Aortic Neocuspidization with Autologous Pericardium: Initial Experience of Single Center

Background: Aortic neo-cuspidization (AVNeo) procedure has been adopted by limited centers with the publication of the mid-long term successful results. The aim of this study was to present initial experience of the AVNeo procedure of a single center. Methods: The medical records of 24 patients who underwent AVNeo with or without concomitant cardiac surgery between February 2019 and February 2021 at our tertiary hospital were scanned retrospectively. Results: The mean age of patients was aged 58.21 ± 13.14 years and 16 (66.7%) of them were men. 16 patients were operated on for aortic stenosis (66.67%). Morphology of the aortic valve was tricuspid in 21 (87.5%) and bicuspid in 3 (12.5%) of the patients. Additional cardicac surgery was performed in 13 (54.17%) patients. No patients needed reoperation for bleeding, pacemaker implantations, conversion to classical prosthetic aortic valve replacement, or infective endocarditis. Two patients died due to non-cardiac reasons. Preoperative peak and mean aortic valve pressures improved significantly at 1st and 6th months (Preop: 89.06 ± 21.88 mmHg and 56.38 ± 15.09 mmHg 1st month: 22.00 ± 3.93 mmHg and 8.73 ± 2.60 mmHg, 6th month: 18.13 ± 3.02 mmHg and 6.93 ± 1.83 mmHg). Conclusion: In conclusion, the AVNeo procedure is a feasible technique for aortic valve pathologies, with the advantages of avoiding anticoagulants and the applicability of concomitant surgical procedures. Although this procedure requires meticulous experience, results similar to the available published literature can be obtained and reproducible even during learning curve when technical steps are strictly followed.

Plume diagnostics of BUSTLab microwave electrothermal thruster using Langmuir and Faraday probes

This study presents the Langmuir and Faraday probe measurements conducted to determine the plume characteristics of the BUSTLab microwave electrothermal thruster(MET).The thruster,designed to operate at 2.45 GHz frequency,is run with helium,argon and nitrogen gases as the propellant.For the measurements,the propellant volume flow rate and the delivered microwave power levels are varied.Experiments with nitrogen gas revealed certain operation regimes where a very luminous plume is observed.With the use of in-house-built Langmuir probes and a Faraday probe with guard ring,thruster plume electron temperature,plasma density and ion current density values are measured,and the results are presented.The measurements show that MET thruster plume effects on spacecraft will likely be similar to those of the arcjet plume.It is observed that the measured plume ion flux levels are very low for the high volume flow rates used for the operation of this thruster.

Acute myocardial infarction with normal coronary artery (MINCA) in a patient with multiple sclerosis

Interestingly, some patients with ST elevation myocardial infarction have normal coronary artery anatomy at cooronary angiography. This situation is called as MINCA (acute myocardial infarction with normal coronary artery). The incidence of MINCA varies between 1.0% and 8.5%. Although some reasons have been propounded, the exact underlying mechanism remains unclear. Nevertheless, thoracic myelitis can be as a possible cause of myocardial infarction. Herein, we report a case of acute myocardial infarction with normal coronary artery in a patient with multiple sclerosis.