，术后两周23例患者顺利在DSA下取出滤网，术中造影显示滤网位置无移位，其余5例患者术后随访3个月，滤网位置均无移动，其中1例滤网内发现少许血栓，28例患者均未见肺栓塞形成。结论 彩超引导下下腔静脉滤网置入术适用于ICU或者病房床旁不适合搬动的患者，尤其对于重症患者安全、手术时间短、定位引导准确、减少医务人员和患者的放射损伤，适用于对于放射造影剂过敏或肝、肾功能不全的患者，同时减少穿刺并发症，能有效地预防肺栓塞形成，能为临床治疗提供一种新途径。     

非均整模式的脑转移癌分次立体定向放射治疗的剂量学研究

目的：分析非均整模式与均整模式在脑转移癌分次立体定向放射治疗中的剂量学差异，为FFF模式的脑转移癌FSRT提供剂量学参考。方法：回顾性分析2017年7月至2018年9月间，我院收治的全部实施FSRT的脑转移癌患者，共17例。对所有患者按照临床治疗计划优化参数重新设计FF模式治疗计划。比较FFF模式和FF模式计划之间靶区剂量学参数、正常脑组织剂量参数和治疗效率参数，配对t检验其差异。结果： FFF与FF计划相比，梯度指数更低(3.31±0.97 vs. 3.45±0.87，P=0.017)，差异有统计学意义。FFF及FF计划的D5%、D50%、非均匀性指数、适形度指数差异均无统计学意义。相较于FF模式，FFF模式计划中V12GyBED-Brain及Dmean-Brain均较小[（43.55±35.72） cm3 vs.( 47.75±38.79) cm3；(648.39±411.86)Gy vs. (667.15± 418.01Gy）]，P值分别为0.003和0.006，差异有统计学意义。FFF模式计划的MU为1320.46± 354.99，高于FF模式（1220.74±267.86）， P=0.004，差异有统计学意义。结论：FFF模式靶区外剂量跌落更快，正常脑组织剂量更低，有利于更好地保护正常脑组织。FFF模式计划未提高FSRT的治疗效率。     

Breast reconstruction after therapeutic or prophylactic mastectomy for breast cancer: A comparison of guideline recommendations

BackgroundThe purpose of this article is to illuminate differences in published clinical practice guideline recommendations for breast reconstruction after prophylactic and therapeutic mastectomy.MethodsTen guidelines were identified through a systematic search of websites and databases of reputable oncology guideline developers, and key differences and gaps in recommendations were noted. Quality assessment of the guidelines was conducted by three reviewers using the AGREE II tool, focusing on breast reconstruction specific documents rather than the general breast cancer guidelines.ResultsThe most comprehensive guidelines were published by Alberta Health Services, Cancer Care Ontario, the American Society of Plastic Surgeons, and the Association of Breast Surgery/British Association of Plastic Reconstructive and Aesthetic Surgeons. AGREE II scores in the domains of “Scope and Purpose” and “Clarity and Presentation” were ranked relatively high for all four guidelines while “Applicability” and “Editorial Independence” were ranked relatively low. The Alberta and Ontario guidelines were the overall highest ranked guidelines across all domains.ConclusionOverall, these guidelines provide consistent recommendations on who should receive breast reconstruction education, who is a candidate for postmastectomy breast reconstruction, and the appropriate timing of reconstruction and extent of mastectomy. Future updates from all should focus on expanding to include alloplastic and autologous forms of reconstruction and should include a broad scope of relevant questions.     

血氧测量快速滤波与实时算法设计

目的血氧饱和度是人体的重要参数,为适应无线监护系统的需要,针对无线血氧测量节点内存小、运算速度慢的特点,本文设计了一套递推型快速处理算法。方法该算法充分利用递推方式和形态滤波算法过程的中间结果,加速滤波算法的处理速度,提取出测量和控制的关键数据,保证了数据的快速处理和测量系统的实时控制。结果通过分析采样数据和模拟处理过程发现,该算法可有效消除基线漂移、抖动等干扰,保证测量的稳定可靠。结论该算法计算量小,抗干扰能力强,适合无线血氧测量节点实时测量的需求。     

新型生物可降解腔静脉滤器的设计研究

目的为了弥补目前临床应用中腔静脉滤器的缺陷,本研究设计了一款新型生物可降解型腔静脉滤器,在肺栓塞危险期度过后,滤器可缓慢的降解、吸收,避免了二次取出手术。方法该款滤器由手工制作,分为上下2部分:上方是由6条聚糖乳酸缝线组成的圆锥形过滤结构;下方是聚己内酯支架,支架展开后实现滤器在腔静脉的中央型固定。在超声引导下,将滤器植入到10只犬体内。术后6周手术取出滤器,下腔静脉和肺组织行病理学检查,观察滤器的降解情况、下腔静脉壁的改变以及滤器的降解产物是否导致医源性肺栓塞。结果本研究手工制作了生物可降解滤器,并成功的植入到10只杂交犬的下腔静脉。术后所有犬均正常存活,未发生异常生命体征及伤口感染,有1例犬出现双下肢肿胀。1滤器移位:所有滤器不同程度的向头端移位。有1例犬的植入滤器移位至右房室孔,剩余的9例,滤器移位小于2 cm,仍位于肾静脉以下。2标本肉眼所见:所有的可降解支架被下腔静脉内皮细胞覆盖,肉眼未见明显的变化。滤器植入处下腔静脉壁增厚,但未出现明显狭窄。8例犬可见可吸收缝线完全降解,1例犬出现可吸收缝线被下腔静脉壁包裹,管腔内可见增生的纤维结缔组织和少量炎性细胞浸润,导致约70%的管腔阻塞。3标本HE染色:9例犬下腔静脉均存在炎性反应,中膜和内膜增厚,肺组织切片未见到降解产物所致的肺动脉栓塞和肺动脉壁的炎性反应。结论本研究成功设计了一款生物可降解腔静脉滤器,并通过动物体内实验证实这款滤器具有良好的生物相容性和可降解性。     

Impact of dose reduction and the use of an advanced model-based iterative reconstruction algorithm on spectral performance of a dual-source CT system: A task-based image quality assessment

PurposeTo assess the impact of dose reduction and the use of an advanced modeled iterative reconstruction algorithm (ADMIRE) on image quality in low-energy monochromatic images from a dual-source dual energy computed tomography CT (DSCT) platform.Materials and methodsAcquisitions on an image-quality phantom were performed using DSCT equipment with 100/Sn150 kVp for four dose levels (CTDI_vol: 20/11/8/5mGy). Raw data were reconstructed for six energy levels (40/50/60/70/80/100 keV) using filtered back projection and two levels of ADMIRE (A3/A5). Noise power spectrum (NPS) and task-based transfer function (TTF) were calculated on virtual monoenergetic images (VMIs). Detectability index (d′) was computed to model the detection task of two enhanced iodine lesions as function of keV.ResultsNoise-magnitude was significantly reduced between 40 to 70 keV by ?56 ± 0% (SD) (range: ?56%–?55%) with FBP; ?56 ± 0% (SD) (?56%–?56%) with A3; and ?57 ± 1% (SD) (range: ?57%–?56%) with A5. The average spatial frequency of the NPS peaked at 70 keV and decreased as ADMIRE level increased. TTF values at 50% were greatest at 40 keV and shifted towards lower frequencies as the keV increased. The detectability of both lesions increased with increasing dose level and ADMIRE level. For the simulated lesion with iodine at 2 mg/mL, d’ values peaked at 70 keV for all reconstruction types, except for A3 at 20 mGy and A5 at 11 and 20 mGy, where d’ peaked at 60 keV. For the other simulated lesion, d’ values were highest at 40 keV and decreased beyond.ConclusionAt low keV on VMIs, this study confirms that iterative reconstruction reduces the noise magnitude, improves the spatial resolution and increases the detectability of enhanced iodine lesions.