Reintervention for the trifecta aortic bioprosthesis: large single-centre series

Introduction

Aortic valve replacement with the Trifecta aortic bioprosthesis has reported favourable haemodynamic performance. However, several reports of structural valve deterioration have raised concerns of design risks and its long-term durability.

Purpose

We conducted this study to assess reintervention and outcomes in a large single-centre cohort of 944 patients receiving the Trifecta valve over a 10-year period.

Methods

Consecutive patients undergoing aortic valve replacement with the Trifecta valve between October 2011 and October 2020 in our centre were included in this study. Perioperative patient and operative characteristics were prospectively recorded in an independent database. Reintervention was recorded as a surrogate for structural valve deterioration, and survival data was analysed.

Results

A total of 944 patient (mean age 72.82 years ± 8.13, range 28–91, 58% male) underwent aortic valve replacement with the Trifecta valve in our centre between October 2011 and October 2020. At 10-years, 1.4% of patients required a redo operation for aortic valve replacement, giving an overall freedom reintervention of 98.6%, with a 99.3% and 99.4% freedom from reintervention due to structural valve deterioration and infection, respectively. The mean time to all-cause reintervention was 48.87 months, and the mean time to reintervention due to SVD was 68.87 months. Patients that did not require reintervention had a 97.74% freedom from mortality and those that underwent reintervention had a freedom from mortality of 84.62% with a median survival of 69-days.

Conclusions

In a large single-centre cohort, the Trifecta aortic bioprosthesis was safe with a 1.4% all-cause reintervention rate and a 0.7% reintervention rate for structural valve deterioration at 10-years.

Funding Acknowledgement

Type of funding sources: None.

Feature fusion of Raman chemical imaging and digital histopathology using machine learning for prostate cancer detection

The diagnosis of prostate cancer is challenging due to the heterogeneity of its presentations, leading to the over diagnosis and treatment of non-clinically important disease. Accurate diagnosis can directly benefit a patient's quality of life and prognosis. Towards addressing this issue, we present a learning model for the automatic identification of prostate cancer. While many prostate cancer studies have adopted Raman spectroscopy approaches, none have utilised the combination of Raman Chemical Imaging (RCI) and other imaging modalities. This study uses multimodal images formed from stained Digital Histopathology (DP) and unstained RCI. The approach was developed and tested on a set of 178 clinical samples from 32 patients, containing a range of non-cancerous, Gleason grade 3 (G3) and grade 4 (G4) tissue microarray samples. For each histological sample, there is a pathologist labelled DP-RCI image pair. The hypothesis tested was whether multimodal image models can outperform single modality baseline models in terms of diagnostic accuracy. Binary non-cancer/cancer models and the more challenging G3/G4 differentiation were investigated. Regarding G3/G4 classification, the multimodal approach achieved a sensitivity of 73.8% and specificity of 88.1% while the baseline DP model showed a sensitivity and specificity of 54.1% and 84.7% respectively. The multimodal approach demonstrated a statistically significant 12.7% AUC advantage over the baseline with a value of 85.8% compared to 73.1%, also outperforming models based solely on RCI and mean and median Raman spectra. Feature fusion of DP and RCI does not improve the more trivial task of tumour identification but does deliver an observed advantage in G3/G4 discrimination. Building on these promising findings, future work could include the acquisition of larger datasets for enhanced model generalization.

High Cysteinyl Leukotriene Receptor 1 Expression Correlates with Poor Survival of Uveal Melanoma Patients and Cognate Antagonist Drugs Modulate the Growth, Cancer Secretome, and Metabolism of Uveal Melanoma Cells

Metastatic uveal melanoma (UM) is a rare, but often lethal, form of ocular cancer arising from melanocytes within the uveal tract. UM has a high propensity to spread hematogenously to the liver, with up to 50% of patients developing liver metastases. Unfortunately, once liver metastasis occurs, patient prognosis is extremely poor with as few as 8% of patients surviving beyond two years. There are no standard-of-care therapies available for the treatment of metastatic UM, hence it is a clinical area of urgent unmet need. Here, the clinical relevance and therapeutic potential of cysteinyl leukotriene receptors (CysLT1 and CysLT2) in UM was evaluated. High expression of CYSLTR1 or CYSLTR2 transcripts is significantly associated with poor disease-free survival and poor overall survival in UM patients. Digital pathology analysis identified that high expression of CysLT1 in primary UM is associated with reduced disease-specific survival (p = 0.012; HR 2.76; 95% CI 1.21-6.3) and overall survival (p = 0.011; HR 1.46; 95% CI 0.67-3.17). High CysLT1 expression shows a statistically significant (p = 0.041) correlation with ciliary body involvement, a poor prognostic indicator in UM. Small molecule drugs targeting CysLT1 were vastly superior at exerting anti-cancer phenotypes in UM cell lines and zebrafish xenografts than drugs targeting CysLT2. Quininib, a selective CysLT1 antagonist, significantly inhibits survival (p < 0.0001), long-term proliferation (p < 0.0001), and oxidative phosphorylation (p < 0.001), but not glycolysis, in primary and metastatic UM cell lines. Quininib exerts opposing effects on the secretion of inflammatory markers in primary versus metastatic UM cell lines. Quininib significantly downregulated IL-2 and IL-6 in Mel285 cells (p < 0.05) but significantly upregulated IL-10, IL-1β, IL-2 (p < 0.0001), IL-13, IL-8 (p < 0.001), IL-12p70 and IL-6 (p < 0.05) in OMM2.5 cells. Finally, quininib significantly inhibits tumour growth in orthotopic zebrafish xenograft models of UM. These preclinical data suggest that antagonism of CysLT1, but not CysLT2, may be of therapeutic interest in the treatment of UM.

Improving the uniformity of holographic recording using multilayer photopolymer. Part I. Theoretical analysis

An experimental and theoretical investigation of the preparation and exposure of multilayer photosensitive materials is presented. It is shown how the recorded change in the refractive index in each layer depends on the dye (photosensitizer) concentrations in each layer. It is also shown how the photosensitive material properties in each layer can be controlled to optimize some recording characteristics for particular applications. To do so, a set of equations, predicting the amplitude of higher harmonics refractive index amplitudes induced in the material layers with depth during exposure, is derived. This results in a technique for varying the dye concentration in each layer of a multilayer, so as to optimize volume diffraction grating performance. In part I of this paper, the 3D nonlocal photopolymerization-driven diffusion (NPDD) model is applied to calculate the resulting combined multilayer absorption and polymerization processes. The NPDD describes the time-varying behaviors taking place during exposure in such photopolymer materials. Simulations are performed for an acrylamide/polyvinyl alcohol-based photopolymer containing erythrosine-B dye. It is predicted that, in general, non-uniform gratings are formed, with the resulting refractive index being distorted both from the ideal sinusoidal cross-sectional spatial distribution and also with depth. This agrees with previous results indicating that increasing the thickness of a single photopolymer layer does not in practice lead to ever-increasing angular selectivity. In part II of this paper, it is confirmed experimentally that a suitably modified multilayer can be used to increase grating angular selectivity, i.e., reduce the width of the off-Bragg replay curve.

Improving the uniformity of holographic recording using multi-layer photopolymer: Part II. Experimental results

In the first part of this study, a 3D nonlocal photopolymerization driven diffusion model was developed and applied to simulate the absorption and polymerization taking place during holographic exposures of a multi-layer. The Beer-Lambert law was used to choose appropriate dye concentrations for each layer, with the objective of improving the resulting volume grating uniformity and thus diffraction characteristics. The predictions made, using previously estimated physical parameter values, indicated that improvements in the uniformity of the recorded modulation were possible. In this paper the results of experiments carried out to explore the validity of these predictions are presented. Improvements in material response are demonstrated experimentally, with improved grating diffraction (narrower angular selectivity) being observed for appropriately sensitized multi-layers.

Photoinduced Enhanced Raman from Lithium Niobate on Insulator Template

Photoinduced enhanced Raman spectroscopy from a lithium niobate on insulator (LNOI)-silver nanoparticle template is demonstrated both by irradiating the template with 254 nm ultraviolet (UV) light before adding an analyte and before placing the substrate in the Raman system (substrate irradiation) and by irradiating the sample in the Raman system after adding the molecule (sample irradiation). The photoinduced enhancement enables up to an ∼sevenfold increase of the surface-enhanced Raman scattering signal strength of an analyte following substrate irradiation, whereas an ∼threefold enhancement above the surface-enhanced signal is obtained for sample irradiation. The photoinduced enhancement relaxes over the course of ∼10 h for a substrate irradiation duration of 150 min before returning to initial signal levels. The increase in Raman scattering intensity following UV irradiation is attributed to photoinduced charge transfer from the LNOI template to the analyte. New Raman bands are observed following UV irradiation, the appearance of which is suggestive of a photocatalytic reaction and highlight the potential of LNOI as a photoactive surface-enhanced Raman spectroscopy substrate.

Micro- or nanorod and nanosphere structures derived from a series of phenyl-porphyrins

We examine here a series ofmeso-phenyl porphyrin micro- and nanostructures.

Combined left pneumonectomy and off-pump coronary artery bypass through left thoracotomy

Concomitant pneumonectomy and coronary artery bypass grafting (CABG) carry a high morbidity and mortality rate. We present the case of a patient operated on for left pneumonectomy and off pump CABG through a left thoracotomy incision in a one-stage procedure with a 1-year disease-free follow-up. To the best of our knowledge, simultaneous surgical management as presented in this patient has not been previously reported.

Thoracoscopic IMA takedown

In recent years, the field of minimally invasive cardiac surgery has grown rapidly beginning with the MIDCAB operation and evolving toward totally endoscopic coronary artery bypass grafting (CABG). It promotes the goal of decreasing surgical trauma while maintaining surgical efficacy. For MIDCAB, a limited anterior thoracotomy or mediastotomy have been proposed to harvest the internal mammary artery (IMA). However, complete graft harvesting of the IMA is difficult under direct vision in these circumstances and may necessitate costal resection and important chest wall retraction. Additionally, it carries the potential risk of kinking or coronary steal syndrome. Thoracoscopic harvesting of the IMA avoids these hazards. It permits complete dissection from the subclavian artery to the sixth inter-costal space (ICS) with section of all collateral branches issuing from the IMA without any traumatic retraction. The technique of IMA takedown described herein has been used regularly by us since 1995. Our current experience shows that it is safe and reproducible after a reasonable period of training. Furthermore, in the objective of performing a totally endoscopic and/or robotic CABG, thoracoscopic IMA takedown would be a prerequisite.