Papillary Muscle Repositioning as a Subvalvular Apparatus Preservation Technique in Mitral Stenosis Patients With Normal Left Ventricular Systolic Function

Subvalvular apparatus preservation is an important concept in mitral valve replacement (MVR) surgery that is performed to remedy mitral regurgitation. In this study, we sought to determine the effects of papillary muscle repositioning (PMR) on clinical outcomes and echocardiographic left ventricular function in rheumatic mitral stenosis patients who had normal left ventricular systolic function. We prospectively assigned 115 patients who were scheduled for MVR surgery with mechanical prosthesis to either PMR or MVR-only groups. Functional class and echocardiographic variables were evaluated at baseline and at early and late postoperative follow-up examinations. All values were compared between the 2 groups. The PMR group consisted of 48 patients and the MVR-only group of 67 patients. The 2 groups’ baseline characteristics and surgery-related factors (including perioperative mortality) were similar. During the 18-month follow-up, all echocardiographic variables showed a consistent improvement in the PMR group; the mean left ventricular ejection fraction deteriorated significantly in the MVR-only group. Comparison during follow-up of the magnitude of longitudinal changes revealed that decreases in left ventricular end-diastolic and end-systolic diameters and in left ventricular sphericity indices, and increases in left ventricular ejection fractions, were significantly higher in the PMR group than in the MVR-only group. This study suggests that, in patients with rheumatic mitral stenosis and preserved left ventricular systolic function, the addition of papillary muscle repositioning to valve replacement with a mechanical prosthesis improves left ventricular dimensions, ejection fraction, and sphericity index at the 18-month follow-up with no substantial undesirable effect on the surgery-related factors

Effect of tandem lesions on hemodynamic parameters: an experimental study

WOS: 000424153600005PubMed ID: 28832097Background and aim: The morphology and extensity of the stenotic lesion is crucial as well as the obstruction ratio. It is well known that the complexity of lesion has direct impact on endovascular treatment (PTCA/stent), however; different arrangement of the lesions is underestimated and not well studied. We sought to evaluate the hemodynamic effects of different stenotic lesion models and arrangements in vitro Methods: Vascular circulation was simulated in vitro. Oxygenator, tubing set, polytetrahidroflouroethylene synthetic graft, pressure and flow rate sensors were used to build the simulation model. Measurements of isolated short, isolated long, identical stenotic tandem short, identical stenotic tandem long, sub-critical long and critical short lesion combination were performed and hemodynamic parameters were recorded. Results: Tandem lesions were more likely to result critical stenosis comparing single lesions with same obstruction ratio. This difference became more significant as the obstruction ratio was raised. Tandem long lesions were also resulted more critical stenosis than tandem short lesions. It can be claimed that tandem lesions can result more flow restriction with reference to single lesions with same stenotic ratio. Contrary to expectations, tandem short lesions were found more stenotic compared with the same degree long individual lesions. Conclusions: It is effortless to give decision for simple, discrete and individual lesions while ideal decision for long and complicated lesions may remain unclear. Even if these "gray zone" lesions considered non-critical while investigating them one by one, it must be kept in mind overall stenotic effect of these lesions may lead to a more hemodynamic impairment.Hitit University Faculty of Medicine Scientific Research Projects [TIP19002.14.002]The study was funded with the project number of TIP19002.14.002 under the coverage of Hitit University Faculty of Medicine Scientific Research Projects

Long-Term Protective Effects of Single-Dose Cardioplegic Solutions in Cell Culture Models

Despite the popularity of single-dose cardioplegic techniques, the time window and targeted population for successful reperfusion remain unclear. We tested currently available techniques based on cell viability and integrity to demonstrate long-term cardioprotection and clarify whether these solutions were performed on neonatal/adult endothelium and myocardium by examining different cell lines. Cell viability with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test proliferation assay and membrane integrity with the lactic dehydrogenase (LDH) cytotoxicity test were documented in a cell culture/microscopy setting on adult (human umbilical vein endothelium [HUVEC]), neonatal (H9C2-cardiomyocytes), and myofibroblast (L929) cell lines. Apoptotic cell activity and necrosis were evaluated by acridine orange/propidium iodide (AO/PI) staining. Twenty-four hours after seeding, cells were incubated in control (Dulbecco\u27s modified Eagle), St. Thomas and blood cardioplegia (4:1), histidine-tryptophan-ketoglutarate (HTK), and del Nido solutions at 32°C followed by an additional 6, 24, and 48 hours in standard conditions (37°C, 5% CO2). Experiments were repeated eight times. In MTT cell viability analysis, HTK protection was significantly better than the control medium in L929 cell lines at 48th hours follow-up and acted markedly better on the HUVEC cell line at 24th and 48th hours. del Nido and HTK provided significantly better protection on H9C2 (at 24th and 48th hours). Apoptotic and necrotic cell scoring as a result of AO/PI staining was found consistent with MTT results. The LDH test demonstrated that the level of cell disruption was significantly higher for St. Thomas and blood cardioplegia in H9c2 cells. Experimental studies on cardioplegia aimed at assessing myocardial protection use time-consuming and often expensive approaches that are unrealistic in clinical practice. We have focused on identifying the most effective cell types and the direct consequences of different cardioplegia solutions to document long-term effects that we believe are the most underestimated ones in the cardioplegia literature

Minimally Invasive Aortic Valve Replacement on Minimally Invasive Extracorporeal Circulation: Going beyond Aesthetics

We present our multidisciplinary and multistep strategy in patients undergoing minimally invasive aortic valve replacement (mAVR) on minimally invasive extracorporeal circulation (MiECC) compared with control groups of a single strategy and conventional techniques. This cohort study included high-risk patients (Society of Thoracic Surgeons [STS] risk score \u3e8%) undergoing aortic valve surgery under different strategies during the period from January 2017 until March 2019. Patients were matched for age, gender, body mass index, and STS score: group 1 (MiAVR) based on a minimally invasive technique with J-mini-sternotomy, rapid deployment valve (RDV), and type IV customized MiECC; group 2 (control-mAVR) consisted of minimally invasive technique with only J mini-sternotomy and RDV on a conventional extracorporeal system; group 3 (control-MiECC): full sternotomy and type IV customized MiECC; and group 4 (control): full sternotomy on a conventional extracorporeal system. The MiAVR group had significantly less duration of x-clamp time (35.4 ± 11 minutes), postoperative respiratory support (4.1 ± 1 hour), postoperative hemorrhage (250 ± 50 mL), and intensive care unit stay (1 ± .5 days) than the control-conventional (group 4) group. Seventy-six percent of patients did not receive any blood products in MiAVR (p = .025 vs. group 4). Incidence of atrial fibrillation (8%) and low cardiac output (14%) in MiAVR were significantly better than control. Critics of minimally invasive techniques sustain that potential advantages are offset by a longer cross-clamp and cardiopulmonary bypass duration, which may translate into inferior clinical outcomes. We advocate that our multidisciplinary approach supported by multiple technologies may be associated with faster recovery and superior outcomes than conventional minimally/conventional techniques