Open Chest Surgery Research Articles

Acute changes of global and longitudinal right ventricular function: an exploratory analysis in patients undergoing open-chest mitral valve surgery, percutaneous mitral valve repair and off-pump coronary artery bypass grafting

BackgroundRight ventricular (RV) function is an important prognostic indicator. The acute effects of cardiac interventions or cardiac surgery on global and longitudinal RV function are not entirely understood. In this study, acute changes of RV function during mitral valve surgery (MVS), percutaneous mitral valve repair (PMVR) and off-pump coronary artery bypass surgery (OPCAB) were investigated employing 3D echocardiography.MethodsTwenty patients scheduled for MVS, 23 patients scheduled for PMVR and 25 patients scheduled for OPCAB were included retrospectively if patients had received 3D transesophageal echocardiography before and immediately after MVS, PMVR or OPCAB, respectively. RV global and longitudinal function was assessed using a 3D multiparameter set consisting of global right ventricular ejection fraction (RVEF), tricuspid annular plane systolic excursion (TAPSE), longitudinal contribution to RVEF (RVEFlong) and free wall longitudinal strain (FWLS).ResultsLongitudinal RV function was significantly depressed immediately after MVS, as reflected by all parameters (RVEFlong: 20 ± 5% vs. 13 ± 6%, p < 0.001, TAPSE: 13.1 ± 5.1 mm vs. 11.0 ± 3.5 mm, p = 0.04 and FWLS: −20.1 ± 7.1% vs. -15.4 ± 5.1%, p < 0.001, respectively). The global RVEF was slightly impaired, but the difference did not reach significance (37 ± 13% vs. 32 ± 9%, p = 0.15). In the PMVR group, both global and longitudinal RV function parameters were unaltered, whereas the OPCAB group showed a slight reduction of RVEFlong only (18 ± 7% vs. 14 ± 5%, p < 0.01). RVEFlong yielded moderate case-to-case but good overall reproducibility.ConclusionsTAPSE, FWLS and RVEFlong reflect the depression of longitudinal compared to global RV function initially after MVS. PMVR alone had no impact, while OPCAB had a slight impact on longitudinal RV function. The prognostic implications of these phenomena remain unclear and require further investigation.

Two coronary artery aneurysms complicated by acute myocardial infarction and treated with open chest surgery.

Two coronary artery aneurysms complicated by acute myocardial infarction and treated with open chest surgery.

1-9HYPERTENSION AND ATRIAL VOLTAGES AT ATRIAL APPENDAGES

Background: Hypertension has been linked with alterations of atrial electrophysiology, which related to the substrate of atrial fibrillation. However, atrial voltages at atrial appendages and their relationship with hypertension remain undiscovered. The study aimed to investigate atrial voltages at both right and left atrial appendages (RAA and LAA) and their correlations with hypertension in patients with underlying heart disease. Materials &amp; Methods: Subjects with ischemic and/or valvular heart disease undergoing cardiac surgery at Erasmus Medical Center Rotterdam were included. After the heart was exposed during open chest surgery, high-resolution epicardial mapping of the LAA and the RAA during sinus rhythm was performed before starting cardiopulmonary bypass. Custom-made software was used to measure atrial voltages. A history of hypertension was obtained from the electronic medical record before undergoing surgery. Results: Among 133 patients undergoing cardiac surgery, 88 patients (66%) had hypertension. Atrial voltages at the LAA were higher in hypertensive patients compared to non-hypertensive patients (median = 5.36 vs 3.59 p &lt; 0.05), also a correlation between hypertension and atrial voltages at the LAA was identified (r = 0.247, p &lt; 0.05). On the other hand, atrial voltages at the RAA were comparable between hypertensive and non-hypertensive patients (median = 4.30 vs 3.96, p &gt; 0.05), without any correlation was found between hypertension and atrial voltages at the RAA. Conclusions: Atrial voltages at the LAA are higher compared to the RAA within hypertensive patients. Hypertension is also correlated with higher atrial voltages at the LAA. High atrial voltages at the LAA might be associated with structural changes of the LAA impacted by systemic hypertension.

The public health task force in the management of the Mycobacterium chimaera case in the Vicenza hospital, Italy

BACKGROUND Since 2013, an ongoing global outbreak of Mycobacterium chimaera among patients who underwent open-chest surgery has been recognized with all cases linked to contamination of a specific brand of heater-cooler device (HCD). Nine cases were diagnosed with disseminated M. chimaera infectionin our hospital. Following the first cases HCD was changed with different technology assuring no release of contaminated particles. The potentially at-risk population was managed throughout a multidisciplinary task force. METHODS In November 2018, following an infected patient’ death, a huge impact on public opinion was registered following mass media publicity of the case. A task force was built up to face the concern of the population: apress release [https://context.reverso.net/traduzione/inglese-italiano/press+release]and an official note were publicly released addressing risk factors and critical symptoms and a call center was activated. The notice was transmitted to general practitioners too. People complaining symptoms suggestive for infection, primarily screened by an expert group through telephone interview, were addressed to an infectious consultation. RESULTS The official note was delivered to 2181 potentially at risk patients chosen by cardio surgery registry and 567 of them called back the call center and were interviewed. 66 patients were judged to need infectious specialist consultation: 12 were submitted to further microbiological analysis and 4 required hospitalization. No new cases of infectious were detected. CONCLUSION The public health task force promptly activated granted safety measures for the population; furthermore HCD will soon be settled in separated place out from operating room.

Challenges in using anesthesia for open chest and aorta surgery in swine

Anesthesia for aorta surgery in pigs remains challenging due to the requirements for mechanical ventilation and the need for maintaining adequate homeostasis. We report an improved anesthesia protocol in an in vivo animal model to test a novel bacterial nanocellulose (BNC) within the ‘Kardio-BNC’ trial. Forty-four 6-month-old DanBred pigs comprising 6 males and 38 females (body weight ca. 82 kg) underwent implantation of pericardium reconstructive patches (n = 8), thoracic aorta prostheses (n = 15), or both procedures (n = 17) to test the biocompatibility of the novel BNC. The primary endpoint was 90-day survival, and the secondary outcome was death for any reason before reaching the study endpoint. Univariate analysis and linear regression were used to identify variables associated with premature mortality. Of the 44 pigs that underwent surgery, 10 (23%) were lost intra-operatively because of arrhythmia (n = 1), anesthesiological causes (n = 4), or surgical complications (n = 5). Modifications to tracheal intubation, tube fixation, temperature maintenance, and vascular catheterization increased the survival rate to 91% in the last quartile of the animals that underwent surgery. Of the 34 animals that survived surgery, n = 10 (29%) were lost post-operatively because of hematoma (n = 2), pneumothorax (n = 1), or infection (n = 7). Infection was associated with the type of surgery (highest prevalence in animals undergoing the combined procedure; p = 0.02), azaperone dose (p = 0.03), intra-operative heart rate variability (p = 0.03), and crystalloid transfusion (p = 0.04). The anesthesiological strategies and modifications to surgery described here allowed safe open chest and aorta surgery in up to 91% of the procedures performed

Efficacy of paravertebral block techniques in thoracic surgery

Introduction: Postoperative pain in thoracic surgery in adults is usually severe, and to control it there are many analgesic methods that include paravertebral blockade (PVB). Until now, there is no clarity on which is the most effective technique to perform this blockade. Objective: To describe the different PVB techniques and its analgesic effect in thoracic surgery. Methods: A systematic review of the literature was performed. We included studies that analyzed patients in open chest surgery and used PVB as analgesic technique. The Cochrane and Grading of Recommendation Assessment, Development and Evaluation strategies were used to analyze biases and evidence. The results are presented graphically by means of a visual analog scale (VAS) pain and opioid consumption equivalent to morphine for each technique found. We summarize the results with a qualitative approach without meta-analysis. Results: A total of 38 articles were analyzed (2188 patients). 13 using PVB guided by surface anatomy (SA-PVB), 7 Ultrasound-guided PVB (US-PVB), 1 neurostimulation guided PVB (NE-PVB) and the remaining using PVB performed under direct visualization by the surgeon (S-PVB). A VAS of less than 3 was found in studies with SA-PVB and US-PVB, and greater than 5 in studies with S-PVB; however, opioid consumption in the postoperative period was similar between the techniques described. Conclusion: PVB can be performed through 4 techniques. Techniques of US-PVB or SA-PVB have shown better consistency to manage postoperative acute pain in thoracic surgery.

Quantitative Efficacy and Fate of Mesenchymal Stromal Cells Targeted to Cardiac Sites by Radiofrequency Catheter Ablation

Engraftment and functional integration of stem cells or stem cell-derived cells within cardiac tissue is an important prerequisite for cell replacement therapy aiming at the treatment of heart disease. Recently, a novel intravenous approach for application of mesenchymal stromal cells (MSCs) to cardiac sites has been established using radiofrequency catheter ablation (RFCA)-guided targeting, bypassing the need for open chest surgery or direct myocardial cell injection. However, little is known about the quantitative efficacy and longevity of this strategy. We performed selective power-controlled RFCA with eight ablation pulses (30 W, 60 s each) to induce heat-mediated lesions at the right atrial appendices (RAAs) of pigs. Different concentrations of human bone marrow-derived MSCs (105 to 1.6 × 106 cells/kg bodyweight) labeled with superparamagnetic iron oxide (SPIO) particles were infused intravenously in nine pigs one d after RFCA treatment and hearts were explanted 8 d later to quantify the number of engrafted cells. Prussian blue staining revealed high numbers of SPIO-labeled cells in areas surrounding the RFCA-induced lesions. Cell numbers were evaluated by quantitative real-time polymerase chain reaction using specific primers for human MSCs (hMSCs), which indicated that up to 106 hMSCs, corresponding to ∼3.9% of the systemically applied human cells, engrafted within the RAAs of RFCA-treated pigs. Of note, infused hMSCs were observed in nontargeted organs, as well, but appeared at very low concentrations. To assess long-term deposition of MSCs, RAAs of three pigs were analyzed after 6 months, which revealed few persisting hMSCs at targeted sites. RFCA-mediated targeting of MSCs provides a novel minimal invasive strategy for cardiac stem cell engraftment. Qualitative and quantitative results of our large animal experiments indicate an efficient guidance of MSCs to selected cardiac regions, although only few cells remained at targeted sites 6 mo after cell transplantation.

Finite Element Analysis of a Novel Aortic Valve Stent.

Worldwide, one of the leading causes of death for patients with cardiovascular disease is aortic valve failure or insufficiency as a result of calcification and cardiovascular disease. The surgical treatment consists of repair or total replacement of the aortic valve. Artificial aortic valve implantation via a percutaneous or endovascular procedure is the minimally invasive alternative to open chest surgery, and the only option for high-risk or older patients. Due to the complex anatomical location between the left ventricle and the aorta, there are still engineering design optimization challenges which influence the long-term durability of the valve. In this study we developed a computer model and performed a numerical analysis of an original self-expanding stent for transcatheter aortic valve in order to optimize its design and materials. The study demonstrates the current valve design could be a good alternative to the existing commercially available valve devices.

Safety and effectiveness of a transaortic approach for TAVI: procedural and midterm outcomes of 265 consecutive patients in a single centre.

Transcatheter aortic valve implantation with a transaortic approach (TAo-TAVI) is an alternative to transapical or femoral access. We studied the procedural and midterm efficacy and safety of TAo-TAVI with Edwards Sapien XT and Medtronic CoreValve devices. Among 901 patients receiving TAVI since 2006, 265 consecutive patients underwent TAo-TAVI between January 2011 and September 2014. Procedural and midterm results were evaluated according to Valve Academic Research Consortium-2 criteria. The mean age was 83 ± 5 years. Sapien XT and CoreValve were used in 191 (72.1%) and 74 (27.9%) patients, respectively. Full sternotomy made elective concomitant off-pump coronary artery bypass grafting possible in 38 patients (14.3%) with severe coronary artery disease unsuitable for percutaneous coronary intervention. The device success rate was 95.5%. Postprocedural paravalvular leak ≥2/4 was observed in 16 patients (6.4%). Emergency open chest surgery was required in 10 patients (3.8%) (3 aortic dissections, 3 valve embolizations, 2 LMCA occlusions, 1 aortic annulus rupture and 1 aortic rupture). Cerebrovascular accidents occurred in 3 patients (1.1%). Transfusions ≥4 units were required in 36 patients (13.6%). New pacemakers were implanted in 26 patients (9.8%). Thirty-day and 1-year mortality were 8.7% and 16.2%, respectively. Mean follow-up duration was 24 ± 6 months. At 3 years, freedom from all-cause death was 80% ± 4%. New York Heart Association class <III included 81% (n = 172) of patients alive and without prosthetic echocardiographic dysfunction at follow-up (mean gradient 10.5 ± 5.6 mmHg). The TAo-TAVI approach confirms its safety and effectiveness with satisfactory procedural and midterm outcomes with both currently available devices.

Invasive Hemodynamic Assessment for the Right Ventricular System and Hypoxia-Induced Pulmonary Arterial Hypertension in Mice.

Pulmonary arterial hypertension (PAH) is a chronic and severe cardiopulmonary disorder. Mice are a popular animal model used to mimic this disease. However, the evaluation of right ventricular pressure (RVP) and pulmonary artery pressure (PAP) remains technically challenging in mice. RVP and PAP are more difficult to measure than left ventricular pressure because of the anatomical differences between the left and right heart systems. In this paper, we describe a stable right heart hemodynamic measurement method and its validation using healthy and PAH mice. This method is based on open-chest surgery and mechanical ventilation support. It is a complicated procedure compared to closed chest procedures. While a well-trained surgeon is required for this surgery, the advantage of this procedure is that it can generate both RVP and PAP parameters at the same time, so it is a preferable procedure for the evaluation of PAH models.

Reduction of turnaround time for non-tuberculous mycobacteria detection in heater–cooler units by propidium monoazide–real-time polymerase chain reaction

Invasive non-tuberculous mycobacteria (NTM) infections are emerging worldwide in patients undergoing open-chest cardiac bypass surgery exposed to contaminated heater-cooler units (HCUs). Although this outbreak has been investigated by culturing bacteria isolated from HCU aerosol and water samples, these conventional methods have low-analytic sensitivity, high rates of sample contamination, and long turnaround time. To develop a simple and effective method to detect NTM in HCUs by real-time polymerase chain reaction (PCR), with a short laboratory turnaround time and reliable culture results. A total of 281 water samples collected from various HCUs at seven Italian hospitals were simultaneously screened for NTM by a propidium monoazide (PMA)-PCR assay and by conventional culture testing. The results were analysed with culture testing as the reference method. (i) The agreement between culture testing and PMA-PCR was 85.0% with a cycle threshold (CT) cut-off value of <38 vs 80.0% with a CT of <43, with a moderate Cohen's κ-coefficient; (ii) the CT cut-off value of <42 was deemed more suitable for predicting positive specimens; (iii) given the low concentration of target DNA in water samples, the minimum volume to be tested was 1 L. The use of PMA-PCR for fast detection of NTM from environmental samples is highly recommended in order to ascertain whether HCUs may represent a potential source of human exposure to NTM. This reliable and simple method reduces laboratory turnaround time compared to conventional methods (one to two days vs eight weeks, respectively), thereby improving control strategies and effective management of HCUs.

3050Non valvular atrial fibrillation, contraindication to anticoagulation or antiplatelet therapy and heart team approach: a single centre experience

Abstract Introduction Left atrial appendage is the source of more than 90% of thrombi in patients with atrial fibrillation (AF). Protect-AF and Prevail trials have tested the non inferiority of left appendage percutaneous closure to warfarin for stroke prevention but contraindication to anticoagulation was an exclusion criteria for enrollment. On the surgical side recent studies have shown the efficacy of left appendage exclusion concomitant to open chest cardiac surgery or totally thoracoscopic Maze. In these studies all patients were on anticoagulation or antiplatelet regime at discharge and follow up. Here we give our contribute to the issue of safety and efficacy of stand alone totally thoracoscopic left appendage clipping for non valvular AF related stroke prevention in patients with contraindication to oral anticoagulant or antiplatelet therapy. Materials and methods 20 patients with non valvular AF and cerebral hemorrhages (16 males, patients age range 53–87, CHAD-VASC range 4–8, HASBLED range 4–7), underwent stand alone totally thoracoscopic appendage exclusion with a clipping device. All patients, after Heart Team evaluation, were screened preoperatively with 3D CT scan, transesophageal echocardiography and cerebrovascular doppler ultrasound. Intraoperative device positioning and atrial appendage exclusion were guided and confirmed by transesophageal echo. All patients were not on anticoagulation nor antiplatelet therapy from the time of surgery to the control visit. Follow up (range 6–21 months) included outpatient visit, CT scan or TEE. Perioperative mortality and early and late morbidity were analyzed by chart evaluation and full outpatient neurological examination including the Questionnaire for Verifying Stroke Free Status. Results Mean duration of surgery “skin to skin” was 62 minutes; all patients were extubated shortly after the procedure. There were no deaths or pulmonary procedure related morbidities, only one case of pericarditis treated with colchicine was documented. On CT or TEE follow up 100% of patients had complete exclusion of the left appendage with residual stumps less than 1 cm and no dislodgement of the clip detected. Freedom from neurological events in all patients was documented in absence of anticoagulation or antiplatelet regime from the time of surgery to the time of the follow up visit. Conclusion Totally thoracoscopic left appendage exclusion is a safe, expeditous and effective procedure in preventing non valvular AF related strokes in patients with contraindication to oral anticoagulation or antiplatelet therapy. The efficacy of the procedure is comparable to open chest surgery and this procedure may be considered as valid therapeutic option in patients at high risk of hemorrhage if on anticoagulant or antiplatelet therapy. Clearly further data, longer follow up and possibly an European registry are needed to confirm this preliminary results.

P1865Incidence and predictors of invasively-treated pericardial effusion during catheter ablation of atrial fibrillation in Japan

Abstract Purpose and method Japanese Heart Rhythm Society requested electrophysiology centers to register the data of patients who underwent catheter ablation for atrial fibrillation (AF) in designated eight months from 2011 to 2017. We assessed the incidence and predictors of pericardial effusion (PE) as an early complication of AF ablation. Results More than two hundred EP centers reported the data of 13,233 AF ablation cases (age; 64.2±10.7 years, male; 72.6%, paroxysmal AF; 63.4%). Clinically significant complications occurred in 601 subjects (4.5%). Critical PE occurred in 116 patients (0.8%), while six of them required open-chest surgery. Overall complication rate did not show significant changes. In contrast, incidence of PE declined over time (2012:1.2%, 2017:0.5%, p=0.003). Multiple logistic regression analysis showed that seven factors were related with higher incidence of PE. Among these factors, primary extra-PV ablation and hypertrophic cardiomyopathy (HCM) were more remarkably associated with higher rate of PE (PVI[−] vs. PVI[+]= 9.0% vs. 0.8%, OR 12.3, p&lt;0.001; HCM: [+] vs. [−] = 2.6% vs. 0.8%, OR 3.26, p=0.001). Comorbidity of coronary artery disease (CAD) and use of CARTO system were related with lower PE rate (CAD: [+] vs [−] = 0.2% vs. 0.9%, OR 0.22 [p=0.034], CARTO: [+] vs [−] = 0.7% vs. 1.2%, OR 0.52 [p=0.001]). None of cryobaloon ablation, gender, type of AF, center volume, periprocedural oral anticoagulant, or left atrial diameter was significantly related with the occurrence of PE. Conclusions Incidence of critical PE decreased recently. HCM and primary extra-PV ablation were outstanding predictors of critical PE.

Effects of combined ultrasound-guided erector spinae plane block and patient controlled intravenous analgesia on postoperative pain in patients undergoing radical resection of esophageal carcinoma

Objective To observe the effects of one time erector spinae plane block (ESPB) combined with patient controlled intravenous analgesia(PCIA) on postoperative pain and satisfactory extent of patients undergoing radical resection of esophageal carcinoma by thoracotomy operation. Methods Forty patients[20 males and 20 females, American Society of Anesthesiologists (ASA) status Ⅰ or Ⅱ], scheduled for radical resection of esophageal carcinoma by open chest surgery, were randomly assigned into two groups: ESPB combined with PCIA group(group EP) and PCIA only group (group IA). ESPB was performed in group EP before anesthesia induction. The effect was evaluated by detecting the area of block after 20 min. The patients in both group used PCIA after surgery. Visual Analogue Scale (VAS) scores were recorded at 1, 6, 12, 24 h and 48 h after operation both in the resting and the coughing state. The times of pressing analgesic pump, the total volume of analgesic drugs infused by analgesic pump, the frequency and extent of adverse reaction and satisfactory extent of patients were recorded as well. Results Twenty min after EPSB, pain sense of patients in group EP was successfully blocked in the skin area innervated by spinal nerve between T3 to T9. The VAS scores both at rest and during coughing in group EP were lower than those in group IA(P<0.05). The times of pressing analgesic pump and the volume of infused analgesic drugs were significantly less in group EP than the times and volume in group IA (P<0.05). Meanwhile, the frequencies of nausea and vomiting in group EP were significantly lower than those in group IA (P<0.05). Also, the degree of satisfaction in group EP was significantly higher than the degree in group IA(P<0.05). Conclusions For radical resection of esophageal carcinoma by thoracotomy, ESPB combined with PCIA is a more effective method for postoperative analgesia than PCIA only. Also, the gross satisfactory extent is significantly higher in group EP than that in group IA. Less adverse effects were observed in patients of group EP. Key words: Erector spinae plane block; Patient controlled intravenous analgesia; Radical resection of esophageal carcinoma; Analgesic effect; Degree of satisfaction

Application of transesophageal ultrasound-guided minimally invasive surgical closure for congenital heart disease

The clinical data of 31 patients with congenital heart disease (CHD) receiving minimally invasive surgical closure through chest or femoral venous catheter from June 2016 to September 2017 were analyzed retrospectively. All patients were diagnosed with esophageal echocardiography before operation. During the operation, the insert of guide wire and the sheath tube, and the placement of the sealing parasol were monitored and guided by transesophageal echocardiography (TEE). Satisfactory results were obtained in 30 patients. In 1 patients, the sealing parasol was detached, and open chest surgery was performed to remove the detached parasol and to repair the defect. TEE-guided minimally invasive surgical closure through chest or femoral vein catheter is safe and effective in the treatment of congenital heart disease and has certain clinical applicative value. Key words: Surgical; Congenital heart disease; Minimally invasive block; Transesophageal echocardiography

Optimal timing of video-assisted thoracoscopic surgery for patent ductus arteriosus in preterm infants born at≤28weeks of gestation.

Video-assisted thoracoscopic surgery for patent ductus arteriosus (VATS-PDA) is an alternative surgical procedure to open chest surgery, even in premature infants. This study investigated whether the timing of VATS-PDA has a prognostic impact in premature infants whose operative indication was determined according to the symptomatic PDA and the ineffectiveness of or contraindication to indomethacine therapy. We studied 49 infants born at or before 28weeks of gestation who were admitted to the neonatal intensive care unit between January 2004 and June 2016, and who underwent VATS-PDA. The patients were divided into two groups according to median age at the time of surgery (early group, 24 infants who underwent surgery at≤24days of life; late group, 25 infants who underwent surgery at≥25days of life). No significant differences were found in bodyweight at 30days of age and 40weeks of corrected gestational age between the groups. The timing of surgery did not affect the operative procedure or postoperative complications. In addition, no differences were observed between the early and late groups in terms of complications associated with prematurity, including intraventricular hemorrhage, incidence and severity of bronchopulmonary dysplasia, and necrotizing enteropathy. Video-assisted thoracoscopic surgery for patent ductus arteriosus can be safely performed in premature infants without a preferential timing for the intervention, suggesting that this procedure allows for an elective basis approach after heart failure management with conservative and/or drug therapy in premature infants with PDA.

Myocardial hypothermia increases autophagic flux, mitochondrial mass and myocardial function after ischemia-reperfusion injury

Animal studies have demonstrated beneficial effects of therapeutic hypothermia on myocardial function, yet exact mechanisms remain unclear. Impaired autophagy leads to heart failure and mitophagy is important for mitigating ischemia/reperfusion injury. This study aims to investigate whether the beneficial effects of therapeutic hypothermia are due to preserved autophagy and mitophagy. Under general anesthesia, the left anterior descending coronary artery of 19 female farm pigs was occluded for 90 minutes with consecutive reperfusion. 30 minutes after reperfusion, we performed pericardial irrigation with warm or cold saline for 60 minutes. Myocardial tissue analysis was performed one and four weeks after infarction. Therapeutic hypothermia induced a significant increase in autophagic flux, mitophagy, mitochondrial mass and function in the myocardium after infarction. Cell stress, apoptosis, inflammation as well as fibrosis were reduced, with significant preservation of systolic and diastolic function four weeks post infarction. We found similar biochemical changes in human samples undergoing open chest surgery under hypothermic conditions when compared to the warm. These results suggest that autophagic flux and mitophagy are important mechanisms implicated in cardiomyocyte recovery after myocardial infarction under hypothermic conditions. New therapeutic strategies targeting these pathways directly could lead to improvements in prevention of heart failure.

Mitral Valve Pathology.

This review describes numerous pathologic entities that cause structural abnormalities of the mitral valve. Different pathologic entities involve different components of the so-called mitral apparatus: atrial wall, annulus, leaflets, chordae, papillary muscles, and/or left ventricular free wall. These abnormalities can cause valvular stenosis, regurgitation, or both. Currently, in addition to open-chest surgery to replace or repair the damaged mitral valve, there are less invasive percutaneous approaches to address mitral valve dysfunction. These include narrowing the orifice, clipping the leaflets, and inserting bioprostheses percutaneously. Understanding the structural abnormalities discussed in this review is essential for choosing the optimal therapeutic intervention for mitral valve disease.

Epidemiology, Clinical Presentation, Diagnosis and Treatment of Infections Caused by Mycobacterium chimaera

The recognition, correct diagnosis and adequate clinical management of infections caused by atypical mycobacteria are challenging tasks in clinical practice. Invasive infections caused by Mycobacterium chimaera, a member of the Mycobacterium avium-intracellulare complex, have been increasingly reported over the past few years. Most infections occurred in patients who had undergone open-chest cardiothoracic surgery. Epidemiological and molecular studies showed that transmission of M. chimaera occurred through intraoperative aerosols derived from contaminated heater-cooler units, i. e. devices that are used to enable the extracardiac circuit in cardiothoracic surgery. Thus far, approximately 120 patient cases have been reported worldwide. The latency between exposure and onset of clinical symptoms may comprise several years. Clinical manifestations of M. chimaera infections include not only endocarditis and implant-associated infections, but also non-cardiac entities such as sarcoidosis-like symptoms, vertebral osteomyelitis and chorioretinitis. The pathogen can be detected in blood culture vials and in surgically obtained specimens from affected tissues, if specific microbiological tests for detection of mycobacteria are employed. There are no simple-to-use screening tests and a high clinical index of suspicion is thus mandatory in patients with previous exposure and compatible signs and symptoms. The successful treatment of M. chimaera infections requires the removal of infected devices and prolonged combination therapy with antimycobacterial drugs. This review summarises the clinical relevance, epidemiology, symptomatology, diagnosis and treatment of infections caused by M. chimaera, with a specific focus on pneumological aspects.

Minimally invasive percutaneous epicardial placement of a prototype miniature pacemaker with a leadlet under direct visualization: A feasibility study in an infant porcine model

Pacemaker implantation in infants is limited to epicardial lead placement and an abdominal generator pocket. We propose a minimally invasive solution using a prototype miniature pacemaker with a steroid-eluting leadlet that can affix against the epicardium under thoracoscopy. The purpose of this study was to evaluate the safety and feasibility of acute implantation of a prototype miniature pacemaker in an infant porcine model. A self-anchoring 2-channel access port was inserted into a 1-cm incision left of the subxiphoid space. A rigid thoracoscope with variable viewing angle was inserted through the main channel to visualize the heart under insufflation. An 18-G needle through the second channel accessed the pericardial space, which was secured with a 7-F sheath. The leadlet was affixed against the epicardium using a distal helical side-biting electrode. The sheath, thoracoscope, and port were removed, and the pacemaker was tucked into the incision. Ventricular sensing, lead impedances, and capture thresholds were measured. Twelve piglets (weight 4.8 ± 1.9 kg) had successful device implantation. The median time from incision to leadlet fixation was 21 minutes (interquartile range [IQR] 18-31 minutes). The median lead impedance was 510 Ω (IQR 495-620 Ω). The median R-wave amplitude was 5.7 mV (IQR 4.2-7.0 mV). The median capture threshold was 1.63 V (IQR 1.32-2.97 V) at 0.4 ms pulse width and 1.50 V (IQR 1.16-2.38 V) at 1.0 ms pulse width. There were no complications. Minimally invasive epicardial placement of a prototype miniature pacemaker under thoracoscopy was safe and avoided open chest surgery and creation of an abdominal generator pocket.