Geographic variation in aortic stenosis treatment and outcomes among Medicare beneficiaries in the United States.

BACKGROUND: Transcatheter aortic valve replacement (TAVR) has changed the landscape of aortic stenosis (AS) management. AIM: To describe and evaluate geographic variation in AS treatment and outcomes among a sample of Medicare beneficiaries. METHODS: A retrospective analysis of administrative claims data was conducted on a 20% sample of Medicare fee-for-service beneficiaries aged 65 and older with a diagnosis of AS (2015-2018). Estimates of demographic, comorbidity, and healthcare resources were obtained from Medicare claims and the Dartmouth Atlas of Health Care at the hospital referral region (HRR), which represents regional tertiary medical care markets. Linear regression was used to explain HRR-level variation in rates of surgical aortic valve replacement (SAVR) and TAVR, and 1-year mortality and readmission rates. RESULTS: A total of 740,899 beneficiaries with AS were identified with a median prevalence of AS of 39.9 per 1000 Medicare beneficiary years. The average HRR-level rate of SAVR was 26.3 procedures per 1000 beneficiary years and the rate of TAVR was 20.3 procedures per 1000 beneficiary years. HRR-level comorbidities and number of TAVR centers were associated with a lower SAVR rate. Demographics and comorbidities explained most of the variation in HRR-level 1-year mortality (15.2% and 18.8%) and hospitalization rates (20.5% and 16.9%), but over half of the variation remained unexplained. CONCLUSION: Wide regional variation in the treatment and outcomes of AS was observed but were largely unexplained by patient factors and healthcare utilization. Understanding the determinants of AS treatment and outcomes can inform population health efforts for these patients.

CRIMSON: An open-source software framework for cardiovascular integrated modelling and simulation.

In this work, we describe the CRIMSON (CardiovasculaR Integrated Modelling and SimulatiON) software environment. CRIMSON provides a powerful, customizable and user-friendly system for performing three-dimensional and reduced-order computational haemodynamics studies via a pipeline which involves: 1) segmenting vascular structures from medical images; 2) constructing analytic arterial and venous geometric models; 3) performing finite element mesh generation; 4) designing, and 5) applying boundary conditions; 6) running incompressible Navier-Stokes simulations of blood flow with fluid-structure interaction capabilities; and 7) post-processing and visualizing the results, including velocity, pressure and wall shear stress fields. A key aim of CRIMSON is to create a software environment that makes powerful computational haemodynamics tools accessible to a wide audience, including clinicians and students, both within our research laboratories and throughout the community. The overall philosophy is to leverage best-in-class open source standards for medical image processing, parallel flow computation, geometric solid modelling, data assimilation, and mesh generation. It is actively used by researchers in Europe, North and South America, Asia, and Australia. It has been applied to numerous clinical problems; we illustrate applications of CRIMSON to real-world problems using examples ranging from pre-operative surgical planning to medical device design optimization.

Simultaneous Removal of Antibiotic Resistant Bacteria, Antibiotic Resistance Genes, and Micropollutants by FeS2@GO-Based Heterogeneous Photo-Fenton Process.

The co-occurrence of various chemical and biological contaminants of emerging concerns has hindered the application of water recycling. This study aims to develop a heterogeneous photo-Fenton treatment by fabricating nano pyrite (FeS2) on graphene oxide (FeS2@GO) to simultaneously remove antibiotic resistant bacteria (ARB), antibiotic resistance genes (ARGs), and micropollutants (MPs). A facile and solvothermal process was used to synthesize new pyrite-based composites. The GO coated layer forms a strong chemical bond with nano pyrite, which enables to prevent the oxidation and photocorrosion of pyrite and promote the transfer of charge carriers. Low reagent doses of FeS2@GO catalyst (0.25 mg/L) and H2O2 (1.0 mM) were found to be efficient for removing 6-log of ARB and 7-log of extracellular ARG (e-ARG) after 30 and 7.5 min treatment, respectively, in synthetic wastewater. Bacterial regrowth was not observed even after a two-day incubation. Moreover, four recalcitrant MPs (sulfamethoxazole, carbamazepine, diclofenac, and mecoprop at an environmentally relevant concentration of 10 µg/L each) were completely removed after 10 min of treatment. The stable and recyclable composite generated more reactive species, including hydroxyl radicals (HO•), superoxide radicals (O2• -), singlet oxygen (1O2). These findings highlight that the synthesized FeS2@GO catalyst is a promising heterogeneous photo-Fenton catalyst for the removal of emerging contaminants.

False lumen pressure estimation in type B aortic dissection using 4D flow cardiovascular magnetic resonance: comparisons with aortic growth.

BACKGROUND: Chronic type B aortic dissection (TBAD) is associated with poor long-term outcome, and accurate risk stratification tools remain lacking. Pressurization of the false lumen (FL) has been recognized as central in promoting aortic growth. Several surrogate imaging-based metrics have been proposed to assess FL hemodynamics; however, their relationship to enlarging aortic dimensions remains unclear. We investigated the association between aortic growth and three cardiovascular magnetic resonance (CMR)-derived metrics of FL pressurization: false lumen ejection fraction (FLEF), maximum systolic deceleration rate (MSDR), and FL relative pressure (FL ΔPmax). METHODS: CMR/CMR angiography was performed in 12 patients with chronic dissection of the descending thoracoabdominal aorta, including contrast-enhanced CMR angiography and time-resolved three-dimensional phase-contrast CMR (4D Flow CMR). Aortic growth rate was calculated as the change in maximal aortic diameter between baseline and follow-up imaging studies over the time interval, with patients categorized as having either 'stable' (< 3 mm/year) or 'enlarging' (≥ 3 mm/year) growth. Three metrics relating to FL pressurization were defined as: (1) FLEF: the ratio between retrograde and antegrade flow at the TBAD entry tear, (2) MSDR: the absolute difference between maximum and minimum systolic acceleration in the proximal FL, and (3) FL ΔPmax: the difference in absolute pressure between aortic root and distal FL. RESULTS: FLEF was higher in enlarging TBAD (49.0 ± 17.9% vs. 10.0 ± 11.9%, p = 0.002), whereas FL ΔPmax was lower (32.2 ± 10.8 vs. 57.2 ± 12.5 mmHg/m, p = 0.017). MSDR and conventional anatomic variables did not differ significantly between groups. FLEF showed positive (r = 0.78, p = 0.003) correlation with aortic growth rate whereas FL ΔPmax showed negative correlation (r = - 0.64, p = 0.026). FLEF and FL ΔPmax remained as independent predictors of aortic growth rate after adjusting for baseline aortic diameter. CONCLUSION: Comparative analysis of three 4D flow CMR metrics of TBAD FL pressurization demonstrated that those that focusing on retrograde flow (FLEF) and relative pressure (FL ΔPmax) independently correlated with growth and differentiated patients with enlarging and stable descending aortic dissections. These results emphasize the highly variable nature of aortic hemodynamics in TBAD patients, and suggest that 4D Flow CMR derived metrics of FL pressurization may be useful to separate patients at highest and lowest risk for progressive aortic growth and complications.

Endovascular ascending aortic repair in type A dissection: A systematic review.

PURPOSE: Up to 10% of acute type A aortic dissection (TAAD) patients are deemed unfit for open surgical repair, exposing these patients to high mortality rates. In recent years, thoracic endovascular aortic repair has proven to be a promising alternative treatment modality in specific cases. This study presents a comprehensive overview of the current state of catheter-based interventions in the setting of primary TAAD. METHODS: A literature search was conducted, using MEDLINE and PubMed databases according to PRISMA guidelines, updated until January 2020. Articles were selected if they reported on the endovascular repair of DeBakey Type I and II aortic dissections. The exclusion criteria were retrograde type A dissection, hybrid procedures, and combined outcome reporting of mixed aortic pathologies (e.g., pseudoaneurysm and intramural hematoma). RESULTS: A total of 31 articles, out of which 19 were case reports and 12 case series, describing a total of 92 patients, were included. The median follow-up was 6 months for case reports and the average follow-up was 14 months for case series. Overall technical success was 95.6% and 30-day mortality of 9%. Stroke and early endoleak rates were 6% and 18%, respectively. Reintervention was required in 14 patients (15%). CONCLUSION: This review not only demonstrates that endovascular repair in the setting of isolated TAAD is feasible with acceptable outcomes at short-term follow-up, but also underlines a lack of mid-late outcomes and reporting consistency. Studies with longer follow-up and careful consideration of patient selection are required before endovascular interventions can be widely introduced.

Impaired microcirculatory perfusion in a rat model of cardiopulmonary bypass: the role of hemodilution.

Although hemodilution is attributed as the main cause of microcirculatory impairment during cardiopulmonary bypass (CPB), this relationship has never been investigated. We investigated the distinct effects of hemodilution with or without CPB on microvascular perfusion and subsequent renal tissue injury in a rat model. Male Wistar rats (375-425 g) were anesthetized, prepared for cremaster muscle intravital microscopy, and subjected to CPB (n = 9), hemodilution alone (n = 9), or a sham procedure (n = 6). Microcirculatory recordings were performed at multiple time points and analyzed for perfusion characteristics. Kidney and lung tissue were investigated for mRNA expression for genes regulating inflammation and endothelial adhesion molecule expression. Renal injury was assessed with immunohistochemistry. Hematocrit levels dropped to 0.24 ± 0.03 l/l and 0.22 ± 0.02 l/l after onset of hemodilution with or without CPB. Microcirculatory perfusion remained unaltered in sham rats. Hemodilution alone induced a 13% decrease in perfused capillaries, after which recovery was observed. Onset of CPB reduced the perfused capillaries by 40% (9.2 ± 0.9 to 5.5 ± 1.5 perfused capillaries per microscope field; P < 0.001), and this reduction persisted throughout the experiment. Endothelial and inflammatory activation and renal histological injury were increased after CPB compared with hemodilution or sham procedure. Hemodilution leads to minor and transient disturbances in microcirculatory perfusion, which cannot fully explain impaired microcirculation following cardiopulmonary bypass. CPB led to increased renal injury and endothelial adhesion molecule expression in the kidney and lung compared with hemodilution. Our findings suggest that microcirculatory impairment during CPB may play a role in the development of kidney injury.

Racial and ethnic disparities in diagnosis, management and outcomes of aortic stenosis in the Medicare population.

IMPORTANCE: Aortic stenosis (AS) is one of the most common heart valve conditions and its incidence and prevalence increases with age. With the introduction of transcatheter aortic valve replacement (TAVR), racial and ethnic disparities in AS diagnosis, treatment and outcomes is poorly understood. OBJECTIVE: In this study we assessed racial and ethnic disparities in AS diagnosis, treatment, and outcomes among Medicare beneficiaries. DESIGN: We conducted a population-based cohort study of inpatient, outpatient, and professional claims from a 20% sample of Medicare beneficiaries. MAIN OUTCOMES AND MEASURES: Incidence and Prevalence was determined among Medicare Beneficiaries. Outcomes in this study included management; the number of (non)-interventional cardiology and cardiothoracic surgery evaluation and management (E&M) visits, and number of transthoracic echocardiograms (TTE) performed. Treatment, which was defined as Surgical Aortic Valve Replacement and Transthoracic Aortic Valve Replacement. And outcomes described as All-cause Hospitalizations, Heart Failure Hospitalization and 1-year mortality. RESULTS: A total of 1,513,455 Medicare beneficiaries were diagnosed with AS (91.3% White, 4.5% Black, 1.1% Hispanic, 3.1% Asian and North American Native) between 2010 and 2018. Annual prevalence of AS diagnosis was lower for racial and ethnic minorities compared with White patients, with adjusted rate ratios of 0.66 (95% CI 0.65 to 0.68) for Black patients, 0.67 (95% CI 0.64 to 0.70) for Hispanic patients and 0.75 (95% CI 0.73 to 0.77) for Asian and North American Native patients as recent as 2018. After adjusting for age, sex and comorbidities, cardiothoracic surgery E&M visits and treatment rates were significantly lower for Black, Hispanic and Asian and North American Native patients compared with White patients. All-cause hospitalization rate was higher for Black and Hispanic patients compared with White patient. 1-year mortality was higher for Black patients, while Hispanic and Asian and North American Native patients had lower 1-year mortality compared with White patients. CONCLUSIONS AND RELEVANCE: We demonstrated significant racial and ethnic disparities in the diagnosis, management and outcomes of AS. The factors driving the persistence of these disparities in AS care need to be elucidated to develop an equitable health care system.

Roles of reactive oxygen species in antibiotic resistant bacteria inactivation and micropollutant degradation in Fenton and photo-Fenton processes.

Reactive oxygen species play a critical role in degrading chemical or biological contaminants in advanced oxidation processes. However, it is still not clear whether conventional Fenton and photo-Fenton processes generate different reactive oxygen species, respectively. This study revealed the roles of reactive oxygen species (ROS) for simultaneous removal of antibiotic resistant bacteria (ARB) and recalcitrant micropollutant using three processes, i.e., conventional Fenton, photo-Fenton, and ethylenediamine-N, N'-disuccinic acid (EDDS) modified photo-Fenton. Both chemical scavengers and electron paramagnetic resonance spectroscopy confirmed the generation of various ROS and their contribution towards bacterial inactivation and micropollutant degradation. Results showed ARB and carbamazepine (CBZ) elimination efficiency in the order: EDDS modified photo-Fenton process > photo-Fenton process > Fenton process. The ARB detection limit (6-log ARB) was observed within 10 min at lower doses of 0.1 mM Fe3+, 0.2 mM EDDS, and 0.5 mM hydrogen peroxide (H2O2). With the same dose, it took longer (60 min) to remove CBZ, while 2.5 times higher H2O2 dose (1.25 mM) removed around 99% of CBZ within 10 min treatment. The present study highlighted that the hydroxyl radical (HO•) plays a dominant role, while singlet oxygen (1O2) and superoxide radical anion (O2•-) exhibit moderate effects to remove the hazards. Our findings provide mechanistic insights into the role of various reactive oxygen species on degrading micropollutants and inactivating ARB.

Natural history and clinical significance of aortic focal intimal flaps.

Objective: Focal intimal flaps (FIF) are a variety of defects of the aorta that result in a short, flap-like projection into the lumen, and are often encountered in asymptomatic patients undergoing computed tomography angiography (CTA) surveillance for aortic aneurysm, but the natural history and clinical significance of such lesions has not yet been studied. Methods: We retrospectively identified patients with an asymptomatic FIF and available imaging follow-up (>1 year). FIF was defined as flap-like intimal irregularity < 4 cm in length involving the thoracic aorta (TA), abdominal aorta (AA) or common iliac arteries (CIA). FIF characteristics included length and circumferential extent as well as the presence and size (width and depth) of associated penetrating aortic ulcers (PAUs). Patient characteristics, adverse events and history of surgical repair was determined by chart review. FIFs and associated PAUs were assessed for progression by comparing baseline and follow-up CTA studies. Results: A total of 84 FIFs were identified in 77 patients. Average age was 69.2 ± 10.1 years, and 81% were male (81%). Common co-morbidities included: hypertension (78%), hyperlipidemia (68%), smoking (60%), coronary artery disease (41%), aortic aneurysm (34%), type II diabetes mellitus (27%) and prior cardiovascular surgery (25%). FIFs were most commonly located in the abdominal aorta (n = 50, 60%). Nearly all FIFs were associated with local atherosclerotic plaque (93%). Mean follow-up interval was 3.5 ± 2.6 years (259 cumulative follow-up years). Change in FIF length and local aortic diameter over follow-up were 0.7 ± 2.3 mm and 0.8 ± 1.1 mm, respectively. Nearly half (47%) of FIFs were associated with penetrating aortic ulcers (PAU) with baseline depth of 7.3 mm (IQR: 6.1-10.2) and change in depth of 0.5 ± 1.4 mm. Only 12% of FIFs and 0% of associated PAUs demonstrated growth (≥3 mm) at follow-up. No acute pathology developed in the location of FIFs and no aortic interventions were performed specifically to treat FIFs. Conclusion: Focal intimal flaps identified in asymptomatic patients with aortic disease were co-localized with atherosclerotic plaque and PAUs, and demonstrated indolent behavior, not leading to significant growth or acute aortic events, supporting a conservative management approach.

Aberrant Subclavian Arteries and Associated Kommerell Diverticulum: Endovascular vs Open Repair.

BACKGROUND: Various surgical options have been described for the treatment of aberrant subclavian arteries and an associated Kommerell diverticulum. METHODS: Between 1999 and 2019, 43 patients underwent a repair, comprising 26 (61%) endovascular and 17 (39%) open approaches. The endovascular approach consisted of initial subclavian revascularization followed by thoracic endovascular aortic repair. The open approach included total arch replacement (12%) and reverse hemiarch repair with left thoracotomy (53%) or right thoracotomy (35%). The perioperative and long-term outcomes were retrospectively reviewed. RESULTS: No mortality occurred in the endovascular group, whereas there was 1 (6%) in the open approach group. Patients in the endovascular group demonstrated a shorter hospital stay (3.5 days vs 10.0 days; P = .001) and less frequent prolonged mechanical ventilation (0% vs 24%; P = .019), with a lower occurrence of pneumonia (0% vs 24%; P = .019). Among patients who had the endovascular approach, shrinkage of Kommerell diverticulum or aberrant vessel origin was seen in 96%. Furthermore, relief of dysphagia was confirmed in 92% (12/13), including patients without Kommerell diverticulum (n = 3) after endovascular repair. The cumulative incidence of treatment failure or aortic reintervention at 7 years was 21% and 14 % in the endovascular and open approach groups, respectively (P = .62). Two (8%) patients in the endovascular group required an open reintervention. One reintervention was performed for persistent dysphagia in the setting of an untreated complete vascular ring, and the other was for persistent false lumen flow associated with aortic dissection. CONCLUSIONS: The treatment approach should be individualized on the basis of the aortic disease and comorbidities. The endovascular approach is a viable and effective alternative in the presence of suitable landing zones.

Trends in Medicare Payments for Beneficiaries With Aortic Stenosis.

Background Aortic stenosis (AS) is the most common form of valvular heart disease with an increasing prevalence. Management of AS has changed dramatically with the introduction of transcatheter aortic valve replacement (AVR). The shift in management of AS, combined with an aging population, may increase the cost of patients with AS in the US health care system. Methods and Results We performed a retrospective cohort study, using inpatient, carrier, and outpatient data from a 20% Medicare fee-for-service beneficiaries' sample from 2008 to 2019 and included beneficiaries, aged ≥65 years. We identified beneficiaries with a diagnosis of AS and stratified the sample into 3 age groups: 66 to 74, 75 to 84, and ≥85 years. We evaluated the crude and adjusted changes in annual Medicare payments (total and component) per beneficiary. We identified 1 887 340 (1.6%) Medicare beneficiaries diagnosed with AS. The average annual spending for Medicare beneficiaries with AS was $19 241 in 2010 and increased annually by $301 to $23 174 in 2019 (P<0.0001). Annual Medicare payments on patients with AS increased from $2 894 995 131 in 2010 to $4 619 077 182 in 2019, a difference of >1.7 billion dollars. Inpatient spending increased 1.1% per year, with the highest increase in patients aged ≥85 years (1.9%). The percentage of beneficiaries undergoing surgical AVR decreased from 3.7% to 1.6%, and annual spending on surgical AVR decreased an average of 7.2% per year. The percentage of beneficiaries undergoing transcatheter AVR increased from 0% in 2010 to 3.8% in 2019, and annual spending for transcatheter AVR increased by 458.7% per year. Conclusions Although average annual Medicare spending per beneficiary modestly increased over the study period, the increase in the prevalence of AS and the proportion of beneficiaries undergoing (transcatheter) interventions for AS led to a substantial increase in overall Medicare spending among patients with AS.

Patient-Specific Computational Modeling of Different Cannulation Strategies for Extracorporeal Membrane Oxygenation.

Institution of extracorporeal membrane oxygenation (ECMO) results in unique blood flow characteristics to the end-organ vascular beds. We studied the interplay between cardiac-driven and extracorporeal membrane oxygenation (ECMO)-driven flow to vascular beds in different ECMO configurations using a patient-specific computational fluid dynamics (CFD) analysis. A computational ECMO model (femoral artery cannulation [FAC]) was constructed using patient-specific imaging and hemodynamic data. Following model calibration, we augmented the 3D geometrical model to represent alternative ECMO configurations (ascending aorta cannulation [AAC] and subclavian artery cannulation [SAC]). We performed CFD analyses, including a novel virtual color-dye analysis to compare global and regional blood flow and pressure characteristics as well as contributions of cardiac and ECMO-derived flow to the various vascular beds. Flow waveforms at all the aortic branch vessels were pulsatile, despite low cardiac output and predominant nonpulsatile ECMO-driven hemodynamics. Virtual color-dye analysis revealed differential contribution of cardiac and ECMO-derived flow to the end-organ vascular beds in the FAC model, while this was more evenly distributed in the AAC and SAC models. While global hemodynamics were relatively similar between various ECMO configurations, several distinct hemodynamic indices, in particular wall shear stress and oscillatory shear patterns, as well as differential contribution of ECMO-derived flow to various vascular beds, showed remarkable differences. The clinical impact of this study highlighting the relevance of CFD modeling in assessment of complex hemodynamics in ECMO warrants further evaluation.

Simultaneous removal of antibiotic resistant bacteria, antibiotic resistance genes, and micropollutants by a modified photo-Fenton process.

Although photo-driven advanced oxidation processes (AOPs) have been developed to treat wastewater, few studies have investigated the feasibility of AOPs to simultaneously remove antibiotic resistant bacteria (ARB), antibiotic resistance genes (ARGs) and micropollutants (MPs). This study employed a modified photo-Fenton process using ethylenediamine-N,N'-disuccinic acid (EDDS) to chelate iron(III), thus maintaining the reaction pH in a neutral range. Simultaneous removal of ARB and associated extracellular (e-ARGs) and intracellular ARGs (i-ARGs), was assessed by bacterial cell culture, qPCR and atomic force microscopy. The removal of five MPs was also evaluated by liquid chromatography coupled with mass spectrometry. A low dose comprising 0.1 mM Fe(III), 0.2 mM EDDS, and 0.3 mM hydrogen peroxide (H2O2) was found to be effective for decreasing ARB by 6-log within 30 min, and e-ARGs by 6-log within 10 min. No ARB regrowth occurred after 48-h, suggesting that the proposed process is an effective disinfectant against ARB. Moreover, five recalcitrant MPs (carbamazepine, diclofenac, sulfamethoxazole, mecoprop and benzotriazole at an initial concentration of 10 µg/L each) were >99% removed after 30 min treatment in ultrapure water. The modified photo-Fenton process was also validated using synthetic wastewater and real secondary wastewater effluent as matrices, and results suggest the dosage should be doubled to ensure equivalent removal performance. Collectively, this study demonstrated that the modified process is an optimistic 'one-stop' solution to simultaneously mitigate both chemical and biological hazards.

New insights of phenolic compounds from optimized fruit extract of Ficus auriculata.

In this study, the extraction conditions extracted maximize amounts of phenolic and bioactive compounds from the fruit extract of Ficus auriculata by using optimized response surface methodology. The antioxidant capacity was evaluated through the assay of radical scavenging ability on DPPH and ABTS as well as reducing power assays on total phenolic content (TPC). For the extraction purpose, the ultrasonic assisted extraction technique was employed. A second-order polynomial model satisfactorily fitted to the experimental findings concerning antioxidant activity (R2 = 0.968, P < 0.0001) and total phenolic content (R2 = 0.961, P < 0.0001), indicating a significant correlation between the experimental and expected value. The highest DPPH radical scavenging activity was achieved 85.20 ± 0.96% at the optimum extraction parameters of 52.5% ethanol (v/v), 40.0 °C temperature, and 22 min extraction time. Alternatively, the highest yield of total phenolic content was found 31.65 ± 0.94 mg GAE/g DF at the optimum extraction conditions. From the LC-ESI-MS profiling of the optimized extract, 18 bioactive compounds were tentatively identified, which may regulate the antioxidant activity of fruits of F. auriculata.

Vascular Deformation Mapping of Abdominal Aortic Aneurysm.

Abdominal aortic aneurysm (AAA) is a complex disease that requires regular imaging surveillance to monitor for aneurysm stability. Current imaging surveillance techniques use maximum diameter, often assessed by computed tomography angiography (CTA), to assess risk of rupture and determine candidacy for operative repair. However, maximum diameter measurements can be variable, do not reliably predict rupture risk and future AAA growth, and may be an oversimplification of complex AAA anatomy. Vascular deformation mapping (VDM) is a recently described technique that uses deformable image registration to quantify three-dimensional changes in aortic wall geometry, which has been previously used to quantify three-dimensional (3D) growth in thoracic aortic aneurysms, but the feasibility of the VDM technique for measuring 3D growth in AAA has not yet been studied. Seven patients with infra-renal AAAs were identified and VDM was used to identify three-dimensional maps of AAA growth. In the present study, we demonstrate that VDM is able to successfully identify and quantify 3D growth (and the lack thereof) in AAAs that is not apparent from maximum diameter. Furthermore, VDM can be used to quantify growth of the excluded aneurysm sac after endovascular aneurysm repair (EVAR). VDM may be a useful adjunct for surgical planning and appears to be a sensitive modality for detecting regional growth of AAAs.

False lumen enhancement characteristics on computed tomography angiography predict risk of aneurysm formation in acute type B aortic dissection.

OBJECTIVES: Differential luminal enhancement [between true lumen (TL) and false lumen (FL)] results from differential flow patterns, most likely due to outflow restriction in the FL. We aimed to assess the impact of differential luminal enhancement at baseline computed tomography angiography on the risk of adverse events in patients with acute type B aortic dissection (TBAD). METHODS: Baseline computed tomography angiographies of patients with acute TBAD between 2007 and 2016 (n = 48) were analysed using three-dimensional software at multiple sites along the descending thoraco-abdominal aorta. At each location, we measured contrast density in TL and FL [Houndsfield unit (HU)], maximal diameter (cm) and circumferential FL extent (°). Outcome data were collected via retrospective chart review. Multivariable logistic regression models were employed to determine the independent risk of TL-FL differential luminal enhancement on aneurysm formation (maximal diameter ≥55 mm) and medical treatment failure. RESULTS: Patients were predominately male (75%) and 52.8±12.9 years at diagnosis. The mean follow-up was 5.9±2.6 years, and 42% (n = 20/48) patients were diagnosed with thoraco-abdominal aortic aneurysm. The baseline absolute difference between FL and TL contrast density measured at 2 cm distal to primary entry tear (TL-FLabs-Tear) was significantly higher among patients who developed aneurysm (26 HU, IQR: 15-53 vs 13 HU, IQR: 4-24, P = 0.001). Aneurysm development during follow-up was predicted by TL-FLabs-Tear (odds ratio 1.07, P = 0.012) and baseline maximal aortic diameter (odds ratio 1.90, P < 0.001). High (≥18 HU) differential luminal enhancement was associated with lower rates of aneurysm-free survival and higher rates of medical treatment failure. CONCLUSIONS: Differential luminal enhancement may be a novel predictor of aneurysm formation among patients with acute TBAD.

Interventional Planning for Endovascular Revision of a Lateral Tunnel Fontan: A Patient-Specific Computational Analysis.

INTRODUCTION: A 2-year-old female with hypoplastic left heart syndrome (HLHS)-variant, a complex congenital heart defect (CHD) characterized by the underdevelopment of the left ventricle, presented with complications following single ventricle palliation. Diagnostic work-up revealed elevated Fontan pathway pressures, as well as significant dilation of the inferior Fontan pathway with inefficient swirling flow and hepatic venous reflux. Due to the frail condition of the patient, the clinical team considered an endovascular revision of the Fontan pathway. In this work, we performed a computational fluid dynamics (CFD) analysis informed by data on anatomy, flow, and pressure to investigate the hemodynamic effect of the endovascular Fontan revision. METHODS: A patient-specific anatomical model of the Fontan pathway was constructed from magnetic resonance imaging (MRI) data using the cardiovascular modeling software CardiovasculaR Integrated Modeling and SimulatiON (CRIMSON). We first created and calibrated a pre-intervention 3D-0D multi-scale model of the patient's circulation using fluid-structure interaction (FSI) analyses and custom lumped parameter models (LPMs), including the Fontan pathway, the single ventricle, arterial and venous systemic, and pulmonary circulations. Model parameters were iteratively tuned until simulation results matched clinical data on flow and pressure. Following calibration of the pre-intervention model, a custom bifurcated endograft was introduced into the anatomical model to virtually assess post-intervention hemodynamics. RESULTS: The pre-intervention model successfully reproduced the clinical hemodynamic data on regional flow splits, pressures, and hepatic venous reflux. The proposed endovascular repair model revealed increases of mean and pulse pressure at the inferior vena cava (IVC) of 6 and 29%, respectively. Inflows at the superior vena cava (SVC) and IVC were each reduced by 5%, whereas outflows at the left pulmonary artery (LPA) and right pulmonary artery (RPA) increased by 4%. Hepatic venous reflux increased by 6%. CONCLUSION: Our computational analysis indicated that the proposed endovascular revision would lead to unfavorable hemodynamic conditions. For these reasons, the clinical team decided to forgo the proposed endovascular repair and to reassess the management of this patient. This study confirms the relevance of CFD modeling as a beneficial tool in surgical planning for single ventricle CHD patients.

Imaging surveillance after open aortic repair: a feasibility study of three-dimensional growth mapping.

OBJECTIVES: Confident growth assessment during imaging follow-up is often limited by substantial variability of diameter measurements and the fact that growth does not always occur at standard measurement locations. There is a need for imaging-based techniques to more accurately assess growth. In this study, we investigated the feasibility of a three-dimensional aortic growth assessment technique to quantify aortic growth in patients following open aortic repair. METHODS: Three-dimensional aortic growth was measured using vascular deformation mapping (VDM), a technique which quantifies the localized rate of volumetric growth at the aortic wall, expressed in units of Jacobian (J) per year. We included 16 patients and analysed 6 aortic segments per patient (96 total segments). Growth was assessed by 3 metrics: clinically reported diameters, Jacobian determinant and targeted diameter re-measurements. RESULTS: VDM was able to clearly depict the presence or absence of localized aortic growth and allows for an assessment of the distribution of growth and its relation to anatomic landmarks (e.g. anastomoses, branch arteries). Targeted diameter change showed a stronger and significant correlation with J (r = 0.20, P = 0.047) compared to clinical diameter change (r = 0.15, P = 0.141). Among 20/96 (21%) segments with growth identified by VDM, growth was confirmed by clinical measurements in 7 and targeted re-measurements in 11. Agreement of growth assessments between VDM and diameter measurements was slightly higher for targeted re-measurements (kappa = 0.38) compared to clinical measurements (kappa = 0.25). CONCLUSIONS: Aortic growth is often uncertain and underappreciated when assessed via standard diameter measurements. Three-dimensional growth assessment with VDM offers a more comprehensive assessment of growth, allows for targeted diameter measurements and could be an additional tool to determine which post-surgical patients at high and low risk for future complications.

Efficient inactivation of antibiotic resistant bacteria and antibiotic resistance genes by photo-Fenton process under visible LED light and neutral pH.

Antibiotic resistance has been recognized as a major threat to public health worldwide. Inactivation of antibiotic resistant bacteria (ARB) and degradation of antibiotic resistance genes (ARGs) are critical to prevent the spread of antibiotic resistance in the environment. Conventional disinfection processes are effective to inactivate water-borne pathogens, yet they are unable to completely eliminate the antibiotic resistance risk. This study explored the potential of the photo-Fenton process to inactivate ARB, and to degrade both extracellular and intracellular ARGs (e-ARGs and i-ARGs, respectively). Using Escherichia coli DH5α with two plasmid-encoded ARGs (tetA and blaTEM-1) as a model ARB, a 6.17 log ARB removal was achieved within 30 min of applying photo-Fenton under visible LED and neutral pH conditions. In addition, no ARB regrowth occurred after 48-h, demonstrating that this process is very effective to induce permanent disinfection on ARB. The photo-Fenton process was validated under various water matrices, including ultrapure water (UPW), simulated wastewater (SWW) and phosphate buffer (PBS). The higher inactivation efficiency was observed in SWW as compared to other matrices. The photo-Fenton process also caused a 6.75 to 8.56-log reduction in eARGs based on quantitative real-time PCR of both short- and long amplicons. Atomic force microscopy (AFM) further confirmed that the extracellular DNA was sheared into short DNA fragments, thus eliminating the risk of the transmission of antibiotic resistance. As compared with e-ARGs, a higher dosage of Fenton reagent was required to damage i-ARGs. In addition, the tetA gene was more easily degraded than the blaTEM-1 gene. Collectively, our results demonstrate the photo-Fenton process is a promising technology for disinfecting water to prevent the spread of antibiotic resistance.

Aortic coarctation repair through left thoracotomy: results in the modern era.

OBJECTIVES: Surgical repair of coarctation of the aorta (CoA) is often possible through left thoracotomy and without the use of cardiopulmonary bypass. Recent studies reporting the outcome after CoA repair through left thoracotomy are limited. Therefore, the aim of this study is to evaluate the results of CoA repair through left thoracotomy in children who were operated on in our centre over the past 21 years. METHODS: From January 1995 to December 2016, 292 patients younger than 18 years underwent primary CoA repair through left thoracotomy at our 2 institutions. Peri- and postoperative data and follow-up data collected from our hospital and the referring hospitals were retrospectively reviewed. RESULTS: Median age at operation was 64 days (range 2 days-17 years). Most patients underwent the resection of the CoA followed by an (extended) end-to-end anastomosis (93%). Six patients died perioperatively and 2 more patients died during the follow-up, of which 7 patients had other major comorbidities. Actuarial survival was 97% at 5 years, 96% at 10 years and 96% at 15 years. Second arch interventions due to recoarctation were performed in 9.9% (n = 29) of patients, consisting of balloon dilatation in all but 2 patients. Recoarctation occurred significantly more often after initial repair in the neonatal period (21%) and could occur as late as 14 years after initial surgery. There were 7 re-recoarctations, and 14% of patients were on hypertensive medication during the follow-up. CONCLUSIONS: Repair of CoA through left thoracotomy is a safe procedure with low rates of mortality. The long-term follow-up is necessary due to the significant risk of recoarctation requiring reintervention.