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1.
Medicine (Baltimore) ; 99(40): e22186, 2020 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-33019393

RESUMO

This study aimed to verify the relationship between the number of fusion level and the risk of screw loosening by using cortical bone trajectory (CBT) screws in patients with lumbar degenerative disease.We retrospectively reviewed the serial plain radiograph images of lumbar degenerative disease patients who had undergone posterior fixation and fusion surgery with CBT from 2014. All included patients should have been followed-up with computed tomography scan or plain radiograph for at least 6 months after operation. We individually evaluated the prevalence of screw loosening according to each vertebral level. We also determined whether the number of screw fixation affected the prevalence of screw loosening and whether S1 fixation increased the risk of screw loosening.The screw-loosening rates were high at the S1 level. Moreover, although fixation involved to S1, the loosening rates evidently increased (Fisher exact test, P = .002). The screw-loosening rate was 6.56% in 2 level fusion. However, it increased with the number of fusion levels (3 level: 25.00%, 4 level: 51.16%, and 5 level: 62.50%). To investigate if the number of fusion level affected the S1 screw loosening, we classified the cohort of patients into either involving S1 (S1+ group) or not (S1- group) according to different fusion levels (). The screw loosening between 2 group in 2 (5.56% vs 6.98%) and 3 fusion level (26.32% vs 22.73%) did not exhibit any significant difference. Interestingly, significantly high screw loosening was found in 4 fusion level (60.00% vs 15.38%), indicating that the higher fusion level (4 level) can directly increase the risk of S1 screw loosening.Our data confirmed that the screw-loosening rate increases rate when long segment CBT fixation involves to S1. Therefore, in case of long-segment fixation by using CBT screw, surgeons should be aware of the fusion level of S1.


Assuntos
Parafusos Ósseos , Degeneração do Disco Intervertebral/cirurgia , Deslocamento do Disco Intervertebral/cirurgia , Fusão Vertebral/instrumentação , Osso Cortical/diagnóstico por imagem , Análise de Falha de Equipamento/métodos , Feminino , Humanos , Vértebras Lombares/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Tomografia Computadorizada por Raios X
3.
Ultrasonics ; 107: 106167, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32402858

RESUMO

Current in vitro sonication experiments show immense variability in experimental set-ups and methods used. As a result, there is uncertainty in the ultrasound field parameters experienced by sonicated samples, poor reproducibility of these experiments and thus reduced scientific value of the results obtained. The scope of this narrative review is to briefly describe mechanisms of action of ultrasound, list the most frequently used experimental set-ups and focus on a description of factors influencing the outcomes and reproducibility of these experiments. The factors assessed include: proper reporting of ultrasound exposure parameters, experimental geometry, coupling medium quality, influence of culture vessels, formation of standing waves, motion/rotation of the sonicated sample and the characteristics of the sample itself. In the discussion we describe pros and cons of particular exposure geometries and factors, and make a few recommendations as to how to increase the reproducibility and validity of the experiments performed.


Assuntos
Terapia por Ultrassom/métodos , Técnicas de Cultura de Células , Simulação por Computador , Desenho de Equipamento , Análise de Falha de Equipamento , Técnicas In Vitro , Modelos Biológicos , Reprodutibilidade dos Testes , Sonicação
4.
Vascular ; 28(5): 612-618, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32356682

RESUMO

OBJECTIVES: Resuscitative endovascular balloon occlusion of the aorta is an alternative to resuscitative thoracotomy in non-compressible torso haemorrhage. Low-profile, compliant balloon catheter systems have been developed, which can be deployed without the need for fluoroscopy. However, concern exists for over inflation and aortic injury, especially as compliant balloon material can stretch reducing syringe feedback and limiting the effectiveness of a safety valve. An alternative material would be a semi-compliant balloon material, but its performance is unknown. The aim of this study was to compare the inflation characteristics of compliant versus semi-compliant balloon systems and to determine whether a pressure relief safety valve can be practically applied to a semi-compliant balloon catheter as a safety device. METHODS: This was an ex vivo study using porcine segments of thoracic aorta. The study consisted of two phases. The first phase involved intermittent inflation of six compliant balloon and six semi-compliant balloon balloons until balloon or aortic rupture. In the second phase, six semi-compliant balloons with the pressure-relief valve set at 0.45 atmospheres were inflated in the aortas until the valve release, followed by injection with additional 30 mL. Data including pressure, volume, balloon working length, diameter and circumferential stretch ratio were collected. RESULTS: At failure, mean balloon volume was almost double in compliant balloon group vs semi-compliant balloon group - 49.83 mL (±23.25) and 25.16 mL (±8.93), respectively (p = 0.004), with 36% increase in working length in the compliant balloon group - 81.17 mm (±19.11) vs 59.49 (±4.86) for semi-compliant balloon (p = 0.023). When plotted, the relationship pattern between volume and pressure fit a linear model for the compliant balloon, and a quadratic model for the semi-compliant balloon. Following attempted over inflation with the pressure valve, there was no change in parameters before and after attempted over inflation. CONCLUSIONS: The inflation profile differs between balloon designs. In contrast to semi-compliant balloons, compliant balloons will accommodate more volume to mitigate increase in pressure. This does not completely eliminate the risk of over inflation. The inflation characteristics of the semi-compliant balloon permit pairing it with a safety valve, which could lead to a development of a safer balloon technology in the future.


Assuntos
Aorta Torácica , Oclusão com Balão/instrumentação , Procedimentos Endovasculares/instrumentação , Dispositivos de Acesso Vascular , Animais , Desenho de Equipamento , Análise de Falha de Equipamento , Pressão , Sus scrofa
5.
J Shoulder Elbow Surg ; 29(4): 743-754, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32197764

RESUMO

BACKGROUND: An important reason for failure of anatomic total shoulder arthroplasty is glenoid component loosening. We investigated the effect of backside bone support on the risk of failure of a glenoid component. METHODS: A finite element model was developed. Virtual surgery was performed for 2 types of glenoid components (cemented all polyethylene [PE] vs. metal backed [MB]), both with gradually decreasing backside bone support. Both bone failure and fixation failure were analyzed. The percentages of bone failure and fixation failure in terms of the critical cement volume (CCV) and micromotion-threshold percentage ratio (MTPR) for the PE and MB components, respectively, were defined and compared. RESULTS: For the reference PE model, the percentages of bone failure and fixation failure (CCV) were 17% and 34%, respectively. With eccentric loading for the MB component, the percentages of bone failure and fixation failure (MTPR) were 6% and 3%, respectively. A global increase in failure was observed with decreasing bone support. The increase in fixation failure, starting from the reference values (MTPR vs. CCV), was relatively more pronounced for the MB component (136% vs. 128%). DISCUSSION: Decreasing backside bone support for an anatomic glenoid component leads to an increased risk of fixation and bone failure. For PE components, decreasing backside support to 95% bone support had only a limited effect. In the case of an MB component, we noticed an increase in micromotion and bone failure already starting from 97% bone support. We conclude that an anatomic glenoid component should always be implanted while maximizing backside bone support.


Assuntos
Artroplastia do Ombro/efeitos adversos , Cavidade Glenoide , Falha de Prótese/etiologia , Prótese de Ombro/efeitos adversos , Cimentos para Ossos , Análise de Falha de Equipamento , Análise de Elementos Finitos , Cavidade Glenoide/cirurgia , Humanos , Metais , Polietileno , Desenho de Prótese , Articulação do Ombro/cirurgia
6.
JACC Cardiovasc Interv ; 13(6): 667-678, 2020 03 23.
Artigo em Inglês | MEDLINE | ID: mdl-32113932

RESUMO

OBJECTIVES: The aim of this study was to examine the effect of different transcatheter heart valves (THVs) on valve leaflet displacement when deployed within bioprosthetic surgical valves and, thereby, risk for coronary obstruction. BACKGROUND: Coronary obstruction is a potentially devastating complication during valve-in-valve (ViV) transcatheter aortic valve replacement. Strategies such as provisional stenting and intentional bioprosthetic valve leaflet laceration have been developed to mitigate this risk. Alternatively, the use of a THV that retracts the bioprosthetic leaflet away from the coronary ostium may prevent coronary obstruction. METHODS: A 25-mm J-Valve, a 26-mm Evolut Pro, and a 23-mm JenaValve were implanted into both a 25-mm Trifecta surgical valve and a 25-mm Mitroflow surgical valve. A 23-mm and a 26-mm SAPIEN 3 were deployed into the Trifecta and Mitroflow, respectively. Displacement of the surgical valve leaflets (retraction vs. expansion) was measured with implantation of each THV by measuring displacement angle and maximal displacement distance. RESULTS: Within both the Trifecta and Mitroflow valves, implantation of the J-Valve and JenaValve resulted in retraction of the surgical valve leaflets, and placement of the Evolut Pro and SAPIEN 3 resulted in tubular expansion of the surgical valve leaflets. There were significant differences in displacement angles and distances between both the J-Valve and JenaValve and the SAPIEN 3 and Evolut Pro (p < 0.0001). CONCLUSIONS: ViV implantation with new-generation THVs that directly interact with bioprosthetic valve leaflets results in surgical valve leaflet retraction. This might mitigate the risk for coronary obstruction in selected cases of ViV transcatheter aortic valve replacement and also facilitate coronary reaccess after ViV TAVR.


Assuntos
Bioprótese , Estenose Coronária/prevenção & controle , Implante de Prótese de Valva Cardíaca/instrumentação , Próteses Valvulares Cardíacas , Falha de Prótese , Substituição da Valva Aórtica Transcateter/instrumentação , Estenose Coronária/etiologia , Análise de Falha de Equipamento , Implante de Prótese de Valva Cardíaca/efeitos adversos , Humanos , Teste de Materiais , Desenho de Prótese , Medição de Risco , Fatores de Risco , Substituição da Valva Aórtica Transcateter/efeitos adversos
8.
Bone Joint J ; 102-B(2): 170-176, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32009432

RESUMO

AIMS: We aimed to examine the long-term mechanical survivorship, describe the modes of all-cause failure, and identify risk factors for mechanical failure of all-polyethylene tibial components in endoprosthetic reconstruction. METHODS: This is a retrospective database review of consecutive endoprosthetic reconstructions performed for oncological indications between 1980 and 2019. Patients with all-polyethylene tibial components were isolated and analyzed for revision for mechanical failure. Outcomes included survival of the all-polyethylene tibial component, revision surgery categorized according to the Henderson Failure Mode Classification, and complications and functional outcome, as assessed by the Musculoskeletal Tumor Society (MSTS) score at the final follow-up. RESULTS: A total of 278 patients were identified with 289 all-polyethylene tibial components. Mechanical survival was 98.4%, 91.1%, and 85.2% at five, ten and 15 years, respectively. A total of 15 mechanical failures were identified at the final follow-up. Of the 13 all-polyethylene tibial components used for revision of a previous tibial component, five (38.5%) failed mechanically. Younger patients (< 18 years vs > 18 years; p = 0.005) and those used as revision components (p < 0.001) had significantly increased rates of failure. Multivariate logistic regression modelling showed revision status to be a positive risk factor for failure (odds ratio (OR) 19.498, 95% confidence interval (CI) 4.598 to 82.676) and increasing age was a negative risk factor for failure (OR 0.927, 95% CI 0.872 to 0.987). Age-stratified risk analysis showed that age > 24 years was no longer a statistically significant risk factor for failure. The final mean MSTS score for all patients was 89% (8.5% to 100.0%). CONCLUSION: The long-term mechanical survivorship of all-polyethylene tibial components when used for tumour endoprostheses was excellent. Tumour surgeons should consider using these components for their durability and the secondary benefits of reduced cost and ease of removal and revision. However, caution should be taken when using all-polyethylene tibial components in the revision setting as a significantly higher rate of mechanical failure was seen in this group of patients. Cite this article: Bone Joint J. 2020;102-B(2):170-176.


Assuntos
Neoplasias Ósseas/cirurgia , Fêmur/cirurgia , Próteses e Implantes/efeitos adversos , Implantação de Prótese/efeitos adversos , Tíbia/cirurgia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Materiais Biocompatíveis , Criança , Análise de Falha de Equipamento , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Polietileno , Desenho de Prótese , Falha de Prótese/etiologia , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Adulto Jovem
9.
J Endovasc Ther ; 27(2): 258-265, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32096435

RESUMO

Purpose: To compare experimentally the biomechanical properties of the Viabahn Balloon-Expandable Stent Graft (VBX) with the widely used Advanta V12/iCast in the role of bridging stent-grafts for fenestrated endovascular aortic repair. Materials and Methods: Test sheets made of polyester having 2 rows of 5 fenestrations in 6-mm and 8-mm diameters were used to simulate a commercially made fenestrated aortic endograft. In total, 40 stent-grafts measuring 6×39 mm and 8×39 mm (10 of each size for each stent-graft) were implanted in fenestration sheets immersed in a 37°C water bath. After flaring, all stent-grafts were evaluated using microscopy and radiography. Biomechanical evaluation included pullout and the shear stress force testing; results are reported in Newtons (N) as the median (minimum-maximum). Results: After flaring, no damage or fracture to the stent-graft structures were detected. Pullout forces for the 6-mm stent-grafts were 27.1 N (20.0-28.9) for the VBX and 16.6 N (14.7-19.2) for the Advanta (p=0.008). Pullout forces for the 8-mm stent-grafts were 20.1 N (14.8-21.5) for the VBX and 15.8 N (12.4-17.5) for the Advanta (p=0.095). The shear stress forces necessary to dislocate the device at 150% stent diameter displacement was 12.5 N (VBX) vs 14.7 N (Advanta) for the 6-mm devices and 23.3 N (VBX) vs 20.2 N (Advanta) for the 8-mm stents (p>0.99 and p=0.222, respectively). Conclusion: In vitro tests simulating external pull and shear forces on bridging stent-grafts implanted in fenestrations showed that the VBX had resistance to dislocation equivalent to a well-known control device.


Assuntos
Implante de Prótese Vascular/instrumentação , Prótese Vascular , Procedimentos Endovasculares/instrumentação , Stents , Implante de Prótese Vascular/efeitos adversos , Procedimentos Endovasculares/efeitos adversos , Análise de Falha de Equipamento , Migração de Corpo Estranho/etiologia , Teste de Materiais , Desenho de Prótese , Falha de Prótese , Fatores de Risco , Estresse Mecânico
10.
Circ Arrhythm Electrophysiol ; 13(2): e008092, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31985260

RESUMO

Impedance is the ratio of voltage to current in an electrical circuit. Cardiovascular implantable electronic devices measure impedance to assess the structural integrity electrical performance of leads, typically using subthreshold pulses. We review determinants of impedance, how it is measured, variation in clinically measured pacing and high-voltage impedance and impedance trends as a diagnostic for lead failure and lead-device connection problems. We consider the differential diagnosis of abnormal impedance and the approach to the challenging problem of a single, abnormal impedance measurement. Present impedance provides a specific but insensitive diagnostic. For pacing circuits, we review the complementary roles of impedance and more sensitive oversensing diagnostics. Shock circuits lack a sensitive diagnostic. This deficiency is particularly important for insulation breaches, which may go undetected and present with short circuits during therapeutic shocks. We consider new methods for measuring impedance that may increase sensitivity for insulation breaches.


Assuntos
Desfibriladores Implantáveis , Impedância Elétrica , Análise de Falha de Equipamento , Diagnóstico Diferencial , Humanos
12.
Ann Vasc Surg ; 66: 160-170, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31978487

RESUMO

BACKGROUND: Although recent data on the treatment of thoracoabdominal aortic aneurysms (TAAAs) are promising, in some cases, the paravisceral segment of the aorta may not be suitable for a branched endograft due to space restrictions. A combination of a fenestrated aneurysm repair (FEVAR) with a thoracic aneurysm repair (TEVAR) may represent a feasible treatment option. The current investigation was performed to assess the stability of a fenestrated Anaconda device implanted into a set of thoracic endografts from different manufacturers. We then assessed our clinical results with the FEVAR/TEVAR combination. METHODS: Pull-out forces were measured in vitro after docking a fenestrated Anaconda graft within the distal end of different TEVAR devices. Anaconda devices were implanted in 28- or 30-mm thoracic tube grafts (oversizing of at least 2 mm: 13.3-21.4; minimum overlap of 15 mm). Continuously increasing longitudinal pull forces of up to 100 N were applied on an Instron Tensile Tester. Initial break point and damage to the endografts were documented. Clinical results of patients treated with such an FEVAR/TEVAR combination at our institution are presented as a second part of this study. RESULTS: Median pull-out forces ranged from 2.38 N to 55.0 N. The highest stability was achieved with 34-mm Anaconda devices in 28-mm thoracic tube grafts. Grafts with either thinner Dacron material or those featuring a polytetrafluorethylene membrane seemed especially vulnerable to punctures and tears caused by the downward-looking hooks of the Anaconda device. Between April 1, 2013 and December 31, 2018, in 28 of 172 patients treated with a fenestrated Anaconda device, prior implantation of a thoracic tube graft was necessary to create a sufficient proximal landing zone. In 25 cases (89.3%), the aneurysm was successfully treated. Although the 30-day reintervention rate in this subgroup was relatively high at 28.6%, none of these was due to a failure of the FEVAR/TEVAR combination. Upon an average follow-up of 15 months, no failure of the graft connection and no type III endoleak due to membrane damage were observed. CONCLUSIONS: The combination of a thoracic tube graft and a fenestrated Anaconda device is a viable option for the treatment of patients with Extent I or IV TAAAs with no adequate landing zone above the celiac trunk. Although pull-out testing has shown good stability with most assessed grafts, the thoracic devices with thicker Dacron membranes seemed to be especially suitable.


Assuntos
Aneurisma da Aorta Torácica/cirurgia , Implante de Prótese Vascular/instrumentação , Prótese Vascular , Procedimentos Endovasculares/instrumentação , Falha de Prótese , Stents , Idoso , Idoso de 80 Anos ou mais , Aneurisma da Aorta Torácica/diagnóstico por imagem , Implante de Prótese Vascular/efeitos adversos , Bases de Dados Factuais , Endoleak/etiologia , Endoleak/prevenção & controle , Procedimentos Endovasculares/efeitos adversos , Análise de Falha de Equipamento , Feminino , Migração de Corpo Estranho/etiologia , Migração de Corpo Estranho/prevenção & controle , Humanos , Masculino , Teste de Materiais , Pessoa de Meia-Idade , Polietilenotereftalatos , Politetrafluoretileno , Desenho de Prótese , Estudos Retrospectivos , Estresse Mecânico , Resistência à Tração , Resultado do Tratamento
13.
J Thorac Cardiovasc Surg ; 159(3): 1051-1059.e1, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31383558

RESUMO

BACKGROUND: The Carpentier Edwards Perimount Magna Ease aortic valvular prosthesis (Edwards Lifesciences, Irvine, Calif) has been among the most frequently and successfully used tissue prosthetic cardiac valves. Furthermore, this prosthesis has been used off-label in the pulmonary position. Until now, there has been a paucity of data regarding the functioning of tissue prosthetic valves under pulmonary conditions. METHODS: Using a pulse duplicator, hydrodynamic characteristics of a 21-mm and 25-mm Magna Ease valve were evaluated. Among parameters evaluated were leakage orifice area, closing time (ie, time required to close), and leakage duration. This procedure was performed under different pulmonic pressure conditions (15/5 mm Hg, 28/11 mm Hg, 73/32 mm Hg) and normal aortic pressure (120/80 mm Hg) as a reference. Moving images were obtained using a Phantom MIRO M320S high-speed camera (Vision Research Inc, Wayne, NJ) at 600 frames per second and used to analyze valve area in closed position. RESULTS: Under normal pulmonic conditions (28/11 mm Hg) the leakage orifice area was 0.020 ± 0.012 mm2 for the 21-mm valve and 0.054 ± 0.041 mm2 for the 25-mm valve (P = .03). Hydrodynamic characteristics of the valves differed between pulmonary and aortic testing condition. Valve closing volumes were significantly lower under pulmonary hypotension and normal pulmonary conditions than under normal aortic conditions (P < .05). CONCLUSIONS: Under normal pulmonary pressure conditions, the hydrodynamic characteristics of Magna Ease valves are significantly different compared with aortic conditions. Further research is needed to determine whether these results are associated with prosthetic valve failure.


Assuntos
Pressão Arterial , Bioprótese , Próteses Valvulares Cardíacas , Pericárdio/transplante , Circulação Pulmonar , Animais , Bovinos , Análise de Falha de Equipamento , Xenoenxertos , Hipertensão Pulmonar/fisiopatologia , Teste de Materiais , Desenho de Prótese , Falha de Prótese , Fatores de Risco , Função Ventricular Esquerda , Função Ventricular Direita , Pressão Ventricular
14.
Int Orthop ; 44(2): 253-260, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31758218

RESUMO

BACKGROUND: The aim of this retrospective study was to evaluate the clinical, radiologic, and survival results of dual mobility (DM) sockets in revision total hip arthroplasty (THA) performed for instability versus revision THAs performed for other reasons. METHODS: From a computerized database, we identified 84 revision THAs using a modern DM socket performed in 81 patients with a mean age of 71 years. Indication for revision was recurrent dislocation in 47 hips, and other reasons in the remaining 37 hips. A survivorship analysis according to the actuarial method was carried out on the entire series using revision for any cause, revision for dislocation, and radiological cup loosening revised or not, as the end points. RESULTS: Of the 81 patients, twelve died, six were lost to follow-up, eight had been revised, and 55 patients (58 hips) were unrevised and alive at a mean follow-up of 6.4 years. Dislocation occurred in four of the 47 (8.5%) hips for which indication for revision was dislocation versus one of the remaining 37 (2.7%) hips [odds ratio = 3.4 (0.4-31.3), p = 0.07]. According to our criteria, three acetabular components of which one was revised were considered as loosened. When using revision for dislocation as the end-point, the survival rate at seven years was 90.4 ± 5.3% (IC95%, 79.9-100) in the 47 hips for which the indication for revision was dislocation versus 100% in the remaining 37 hips (log-rank, p = 0.5). CONCLUSIONS: The current study indicated that DM sockets represent an interesting solution to prevent dislocation in revision THAs at mid-term follow-up.


Assuntos
Artroplastia de Quadril/efeitos adversos , Luxação do Quadril/cirurgia , Articulação do Quadril/cirurgia , Prótese de Quadril , Instabilidade Articular/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Artroplastia de Quadril/instrumentação , Artroplastia de Quadril/métodos , Análise de Falha de Equipamento , Feminino , Seguimentos , Luxação do Quadril/prevenção & controle , Humanos , Instabilidade Articular/prevenção & controle , Masculino , Pessoa de Meia-Idade , Desenho de Prótese , Falha de Prótese , Recidiva , Reoperação , Estudos Retrospectivos
15.
J Hosp Infect ; 104(3): 336-343, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31545991

RESUMO

BACKGROUND: The reliability of N95 filtering facepiece respirators (FFRs) depends on correct fitting. The perceived usability of FFRs is equally important because discomfort during usage may affect compliance. Body movements during nursing procedures may also increase the risk of face seal leakage. AIM: To evaluate the mask fit and usability of the best-fitting 3M N95 FFR and the nanofibre N95 FFR before and after nursing procedures. The physical properties of these FFRs were also examined. METHODS: This experimental study had a one-group multiple comparison design. In total, 104 nursing students participated, and performed nursing procedures for 10 min when wearing the best-fitting 3M FFR and the nanofibre FFR. Mask fit and perceived usability of the FFRs were evaluated. FINDINGS: More participants failed to obtain a fit factor ≥100 when using the best-fitting 3M FFR than when wearing the nanofibre FFR (33.7% vs 21.2%) after the procedures (P=0.417). The nanofibre FFR also demonstrated higher usability than the 3M FFRs in terms of facial heat, breathability, facial pressure, speech intelligibility, itchiness, difficulty of maintaining the mask in place, and comfort level (P<0.001). The nanofibre FFR was also lighter, thinner and had slightly higher bacterial filtration efficiency than the 3M FFRs. CONCLUSION: The nanofibre FFR demonstrated significantly better usability than the 3M FFRs. None of the respirators were able to provide consistent protection for the wearer, as detected by face seal leakage after performing nursing procedures. Further improvement in the prototype design is needed to increase compliance and ensure the respiratory protection of users.


Assuntos
Desenho de Equipamento , Exposição Ocupacional/prevenção & controle , Dispositivos de Proteção Respiratória , Estudantes de Enfermagem , Desenho de Equipamento/normas , Análise de Falha de Equipamento , Feminino , Filtração , Humanos , Exposição por Inalação/prevenção & controle , Masculino , Teste de Materiais , Nanofibras , Dispositivos de Proteção Respiratória/normas
16.
Ann Biol Clin (Paris) ; 77(6): 665-667, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31859643

RESUMO

Continuous monitoring of the performances of blood culture instrument can be based on the indicators proposed by the QUAMIC. Of these, the analytic performance indicator evaluates the rate of false-positive vials. False-positives vials can be reported by the device in case of leukocytosis or when vials are overfilled. In our laboratory, we record prospectively in our software all false positive vials as well as the position used for their incubation. These data are analyzed at least twice a year. For the first half of 2016, this strategy allowed us to identify a defective position. We then evaluated the impact of this anomaly as very weak. The one-year follow-up after the position repair confirmed a correction of the problem. Thus, traceability of positions reporting unexplained false-positive vials (i.e. neither due to leukocytosis nor overfilled vials) can allow laboratories to identify a defective position. This survey, if done prospectively, is simple to perform and not time-consuming. It could usefully complement the analytical performance indicator based on the false-positive rate.


Assuntos
Hemocultura/instrumentação , Análise de Falha de Equipamento , Leucocitose/diagnóstico , Artefatos , Hemocultura/métodos , Hemocultura/normas , Coleta de Amostras Sanguíneas/instrumentação , Coleta de Amostras Sanguíneas/métodos , Coleta de Amostras Sanguíneas/normas , Meios de Cultura/farmacologia , Reações Falso-Positivas , Seguimentos , Violeta Genciana , Humanos , Contagem de Leucócitos/instrumentação , Contagem de Leucócitos/normas , Leucocitose/sangue , Fenazinas , Reprodutibilidade dos Testes
17.
Drug Discov Ther ; 13(5): 280-287, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31723100

RESUMO

Few studies have investigated the molecular mechanisms of catheter failure (CF). Herein, we performed histological and molecular biological analyses of the catheter tip to demonstrate its potential as a resource for biological investigation. Additionally, we searched for risk factors for the development of inflammation and coagulation, which are pathological conditions clarified by biological analysis. The CF group included 30 failed catheters involving thrombus and subcutaneous edema identified by ultrasonography. The No-CF group included 26 catheters with no complications. The removed catheter tips were fixed for hematoxylin-eosin (HE) staining with the application of a real-time reverse transcriptase polymerase chain reaction for eukaryotic 18S ribosomal RNA (rRNA), interleukin 1ß, tumor necrosis factor α, tissue plasminogen activator, and plasminogen activator inhibitor 1 (SERPINE1). HE staining identified attached nuclear cells on the inner surfaces of both CF and No-CF catheters. The 18S rRNA was amplified in all samples. The expression level of SERPINE1 was significantly higher in the CF group than in the No-CF group (p = 0.01), whereas the expression levels of other genes did not differ between the groups. Symptoms of CF associated with the expression of SERPINE1 were analyzed. The catheter being in contact with blood vessels during placement was a suggested factor related to the high expression of SERPINE1 (p = 0.04). Catheter tips are a potential resource for biological investigation, and expression analysis of the attached cells can reflect the pathological condition of the catheterized tissue. Further studies using catheter tips are required to elucidate the molecular mechanisms of CF.


Assuntos
Cateteres/efeitos adversos , Análise de Falha de Equipamento/estatística & dados numéricos , Idoso , Estudos de Casos e Controles , Feminino , Expressão Gênica , Humanos , Leucócitos/metabolismo , Masculino , Inibidor 1 de Ativador de Plasminogênio/biossíntese
18.
BMC Musculoskelet Disord ; 20(1): 544, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31730452

RESUMO

BACKGROUND: Several methods are available for the treatment of early-stage osteonecrosis of the femoral head. Core decompression with implantation is a widely-used treatment. However, no single implant is recognized as the most effective way to prevent disease progression. Silk has high strength and resiliency. This study explored the possibility of a strong and resilient silk protein biomaterial as a new alternative implant. METHODS: We investigated the biomechanical properties of the silk protein material by regular compression, torsion, and three-point bending tests. We established three-dimensional finite element models of different degrees of femoral head osteonecrosis following simple core decompression, fibula implantation, porous tantalum rod implantation, and silk protein rod implantation. Finally, we compared the differences in displacement and surface stress under load at the femoral head weight-bearing areas between these models. RESULTS: The elastic modulus and shear modulus of the silk protein material was 0.49GPa and 0.66GPa, respectively. Three-dimensional finite element analyses demonstrated less displacement and surface stress at the femoral head weight-bearing areas following silk protein rod implantation compared to simple core decompression (p < 0.05), regardless of the extent of osteonecrosis. No differences were noted in the surface deformation or surface stress of the femoral head weight-bearing areas following silk protein rod, fibula or tantalum rod implantation (p > 0.05). CONCLUSIONS: When compared with simple core decompression, silk protein rod implantation demonstrated less displacement and surface stress at the femoral head weight-bearing area, but more than fibula or tantalum rod implantation. Similar effects on the surface stress of the femoral head between the silk rod, fibula and tantalum rod implantations, combined with additional modifiable properties support the use of silk protein as a suitable biomaterial in osteonecrosis surgery.


Assuntos
Benzidamina/química , Descompressão Cirúrgica , Necrose da Cabeça do Fêmur/cirurgia , Cabeça do Fêmur/cirurgia , Proteínas de Insetos/química , Procedimentos Ortopédicos/instrumentação , Implantação de Prótese/instrumentação , Seda/química , Adulto , Fenômenos Biomecânicos , Força Compressiva , Módulo de Elasticidade , Análise de Falha de Equipamento , Cabeça do Fêmur/diagnóstico por imagem , Cabeça do Fêmur/fisiopatologia , Necrose da Cabeça do Fêmur/diagnóstico por imagem , Necrose da Cabeça do Fêmur/fisiopatologia , Análise de Elementos Finitos , Humanos , Masculino , Teste de Materiais , Desenho de Prótese , Falha de Prótese , Estresse Mecânico , Propriedades de Superfície , Resistência à Tração
19.
PLoS One ; 14(11): e0224699, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31675364

RESUMO

Pedicle screws are commonly used for posterior stabilization of the spine. When used in deformed or degenerated segments, the pedicle screws are often not fully inserted into the bone, but instead the threaded portion is exposed by 1 or 2 threads to accommodate rod placement and ensure alignment between the tulip of the screw and the rod. However, broken pedicle screws have been reported with the use of this method. The aim of this study was to determine how the fatigue life of the screw is affected by not fully inserting the screw into the bone. Spinal constructs were evaluated in accordance with ASTM F1717. The following three screw positions were subjected to compression bending fatigue loading; (i) pedicle screw fully inserted in the test block with no threads exposed (EXP-T0), (ii) pedicle screw inserted with one thread exposed outside the test block (EXP-T1), (iii) pedicle screw inserted with two threads exposed outside the test block (EXP-T2). Corresponding finite element models FEM-T0, FEM-T1 and FEM-T2 were also constructed and subjected to the same axial loading as the experimental groups to analyze the stress distribution in the pedicle screws and rods. The results showed that under a 190 N axial load, the EXP-T0 group survived the full 5 million cycles, the EXP-T1 group failed at 3.7 million cycles on average and the EXP-T2 groups failed at 1.0 million cycles on average, while the fatigue strength of both the EXP-T1 and EXP-T2 groups was 170 N. The constructs failed through fracture of the pedicle screw. In comparison to the FEM-T0 model, the maximum von Mises stress on the pedicle screw in the FEM-T1 and FEM-T2 models increased by 39% and 58%, respectively. In conclusion, this study demonstrated a drastic decrease in the fatigue life of pedicle screws when they are not full inserted into the plastic block.


Assuntos
Parafusos Pediculares/efeitos adversos , Falha de Prótese/etiologia , Fenômenos Biomecânicos , Força Compressiva , Análise de Falha de Equipamento , Humanos , Coluna Vertebral/cirurgia , Suporte de Carga
20.
BMC Health Serv Res ; 19(1): 695, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31615497

RESUMO

BACKGROUND: Bar code- or radio frequency identification (RFID)-based medical instrument management systems have gradually been introduced in the field of surgical medicine for the individual management and identification of instruments. We hypothesized that individual management of instruments using RFID tags can provide previously unavailable information, particularly the precise service life of an instrument. Such information can be used to prevent medical accidents caused by surgical instrument failure. This study aimed to predict the precise service life of instruments by analyzing the data available in instrument management systems. METHODS: We evaluated the repair history of instruments and the usage count until failure and then analyzed the data by the following three methods: the distribution of the instrument usage count was determined, an instrument failure probability model was generated through logistic regression analysis, and survival analysis was performed to predict instrument failure. RESULTS: The usage count followed a normal distribution. Analysis showed that instruments were not used uniformly during surgery. In addition, the Kaplan-Meier curves plotted for five types of instruments showed significant differences in the cumulative survival rate of different instruments. CONCLUSIONS: The usage history of instruments obtained with RFID tags or bar codes can be used to predict the probability of instrument failure. This prediction is significant for determining the service life of an instrument. Implementation of the developed model in instrument management systems can help prevent accidents due to instrument failure. Knowledge of the instrument service life will also help in developing a purchase plan for instruments to minimize wastage.


Assuntos
Dispositivo de Identificação por Radiofrequência , Instrumentos Cirúrgicos/normas , Análise de Falha de Equipamento/instrumentação , Análise de Falha de Equipamento/métodos , Utilização de Equipamentos e Suprimentos , Humanos , Análise de Regressão , Instrumentos Cirúrgicos/estatística & dados numéricos
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