Modeling of valve-in-valve transcatheter aortic valve implantation after aortic root replacement using a 3-dimensional artificial intelligence algorithm.

OBJECTIVE: Aortic root replacement requires construction of a composite valve-graft and reimplantation of coronary arteries. This study assessed the feasibility of valve-in-valve transcatheter aortic valve implantation after aortic root replacement. METHODS: A retrospective review was conducted on 74 consecutive patients who received a composite valve-graft at a single institution from 2019 to 2021. Forty patients had bioprosthetic valves with adequate postoperative gated computed tomographic angiography scans. Computational simulations of balloon and self-expanding transcatheter valve deployments were performed. The modeled coronary distances were compared with traditional, manually measured valve-to-coronary distances. RESULTS: There was a statistically significant difference in the modeled versus manual measurements of valve to coronary distances for all patients regardless of valve type or coronary artery analyzed (P < .05). Most patients are low risk for coronary obstruction per 3-dimensional modeling, including those with a valve-to-coronary distance <4 mm. Only 1 patient (2.5%) was at risk for coronary obstruction for the left coronary artery using a balloon valve. No other valve combination was considered high risk of coronary obstruction. Five patients (12.5%) were at risk for possible valve stent deformation at the outflow, due to angulation at the graft anastomosis. CONCLUSIONS: Following aortic root replacement, all patients were candidates for valve-in-valve procedure using 1 or both types of transcatheter heart valves. Self-expanding valves may be at higher risk for stent frame deformation at graft anastomotic lines and balloon-expandable valves may be at higher risk of coronary obstruction.

Beyond Static Planning: Computational Predictive Modeling to Avoid Coronary Artery Occlusion in TAVR.

BACKGROUND: Coronary artery occlusion (CO) during transcatheter aortic valve replacement (TAVR) is a devastating complication. The objective of this study was to assess the clinical impact of a computational predictive modeling algorithm for CO during TAVR planning. METHODS: From January 2020 to December 2022, 116 patients (7.6%) who underwent TAVR evaluation were deemed to be at increased risk of CO on the basis of traditional criteria. Patients underwent prospective computational modeling (DASI Simulations) to assess their risk of CO during TAVR; procedural modifications and clinical results were reviewed retrospectively. RESULTS: Of the 116 patients at risk for CO by traditional methodology, 53 had native aortic valve stenosis (45.7%), 47 had undergone previous surgical AVR (40.5%), and 16 had undergone previous TAVR (13.8%). Transcatheter valve choice, size, or implantation depth was modeled for all patients. Computational modeling predicted an increased risk of CO in 39 of 116 (31.9%) patients. Within this subcohort, 29 patients proceeded with TAVR. Procedural modifications to augment the risk of CO included bioprosthetic or native aortic scallop intentional laceration to prevent iatrogenic coronary artery obstruction during TAVR (n = 10), chimney coronary stents (n = 8), and coronary access without stents (n = 3). There were no episodes of coronary artery compromise among patients after TAVR, either for those predicted to be at high risk of CO (with procedural modifications) or those predicted to be at low risk (standard TAVR). CONCLUSIONS: The use of preoperative simulations for TAVR in patient-specific geometry through computational predictive modeling of CO is an effective enhancement to procedure planning.

Veno-venous extracorporeal membrane oxygenation (VV ECMO) cannula malposition identified with point-of-care ultrasound.

BACKGROUND: Point-of-care ultrasound (POCUS) has become a mainstay in the evaluation of critically ill patients in the intensive care unit (ICU). ECMO patients are susceptible to complications during prolonged ICU stay, including cannula malposition, which has deleterious consequences. Although the literature surrounding utility of ultrasound on ECMO patients is expansive, direct comparison between radiographic imaging versus ultrasound for identification of cannula malposition is lacking. CASE PRESENTATION: The authors identified four patients with cannula malposition discovered through POCUS that was missed on routine radiographic imaging. Identification and correction of malposition changed their ECMO course. CONCLUSION: This case series is the first in literature demonstrating that ultrasound may be superior to radiographic images for ECMO cannula malposition. Further investigation into this subject is warranted.

Disruption of the circadian rhythm of melatonin: A biomarker of critical illness severity.

Circadian dysrhythmias occur commonly in critically ill patients reflecting variable effects of underlying illness, ICU environment, and treatments. We retrospectively analyzed the relationship between clinical outcomes and 24-h urinary 6-sulfatoxymelatonin (aMT6s) excretion profiles in 37 critically ill patients with shock and/or respiratory failure. Nonlinear regression was used to fit a 24-h cosine curve to each patient's aMT6s profile, with rhythmicity determined by the zero-amplitude test. From these curves we determined acrophase, amplitude, phase, and night/day ratio. After assessing unadjusted relationships, we identified the optimal multivariate models for hospital survival and for discharge to home (vs. death or transfer to another facility). Normalized aMT6s rhythm amplitude was greater (p = 0.005) in patients discharged home than in those who were not, while both groups exhibited a phase delay. Patients with rhythmic aMT6s excretion were more likely to survive (OR 5.25) and be discharged home (OR 8.89; p < 0.05 for both) than patients with arrhythmic profiles, associations that persisted in multivariate modelling. In critically ill patients with shock and/or respiratory failure, arrhythmic and/or low amplitude 24-h aMT6s rhythms were associated with worse clinical outcomes, suggesting a role for the melatonin-based rhythm as a novel biomarker of critical illness severity.

Non-tuberculous mycobacterial thoracic osteomyelitis in an immunocompetent host: a rare presentation of Mycobacterium kansasii.

An immunocompetent man in his 40s presented with 3 months of mid-thoracic back pain which progressed to include progressive paraesthesias and lower extremity weakness. Investigations revealed thoracic spine osteomyelitis with signs of cord compression. He underwent neurosurgical intervention, including laminectomy, spinal cord decompression and partial resection of an epidural mass. Initial intraoperative biopsy and surgical pathology results were concerning for an acid-fast bacillus as the causative pathogen, and the patient was given empiric therapy for presumed Mycobacterium tuberculosis However, microbiology speciation revealed the presence of the non-tuberculous mycobacterium (NTM) Mycobacterium kansasii, which resulted in an alteration of his antimicrobial therapy. This case highlights the importance of considering NTM as a possible aetiology of spinal osteomyelitis, even among immunocompetent individuals or in low-prevalence regions.

Evaluation of the Antibacterial Activity of 75 Mushrooms Collected in the Vicinity of Oxford, Ohio (USA).

Antibiotic-resistant bacteria are an increasing and serious health concern worldwide, and multidrug-resistant pathogens are increasingly emerging among patients across the United States. Researchers are exploring sources of traditional medicines, including mushrooms, to find new antibiotic compounds. In this study, the antibiotic activities of 75 mushrooms collected in the area surrounding Oxford, Ohio (USA), were assayed for antibiotic activity against 6 bacterial strains (Pseudomonas aeruginosa reference strains PAO1 and PA14, P. fluorescens, Bacillus subtilis, Staphylococcus epidermidis, and Micrococcus luteus). Mushroom samples were identified by using DNA ribotyping. We used methanol and water extracts of mushrooms in agar diffusion assays to screen for antibiotic activity toward each bacterial strain. A total of 25 mushroom species had antibacterial activity against at least 1 bacterium. Water extracts of Polyporus squamosus, Ganoderma applanatum, Lentinellus subaustralis, Laetiporus sulphureus, G. lucidum, and Trametes versicolor exhibited strong antibiotic activity against all bacterial strains tested. Water and methanol extracts from 25 mushroom species had significant activity against most of the bacteria tested. A minimum inhibitory concentration (MIC) against S. epidermidis was determined for all samples that exhibited antibiotic activity in the disk assay. The G. lucidum and L. sulphureus extracts displayed the strongest inhibition, with an MIC of 0.1 mg/mL.