Application of a high electric field causes an electric shock to the heart. This is utilized in defibrillation to reestablish normal contraction rhythms during dangerous arrhythmias or in cardiac arrest. If shock-induced transmembrane potentials are large enough, they can cause tissue destruction due to irreversible electroporation (EP). Also electrochemotherapy of nearby tissues may have an adverse effect on the heart. Herein, we present experimental data on effects of electroporation in culture of cardiac cells (H9C2). The electric field was applied in short pulses of 25-3250 V/cm, 50 µs each. The viability of cells was tested by MTT assay after 24 hours. For detection of DNA fragmentation, associated with apoptosis, alkaline and neutral comet assays were performed after EP. Additionally phase contrast images of cells obtained directly after EP were analyzed. Although cell images indicated disruption of cell membranes after EP with high intensities, only a few percent of apoptotic cells and no necrotic effects in the cell nucleus could be observed in comet assay tests performed 2 hours post EP. MTT viability test showed that pulse intensities above 375 V/cm are destructive for myocytes viability.
OBJECTIVES This study presents the results of 17 years of experience with bicuspid aortic valve (BAV) repair and the analysis of factors associated with repair failure and early echocardiographic outcome. METHODS Between 2003 and 2020, a total of 206 patients [mean age: 44.5 ± 15.2 years; 152 males (74%)] with BAV insufficiency with or without aortic dilatation underwent elective aortic valve repair performed by a single surgeon with a mean follow-up of 5 ± 3.5 years. The transthoracic echocardiography examinations were reported. RESULTS There were no deaths during the hospital stay, and all but 1 patient survived the follow-up period (99.5%). Overall, 10 patients (5%) developed severe insufficiency and 2 (1%) developed aortic dilatation requiring reoperation. Freedom from reoperation at 7 years reached 91.8%. Type 2 BAV configuration [hazard ratio (HR) 3.9; 95% confidence interval (CI): 1.01–60; P = 0.049], no sinotubular junction remodelling (HR 7; 95% CI: 1.7–23; P = 0.005), no circumferential annuloplasty (HR 3.9; 95% CI: 1.01–64; P = 0.047) and leaflet resection (HR 5.7; 95% CI 1.2–13. P = 0.017) have been identified as a risk factor of redo operation. Parameters of the postoperative left ventricle reverse remodelling improved significantly early after the operation and later at 2 years evaluation. CONCLUSIONS The repair of BAV offers good short- and mid-term results providing a significant reverse left ventricular remodelling. Type 0 BAV preoperative configuration, circumferential annuloplasty and sinotubular junction remodelling are associated with better repair durability.
A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was whether remote ischaemic preconditioning (RIPC) is of benefit to patients undergoing cardiac surgery. Altogether, more than 264 papers were found using the reported search, 16 of which represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. We conclude that RIPC is a safe protocol which could potentially be used in cardiac surgery to provide additional cardiac protection against ischaemia reperfusion injury, although it may not be appropriate for patients on K(+) ATPase channel blockers (sulphonylureas) as they seem to eliminate the effect of RIPC. In our study, we found two meta-analyses of cardiac surgery with or without RIPC. Both unequivocally showed 0.81 and 0.74 standardized mean reduction in myocardial necrosis markers in patients receiving RIPC and cardiac or vascular surgery. No difference in perioperative myocardial infarction incidence or 30-day mortality were found. In adult cardiac surgery, we found 11 randomized control trials (RCTs) ranging in size from 45 to 162 patients. Two representative studies reported no difference in postoperative cardiac troponin I concentration in RIPC vs. controls. In one of the studies (CABG ± RIPC) no additional benefit could have been observed for RIPC regarding intra-aortic balloon pump usage (controls 8.5 vs. RIPC 7.5%), inotropic support (39 vs. 50%) or vasoconstrictor usage (66 vs. 64%). On the other hand, in the other study [CABG ± AVR (aortic valve replacement) ± RIPC] significant reduction of troponin I at 8 h postoperatively (controls, 2.90 µg/l vs. RIPC, 2.54 µg/l, P = 0.043) was shown. Marked reduction in cardiac necrosis markers was also found in several smaller RCTs concerning coronary artery bypass grafting (CABG) patients receiving RIPC preoperatively: with cold crystalloid cardioplegia (44.5% reduction), with cross-clamping and fibrillation (43% reduction) and with cold blood cardioplegia (42.4% reduction). The proof of concept trials summarized here give some early evidence that RIPC may potentially provide some reduction in myocardial injury. If confirmed, in future clinical studies this technique may one day lead to a method to reduce reperfusion injury in clinical practice.
BackgroundExternal wrapping is a surgical technique performed in patients with a dilated ascending aorta. The aim of this study is to present the mid-term results of wrapping of the dilated ascending aorta.Methods34 patients (mean age: 64.4 ± 10.8 years, 21 males) with a dilated ascending aorta were operated on at a single cardiac surgery center using a wrapping technique. The aortas were wrapped with 32–36 mm straight Dacron vascular prostheses. The aortic wall was not excised in any of the patients. Wrapping was performed concomitant to other cardiac surgery procedures in 30 patients (88 %), which involved surgery on the aortic valve in 28 patients (82 %).ResultsThe mean follow-up time was 19.5 ± 8.3 months (median: 18 months, range: 12–36 months). None of the patients died or had aortic complications during the hospital stay and the follow-up period. A rethoracotomy had to be performed due to excessive postoperative bleeding in two patients. One patient was diagnosed with a transient ischemic attack on the 4th postoperative day, while another had respiratory failure requiring prolonged intubation. No redilatation of the ascending aorta or dislocation of the wrap was noticed in any of the patients.ConclusionsAccording to our study, external wrapping of the ascending aorta has good short-term results and may be regarded as a safe surgical option for patients with a moderately dilated ascending aorta.
BackgroundExternal wrapping is a surgical technique used in patients with dilated ascending aorta. To date, there is no available data describing the radiographic features of the aorta subjected to external wrapping using a straight corrugated Dacron vascular prosthesis. The aim of this study was to find distinctive radiographic features of an externally constricted aorta.MethodsPreoperative and early postoperative (7th postoperative day) CT angiography images of ten patients who underwent wrapping procedures were assessed and compared. The images were analyzed in order to find characteristic features of CT angiography images of the ascending aorta subjected to external wrapping.ResultsThe CT-angiography images showed that the aortic wall deformed significantly (the wall plicated) after the wrapping procedure in one patient, whose aortic diameter was decreased by 47 %. The remaining nine patients did not have significant aortic wall deformations. All patients presented with a periaortic mass. This was a collection of blood clots and pericardial fluid that filled the empty space in the pericardium following a decrease in the diameter of the ascending aorta. A very thin (<1 mm) crescent-shaped uncontrasted layer was noticed between the aorta and the periaortic area in all patients. This, in turn, was an empty space between the aorta and the corrugated vascular prosthesis.ConclusionsThe CT-angiography images of the aorta subjected to external wrapping may have unique features that are not observed after other operations on the ascending aorta. The knowledge about the details of this surgical procedure helps to correctly assess these images.
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