Replacement Devices Research Articles

TCT-154 Early Safety and Feasibility Study of a Novel Transcatheter Aortic Valve Replacement Device With Polymer Leaflets in Treating Patients With Severe Calcific Aortic Stenosis: Sekilia Valve

TCT-154 Early Safety and Feasibility Study of a Novel Transcatheter Aortic Valve Replacement Device With Polymer Leaflets in Treating Patients With Severe Calcific Aortic Stenosis: Sekilia Valve

Prostate magnetic resonance imaging (MRI) in patients with hip implants-presetting a protocol using a phantom.

Metal structures are a source of artifacts that significantly complicate the interpretation of magnetic resonance imaging (MRI). The use of prostate MRI as a preliminary test in men with a suspicion on prostate cancer leads to an increased use of the test. The aim of this study was to solve a clinically significant problem: to ensure the reduction of artifacts from metal hip implants during prostate MRI. Another goal was to evaluate the impact of artifact reduction methods on quantitative measurements. The prostate gland (PG) phantom model was a cylinder filled with an aqueous solution of polyvinylpyrrolidone at the concentrations of 40%, 30%, and 20% [central zone (CZ), peripheral zone (PZ), and "lesion", respectively]. Phantom MRI study was conducted on Philips Ingenia 1.5T and Philips Ingenia 3T scanners. For 1.5 T, the reduction in the influence of artifacts inside region of interest (ROI) was observed, expressed in a decrease in the average apparent diffusion coefficient (ADC) (CZ, PZ, "lesion") for the manual artifact reduction (MAR) and ZOOM (title of software artifact reduction) techniques compared to the standard method. For 3T this effect was not detected. The same ADC results were obtained for Standard and MAR techniques, and increased ADC values for ZOOM. Despite the fact that the spread of ADC values on 3.0T scanners was minimal, there was a significant deviation of ADC values from the reference ones (up to 30.4%). Therefore, it is necessary to use a correction coefficient in the ADC calculation for the 3.0 T device. In the presented clinical case, high-quality tomograms were obtained without any artifacts, despite the presence of two hip replacement devices in the scanning area. The accurate prostate MRI in the presence of implants is essential for an accurate diagnosis. This approach allows to reduce artifacts from hip implants, to visualize PG and periprostatic tissue in the best way, and to detect malignant and benign changes.

TMJ Concepts Patient-Fitted TMJ Reconstruction Prosthesis System: Results from an FDA Post-Market Surveillance Prospective Cohort Study

BackgroundCustom-designed and patient-fitted temporomandibular joint replacement devices (TMJR) are employed to manage end-stage TMJ pathology, distorted bony TMJ architecture, or in patients who have undergone multiple prior failed TMJ surgeries. PurposeThis study aimed to measure the frequency of revision or replacement over time, estimate the 1, 2, and 3-year survival rate of implants, and determine what demographic, anatomical, or operative variables may be associated with a device adverse event. Study design, setting, and sampleA prospective cohort study was conducted on consenting adults who could read English, implanted with the TMJ Concepts TMJR prostheses between 2013 and 2015 by private or academic surgeons. Patients under the age of 18 and those who were incapable, unwilling, or unable to complete the perioperative forms were excluded. Outcome variablesThe primary outcome variable was the frequency of adverse events, which is defined as device revision or replacement. The secondary outcome variable was the survival rate for the TMJ Concepts devices. AnalysesDevice survival at 1, 2, and 3 years was estimated using the Kaplan-Meyer methodology. Cox proportional hazards regression was used to analyze the effects of the predictor variables for the device survival rate. A p-value of <0.05 was considered significant. ResultsA total of 738 subjects (1098 joints) were enrolled in the study with 102 (14%) males and 636 (86%) females. The mean age was 45.4 (+ 14.8) years. The median follow-up period was 36.2 months (95% CI: 36.1 – 36.2 months). A total of 187 subjects (25.3%) were lost to follow-up during; the study period. Forty-nine devices (4.46%) were associated with an adverse event at 3 years. The; 3-year device survival was 95.1 % (95% CI: 93.6 – 96.3%). The only significant risk factor for an adverse event was the asymmetry of the mandible (hazard rate ratio = 1.989, p = 0.03). The primary diagnosis was not associated with the time to an adverse event (p-value = 0.8685). Infection (44.7 %, 21 joints) and material sensitivity (12.8 %, 6 joints) were the most common reasons specifically for device removal/replacement in the study cohort. ConclusionsInfection was the primary reason reported for device revision or replacement followed by material sensitivity. In the study cohort, the device survival following implantation of the TMJ Concepts prosthesis was not significantly different than reported by the TMJR stock device.

Efficacy of Sentinel Cerebral Embolic Protection Device in Transcatheter Aortic Valve Replacement: A Meta-Analysis of Randomized Controlled Trials and Propensity Score-Matched Studies.

Transcatheter aortic valve replacement (TAVR) is frequently associated with stroke due to debris embolization. Although the risk of stroke with newer-generation devices is lower, stroke still represents a significant cause of mortality and morbidity post-TAVR. The Sentinel cerebral embolic protection device (CEPD) is a dual-embolic filter device designed to capture debris dislodged during TAVR. A systematic literature search was performed on the major bibliographic databases to retrieve studies that compared TAVR with and without Sentinel CEPD. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using the DerSimonian-Laird random-effects model, with a P value of <0.05 considered statistically significant. This meta-analysis included 6 studies with 25,130 patients undergoing TAVR (12,608: Sentinel CEPD; 12,522: without Sentinel CEPD). The use of the Sentinel CEPD in TAVR was associated with a statistically significant lower risk of acute kidney injury (OR: 0.89; 95% CI: 0.81-0.97; P = 0.01]. The use of Sentinel CEPD in TAVR was associated with a statistically insignificant trend toward a reduction in stroke (OR: 0.80; 95% CI: 0.58-1.10; P = 0.18), all-cause mortality (OR: 0.74; 95% CI: 0.51-1.07; P = 0.11), and major vascular complications (OR: 0.74; 95% CI: 0.46-1.19; P = 0.21). The use of Sentinel CEPD in patients undergoing TAVR does not lead to a statistically significant reduction in stroke, all-cause mortality, or major vascular complications; however, the risk of acute kidney injury is lower. Further randomized studies are warranted to confirm these findings.

Effect of bioprosthetic leaflet anisotropy on stent dynamics of Transcatheter Aortic Valve Replacement devices

The assessment of stent fatigue in Transcatheter Aortic Valve Replacement (TAVR) systems is critical for the design of next-generation devices, both in vitro and in vivo. The mechanical properties of the bioprosthetic heart valves (BHVs) have a significant impact on the fatigue life of the metallic stent and thus must be taken into consideration when evaluating new TAVR device designs. This study aims to investigate the relationship between BHV anisotropic behaviour and the asymmetric deflections of the stent frame observed during in vitro testing.An explicit dynamics finite element model of the nitinol stent with attached bioprosthetic valve leaflets was developed to evaluate the deflections of the TAVR device under haemodynamic loading. Our results demonstrate that pericardium behaviour plays a dominant role in determining stent frame deflection. The anisotropic behaviour of the leaflets, resulting from collagen fibre orientation, affects the extent of deflection encountered by each commissure of the frame. This leads to asymmetric variation in frame deflection that can influence the overall fatigue life of the nitinol stent. This study highlights the importance of considering both the flexible nature of the metallic stent as well as the leaflet anisotropic behaviour in the design and fatigue assessment of TAVR systems.

Early Feasibility Study with the SATURN Transapical Mitral Valve Replacement Device

PurposeTo report the outcomes of the early feasibility study of transapical transcatheter mitral valve replacement (TMVR) with the SATURN System (InnovHeart, Milano, Italy) to treat patients with severe functional mitral regurgitation. DescriptionFive high surgical risk patients underwent transapical transcatheter mitral valve replacement with the SATURN System at a single center. One-year follow-up is complete for all patients. EvaluationThe valve was implanted successfully in all patients without any major adverse events. All patients were alive at the last follow-up. Kansas City Cardiomyopathy Questionnaire improved from a median of 63.5 (interquartile range, 19.6) at baseline to 99.0 (interquartile range, 21.6) at 1 year. Echocardiographic follow-up demonstrates stable valve function, no transvalvular or paravalvular mitral regurgitation, and absence of left ventricular outflow tract obstruction. ConclusionsAt 1 year after transapical SATURN transcatheter mitral valve replacement, all patients are alive with quality of life improvement and favorable device hemodynamics. These initial results are promising and larger scale studies with continued follow-up are required to further elucidate the efficacy and safety of this novel technology.

Removals and Revisions of Cervical Total Disc Replacement Devices in a Consecutive Series of 1626 Patients Beginning With the First Case Experience in 2003.

Retrospective cohort study. The purpose of this study was to investigate the rate of cervical total disc replacement (TDR) device removal or revision. Cervical TDR has gained acceptance as an alternative to anterior cervical discectomy and fusion in appropriately selected patients. There have been concerns over device safety, one measure of which is subsequent surgery related to device problems. A consecutive series of 1626 patients undergoing cervical TDR from 2003 to June 2021 were included, consisting of TDRs up to 3 levels and hybrids (TDR and fusion). TDR removal or revision surgeries and reasons for these surgeries, procedures performed, and duration from index procedure were recorded. Data were analyzed to determine the removal/revision rate and factors possibly related to these events. There were 24 removals/revisions (1.48%) in the 1626 patients. Removal was performed in 23 cases (1.41%) and revision in 1 (0.06%). Among removal cases, anterior cervical discectomy and fusion was performed in 18 and TDR was replaced with another TDR in 5. Removals with fusion included 5 cases of osteolysis with/without Cutibacterium acnes , 4 device displacement/migration, 4 posterior spinal pathology, and one for each of the following: metal allergy, approach-related complications, malpositioning, subsidence, and hypermobility. The revision involved TDR repositioning 3 days after index surgery. There were 66 patients for whom a minimum of 10-year follow-up was confirmed, and none had removal/revision surgery 10 or more years after index surgery. There was no relationship between the occurrence of removal/revision and age, sex, body mass index, or physician experience (learning curve). The removal/revision rate was significantly higher in FDA trials versus postapproval (4.1% vs . 1.3%, P < 0.05). In this large consecutive series of patients, 1.48% of cervical TDRs were removed/revised. The low rate of removals/revisions over a long period of time provides support for the devices' safety. Level IV.

Percutaneous balloon mitral valvuloplasty with shockwave lithotripsy for the treatment of calcific mitral valve stenosis.

Calcific mitral stenosis (calcific MS) presents a challenge for surgical treatment and is a contraindication for most contemporary transcatheter mitral valve replacement devices (TMVR), rendering patients with very limited therapeutic options. This study aims to assess the clinical and hemodynamic follow-up after mitral valve lithotripsy (MVL). All consecutive patients who underwent MVL to treat symptomatic calcific MS at St Michael's Hospital, Toronto, Canada, were included. Patients were deemed unsuitable for mitral surgery or TMVR after heart team assessment. Patients with rheumatic MS or ≥moderate mitral regurgitation (MR) were excluded. The primary endpoint was a reduction in the invasive mitral gradient by ≥50% without significant (≥moderate) MR. Fifteen patients underwent MVL between 2021 and 2023 with a mean age of 74 ± 9 years; 53% were female, with a mean STS score of 10% ± 0.1%. Following MVL, there was a reduction in the invasively measured mean trans-mitral gradient compared to baseline (14 mmHg vs. 6 mmHg; p < 0.05). The primary endpoint was achieved in 8 patients (53%) with no major procedural complications. At follow-up (median 90 days, IQR 58-115 days), 14 (93%) patients reported improved symptoms from New York Heart Association (NYHA) Class III-IV to NYHA Class I-II (p < 0.01) with stable echo-derived mean gradient (7.7 mmHg ± 2 mmHg vs. 8.4 mmHg ± 2.9 mmHg (p = 0.7). In selected patients with symptomatic inoperable calcific MS, MVL was safe and associated with significant short-term clinical and hemodynamic improvement. MVL may represent a new compassionate therapy for this challenging cohort. Further studies are needed to determine the long-term outcomes and help define the role of IVL technology in treating calcific valvular conditions.

Comparison of four in vitro test methods to assess nucleus pulposus replacement device expulsion risk.

Nucleus replacement devices (NRDs) are not routinely used in clinic, predominantly due to the risk of device expulsion. Rigorous in vitro testing may enable failure mechanisms to be identified prior to clinical trials; however, current testing standards do not specify a particular expulsion test. Multiple methods have therefore been developed, complicating comparisons between NRD designs. Thus, this study assessed the effectiveness of four previously reported expulsion testing protocols; hula-hoop (Protocol 1), adapted hula-hoop (Protocol 2), eccentric cycling (Protocol 3), and ramp to failure (Protocol 4), applied to two NRDs, one preformed and one in situ curing. Nucleus material was removed from 40 bovine tail intervertebral disks. A NRD was inserted posteriorly into each cavity and the disks were subjected to one of four expulsion protocols. NRD response was dependent on both the NRD design and the loading protocol. Protocol 1 resulted in higher migration and earlier failure rates compared to Protocol 2 in both NRDs. The preformed NRD was more likely to migrate when protocols incorporated rotation. The NRDs had equal migration (60%) and expulsion (60%) rates when using unilateral bending and ramp testing. Combining the results of multiple tests revealed complimentary information regarding the NRD response. Adapted hula-hoop (Protocol 2) and ramp to failure (Protocol 4), combined with fluoroscopic analysis, revealed complimentary insights regarding migration and failure risk. Therefore, when adopting the surgical approach and animal model used in this study, it is recommended that NRD performance be assessed using both a cyclic and ramp loading protocol.

Fish swim bladders as valve leaflets enhance the durability of transcatheter aortic valve replacement devices

Transcatheter aortic valve replacement (TAVR) has emerged as an effective therapy for inoperable patients with severe aortic stenosis (AS). However, calcification-induced limited durability restricts its application. Fish swim bladders (FSB), which are resistant to calcific degeneration, offer a viable solution to this challenge. In this study, we developed a new TAVR device using FSB as the valve leaflet. Furthermore, the in vitro durability, in vivo performance, and size selection of this TAVR device were assessed by an experimental study and finite element analysis. A self-expandable TAVR device was fabricated by suturing the FSB films into a 23 mm nitinol alloy frame. Further, hemodynamic performance, such as effective orifice area, transvalvular pressure difference and regurgitant fraction, the durability was tested by the pulsatile flow test and accelerated fatigue test, according to the ISO 5840-3. The effect of release size on hydrodynamic performance was also investigated. Finally, the in vivo performance of the TAVR device were examined using a porcine implantation model. The results showed that the strength of the FSB films satisfied the requirements for valve leaflets. The hemodynamic performance of the FSB TAVR device met the requirements of ISO 5840-3 standards. After 400 million cycles, the FSB showed no fiber loss, torn, perforation, or other valve failure phenomena. In porcine models, the devices were well-positioned, functioned well with no stenosis immediately after the operation. Collectively, we successfully developed a TAVR device with FSB as valve leaflets that exhibited good fatigue resistance. Statement of significanceThe source of material for the leaflets of commercialized biological heart valves (BHVs) is mainly bovine pericardium, but this material suffers the following problems: large and uneven thickness of the material, the presence of α-Gal and Neu5Gc antigens, and the susceptibility to structural valve degradation (SVD). New material for BHVs leaflets is rarely reported. In this study, we prepared a transcatheter aortic valve (TAV) and performed long-term in vitro and short-term in vivo studies using fish swim bladder (FSB) as the leaflets. The study confirmed that FSB TAV device can complete 400 million fatigue tests and maintain the good morphology of the leaflets, and that it still maintains good functionality after a certain amount of compression, indicating that FSB is a promising material for leaflets.

Cerebral Embolic Protection Devices for Transcatheter Aortic Valve Replacement: Review of the Literature and Future Perspectives.

Transcatheter aortic valve replacement (TAVR) has been a revolutionary therapy in the treatment of aortic valve stenosis. The risk of stroke associated with TAVR has decreased significantly since its introduction; however, it remains a devastating complication when it does occur. Many of the strokes associated with TAVR occur peri-procedurally and are thought to be due to embolic debris entering the cerebrovascular circulation. A number of different cerebral embolic protection devices (CEPD) have been developed and are in various stages of testing and use. The results from clinical trials evaluating the role for CEPD to reduce the risk of stroke have been mixed. As a result, their uptake has been very heterogeneous. This review provides a summary of the diverse CEPD devices available for use and outlines the clinical evidence available to date.

The Effect of Aortic Angulation on Clinical Outcomes of Patients Undergoing Transcatheter Aortic Valve Replacement.

The aim of this study was to assess the impact of aortic angulation (AA) on periprocedural and in-hospital complications as well as mortality of patients undergoing Evolut™ R valve implantation. A retrospective study was conducted on 264 patients who underwent transfemoral-approach transcatheter aortic valve replacement with self-expandable valve at our hospital between August 2015 and August 2022. These patients underwent multislice computer tomography scans to evaluate AA. Transcatheter aortic valve replacement endpoints, device success, and clinical events were assessed according to the definitions provided by the Valve Academic Research Consortium-3. Cumulative events included paravalvular leak, permanent pacemaker implantation, new-onset stroke, and in-hospital mortality. Patients were divided into two groups, AA ≤ 48° and AA > 48°, based on the mean AA measurement (48.3±8.8) on multislice computer tomography. Multivariable logistic regression analysis was performed to identify predictors of cumulative events, utilizing variables with a P-value < 0.2 obtained from univariable logistic regression analysis, including AA, age, hypertension, chronic renal failure, and heart failure. AA (odds ratio [OR]: 1.73, 95% confidence interval [CI]: 0.89-3.38, P=0.104), age (OR: 1.04, 95% CI: 0.99-1.10, P=0.099), hypertension (OR: 1.66, 95% CI: 0.82-3.33, P=0.155), chronic renal failure (OR: 1.82, 95% CI: 0.92-3.61, P=0.084), and heart failure (OR: 0.57, 95% CI: 0.27-1.21, P=0.145) were not found to be significantly associated with cumulative events in the multivariable logistic regression analysis. This study demonstrated that increased AA does not have a significant impact on intraprocedural and periprocedural complications of patients with new generation self-expandable valves implanted.

Effect of temperature and time on the synthesis of calcium phosphate obtained by microwave hydrothermal method

Bioceramics are materials used in biomedical devices for bone replacement, and calcium phosphate derivatives are widely used in cases of bone defect repair. The aim was to evaluate the influence of temperature and time on the synthesis of calcium phosphate obtained by the microwave hydrothermal method on its structural and morphological characteristics with a view to application as a bone graft. The calcium phosphate powders (calcium octophosphate, hydroxyapatite and calcium triphosphate) were produced using the microwave hydrothermal method. To obtain the calcium phosphate powders, aqueous solutions of Ca (OH)2 and H3 PO4 were used and subjected to the microwave hydrothermal method at temperatures of 110°C and 130°C for 30 and 60 minutes, then calcined at 700°C for 1 hour and characterized using XRD, FTIR, SEM, particle size distribution, apparent density, and apparent porosity. The results obtained by the techniques confirm crystalline and morphological modifications, and homogeneous distribution of the particles, and the phases of interest, octophosphate, hydroxyapatite and calcium β-triphosphate, were identified. The formation of the β-TCP phase was predominant in the samples in which the microwave hydrothermal synthesis was carried out over a longer time and at a higher temperature. It was found that the proposed synthesis method was effective in terms of time/temperature, offering advantages over conventional techniques, such as improving the primary characteristics for choosing a biomaterial to be used in cases of bone regeneration.

Lumbar Total Disk Replacement Device Removals and Revisions Performed During a 20-Year Experience with 2141 Patients.

This was a retrospective study with prospective patient contact attempted to collect current data. The purpose was to investigate the incidence and reasons for lumbar total disk replacement (TDR) removal or revision. A concern regarding lumbar TDR was safety, particularly the need for device removal or revision. This may be particularly important considering removal/revision requires repeat anterior exposure with an increased risk of vascular injury. Data were collected for a series of 2141 lumbar TDR patients, beginning with the first case experience in 2000. The mean follow-up was 78.6 months. For each case of device removal/revision, the reason, duration from index surgery, and procedure performed were recorded. Of 2141 patients, 27 (1.26%) underwent TDR removal or revision. Device removal was performed in 24 patients (1.12%), while three patients underwent revision (0.14%). Of the 24 removals, 12 were due to migration and/or loosening, three developed problems post-trauma, two developed lymphocytic reaction to device materials, two had ongoing pain, and there was one case of each: TDR was too large, vertebral body fracture (osteoporosis), lytic lesion, device subsidence and facet arthrosis, and infection seeded from a chest infection 146 months post-TDR. The three revisions were for Core repositioning (technique error), device repositioning after displacement, and core replacement due to wear/failure. With respect to timing, 37.0% of removals/revisions occurred within one-month postimplantation. Of note, 40.7% of removals/revisions occurred in the first 25 TDR cases performed by individual surgeons. There was one significant vascular complication occurring in a patient whose TDR was removed due to trauma. This was also the only patient among 258 with ≥15-year follow-up who underwent removal/revision. In this large consecutive series, 1.26% of TDRs were removed/revised. The low rate over a 20 year period supports the safety of these devices.

Ten-Year Risk of Recall of Novel Spine Devices.

Observational epidemiological study. This study's primary objective was to examine the risk of recall for novel spine devices over time. Secondarily, we sought to analyze interbody fusion and vertebral body replacement (VBR) devices (corpectomy cages) as a risk factor for recall. The recall risk of a novel spine device over time has not been reported. In addition, FDA regulations were lowered for interbody fusion devices to enter the market in 2007. As well, VBR implants were recently approved by the FDA for use in the cervical spine in 2015. Spine devices cleared between January 1, 2008 and December 31, 2018 were identified from the FDA's 510(k) database. All recall data were collected from the database in January 2021 to provide a 2-year minimum follow-up for a recall to occur. Product labels were used to classify interbody fusion and VBR devices. Cumulative incidence function was conducted to compare the overall risk of recall for FDA-cleared spine devices, and the hazard ratio determined for VBR and all other devices versus interbody implants during the study period. A total of 2384 spine devices were cleared through 510(k) in the study period. The hazard of recall at 5 years was 5.3% (95% CI: 4.4%-6.2%) and 6.5% (95% CI: 5.4%-7.7%) at 10 years. No significant difference in recall risk was identified for interbody fusion and VBR devices. The risk of recall at 5 and 10 years of a novel spine device is about half the 12% rate reported for orthopedic devices in general. Despite lowered FDA regulations for interbody fusion devices and recent approval for VBR device use in the cervical spine, no increased risk of recall was detected. Further research is necessary to explain the reason for the lower risk of recall with spine devices. 4.

Extracorporeal Blood Therapeutic Devices for Renal Replacement: A Review of Current Technologies and Future Directions Toward Microscale-based Devices

Extracorporeal Blood Therapeutic Devices for Renal Replacement: A Review of Current Technologies and Future Directions Toward Microscale-based Devices

Regulatory science promotes the translation of transcatheter tricuspid valve repair/replacement devices.

For patients with symptomatic and severe tricuspid regurgitation but inoperable with open surgery, transcatheter tricuspid valve intervention (TTVI) is a procedure of great clinical value. TTVI products include repair and replacement devices. TTVI products are one of the hotspots of investigation now, with different innovative biomaterials and structural designs in trials to satisfy divergent indications and reduce complications. With the emerging biomaterials, the technical difficulty of structural design will be greatly reduced, spurring further product innovation and development. The innovativeness and complexity of TTVI products have brought challenges to academia, industry, and regulatory agencies. Regulatory science provides a bridge to address these difficulties and challenges. This perspective article introduces the latest development of the TTVI products. With traditional methods, regulatory agencies face challenges in evaluating the safety and efficacy of TTVr/TTVR devices given the uncertainty of clinical use and the diversity of innovative structural design. This perspective article analyzes the regulatory challenges and discusses regulatory science that can be developed to assess the safety, efficacy, quality and performance of such products: including new approaches for innovative devices, pre-review path, computer modeling and simulation, accelerated wear testing methods for transcatheter heart valves and evidence-based research. This article reveals for the first time how to apply regulatory science systematically to TTVI products, which is of great relevance to their development and translation.

Exploration on the Reform of Teaching Methods of Human Function Replacement Devices under the Background of Educational Informatization

Exploration on the Reform of Teaching Methods of Human Function Replacement Devices under the Background of Educational Informatization

Metabolic disturbances potentially attributable to clogging during continuous renal replacement therapy

BackgroundClogging is characterized by a progressive impairment of transmembrane patency in renal replacement devices and occurs due to obstruction of pores by unknown molecules. If citrate-based anti-coagulation is used, clogging can manifest as a metabolic alkalosis accompanied by hypernatremia and hypercalcemia, primarily a consequence of Na3Citrate infusion. An increased incidence of clogging has been observed during the COVID-19 pandemic. However, precise factors contributing to the formation remain uncertain. This investigation aimed to analyze its incidence and assessed time-varying trajectories of associated factors in critically ill patients on continuous renal replacement therapy (CRRT).MethodsIn this retrospective, single-center data analysis, we evaluated COVID-19 patients undergoing CRRT and admitted to critical care between March 2020 and December 2021. We assessed the proportional incidence of clogging surrogates in the overall population and subgroups based on the specific CRRT devices employed at our institution, including multiFiltrate (Fresenius Medical Care) and Prismaflex System (Baxter). Moderate and severe clogging were defined as Na > 145 or ≥ 150 mmol/l and HCO3− > 28.0 or ≥ 30 mmol/l, respectively, with a total albumin-corrected calcium > 2.54 mmol/l. A mixed effect model was introduced to investigate factors associated with development of clogging.ResultsFifty-three patients with 240 CRRT runs were analyzed. Moderate and severe clogging occurred in 15% (8/53) and 19% (10/53) of patients, respectively. Twenty-seven percent (37/136) of CRRTs conducted with a multiFiltrate device met the criteria for clogging, whereas no clogging could be observed in patients dialyzed with the Prismaflex System. Occurrence of clogging was associated with elevated triglyceride plasma levels at filter start (p = 0.013), amount of enteral nutrition (p = 0.002) and an increasing white blood cell count over time (p = 0.002).ConclusionsClogging seems to be a frequently observed phenomenon in critically ill COVID-19 patients. The presence of hypertriglyceridemia, combined with systemic inflammation, may facilitate the development of an impermeable secondary membrane within filters, thereby contributing to compromised membrane patency.

Investigation on the behaviour and performance of replaceable inverted-Y dissipation device in eccentric braced frame steel structures

Investigation on the behaviour and performance of replaceable inverted-Y dissipation device in eccentric braced frame steel structures