Candidates For Implantation Research Articles

Dual-Task Interference in the Assessment of Listening Effort Before and After Cochlear Implantation in Adults: A Longitudinal Study.

This study aimed to assess the magnitude and direction of dual-task interference in a listening effort dual-task paradigm in individuals with severe-to-profound hearing loss before and in the short- and long-term after cochlear implantation. The study sample consisted of 26 adult candidates for cochlear implantation with severe-to-profound hearing loss. The dual-task paradigm consisted of a primary speech understanding task, conducted in a quiet condition, and a favorable and unfavorable noise condition on the one hand and a secondary visual memory task on the other hand. The dual-task effect for both tasks and the derived patterns of dual-task interference were determined. Participants were evaluated at four test moments: before cochlear implantation and at 3 months, 6 months, and 12 months after implantation. Across all listening conditions, a shift was observed from patterns of dual-task interference with worse and stable scores for the primary speech understanding task in the dual-task condition compared to the baseline condition before implantation, toward patterns in which stable or better scores were obtained, respectively, for the primary task in the dual-task condition after implantation. This indicates that more attention could be allocated to the primary speech understanding task during the dual-task condition after implantation, implying a decreased listening effort. A decreased listening effort was found after cochlear implantation. This study provides additional insights into the evolution of dual-task interference after cochlear implantation. It highlights the importance of interpreting both the primary and secondary tasks using a dual-task paradigm in the assessment of listening effort.

Auditory brainstem response thresholds and functional hearing: implications for cochlear implant candidacy.

This study assessed the relevance of auditory brainstem response (ABR) thresholds in evaluating cochlear implantation (CI) candidacy by studying their correlation with functional hearing in patients with sensorineural hearing loss (SNHL). In this retrospective study, we examined correlations between ABR thresholds, speech perception scores in quiet and pure-tone audiometry in 191 adults. We compared these correlations between individuals with different degrees of SNHL to discern differences in potential CI candidates and individual with less severe SNHL. A significant negative correlation was found between ABR thresholds and unaided speech perception scores at 70 dB SPL (R = -0.397, Pcorr<0.0001). For patients scoring 50% or higher on speech audiometry, a significant correlation was observed (R = -0.604, Pcorr<0.004), but not for those scoring less than 50% (R = -0.168, Pcorr=0.084). In the subgroup with ABR thresholds better than 60 dB nHL, a moderate correlation was observed (R = -0.575, Pcorr = 0.032), which was not significant in patients with ABR thresholds of 60 dB nHL or worse (R = -0.175, Pcorr = 0.084). In patients with severe hearing loss (speech perception <50% or ABR thresholds ≥60 dB nHL), the ABR threshold does not correlate with speech perception, limiting its clinical validity for functional auditory performance or CI candidacy evaluation.

Profile of Audiological Assessment for Cochlear Implant Candidacy and Outcome Measures in Children in India

Profile of Audiological Assessment for Cochlear Implant Candidacy and Outcome Measures in Children in India

Towards Accurate Biocompatibility: Rethinking Cytotoxicity Evaluation for Biodegradable Magnesium Alloys in Biomedical Applications.

Magnesium and its alloys represent promising candidates for biomedical implants due to their biodegradability and mechanical properties, which are similar to natural bone. However, their rapid degradation process characterized by dynamic pH fluctuations and significant hydrogen gas evolution during biocorrosion adversely affects both in vitro and in vivo assessments. While the ISO 10993-5 and 12 standards provide guidelines for evaluating the in vitro biocompatibility of biodegradable materials, they also introduce testing variability conditions that yield inconsistent results. To address these inherent characteristics of Mg alloys, developing improved methods that accurately simulate the physiological environment for in vitro biocompatibility testing is essential. This study introduces two novel extraction approaches for evaluating Mg alloys: a buffered solution utilizing PBS/DMEM with quaternary dilutions and a modified ISO standard protocol employing decuple dilution of conventional unbuffered extracts. The present findings establish that controlled optimization of extraction conditions, specifically buffer composition and dilution parameters, enables reliable in vitro cytotoxicity assessment of Mg alloys, providing a robust methodology that advances the preclinical evaluation of these promising biodegradable materials.

Radiological Perspectives in Congenital Sensorineural Hearing Loss: Insights from Cochlear Implant Candidates.

Objectives: Congenital hearing loss is a significant health concern, with diverse etiologies encompassing cochlear and cochleovestibular pathologies. Preoperative radiological evaluation in cochlear implant candidates is pivotal for treatment planning. We aim to elucidate the spectrum of radiological findings in patients with congenital hearing loss undergoing cochlear implant assessment. Methods: An analysis included 389 sensorineural hearing loss (SNHL) patients who underwent cochlear implantation at a tertiary university hospital, of which 177 were congenital SNHL. Computed tomography (CT) and magnetic resonance imaging (MRI) data were meticulously assessed for diverse congenital pathologies, focusing on congenital malformations. Results: In the congenital SNHL group, comprising 177 patients (80 females and 97 males), congenital cochleovestibular malformations were evident in 56 ears of 29 cases. Different congenital cochleovestibular malformations, ranging from labyrinthine aplasia to isolated large vestibular aqueducts, were detected. Among the various anomalies, incomplete partitions and cochlear hypoplasia emerged as more frequent patterns. Conclusions: This study offers a comprehensive radiological analysis of congenital SNHL patients undergoing cochlear implantation, revealing a spectrum of anomalies. It demonstrates the diverse nature of anomalies affecting the external auditory canal, middle ear structures, and cochleovestibular system. These insights provide a deeper understanding of congenital SNHL and contribute to developing informed treatment strategies.

How Does Deep Neural Network-Based Noise Reduction in Hearing Aids Impact Cochlear Implant Candidacy?

Adult hearing-impaired patients qualifying for cochlear implants typically exhibit less than 60% sentence recognition under the best hearing aid conditions, either in quiet or noisy environments, with speech and noise presented through a single speaker. This study examines the influence of deep neural network-based (DNN-based) noise reduction on cochlear implant evaluation. Speech perception was assessed using AzBio sentences in both quiet and noisy conditions (multi-talker babble) at 5 and 10 dB signal-to-noise ratios (SNRs) through one loudspeaker. Sentence recognition scores were measured for 10 hearing-impaired patients using three hearing aid programs: calm situation, speech in noise, and spheric speech in loud noise (DNN-based noise reduction). Speech perception results were compared to bench analyses comprising the phase inversion technique, employed to predict SNR improvement, and the Hearing-Aid Speech Perception Index (HASPI v2), utilized to predict speech intelligibility. The spheric speech in loud noise program improved speech perception by 20 to 32% points as compared to the calm situation program. Thus, DNN-based noise reduction can improve speech perception in noisy environments, potentially reducing the need for cochlear implants in some cases. The phase inversion method showed a 4-5 dB SNR improvement for the DNN-based noise reduction program compared to the other two programs. HASPI v2 predicted slightly better speech intelligibility than was measured in this study. DNN-based noise reduction might make it difficult for some patients with significant residual hearing to qualify for cochlear implantation, potentially delaying its adoption or eliminating the need for it entirely.

Tympanic Pre-Operative Electrically Evoked Auditory Late Response (TympEALR) as an Alternative to Trans-Tympanic Tests Using Anesthesia in Cochlear Implant Candidacy.

Background/Objectives: Before a cochlear implant is considered, patients undergo various audiological tests to assess their suitability. One key test measures the auditory brainstem response (ABR) to acoustic stimuli. However, in some cases, even with maximum sound stimulation, no response is detected. Methods: The promontory test involves electrical stimulation near the auditory nerve, allowing patients to associate the sensation. Ideally, the electrode is placed in the middle ear after opening the eardrum. This method, along with trans-tympanic electrically evoked ABR in local anesthesia (LA-TT-EABR) and the cortical equivalent (LA-TT-EALR), helps assess the auditory nerve's existence and excitability. The TympEALR test, utilizing a "tympanic LA-TT-EALR", provides an alternative measurement. Previous research has shown the possibility of deriving brainstem and cortical potentials through trans-tympanic electrical stimulation, allowing for objective assessment of the auditory nerve's integrity and potentially objectifying patient sensations. Results: Sixteen patients have been tested using TympEALR. In seven of these, we found a positive response. The morphology was similar to other electrically evoked cortical auditory responses (EALR), e.g., using cochlear implants or trans-tympanic stimulation electrodes. We observed a higher influence of electrical artifacts than in other EALRs. Conclusions: TympEALR showed positive results in nearly half of the study participants, potentially avoiding invasive procedures. TympEALR can be a valuable alternative to trans-tympanic methods. More research is needed to determine if a negative result suggests against cochlear implantation.

380 MPa-30% grade biodegradable Zn-Mn-Mg-Ca alloy: Bimodal grain structure, large work-hardening strain, and enhanced biocompatibility.

Strain softening is a common issue for high-strength biodegradable Zn alloys. We developed Zn-0.6Mn-0.05Mg-0.05Ca alloy with a bimodal grain structure by extrusion and caliber rolling, refer to as ZMMC063 (CRD). The alloy exhibits the best strength-ductility synergy among Zn-Mn based alloys, which shows a yield strength of 386 MPa, an ultimate tensile strength of 443 MPa, and an elongation rate of 31%. This is the first 380 MPa-30% grade Zn-Mn based alloy, surpassing the previous reported Zn alloy with 320 MPa-20% grade. Its work-hardening strain reaches as high as 11.6%, which is 4 times greater than that of other 300 MPa Zn-Mn based alloys. This is owing to hetero-deformation induced strengthening effect of the bimodal grain. Additionally, it demonstrates for the first time that micro-galvanic corrosion happens between coarse and fine Zn grains, thereby accelerating degradation of the alloy. This provides a feasible protocol for controlling degradation of Zn alloys. Compared with the extruded Zn-0.6Mn-0.05Mg-0.05Ca alloy, refer to as ZMMC063 (HE), the increased release of Mg2+ and Ca2+ ions in ZMMC063 (CRD) improves tolerance of MC3T3-E1 cells to Zn2+. Consequently, ZMMC063 (CRD) shows higher antibacterial abilities against E. coli and S. aureus, meanwhile much less toxicity to MC3T3-E1 cells. Synergistic effect of Zn2+, Mg2+ and Ca2+ ions promote expression of ALP, COl-1, OCN and Runx-2, so that ZMMC063 (CRD) exhibits better ability to induce osteogenic differentiation. This paper suggests that ZMMC063 (CRD) is a promising candidate for orthopedic implants. STATEMENT OF SIGNIFICANCE: : Previously the highest yield strength-elongation level of Zn-Mn based alloys is 320 MPa-20% grade. At such a high strength, the alloys' work-hardening strain (Ewh) values are below 4%. To further improve comprehensive properties of Zn-Mn based alloys, 380 MPa-30% grade Zn-0.6Mn-0.05Mg-0.05Ca alloy with bimodal grain structure is developed by extrusion and caliber rolling. The alloy's Ewh reaches as high as 11.6%, due to the hetero-deformation induced effect of bimodal grain structure. Additionally, micro-galvanic corrosion happens between bimodal grains, which accelerates the alloy's degradation. In vitro studies show that the alloy exhibits enhanced antibacterial activity, good cytocompatibility, and promising osteogenic effect, indicating that it is a promising candidate for orthopedic implants.

Cochlear nerve visualization in Normal anatomy and inner ear malformations.

This study aimed to qualitatively evaluate the variations in nerve bundles between patients with normal anatomy and those with inner-ear anomalies. Magnetic resonance imaging (MRI) scans of the temporal bones of candidates for cochlear implants (CIs) enrolled at a tertiary center were retrospectively reviewed from the clinical database. The 3.0-Tesla MRI scans were analyzed using a three-dimensional slicer to visualize the nerve bundles in the internal auditory canal. A total of 49 ears were analyzed. Twenty ears exhibited normal inner ear anatomy, whereas 29 ears had various inner-ear malformations. The cochlear nerve (CN) was visible on all 20 scans with normal inner-ear anatomy. In addition, the CN was visualized in 18 scans with inner ear malformations. Furthermore, the CN was identified in six of the eight scans with IP type I, whereas in two scans, the CN and vestibular nerve were unclear. Three scans with a common cavity showed only two nerve bundles. The findings of this study show that the CN can be visualized in most inner-ear anatomical types. Even in severely malformed inner ears, the common nerve bundle that represents the cochlear and vestibular nerves can be visualized. The MRI is highly recommended for CN assessment before CI surgery. Level IV.

Fabrication of nanoparticle-reinforced composite hydrogel for improved durability, antifouling, and thrombosis-resistance in arteriovenous grafts

Arteriovenous grafts are routinely designed to provide a deliberate connection between an artery and vein in patients during hemodialysis. The commonly used grafts present significant drawbacks such as thrombosis, bacterial infection, and biofouling which prevents their functionality. To endow hydrogels with improved anti-thrombosis, stable antifouling, and strong mechanical strength, a surface-modified nanoparticle-reinforced nanohybrid hydrogel is developed. In brief, zwitterionic sulfobetaine methacrylate (SBMA) is coated on bentonite clay (BC) nanoparticles via a simple method. BC-SBMA nanoparticles were then loaded onto sodium alginate /polyvinyl alcohol hydrogel composite. Calcium chloride (Ca2+) crosslinking is employed to form stable network and optimize polyvinyl alcohol/sodium alginate (PS) hydrogel composite. BC-SBMA particles were dispersed into PS hydrogel and crosslinked to form nanohybrid hydrogel (PS@BC-SBMA). The nanohybrid hydrogel was characterized for its morphological, mechanical, physicochemical, antibacterial, biocompatibility, antifouling, ex-vivo anti-thrombogenic, and in-vivo anti-inflammatory properties. The results revealed that the presence ofBC-SBMA particles boosted the mechanical strength and facilitated biocompatibility. The presence of zwitterionic polymers provided excellent antifouling properties toward blood platelets, unnecessary proteins, and bacterial strains. Hence, the cooperative effects of the nanohybrid hydrogel such as biocompatibility, antifouling, and mechanical properties lead to a desirable candidate for blood-contacting implants.

Formation and Biological Properties of Hydroxyapatite-Magnesium Oxide Composite Coatings on Mg-1Zn-1Gd Alloys Though Anodization, Electrodeposition, and Solution Treatment Processes

Magnesium and its alloys have received extensive attention in the biomedical field due to their excellent mechanical properties, good biocompatibility, and biodegradability. However, Mg alloys typically suffer from rapid degradation rates in physiological environments due to their active chemical properties and poor corrosion resistances of naturally formed oxide films, which greatly hinders their widespread applications in biomaterials. Besides, rapid degradation rates are usually accompanied by excessive release of hydrogen and alkaline substances in the vicinity of related tissues instantaneously. Consequently, the degradation rates of Mg alloys must be controlled to meet the requirements of biodegradable implants. Surface coating technologies including anodization and electrodeposition, and conversion coating are considered as effective approaches to improve the corrosion resistances of metallic materials. In special, it is known that making composite films, such as metal hydroxides and calcium phosphate salts, and adding other elements to the anodic porous films are effective methods to improve the wear resistance and biocompatibility of Mg alloys. Calcium phosphate compounds, particularly hydroxyapatite (HAp), are favorable and safe candidates for implants as they constitute the main components of human bones. Abundant calcium phosphate can fulfill the required porosity for bone ingrowth and provide certain mechanical strength and enhanced adhesive force, addressing the brittleness of hydroxyapatite.In this study, various hydroxyapatite-magnesium oxide coatings were prepared on a Mg-1Zn-1Gd alloy base material using successive anodization, electrodeposition, and solution treatment, to enhance the long-term corrosion resistance and biocompatibility of Mg alloy. The effects of different treatment methods on the deposition of Ca-P substances, coating morphology, structure, and corrosion resistance were investigated. SEM results confirmed that the solution treatment method effectively repaired the pores and cracks on the anodic oxide film, and the morphology of the coating differed from that of the electrodeposited treatment. In particular, the samples treated with the solution method exhibited a denser coating with a greater thickness. Additionally, the corrosion performance of the coatings was evaluated through electrochemical characterization, immersion tests, XRD, and SECM. The samples treated with the solution method demonstrated the strongest long-term corrosion resistance during the immersion process, which can be attributed to the denser structure and greater thickness of the coating, as well as the reparative effect of hydroxyapatite on the coating. In summary, the anodic oxidation coatings improved the corrosion resistance of the magnesium alloy, while the hydroxyapatite coating further enhanced its long-term corrosion resistance.Fig.1 shows the surface morphology of the anodized magnesium oxide film layer and the anodized hydroxyapatite composite coating. We used electrodeposition and solution treatment to prepare hydroxyapatite coating on anodized film, and the two methods produced different morphologies. This is due to the different driving forces of the two methods leading to different crystallization orientations of hydroxyapatite. The corrosion resistance of solution treated oxide film is better than that of electrodeposited samples, which is mainly due to the formation of a denser and thicker composite film on the surface of samples. In the cell proliferation experiment, hydroxyapatite coating can obviously promote the biocompatibility and cell activity of anodized samples, and cell morphology experiment shows that different microstructure characteristics and components can affect the cell survival rate, and the solution treated samples have more obvious promotion on cell proliferation and growth. Figure 1

The Role of Imaging Modalities in Diagnosis and Outcome of Otitis Media with Effusion in Cochelear Implant Candidates

Objective: We investigated the accuracy of imaging modalities in diagnosis and outcome of otitis media with effusion by correlating the imaging findings with the preoperative otomicroscopic examinations, tympanometric results, and intraoperative findings in patients who underwent cochlear implant surgery. Methods: The results of the preoperative physical examination and intraoperative findings of patients younger than 18 years who underwent cochlear implant surgery at a single tertiary institution were recorded from their medical charts. Tympanometries, which were performed in maximum 1 week prior to imaging modalities, were analyzed. The high resolution computed tomography of temporal bone and magnetic resonance imaging of internal acoustic meati findings were reviewed. The mastoid cavity and middle ears were evaluated separately. Results: The data comprising of 280 ears were evaluated. The correlation between imaging findings and both physical examination and tympanometries were statistically significant (p = 0.000). The intraoperative findings supported this correlation. Conclusions: Our study showed that imaging modalities might detect the middle ear and mastoid cavity effusions. The severity of these changes may differ according to the severity of disease.

Coronary CT angiography instead of invasive angiography before TAVI: Feasibility and outcomes

AimsConcomitant coronary artery disease (CAD) is frequent in transcatheter aortic valve implantation (TAVI) candidates. Despite societal recommendations of performing invasive coronary angiography (ICA) for coronary assessment in the pre-TAVI diagnostic workup, the prognostic value of ICA and beneficial effect of revascularization in these patients remains unclear.We aimed to determine feasibility and outcomes following a strategy of cardiac CT + coronary CT angiography (cCTA) rather than cardiac CT + ICA before TAVI. Methods and resultsWe performed a single-center, observational cohort study including all patients, without previous coronary intervention, referred to TAVI between April 2020 and November 2021. CAD was assessed by cCTA, and only patients with proximal stenosis >70 %, or left main stenosis >50 %, or cCTA was non-evaluable regarding proximal segments were subsequently referred to ICA.240 patients were included in the study. No adverse effects to pre-cCTA-scan nitroglycerin administration were observed. On cCTA, 92 % of the patients had atheroscerosis. 191 (80 %) patients had cCTA only performed, while 49 (20 %) patients underwent subsequent ICA. During a median (range) follow-up of 15 (6-25) months, no difference in procedural complication rates, mortality rates, or number of unplanned ICA was observed between patients evaluated with only cCTA vs cCTA+ICA. ConclusionsUpfront cCTA instead of ICA for assessment of obstructive CAD in the diagnostic workup of patients with severe aortic stenosis referred to TAVI is feasible, safe, and with similar procedural and clinical outcomes. Randomized studies are warranted to further validate the safety of using CTA rather than ICA for coronary assessment in TAVI candidates.

Interpretable artificial intelligence-based transthyretin amyloid cardiomyopathy detection in patients with severe aortic stenosis

Abstract Background The concurrent presence of transthyretin amyloid cardiomyopathy (ATTR-CM) in candidates for transcatheter aortic valve implantation (TAVI) with severe aortic stenosis (AS) is frequently observed. Objective This study aims to develop a multimodal artificial intelligence-based model for ATTR-CM detection in patients with severe AS. Methods A total of 263 prospectively enrolled (57% males, 83±4.6 years) patients with severe AS were enrolled. All underwent DPD-scintigraphy, and coexisting ATTR-CM was confirmed in 27 (10.3%). 4D-cardiac computed tomography (CT), electrocardiogram, echocardiography, angiography, clinical, and laboratory data were assessed. Specifically, in the 4D-CT, LV myocardial radiomics features as well as global- and segmental myocardial strain. All features underwent z-score normalization, and those with high correlation were eliminated. Different feature selection and machine learning (ML) techniques were used for classification in single- and multimodality scenarios. Eighty percent of the dataset was used for pre-processing, feature extraction, and tuning, with the remaining 20% for evaluating the final model. The model's effectiveness was assessed with accuracy, F1 score, and ROC-AUC across 100 random seeds to establish a reliable classifier. The SHAP (SHapley Additive exPlanations) model is used to interpret the output of ML models. Results Among the different algorithms used, Logistic Regression offers the most effective detection of ATTR-CM, surpassing other models with AUC scores of 0.85. CT strain (AUC: 0.85), Radiomics (AUC: 0.76), and clinical features (AUC: 0.70) alone and in combination yielded the highest performance (i.e., AUC: &amp;gt;70), while the remaining modalities had AUC scores ranging from 0.52 to 0.56. Conclusion The study shows that AI is effective for non-invasively detecting ATTR-CM in severe aortic stenosis patients, offering a potential alternative to costly DPD-scintigraphy or invasive biopsy.

Close clinical monitoring of patients after TAVI implantation using artificial intelligence with a virtual voice assistant

Abstract Introduction The number of procedures and patients candidates for transcatheter aortic valve implantation (TAVI) has increased considerably due to population ageing and the rise in scientific evidence supporting this technique in patients with increasingly lower surgical risk. Early discharge would allow for a more efficient use of available resources, in addition to improving patients’ functionality and quality of life. Objective The use of a virtual voice assistant based on artificial intelligence, could be an effective and safe alternative to closely monitor patients after TAVI implantation in order to facilitate early identification of complications and a more efficient use of the resources available in Cardiology services. Material and methods Observational, prospective, single-center and consecutive study of the implementation of a technology based on artificial intelligence and natural language processing to monitor all patients undergoing transfemoral TAVI implantation, according to usual clinical practice, in the hemodynamics unit of our hospital in the year 2023. The virtual voice assistant, "Lola", carries out a telephonic follow-up during week 1, week 2, month 1, month 3 and 12. In these calls, it asks a series of questions mainly related to vascular access and with the patient's cardiovascular situation. After finishing the call, all the information collected is uploaded to a web platform where we monitor the collected data and thus take the appropriate measures. Results After 12 months, 274 patients have been included to whom 1,039 calls have been made with a total of 385 hours of autonomous conversation. In 44% of the calls, no alerts were detected and, therefore, did not required further review. From the remaining calls, a total of 926 alerts were collected, the predominant ones being: dizziness (24.9%), contact with the emergency services (11.3%) and alteration of general status (10.4%). The number of alerts decreases as the follow-up progresses, reflecting the need for closer monitoring in the initial stages after implantation. These alerts generated at least one intervention in 57% of the calls, the predominant ones being: medical contact (43.0%), nursing contact (26.3%) and medication adjustment (4.0%). These calls resulted in a total of 15 in-person examinations (5.4% of patients), detecting in 2 of them a 3rd degree atrioventricular block, in 3 a femoral pseudoaneurysm and in 1 a critical stenosis of the common femoral artery. According to a patient survey, 88.9% of patients were satisfied or very satisfied (Customer Satisfaction score 4.68/5). Conclusions The application of artificial intelligence permits strict control of the patient after TAVI implantation, thus facilitating early detection of complications. Patient satisfaction regarding this follow-up system was very high.

Coronary CTA and CT-FFR in trans-catheter aortic valve implantation candidates: a systematic review and meta-analysis

Abstract Objectives To perform a systematic review and meta-analysis on diagnostic accuracy and other outcomes of coronary computed tomography angiography (CCTA) and CT-derived fractional flow reserve (CT-FFR) in candidates for trans-catheter aortic valve implantation (TAVI). Background Screening for obstructive coronary artery disease (CAD) with CCTA during TAVI work-up could prevent unnecessary invasive coronary angiography (ICA). This becomes increasingly relevant as the TAVI-population grows. CT-FFR improves CCTA accuracy in chest pain patients, but its reliability is unknown in the TAVI-population. Methods Pubmed, Embase and Web of Science were searched for studies regarding CCTA and/or CT-FFR in TAVI-candidates. Primary endpoint was correct identification and rule-out of obstructive CAD. Results were pooled in a meta-analysis. Results Twenty-four of the 29 included articles were part of the meta-analysis, reporting results for CCTA and CT-FFR in 3.494 and 797 patients respectively. Reference standard was anatomical severity of CAD in most studies. At patient-level, pooled CCTA sensitivity was 94.3% and specificity 74.8%. CT-FFR sensitivity was 91.5% and specificity 60.3% with strong variation between studies. CCTA correctly ruled out CAD in 52% of all patients, but 42% of positive CCTAs were false positives. CT-FFR correctly ruled out CAD in 47% of all patients included in this meta-analysis, but showed better accuracy than CCTA in studies that compared both. In these studies, sensitivity of CCTA versus CT-FFR was 70.7% versus 79.0% and specificity was 64.4% versus 92.9%. Conclusions Negative CCTA effectively rules-out CAD in the TAVI-population. Adding CCTA to TAVI work-up could lead to significant reduction in pre-TAVI ICA procedures, but the proportion of false-positives remains high. In studies performing a direct comparison, CT-FFR performed better than CCTA. This is not reflected in the CT-FFR meta-analysis. Therefore, diagnostic accuracy of CT-FFR and added value over CCTA in the TAVI-population remains unclear. Further research regarding validation and reliability is warranted.Meta-analysis of CCTA and CT-FFR

3D-printed artificial cornea featuring aligned fibrous structure and enhanced mechanical strength

The global shortage of donor eye bank tissue has significantly impeded advancements in biomaterial for corneal implantation. To address this issue, we have developed a 3D-printed artificial cornea using a composite hydrogel of sodium alginate (SA) and cellulose nanofibers (CNF), crosslinked with poly-L-lysine-co-L-glutamic acid (PLL80GA20, PG) and calcium chloride (CaCl2, CC). The 2 wt% SA/CNF composite hydrogel offers several advantages, including low toxicity, cost-effectiveness, excellent printability, and high mechanical strength, even with low crosslinker concentrations. The PG was synthesized via ring-opening polymerization of L-glutamate N-carboxyl anhydride (BGNCA) and L-lysine N-carboxyl anhydride (CBZNCA). The purity of the monomers was verified through DSC analysis, revealing a melting point of 97 ℃. The molecular weight of the synthesized PG was determined to be 47 kDa. A dual crosslinking strategy was employed, starting with electrostatic crosslinking, followed by ionic crosslinking using varying concentrations of PG and CC at different effective charge concentrations of 6.25 mM, 12.25 mM, and 25 mM. The hydrogel and 3D-printed cornea were comprehensively evaluated for chemical structure, surface functional groups, water content, mechanical strength, orientation, cytotoxicity, biocompatibility, and transparency. Notably, the inclusion of PG significantly enhanced the mechanical properties of the 3D-printed cornea, with the hydrogel achieving a storage modulus of 2,360 kPa at 6.25 mM of PG/CC, while maintaining over 95% water content. The artificial cornea demonstrated 86% transparency, and the cell viability showed 96% viable on Day 7 with degradation rate of 35.9% in 28 days. The superior hydrophilicity, transparency, and mechanical strength of the printed hydrogel highlights its potential for the development of full-thickness corneal structures, making it a promising candidate for future corneal implants.

Corrosion resistance and biocompatibility of magnesium alloy with bioactive glass-reinforced hydrogel composite coatings

Magnesium (Mg) alloy is a promising candidate for biodegradable implants; however, its rapid degradation can create an unstable physiological environment that hampers tissue regeneration. To address this challenge, a polyvinyl alcohol (PVA) hydrogel composite reinforced with bioactive glass (BG) particles was developed as a coating for Mg alloy pellets, which underwent laser surface texturing (LST) and salting-out processes. results demonstrate that these treatments significantly enhance both the adhesiveness and swelling of the hydrogel coating. Notably, electrochemical corrosion assessments reveal a marked improvement in corrosion resistance, with the Mg–B1-L-S specimen exhibiting the highest performance after salting-out treatment. Electrochemical corrosion assessments revealed a significant enhancement in corrosion resistance for Mg alloy with the hydrogel coating, with the Mg–B1-L-S specimen showing superior performance following salting-out treatment. Immersion tests in simulated body fluid (SBF) confirmed the protective effect of the coatings, indicating that the addition of BG particles and salting-out treatment reduced mass loss and maintained pH stability. Biocompatibility evaluations through in vitro viability tests and osteogenic differentiation assays indicate that the Mg–B1-L and Mg–B1-L-S specimens exhibit superior cell activity, surface adhesion, and osteogenic potential. These findings highlight the effectiveness of PVA-BG hydrogel composite coatings in enhancing the corrosion resistance and biocompatibility of Mg alloy implants, positioning this approach as a significant advancement in the development of biodegradable materials for biomedical applications.

Patient selection for left ventricular assist device implantation. The main problems

To analyze the experience of Chazov National Medical Research Center of Cardiology in patient selection for left ventricular assist device (LVAD) implantation. 901 patients, whose documents were sent to Chazov National Medical Research Center of Cardiology from regional medical and prophylactic institutions, were screened as selection for LVAD implantation. Firstly, all patients underwent transthoracic echocardiography performed according to the extended protocol with a comprehensive assessment of the left and right ventricle size and function. Patients who underwent the screening procedure underwent further examination including both laboratory and instrumental diagnostic methods. In addition, the polyclinic database of patients diagnosed with chronic heart failure (CHF) and dilated cardiomyopathy was also analyzed. Among 901 screened patients 7.9% were suitable candidates for LVAD implantation and only 23 (2.6%) patients underwent surgery. Among those not eligible for surgery: 208 (29%) patients were not on optimal medical therapy, 15% of patients had indications for other surgical treatment of CHF, 12% of patients had severe right ventricular failure, 9.8% had severe comorbidities, 6.8% of patients refused surgery. The main problems of selection for LVAD implantation were: low awareness of doctors about the introduction of new treatment methods, poor quality of transthoracic echocardiography, a large percentage of patients not receiving basic therapy for CHF, untimely referral of patients for other types of surgical treatment.

Evaluation of ciliary body cysts in candidates for phakic lens implantation

PurposePhakic lens implantation in the ciliary sulcus of the eye can be complicated by coincident ciliary body cysts (CBC). We developed an ultrasound imaging and mapping protocol for these cysts.MethodsThis is a retrospective case series of all patients who underwent ICL workup at a single institution from April 2015 to October 2019. A standardized ultrasound biomicroscopy (UBM) imaging protocol was developed to screen for CBCs in either the ciliary body or sulcus. The locations and dimensions of all CBCs were graphically represented.ResultsThe prevalence of CBCs in 158 patients undergoing ICL workup was 34.8%. Among the 159 CBCs detected in 55 patients, 83 were in the sulcus (52%) and 76 were restricted to the ciliary body (48%). ICLs were implanted in 40 eyes with CBCs and 3 eyes with CBCs located within the sulcus horizontally required ICL repositioning due to ICL rotation or iris chafing.ConclusionCBCs were incidentally found in 34.8% of patients undergoing ICL workup. ICL implantation was complicated in 3 of the eyes with CBCs in the horizontal sulcus. Although CBCs are not an absolute contraindication for ICL surgery, we recommend preoperative UBM screening of the ciliary sulcus.