Replacement Time Research Articles

A systematic review of the accessibility, acceptability, safety, efficiency, clinical effectiveness, and cost-effectiveness of private cataract and orthopedic surgery clinics.

Many publicly funded health systems use a mix of privately and publicly operated providers of care to deliver elective surgical services. The aim of this systematic review was to assess the role of privately operated but publicly funded provision of surgical services for adult patients who had cataract or orthopedic surgery within publicly funded health systems in high-income countries. Electronic databases (Ovid MEDLINE, OVID Embase, and EBSCO EconLit) were searched on 26 March 2021, and gray literature sources were searched on 6 April 2021. Two reviewers independently applied inclusion and exclusion criteria to identify studies, and extracted data. The outcomes evaluated include accessibility, acceptability, safety, clinical effectiveness, efficiency, and cost/cost-effectiveness. Twenty-nine primary studies met the inclusion criteria and were synthesized narratively. We found mixed results across each of our reported outcomes. Wait times were shorter for patients treated in private facilities. There was evidence that some private facilities cherry-pick or cream-skim by selecting less complex patients, which increases the postoperative length of stay and costs for public facilities, restricts access to private facilities for certain groups of patients, and increases inequality within the health system. Seven studies found improved safety outcomes in private facilities, noting that private patients had a lower preoperative risk of complications. Only two studies reported cost and cost-effectiveness outcomes. One costing study concluded that private facilities' costs were lower than those of public facilities, and a cost-utility study showed that private contracting to reduce public waiting times for joint replacement was cost-effective. Limited evidence exists that private-sector contracts address existing healthcare delivery problems. Value for money also remains to be evaluated properly.

Hospitalised Smokers' and Staff Perspectives of Inpatient Smoking Cessation Interventions and Impact on Smokers' Quality of Life: An Integrative Review of the Qualitative Literature.

To identify, integrate, and appraise the evidence on hospitalised smokers' and staff perspectives of inpatient smoking cessation interventions and the impact on smokers' quality of life. The integrative review method was used to present hospitalised smokers' and staff perspectives of inpatient smoking cessation interventions. Search Method. This integrative review consisted of a comprehensive search on smoking cessation interventions that take place during an inpatient admission to hospital for adults (> age 18 years) of the following online databases: Ovid Medline, Joanna Briggs Institute, APA PsycInfo, CINAHL, Cochrane, Google Scholar, PEDro, and Scopus. The search strategy was inclusive of peer-reviewed studies limited to the English language or translated to English. A search of grey literature and manual searching of reference lists was also conducted to identify further studies not identified in the online database search. All studies that produced any qualitative data (i.e., qualitative, mixed methods, and surveys) on inpatient-initiated smoking cessation programs were included. Outcomes of interest are included but were not limited to education, counselling, and the use of pharmacotherapy. Studies undertaken in the psychiatric, adolescent, and paediatric settings were excluded. The key findings from this integrative review included positive evaluations from both patients and staff involved in inpatient smoking cessation interventions, reporting that hospitalisation was an appropriate opportunity to address smoking cessation. A number of facilitators and barriers to inpatient smoking cessation interventions included creating a supportive patient-centred environment and consideration of the cost of nicotine replacement therapy and time to deliver inpatient smoking cessation interventions. Recommendations/preferences for future inpatient smoking cessation interventions included the use of a program champion and ongoing education to demonstrate the effectiveness of the intervention, and despite the cost of nicotine replacement therapy being identified as a potential barrier, it was identified as a preference for most patients. Although quality of life was only evaluated in two studies, statistically significant improvements were identified in both. This qualitative integrative review provides further insight into both clinician and patient participants' perspectives on inpatient smoking cessation interventions. Overall, they are seen to produce positive benefits, and staff training appears to be an effective means for service delivery. However, insufficient time and lack of resources or expertise appear to be consistent barriers to the delivery of these services, so they should be considered when planning the implementation of an inpatient smoking cessation intervention.

패키징 인쇄를 위한 병렬 오프셋 인쇄 공정의 스케줄링

With the growth of the packaging industry, demand on the packaging printing comes in various forms. Customers’ orders are diversifying and the standards for quality are increasing. Offset printing is mainly used in the packaging printing since it is easy to print in large quantities. However, productivity of the offset printing decreases when printing various order. This is because it takes time to change colors for each printing unit. Therefore, scheduling that minimizes the color replacement time and shortens the overall makespan is required. By the existing manual method based on workers’ experience or intuition, scheduling results may vary for workers and this uncertainty increase the production cost. In this study, we propose an automated scheduling method of parallel offset printing process for packaging printing. We decompose the original problem into assigning and sequencing orders, and ink arrangement for printing problems. Vehicle routing problem and assignment problem are applied to each part. Mixed integer programming is used to model the problem mathematically. But it needs a lot of computational time to solve as the size of the problem grows. So guided local search algorithm is used to solve the problem. Through actual data experiments, we reviewed our method’s applicability and role in the field.

The effect of high temperature climate on the hydration status of the Sudanese top league football players

The study aimed at identifying the effect of high temperature climate on the hydration status of the Sudanese top league football players. A descriptive approach was used , and the study sample included 50 of the Sudanese top league football players who were randomly selected. Questionnaires were used for data collection. Important results were that 60% of the players didn’t drink plenty of fluids one day ahead of the match, and 46% didn’t drink during exercise, and also 54% didn’t have instructions to drink plenty of fluids before the exercise, and also only 20% of the players were weighed by the coach before and after exercises. Moreover it was also found that only 10% of the players used rehydrating fluids during exercise. And finally reduced urine volume was the most common symptom of dehydration, since 92% of the players had it.
 Important recommendations were: To raise awareness about the importance of proper hydration among the players, the staff, and others who are responsible for them, To implement the FIFA instructions regarding playing in hot climates, that is to pause a match allowing time for fluid replacement and rehydration, and finally to use this study for future visions along with other studies concerning hydrations and hot climates, with special regards that the football world cup 2022 is going to be in Qatar.

Is the QRS duration useful for determining the optimal timing of pulmonary valve replacement after tetralogy of Fallot repair?

In pulmonary valve replacement (PVR) after tetralogy of Fallot (TOF) repair, the right ventricular end-diastolic and end-systolic volume index (RVEDVI and RVESVI) of cardiac magnetic resonance imaging (cMRI) are often used as indicators of the RV volume. We examined the utility of QRS duration, cardiothoracic ratio (CTR), and plasma brain natriuretic peptide (BNP) as indicators of the appropriate timing of cMRI to assess the RV volume and function before PVR. We assessed the correlation of QRS duration, CTR, and BNP with RVEDVI and RVESVI on cMRI in 26 patients after TOF repair. Fifteen underwent PVR (age, 45.2 ± 11.4years). Twelve underwent post-PVR cMRI. The RV volume change from before to after PVR was investigated. QRS duration, BNP, and CTR were positively correlated with RVEDVI and RVESVI after TOF repair. The post-PVR QRS duration was also positively correlated with post-PVR RVEDVI (p = 0.017) and RVESVI (p = 0.001). From before to after PVR, in 5 cases with QRS duration ≤ 160ms, the QRS duration decreased from 110.4 ± 28.9 to 101.8 ± 30.5ms (p = 0.063). Both RVEDVI and RVESVI decreased to the normal range in 4 of 5 cases. In contrast, in 7 cases with QRS duration > 160ms, the QRS duration decreased from 183.0 ± 17.4 to 160.3 ± 23.8ms (p = 0.013); however, RVESVI did not normalize in 6 of 7 cases. A prolonged QRS duration is a useful marker of RVEDVI and RVESVI enlargement after TOF repair. We recommend performing cMRI before the QRS duration reaches 160ms due to normalization of the RV volume after PVR.

Optimization of preventive replacements dates and covariate inspections for repairable systems in varying environments

This study investigates the issue of optimal preventive replacement scheduling for a repairable system, considering its failure/repair history and its environment or degradation, as characterised by covariates. The proposed approach is developed within a recurrent event modelling framework, in which the failure behaviour of the system is defined by its failure intensity, and perfect preventive replacements and imperfect corrective repairs are integrated following a virtual age assumption. The observed heterogeneity between systems is integrated through covariates by following a proportional hazard assumption. These covariates are assumed to be either fixed and represent, for example, the manufacturer origin, or to be dynamic and represent the monitored degradation process.The contributions of this study are twofold. First, a dynamic condition-based preventive replacement policy is developed. The maintenance decision rule integrates the available information on both the corrective repair history and covariate behaviour to determine the optimal preventive replacement time. This policy extends the state-of-the-art model of Gilardoni et al. (2016), which considers only the corrective repair history without integrating covariates. Second, the results of this study demonstrate how different levels of knowledge and information regarding the covariates can be integrated into the maintenance decision and lead to different optimal replacement times that are associated with different cost performances of the preventive replacement policy. This performance evaluation enables the optimisation of the monitoring policy and inspection frequency of the covariates. The proposed approach, which follows steps of increasing complexity, is developed and investigated first on static and then on dynamic covariates, considering minimal and imperfect repairs.

CRT-D replacement strategy: results of the BioCONTINUE study.

In patients with cardiac resynchronization therapy defibrillators (CRT-Ds), the need for implantable cardioverter-defibrillator (ICD) back-up may be questionable at time of CRT-D replacement (REP) if ICD implant criteria are no longer met due to an improved left ventricular ejection fraction (LVEF) and if no major ventricular arrhythmic event (VAE) occurred during the CRT-D lifetime. The aim of our study was to assess the relevance of ICD back-up and predictors of VAE after REP in primary prevention CRT-D patients. The prospective, observational, international BioCONTINUE study investigated the rate of patients with at least 1 sustained VAE (sVAE) post-REP and searched for predictive factors of sVAE. Two hundred seventy-six patients (70 ± 10years, 77% men, mean LVEF 40.6 ± 12.6%) were followed for 28.4 ± 10.2months. The rate of patients with sVAE was 8.3%, 10.3%, and 21.2% at 1, 2, and 4years post-REP. Patients without persistent ICD indication at REP still had a sVAE rate of 5.7% (95% CI 2.3-11.5%) at 2years. In multivariate analysis, predictive factors of subsequent sVAE were (i) persistent ICD indication (hazard ratio (HR) 3.6; 95% CI 1.6-8.3; p = 0.003); (ii) 64-72years of age as compared to ≥ 79years (HR 3.7; 95% CI 1.4-9.7; p = 0.008); and (iii) ischemic heart disease (HR 4.4; 95% CI 2.1-9.3; p < 0.0001). The risk of sVAE (21.2% at 4years post-REP) depends on age, ischemic heart disease, and ICD indication at the time of REP. A non-trivial risk of sVAE remains in patients without persistent ICD indication. NCT02323503.

Erlang loss systems with shortest idle server first service discipline: Maintenance considerations

We consider a variation of an Erlang loss system in which jobs are routed to servers according to the Shortest Idle Server First service discipline. Specifically, we consider a system in which idle servers are arranged in a stack; servers are returned to the top of the stack upon service completion; and arriving jobs are assigned to the server currently at the top of the stack. When busy, servers accumulate age and incur an age-dependent operating cost. For such systems, we (i) formulate a continuous-time Markov chain model to characterize the system’s transient behavior, and (ii) develop maintenance policies consisting of two possible actions: server group replacement and stack inversion. The stack inversion may be performed at any time prior to group replacement to achieve a more evenly distributed utilization among servers. We develop an optimization model to determine the optimal inversion and replacement times so as to minimize the long-run expected cost rate. Because the model is nonlinear and non-convex, we develop a set of algorithms to solve for the optimal replacement and inversion time. Lastly, we establish a lower bound for the inversion cost threshold below which it is optimal to invert the stack of servers before their replacement.

A Revisit of Age-Based Replacement Models With Exponential Failure Distributions

This article revisits the optimization problems of age-based replacement models for exponential failure distributions. First, we show the steps how an age replacement time goes to an infinite value when the lifetime of a unit has an exponential distribution, and then, we give two discussions of possible replacement times, by introducing a new concept of cost named as deviation cost per unit of time between replacement and failure. Second, similar discussion is given for a random replacement model when the age replacement time is a random variable with a uniform distribution. Third, the models of age-based replacement first and last with deviation costs are discussed when a random replacement is taken into account for an age replacement model. Numerical examples are illustrated to show the results of the analytical discussions. Finally, necessary proofs are provided in the Appendixes.

Research on advanced treatment of phenolic chemical wastewater and carbon replacement by the multi-layer biological activated carbon filter

After a series of biochemical processes, the wastewater engendered by the production of phenolic resin is ultimately left with a majority of difficult degradation organic matter. Most of these organic compounds are harmful to the water environment and require further advanced treatment before discharge. In this study, the original simple biological activated carbon (BAC) filter column device was improved. The new multi-layer BAC filter does not require backwash after improvement. The treatment efficiency of the multi-layer BAC filter was studied through long-term operation, and the variation of pollutants in the wastewater was analyzed. The results indicated that the multi-layer BAC filter could effectively remove hardly biodegradable organic matter, ammonium‑nitrogen (NH4+-N), and total nitrogen (TN), and its mechanism was mainly that hardly biodegradable organic matter and TN were removed by adsorption and biodegradation, while NH4+-N was only removed by microbial degradation. The pore-size distribution characteristics on the BAC surface were analyzed, and it was found that the adsorption and biodegradation reactions mainly occurred in the microporous region. The experiment on carbon replacement indicated that the service time of the BAC system could be prolonged by choosing the correct time of carbon replacement and adding the appropriate amount of microorganisms. Based on high-throughput sequencing, it was found that the microbial communities on BAC at the same height were significantly different before and after carbon replacement. The results of this paper are of some relevance for the upgrading of advanced treatment processes for chemical wastewater in practical engineering.

Impact on outcomes of measuring lactates prior to ICU in unselected heterogeneous critically ill patients: A propensity score analysis.

Elevated blood lactate levels were reported as effective predictors of clinical outcome and mortality in ICU. However, there have been no studies simply comparing the timing of measuring lactates before vs. after ICU admission. A total of 19,226 patients with transfer time ≤ 24 hr were extracted from the Medical Information Mart for Intensive Care IV database (MIMIC-IV). After 1:1 propensity score matching, the patients were divided into two groups: measuring lactates within 3 hr before (BICU group, n = 4,755) and measuring lactate within 3 hr after ICU admission(AICU group, n = 4,755). The primary and secondary outcomes were hospital mortality, hospital 28-day mortality, ICU mortality, ICU length of stay (LOS), hospital LOS, and restricted mean survival time (RMST). Hospital, hospital 28-day, and ICU mortality were significantly higher in AICU group (7.0% vs.9.8%, 6.7% vs. 9.4%, and 4.6% vs.6.7%, respectively, p<0.001 for all) Hospital LOS and ICU LOS were significantly longer in AICU group (8.4 days vs. 9.0 days and 3.0 days vs. 3.5 days, respectively, p<0.001 for both). After adjustment for predefined covariates, a significant association between the timing of measuring lactate and hospital mortality was observed in inverse probability treatment weight (IPTW) multivariate regression, doubly robust multivariate regression, and multivariate regression models (OR, 0.96 [95%CI, 0.95-0.97], OR 0.52 [95%CI, 0.46-0.60], OR 0.66 [95%CI, 0.56-0.78], respectively, p<0.001 for all), indicating the timing as a significant risk-adjusted factor for lower hospital mortality. The difference (BICU-AICU) of RMST at 28- days after ICU admission was 0.531 days (95%CI, 0.002-1.059, p<0.05). Placement of A-line and PA-catheter, administration of intravenous antibiotics, and bolus fluid infusion during the first 24-hr in ICU were significantly more frequent and faster in the BICU vs AICU group (67.6% vs. 51.3% and 126min vs.197min for A-line, 19.6% vs.13.2% and 182min vs. 274min for PA-catheter, 77.5% vs.67.6% and 109min vs.168min for antibiotics, and 57.6% vs.51.6% and 224min vs.278min for bolus fluid infusion, respectively, p<0.001 for all). Additionally, a significant indirect effect was observed in frequency (0.19879 [95% CI, 0.14061-0.25697] p<0.001) and time (0.07714 [95% CI, 0.22600-0.13168], p<0.01) of A-line replacement, frequency of placement of PA-catheter (0.05614 [95% CI, 0.04088-0.07140], p<0.001) and frequency of bolus fluid infusion (0.02193 [95%CI, 0.00303-0.04083], p<0.05). Measuring lactates within 3 hr prior to ICU might be associated with lower hospital mortality in unselected heterogeneous critically ill patients with transfer time to ICU ≤ 24hr, presumably due to more frequent and faster therapeutic interventions.

Right ventricular echocardiographic remodeling after pulmonary valve replacement in repaired Tetralogy of Fallot

BackgroundMany patients with repaired tetralogy of Fallot require reoperation in the medium to long-term for residual pulmonary valve regurgitation. Best timing for pulmonary valve replacement remains controversial. A balance needs to be found between protecting the patients from permanent right ventricular damage and insertion of a prosthetic valve with its inherent issues. In the current study we sought to investigate the right and left ventricular functional recovery following valve replacement in our tertiary care institution. ResultsIn a retrospective cross-sectional study patients with history of total correction of tetralogy of Fallot who had undergone pulmonary valve replacement due to severe pulmonary regurgitation between 2003–2018 were evaluated for post intervention right and left ventricular functional recovery. Clinical and full echocardiographic data before and after the surgery were recorded and compared. There was statistically significant improvement in RV size and function post pulmonary valve replacement. There was no statistically significant improvement in left ventricular systolic function. Twenty percent of patient had persisting severe right ventricular enlargement at least twelve months post-surgery. No patient had fully normalized right ventricular size and function in follow-up. ConclusionsPulmonary valve replacement leads to improvement in right ventricular size and function in patients with repaired tetralogy of Fallot. However normalization of functional parameters did not occur and the majority of the patients have residual right and left ventricular dysfunction following redo valve replacement surgery.

Predicting the Trajectory of Replacements of SARS-CoV-2 Variants Using Relative Reproduction Numbers.

New variants of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) with high effective reproduction numbers are continuously being selected by natural selection. To establish effective control measures for new variants, it is crucial to know their transmissibility and replacement trajectory in advance. In this paper, we conduct retrospective prediction tests for the variant replacement from Alpha to Delta in England, using the relative reproduction numbers of Delta with respect to Alpha estimated from partial observations. We found that once Delta's relative frequency reached 0.15, the date when the relative frequency of Delta would reach 0.90 was predicted with maximum absolute prediction errors of three days. This means that the time course of the variant replacement could be accurately predicted from early observations. Together with the estimated relative reproduction number of a new variant with respect to old variants, the predicted replacement timing will be crucial information for planning control strategies against the new variant.

Ni-doped A-site excess SrTiO3 thin films modified with Au nanoparticles by a thermodynamically-driven restructuring for plasmonic activity

Plasmonically active nanoparticles offer a promising pathway to extend the absorption range of photocatalysts. While not necessarily catalytically active themselves, these particles allow the absorption of lower energy photons in wide band gap photocatalysts. Here, we present A-site excess SrTiO3 thin films, doped with Ni, where through a subsequent exsolution process we created well-socketed Ni nanoparticles in the surface of SrTiO3. These were galvanically replaced by Au, resulting in well-socketed Au nanoparticles with variable size on the surface, depending on the galvanic replacement time. Photoelectrochemical measurements and electron energy loss spectroscopy revealed the improved photoresponse of the thin films by plasmonic activity of the nanoparticles. The energy of the plasmon peak suggests that the main improvement results from the injection of hot charge carriers. Our study opens new avenues for the design and synthesis of the next generation of photocatalytic materials.

Probabilistic modeling of failure times and replacement maintenance of television transmitter system

Assessment of the state of health and working condition of equipment in the production and service industries is a necessary condition for effective maintenance. Therefore, this work models the failure times and other operational characteristics of television transmitter system with sudden but non-constant failure rate to enhance smooth operation of the system. The failure times was shown to follow lognormal distribution with mean; 𝑥̅=7.6 and variance; 𝑠2=1.4. The Probability functions, hazard, reliability functions/indices, availability and maintainability factors were obtained to described the failure behaviour and ascertain the performance efficiency of the system. Also, a preventive replacement (PR) model for the system yielded an optimal replacement time of 189.112 hours at a minimum total cost of 178.134 naira per unit time. A combination of both estimates of the reliability indices and the PR model is recommended to provide complementary information for efficient maintenance operation of the TV transmitter and similar systems.

Retrospective analysis of SARS-CoV-2 omicron invasion over delta in French regions in 2021–22: a status-based multi-variant model

BackgroundSARS-CoV-2 is a rapidly spreading disease affecting human life and the economy on a global scale. The disease has caused so far more then 5.5 million deaths. The omicron outbreak that emerged in Botswana in the south of Africa spread around the globe at further increased rates, and caused unprecedented SARS-CoV-2 infection incidences in several countries. At the start of December 2021 the first omicron cases were reported in France.MethodsIn this paper we investigate the spreading potential of this novel variant relatively to the delta variant that was also in circulation in France at that time. Using a dynamic multi-variant model accounting for cross-immunity through a status-based approach, we analyze screening data reported by Santé Publique France over 13 metropolitan French regions between 1st of December 2021 and the 30th of January 2022. During the investigated period, the delta variant was replaced by omicron in all metropolitan regions in approximately three weeks. The analysis conducted retrospectively allows us to consider the whole replacement time window and compare regions with different times of omicron introduction and baseline levels of variants’ transmission potential. As large uncertainties regarding cross-immunity among variants persist, uncertainty analyses were carried out to assess its impact on our estimations.ResultsAssuming that 80% of the population was immunized against delta, a cross delta/omicron cross-immunity of 25% and an omicron generation time of 3.5 days, the relative strength of omicron to delta, expressed as the ratio of their respective reproduction rates, frac{hat{R}_{textrm{omicron}}}{hat{R}_{textrm{delta}}}, was found to range between 1.51 and 1.86 across regions. Uncertainty analysis on epidemiological parameters led to frac{hat{R}_{textrm{omicron}}}{hat{R}_{textrm{delta}}} ranging from 1.57 to 2.34 on average over the metropolitan French regions, weighted by population size.ConclusionsUpon introduction, omicron spread rapidly through the French territory and showed a high fitness relative to delta. We documented considerable geographical heterogeneities on the spreading dynamics. The historical reconstruction of variant emergence dynamics provide valuable ground knowledge to face future variant emergence events.

Strain-stream model of epidemic spread in application to COVID-19.

The recently developed model of the epidemic spread of two virus strains in a closed population is generalized to the situation typical for the couple of strains delta and omicron, when there is a high probability of omicron infection soon enough after recovering from delta infection. This model can be considered as a kind of combination of SIR and SIS models for the case of competition of two strains of the same virus with different contagiousness in a population. The obtained equations and results can be directly implemented for practical calculations of the replacement of strains of the SARS-CoV-2 virus. A comparison between the estimated replacement time and the corresponding statistics shows reasonable agreement.

DC Link Capacitor 열화에 따른 태양광 인버터 입출력 특성

The DC-Link capacitor, which is the input terminal of the PV inverter, plays a role in charging/discharging and smoothing the DC voltage and smoothing the ripple. These capacitors are inexpensive, and most aluminum electrolytic capacitors are used due to their relatively fast charging/discharging characteristics. However, in DC-Link capacitors, accidents occur due to electrolyte ejection and explosion due to aging and deterioration due to increased usage time. Also PV inverter manufacturers provide status information according to usage time and related circuit design is not reflected. Therefore, in this paper, a circuit capable of simulating the occurrence of capacitor deterioration was proposed in order to examine the input/output state of the PV inverter according to the capacitance change of the DC-Link stage capacitor. By diagnosing the current state of the photovoltaic inverter due to aging and deterioration due to the change in the capacity of the DC-Link capacitor, it is possible to prevent failures in the photovoltaic system and accidents due to fire in advance. In addition, by monitoring the condition of capacitors according to the progress of deterioration, the contents of the study were proposed so that the safety and reliability of new and renewable energy facilities can be secured by obtaining appropriate information such as the life expectancy of parts and replacement time for maintenance.

Pocket histology at cardiac implantable electronic device replacement: What’s new?

Repeated procedures involving the cardiac implantable electronic device (CIED) pocket increase the infection risk, and the extent of pocket adhesions may prolong the procedure time. Few data on pocket histology at the time of CIED replacement are available. The purpose of this study was to describe CIED pocket histology in a cohort of patients undergoing CIED replacement or upgrade. All consecutive patients undergoing CIED replacement or upgrade at our center between November 2019 and May 2020 were enrolled. Subclinical pocket infection was ruled out by physical inspection and laboratory parameters before the procedure. Pocket tissue specimens from the anterior and posterior pockets were obtained intraoperatively. A systematic histological analysis of capsular thickness, fibrous connective tissue, neovascularization, inflammation, and calcifications was performed. Thirty patients (6 women, 20%) were enrolled. The mean capsular thickness was 0.8 ± 0.3 mm in the anterior wall and 1.1 ± 0.4 mm in the posterior wall. Subcapsular fibrosis was mild and multifocal in the anterior wall and moderate and focal in the posterior wall. Neovascularization was focal in most cases, and vessel remodeling mainly involved the tunica media. Chronic inflammation was usually mild and nongranulomatous, and in a quarter of cases, subacute exudative fibrous inflammation was detected in the posterior pocket wall. The CIED pocket is a histopathologically dynamic environment, given the coexistence of both a subacute foreign body response and fibrous tissue growth, implying continuous remodeling due to an injury-repair mechanism. Strategies to interact with foreign body response might minimize inflammatory pocket activity, especially device encapsulation by tight fibrous tissue, and possibly complications related to repeated CIED procedures.

The impact of concomitant mitral valve intervention on outcomes of aortic root replacement.

To investigate the impact of concomitant mitral valve repair (MVr) or replacement (MVR) at the time of aortic root replacement (ARR). We queried our aortic database for consecutive patients undergoing ARR in combination with MVr or MVR from 1997 to 2021. Patients undergoing valve sparing root replacement (VSRR) were excluded. We compared operative mortality (OM) and a composite of major adverse events (MAE) in those undergoing CVG both with (Group 2) and without a concomitant MV procedure (Group 1). We also analyzed outcomes between patients undergoing MV repair versus MV replacement. Sixty-one patients underwent ARR with concomitant MVr (29/47.5%) or MVR (32/52.5%). Compared to patients in Group 2 (n = 955), those in Group 1 presented with worse NYHA class, lower ejection fraction, higher rate of connective tissue disease, and underwent more frequently urgent/emergent procedures. Group 1 had higher incidence of postoperative MAE (8/61(13%) vs 51/955(5%), p = .03). There was no difference in operative mortality between the two groups (0/61(0%)vs. 3/955(0.3%), p = 1). Compared to the ARR + MVR subgroup, the ARR + MVr subgroup had higher incidence of postoperative MAE (5/29(17.2%) vs. 3/32(9.4%), p = 0.02). Multivariate analysis identified MVr (OR 2.78, 95% confidence interval [CI] [1.03;7.48], p = 0.04) as an independent predictor of MAE. Operative mortality remained low in both groups. The addition of MVR/MVr to composite valve-graft replacement of the aortic root does not increase OM in experienced hands. The incidence of MAEs was higher in those undergoing MVr but may be a reflection of greater preoperative comorbidity rather than issues related to a more complex operation.