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The Perceval sutureless valve has gained in popularity for treating degenerative aortic valve stenosis but not for congenital type 0 bicuspid aortic valve owing to anatomic challenges. We modified implant techniques following the four principles of ECHO-an acronym for elasticity, circularity, height, and orientation-to prevent paravalvular leakage and malposition., (Copyright © 2021 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Background: Some controversy exists regarding the safety of endoaortic balloon clamping in minimal access isolated mitral valve surgery (MIMVS). The aim of this European multicenter study was to analyze the results in 10 experienced centers and compare the outcomes with published data., Methods: The most recent 50 consecutive MIMVS cases from 10 European surgeons who had performed at least 100 procedures were prospectively collected and retrospectively analyzed. All procedures were performed through right minithoracotomy with femoral cannulation and endoaortic balloon occlusion. In-hospital and 30-day outcomes were studied. Mortality and stroke rates were compared with published median sternotomy and MIMVS outcomes., Results: Mean age was 63.2 ± 12.5 years, 289 (57.8%) were male, mean logistic European system for cardiac operative risk evaluation was 6.1 ± 6.2, and 53 (10.6%) procedures had cardiac reoperations. Concomitant procedures were performed in 126 (25.9%) cases. Three patients (0.6%) required conversion to full sternotomy. Ten patients (2.0%) necessitated endoaortic balloon clamping conversion (8 to external clamping), and re-exploration for bleeding was necessary in 24 (4.8%) cases. Mean aortic cross-clamp and cardiopulmonary bypass times were 85.6 ± 30.1 and 129.5 ± 40.2 min, respectively, and were significantly longer for concomitant procedures (p < 0.001). There were no aortic dissections and no deep venous thromboses. Operative mortality (none neurologic) and major stroke occurred in 7 (1.4%) and 4 (0.8%) patients, respectively. These rates compared favorably with the published literature on isolated primary mitral valve surgery (MVS) through sternotomy or minithoracotomy (mortality rates 0.2% to 11.6%, stroke rates 0.6% to 4.4%)., Conclusions: Once procedural proficiency is acquired, endoaortic balloon clamping in MIMVS is a safe and effective technique. Despite the fact that this patient cohort also includes combined and redo procedures, the observed mortality and stroke rate compared favorably with the existing literature on primary isolated mitral valve surgery irrespective of the approach., (Copyright © 2015 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Objective: Current interventional techniques rely heavily on operator familiarity with catheters and wires and on physician skills in effectively navigating through and managing target lesions. A novel robotic technology allows endovascular specialists to remotely control catheter tip deflection and advancement and to coordinate manipulation of currently available wires. The aim of this study was to successfully demonstrate feasibility and safety of navigation to and treatment of iliac and femoral artery lesions using Hansen Medical's vascular control catheter (VCC)., Methods: A total of 20 limbs were included in this analysis for a first-in-man trial of the VCC and vascular catheter control system. The local Institutional Review Board approved the trial, and all patients included had symptomatic femoropopliteal occlusive disease. Preoperative imaging was available on all patients. Target lesions in the contralateral superficial femoral artery ranged from mild stenosis to chronic total occlusions (TransAtlantic Inter-Society A through D). Exclusion criteria included previously treated iliac and femoral lesions in the symptomatic leg and a body mass index >35. The operators comprised three experienced interventionalists (two vascular surgeons and an interventional radiologist) and a novice (cardiac surgeon). The primary end point of the study was to demonstrate successful cannulation of the target vessel (ie, navigation to the lesion with wire and catheter) with the Hansen VCC, with no device-related serious adverse events. Secondary end points were to assess the ability to treat lesions using the flexible catheter defined by successful insertion of a guidewire, angiography of the target vessel, delivery of balloon, and/or stent. Procedure times and radiation delivered were analyzed for the group and by operator, and t-test was performed to determine statistical significance. Complications were assessed by clinical examination and ultrasound., Results: Lesions were successfully and safely cannulated in all limbs treated. The VCC performed as designed in all cases. All interventionalists, regardless of experience, navigated the VCC with ease. However, statistically significant differences in navigation time and radiation per case were observed between the experienced and inexperienced interventionalists. There were no access site complications (hematoma, thrombosis, pseudoaneurysm) as evaluated by ultrasound., Conclusions: This initial experience in flexible robotics demonstrates that this technology is both efficacious and safe in the arterial tree. Although robotics provides superior maneuverability compared with current techniques, endovascular experience is crucial to taking full advantage of the extra capabilities. Valuable future considerations will include off-the-wall (center lumen) navigation with three-dimensional imaging., (Copyright © 2013 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.)

Non-linear analyses of heart rate dynamics reveal subtle changes not evident from conventional heart rate variability measures. Traditionally, the information was inferred from 24-hour ECG recordings, making it less suitable for clinical application. Moreover, only few studies have attempted to evaluate the reliability of non-linear analyses in relation to varying proportion of artifacts in tracings. In 67 patients revascularized with beating-heart technique, fractal dimension and detrended fluctuation analyses were obtained from 24-hour Holter and 15-minute high-resolution ECG recordings pre and postoperatively. We found strong correlations of non-linear indices between 24-hour and 15-minute recordings (0.54-0.77, p<0.001), unaffected by proportion of artifacts.

For a satisfactory computer simulation, a model, which imitates a natural situation, is needed. The Human heart is an irregular 3D object and thus difficult to reproduce. Basic data was taken from Visible Human Dataset (VHD), National Library of Medicine. The heart area was cut out of the original cross-sections and different tissues segmented. All the slices also had to be aligned to assure precise overlapping of the structures. A 3D computer heart model with the resolution of 1mm was designed. The heart model was dedicated to simulations of heat transfer during heart surgery however, it is applicable also to other medical simulations.

Reduced cardiac vagal modulation increases propensity to arrhythmias. Right decubitus position is a vagal enhancer in coronary and congestive heart disease. We evaluated vagal modulation before and after coronary artery bypass grafting (CABG) in 30 patients. Heart rate variability (HRV) indexes in frequency domain were calculated from 10-min digital electrocardiograms. Kolmogorov-Smirnov and paired t-tests were applied, p<0.05 was considered significant. The HRV indexes decreased after CABG. Higher LF/HF ratio and shorter mean RR were observed in right recumbent position postoperatively. Right lateral decubitus position did not give rise to higher vagal modulation after heart surgery.

The protection of ventricular myocardium in aortic valve operations is always an issue because those hearts do not tolerate global ischemia well. A technique of aortic valve replacement is described involving continuous retrograde coronary sinus perfusion with warm oxygenated blood used in 34 patients to date without any complications. This technique maintains a beating heart throughout the procedure.

Topical cardiac cooling (TC) is often used in cardiac surgery. We used a computer simulation to study temperature changes in the heart, especially in the right ventricular wall. A three-dimensional computer heart model, derived from Visible Human Data set, National Library of Medicine was used. The model is made from cubes, with spatial resolution of 1mm. Explicit Finite Different method and temperature diffusion equation were used to calculate new temperatures. Three different simulations were performed and simulated temperatures were drawn on a cross-section of heart model in different colors. The results show that areas not immersed into TC solution are less protected against ischemia. It is important not to rely solely on topical cooling but use appropriate method of myocardial protection technique.

MECG measurements were performed using 35 electrodes in 10 patients operated with partial left ventriculectomy (PLV). Body surface ECG signals were recorded and five measurements were done: prior to PLV, second, third, fourth and fifth postoperative day. This work was concentrated on the following mapping methods: average isopotential ST segment maps (STM), QRS interval isointegral maps (QRM) and isochronal activation maps (IAM). STMs of the patients show a great positive area (elevation) over the anterior aspect of the heart and a great negative area (depression) over the lateral and posterior aspect of the heart before the operation. After the operation, the ST elevation over the anterior, lateral and posterior aspect of the heart was reduced. A substantial positive value over the excised area of the heart was present also on the end of the postoperative monitoring interval. Minimal and maximal values of the QRMs were smaller and also show some kind of normalisation. The area of the left ventricle, where PLV was performed, was carefully analysed for any changes of activation time for different heart regions. IAMs indicate that the start of the first activation was quite stable and in accordance with the position of the QRMs minimum.

Non-uniform recovery of excitability may be essential in triggering malignant ventricular tachycardia after cardiac surgery. Thirty-five channels ECG was recorded for 6 min in 27 patients before and after heart surgery and in 20 control subjects. Off-line analysis was performed. RR interval duration, RR SD, QT SD and power spectra of RR variability were computed from 256 s stable RR and QT interval series. When compared to controls, patients had decreased RR SD and increased QT SD before surgery (p<0.002 and p<0.0005, respectively); RR SD further decreased and QT SD increased after the surgery (p<0.0001 and p<0.0002, respectively). Increase of QT variability and decrease of RR variability after cardiac surgery may reflect disrupted electrophysiological stability of the myocardium and thus electrophysiological substrate for triggering malignant arrhythmia.

The right lateral body position has been proposed as an effective vagal enhancer. However, the possibility of breathing affecting heart rate power spectra in different body positions has not been assessed. The level of vagal modulation in various body positions in normal subjects was estimated by calculating heart rate power spectra. The results suggest that the levels of vagal modulation do not necessarily reflect a change due to assuming different body position, but might be the consequence of changed breathing patterns. Before adopting the right lateral body position as vagal enhancing, the contribution of varying breathing pattern should be eliminated.

We operated on a 34-year-old man with a metastatic tumor that extended from the tricuspid valve to the pulmonary valve and obstructed the right ventricle inflow and outflow tracts. The tumor was removed with preservation of the tricuspid valve. Additional chemotherapy was carried out according to the BEPO (etoposid, eisplatin, bleomycin, vincritin) scheme. Histology revealed metastasis of a choriocarcinoma originating from the right testis. Computed tomography performed after 6 months detected no metastases in the lungs. Magnetic resonance imaging showed a thickened right ventricle free wall and apex. The patient is doing well 18 months postoperatively.

Background: Between 1989 and 1997, 17 patients underwent surgery for excision of primary cardiac tumour at the Department for Cardiovascular Surgery in Ljubljana., Patients and Methods: There were 13 female (76.5%) and four male (23.5%) patients with an average age of 49+/-14 years (mean+/-SD). The study was retrospective. Special attention was paid to clinical presentation, method of diagnosis, elapsed time between the confirmed diagnosis and excision of the tumour, operatively determined location of tumour and post-operative course-diuresis in first 48 h, levels of CK and CK-MB, on first and on second day after operation and time of hospitalization., Results: Thirteen patients (76.5%) had cardiac symptoms at the time of presentation (dyspnoea, syncope, vertigo, palpitations) and four (23. 5%) had embolic complications. In all the patients diagnosis was made by echocardiography. Average elapsed time between the confirmed diagnosis and the operation was 26+/-40 (mean+/-SD) days. Histological examination revealed myxoma in 15 patients (88.2%), one patient had lipoma and one malignant haemangiosarcoma. The most common location of tumour was in the left atrium (12 patients; 70. 6%). Post-operative complications occurred in four patients (23.5%); 76.5% of patients had diuresis in the range between 0.8 and 2.0 ml/h/kg; there was no post-operative oligouric renal failure. Average levels of both CK and CK-MB were statistically significantly lower on the second day after operation, there was no case of peri-operative myocardial infarction and post-operative death did not occur. One patient with multiple myxoma had two recurrences., Conclusions: Symptoms in patients with heart tumours, especially at the beginning of illness, are often uncharacteristic. Due to the non-specific presentation of cardiac tumours, a high index of suspicion is needed. The diagnostic method of choice is echocardiography. Operative removal of tumour is a safe procedure and recurrences in patients with benign tumours are rare., (Copyright 1999 W.B. Saunders Company Ltd.)

In this work, three dimensional modelling and computer simulation of heat transfer on generally-shaped nonhomogeneous bodies is proposed and described. The complexity of the calculation is estimated and the potential use of high performance parallel computers is discussed. The method is focused on applications in medicine. As an example, a numerical algorithm for the parallel computer simulation of heart cooling procedures during surgery is presented. On the basis of simulated results, two different methods of cooling are compared.