Right anterior mini thoracotomy for redo cardiac surgery: case series from North America and Europe.

Background: Right anterior mini thoracotomy (RAMT) for aortic valve replacement (AVR) is a minimally invasive procedure that avoids sternotomy. Herein, we report the outcomes of patients who underwent redo-cardiac via a RAMT approach for AVR. Methods: This case series reports the clinical outcomes of 14 consecutive redo operations, done in Calgary (Canada) and Gdansk (Poland) between 2020 and 2023. Primary outcomes were 30-day mortality and disabling stroke. Secondary outcomes included surgical times, hemodynamics, permanent pacemaker implantation (PPM), length of ICU and hospital stay, new post-operative atrial fibrillation (POAF), post-operative blood transfusion, incidence of acute respiratory distress syndrome (ARDS), rate of continuous renal replacement therapy (CRRT) and/or dialysis, and chest tube output in the first 12-hours after surgery. Results: Nine patients were male, and the mean age was 64.36 years. There were no deaths, while one patient had a disabling stroke postoperatively. Mean cardiopulmonary bypass and cross clamp-times were 136 min and 90 min, respectively. Three patients needed a PPM, 3 patients needed blood transfusions, and 2 developed new onset POAF. Median lengths of ICU and hospital stays were 2 and 12 days, respectively. There was no incidence of paravalvular leak greater than trace and the average transvalvular mean gradient was 12.23 mmHg. Conclusion: The number of patients requiring redo-AVR is increasing. Redo-sternotomy may not be feasible for many patients. This study suggests that the RAMT approach is a safe alternative to redo-sternotomy for patients that require an AVR.

Pericardial fluid troponin in cardiac surgery.

BACKGROUND AND OBJECTIVE: Pericardial Fluid (PF) is a rich reservoir of biologically active factors. Due to its proximity to the heart, the biochemical structure of PF may reflect the pathological changes in the cardiac interstitial environment. This manuscript aimed to determine whether the PF level of cardiac troponins changes in patients undergoing cardiac surgery. METHODS: This scoping review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Medline, EMBASE, Cochrane, ClinicalTrials.gov, and Google Scholar databases were electronically searched for primary studies using the keywords "pericardial fluid," "troponin," and "cardiac surgery." The primary outcome of interest was changes in troponin levels within the PF preoperatively and postoperatively. Secondary outcomes of interest included comparisons between troponin level changes in the PF compared to plasma. RESULTS: A total of 2901 manuscripts were screened through a title and abstract stage by two independent blinded reviewers. Of those, 2894 studies were excluded, and the remaining seven studies underwent a full-text review. Studies were excluded if they did not provide data or failed to meet inclusion criteria. Ultimately, six articles were included that discussed cardiac troponin levels within the PF in patients who had undergone cardiac surgery. Pericardial troponin concentration increased over time after surgery, and levels were significantly higher in PF compared to serum. All studies found that the type of operation did not affect these overall observations. CONCLUSION: Our review of the literature suggest that the PF level of cardiac troponins increases in patients undergoing cardiac surgery, irrespective of the procedure type. However, these changes' exact pattern and clinical significance remain undefined.

Cellular and molecular mechanisms driving cardiac tissue fibrosis: On the precipice of personalized and precision medicine.

Cardiac fibrosis is a significant contributor to heart failure, a condition that continues to affect a growing number of patients worldwide. Various cardiovascular comorbidities can exacerbate cardiac fibrosis. While fibroblasts are believed to be the primary cell type underlying fibrosis, recent and emerging data suggest that other cell types can also potentiate or expedite fibrotic processes. Over the past few decades, clinicians have developed therapeutics that can blunt the development and progression of cardiac fibrosis. While these strategies have yielded positive results, overall clinical outcomes for patients suffering from heart failure continue to be dire. Herein, we overview the molecular and cellular mechanisms underlying cardiac tissue fibrosis. To do so, we establish the known mechanisms that drive fibrosis in the heart, outline the diagnostic tools available, and summarize the treatment options used in contemporary clinical practice. Finally, we underscore the critical role the immune microenvironment plays in the pathogenesis of cardiac fibrosis.

The Perceval Sutureless Bioprosthetic Aortic Valve: Evolution of Surgical Valve Technology.

OBJECTIVE: The surgical treatment of aortic stenosis continues to evolve, and sutureless aortic valve replacement (SUAVR) is an emerging technology. With the Perceval S (Corcym, London, UK) as the only true sutureless valve on the market, the objective of this review is to analyze the current literature on Perceval S. Focusing on valve design and deployment as well as applications of the technology for challenging pathology, clinical outcomes are assessed, including a comparison with transcatheter AVR (TAVR). METHODS: PubMed and MEDLINE were searched by 3 authors for studies analyzing SUAVR from inception to May 19, 2023. RESULTS: SUAVR facilitates minimally invasive surgery and offers an alternative strategy for patients with small aortic annuli. It also has a time-saving advantage for patients who require complex operations. SUAVR results in excellent long-term morbidity, mortality, durability, and hemodynamic function. In comparison with conventional surgical AVR (SAVR), SUAVR does have a greater risk of postoperative pacemaker implantation; however, increasing user experience and refinements in implantation technique have contributed to reductions in this outcome. SUAVR results in morbidity and mortality that is similar to rapid-deployment AVR. Midterm outcomes are superior to TAVR; however, further robust investigation into all of these comparisons is ultimately necessary. CONCLUSIONS: SUAVR bridges the gap in technology between SAVR and TAVR. The application of this exciting technology will undoubtedly grow in the coming years, during which additional investigation is paramount to optimize preoperative planning, valve deployment, and reintervention strategies.

Innovations in Aortic Valve Replacement: A Comprehensive Overview of the Intuity Rapid Deployment Valve.

Rapid deployment/sutureless (RDS) valves have recently emerged as an innovative surgical solution, providing an alternative to traditional methods of surgical aortic valve replacement (SAVR) by eliminating the need for suture placement and tying. This innovation leads to a reduction in aortic crossclamp and cardiopulmonary bypass times, enhancing the efficiency of the procedure. Among the 2 available RDS valves, the Edwards Intuity valve in particular has been demonstrated to be a particularly promising substitute in the field of SAVR. The Intuity valve distinguishes itself from other RDS and conventional valves by yielding superior outcomes, such as a significant reduction in mortality, increase in the longevity of the valve, and a marked decrease in both mean and peak transvalvular pressure gradients. These benefits collectively contribute to its appeal as a favorable new solution. However, further investigation is needed to conclusively determine the long-term outcomes and safety of RDS valves. Nevertheless, the utilization of the Intuity valve presents an exciting solution to the existing limitations of conventional and minimally invasive SAVR, especially for patients afflicted with severe aortic stenosis.

Natriuretic Peptide Receptor B Protects Against Atrial Fibrillation by Controlling Atrial cAMP Via Phosphodiesterase 2.

BACKGROUND: ß-AR (ß-adrenergic receptor) stimulation regulates atrial electrophysiology and Ca2+ homeostasis via cAMP-dependent mechanisms; however, enhanced ß-AR signaling can promote atrial fibrillation (AF). CNP (C-type natriuretic peptide) can also regulate atrial electrophysiology through the activation of NPR-B (natriuretic peptide receptor B) and cGMP-dependent signaling. Nevertheless, the role of NPR-B in regulating atrial electrophysiology, Ca2+ homeostasis, and atrial arrhythmogenesis is incompletely understood. METHODS: Studies were performed using atrial samples from human patients with AF or sinus rhythm and in wild-type and NPR-B-deficient (NPR-B+/-) mice. Studies were conducted in anesthetized mice by intracardiac electrophysiology, in isolated mouse atrial preparations using high-resolution optical mapping, in isolated mouse and human atrial myocytes using patch-clamping and Ca2+ imaging, and in mouse and human atrial tissues using molecular biology. RESULTS: Atrial NPR-B protein levels were reduced in patients with AF, and NPR-B+/- mice were more susceptible to AF. Atrial cGMP levels and PDE2 (phosphodiesterase 2) activity were reduced in NPR-B+/- mice leading to larger increases in atrial cAMP in the presence of the ß-AR agonist isoproterenol. NPR-B+/- mice displayed larger increases in action potential duration and L-type Ca2+ current in the presence of isoproterenol. This resulted in the occurrence of spontaneous sarcoplasmic reticulum Ca2+ release events and delayed afterdepolarizations in NPR-B+/- atrial myocytes. Phosphorylation of the RyR2 (ryanodine receptor) and phospholamban was increased in NPR-B+/- atria in the presence of isoproterenol compared with the wildtypes. C-type natriuretic peptide inhibited isoproterenol-stimulated L-type Ca2+ current through PDE2 in mouse and human atrial myocytes. CONCLUSIONS: NPR-B protects against AF by preventing enhanced atrial responses to ß-adrenergic receptor agonists.

The rare case of double valve surgery in a patient with factor VII deficiency.

Performing cardiac surgery on patients with bleeding diatheses poses significant challenges since these patients are at an increased risk for complications secondary to excessive bleeding. Despite its rarity, patients with factor VII (FVII) deficiency may require invasive procedures such as cardiac surgery. However, we lack guidelines on their pre-, peri-, and post-operative management. As FVII deficiency is rare, it seems unlikely to design and learn from large clinical studies. Instead, we need to base our clinical decision-making on single reported cases and registry data. Herein, we present the rare case of a patient with FVII deficiency who underwent double valve surgery. Pre-operatively, activated recombinant FVII (rFVIIa) was administered to reduce the risk of bleeding. Nevertheless, the patient experienced major bleeding. This case highlights the significance of FVII deficiency in patients undergoing cardiac surgery and emphasizes the importance of adequate and appropriate transfusion of blood products for these patients.

Inferior vena cava tumor thrombus: clinical outcomes at a canadian tertiary center.

OBJECTIVE: This study reports the surgical management and outcomes of patients with malignancies affecting the IVC. METHODS: This was a retrospective study that considered patients undergoing surgery for IVC thrombectomy in Calgary, Canada, from 1 January 2010 to 31 December 2021. Parameters of interest included primary malignancy, the extent of IVC involvement, surgical strategy, and medium-term outcomes. RESULTS: Six patients underwent surgical intervention for malignancies that affected the IVC. One patient had a retroperitoneal leiomyosarcoma, 1 had hepatocellular carcinoma with thrombus extending into the IVC and right atrium, 1 had adrenocortical carcinoma with IVC thrombus extending into the right atrium, and 3 had clear cell renal cell carcinoma with thrombus extending into the IVC. Surgical strategy for the IVC thrombectomy varied where 5 patients required the institution of cardiopulmonary bypass and underwent deep hypothermic circulatory arrest. No patient died perioperatively. One patient died 15-months post-operatively from aggressive malignancy. CONCLUSION: Different types of malignancy can affect the IVC and surgical intervention is usually indicated for these patients. Herein, we have reported the outcomes of IVC thrombectomy at our center.

An international survey-based assessment of minimally invasive mitral valve surgery.

OBJECTIVES: Minimally invasive mitral valve surgery (MIMVS) has been shown to be safe and feasible however its adoption has lagged globally. The international consortium is lacking a set of guidelines that are specific to MIMVS. The aim of this study was to capture the practices of MIMVS in different centres. METHODS: A survey was constructed containing 52 multiple-choice and open-ended questions about various aspects of MIMVS. The survey was sent to centres that routinely and frequently perform MIMVS. All surgeons provided informed consent for participating in the survey and publication of data. RESULTS: The survey was sent to 75 known surgeons from whom 32 (42%) completed the survey. All survey responders performed >25 MIMVS cases annually. Twenty (68%) of the surgeons thought that simulation training, MIMVS fellowship and proctorship are all essential prior to commencing an MIMVS program. Eleven (34%) of the surgeons stated that 50-100 MIMVS cases are required to overcome the learning curve, followed by 6 (18%) who said 21-30 cases should suffice. Eighteen (62%) of the surgeons had adopted a fully endoscopic approach for their MIMVS, followed by 15 (51%) surgeons who had performed cases via endoscopic-assisted strategies, 5 (17%) surgeons had conducted the operation under direct visualization and 6 (20%) surgeons had used a robot for their MIMVS. CONCLUSIONS: The study highlights a marked variability on training and approach to MIMVS. Consensus guidelines should be established to allow standardization of MIMVS.

Echocardiographic and clinical outcomes following beating heart NeoChord DS1000 mitral valve repair: a single centre case series.

Background: The NeoChord DS1000 system implants artificial neochords transapically, through a left mini-thoracotomy to treat degenerative mitral valve regurgitation (MR). Performed without cardiopulmonary bypass, neochord implantation and length adjustment is guided by transesophageal echocardiography. We describe imaging and clinical outcomes for a single center case series using this innovative device platform. Methods: In this prospective series, all study patients had degenerative MR and were considered for conventional mitral valve surgery. Moderate to high-risk candidates were screened for NeoChord DS1000 eligibility based on echocardiographic criteria. Study criteria included isolated posterior leaflet prolapse, leaflet-to-annulus index greater than 1.2, and coaptation length index greater than 5 mm. Patients with bileaflet prolapse, mitral annular calcification, and ischemic MR were excluded from our early experience. Results: Ten patients underwent the procedure, including 6 males and 4 females, with a mean age of 76 ± 9.5 years. All patients had severe chronic MR and normal left ventricular function. One patient required conversion to an open procedure for failure to deploy neochords with the device transapically. The median number of NeoChord sets was 3 (IQR 2.3-3.8). Immediate post-procedure (POD#0) degree of MR on echocardiography ranged from mild or less, and on postoperative day 1 (POD#1) from moderate or less. Average length of coaptation was 0.85 ± 0.21 cm and average depth of coaptation was 0.72 ± 0.15 cm. At 1-month follow-up echocardiography, MR was graded from trivial to moderate and left ventricular inner diameter dimensions decreased from an average of 5.4 ± 0.4 cm to 4.6 ± 0.3 cm. None of the patients who had successful NeoChord implantation required blood products. There was 1 perioperative stroke with no residual deficits. There were no device-related complications or serious adverse events. The median length of hospital stay was 3 (IQR 2.3-10) days. 30-day and 6-weeks postoperative mortality and readmission rates were 0%. Conclusion: We report the first Canadian case series using the NeoChord DS1000 system for off-pump, transapical, beating heart mitral valve repair, through a left mini-thoracotomy. The early surgical outcomes suggest this approach is feasible, safe, and effective in reducing MR. This novel procedure has the advantage of offering a minimally invasive, off-pump option for select patients with high surgical risk.

Super-Repellent and Flexible Lubricant-Infused Bacterial Nanocellulose Membranes with Superior Antithrombotic, Antibacterial, and Fatigue Resistance Properties.

Bacterial nanocellulose (BNC) is a naturally derived hydrogel that has recently paved its way in several biomedical applications. Despite its remarkable tissue-like properties, BNC does not express innate anticoagulant or antimicrobial properties; therefore, appropriate post-modification procedures are required to prevent nonspecific adhesion and enhance the hemocompatibility properties of BNC-based biointerface. Here, we report a new class of flexible, lubricant-infused BNC membranes with superior antithrombotic and antibacterial properties. Using chemical vapor deposition, porous BNC membranes were functionalized with fluorosilane molecules and further impregnated with a fluorocarbon-based lubricant. Compared with unmodified BNC membranes and commercially available poly(tetrafluoroethylene) (PTFE) felts, our developed lubricant-infused BNC samples significantly attenuated plasma and blood clot formation, and prevented bacterial migration, adhesion, and biofilm formation and exhibited superior fat and enzyme repellency properties. Moreover, when subjected to mechanical testing, the lubricant-infused BNC membranes demonstrated a significantly higher tensile strength and greater fatigue resistance when compared with unmodified BNC samples and PTFE felts. Overall, the superior mechanical strength and antithrombotic, antibacterial, and fat/enzyme resistant properties observed in the developed super-repellent BNC-based membranes render their application promising for various biofluid-contacting medical implants and tissue engineering constructs.

Cardiac surgery elicits pericardial inflammatory responses that are distinct compared with postcardiopulmonary bypass systemic inflammation.

Objectives: Cardiac surgery using cardiopulmonary bypass contributes to a robust systemic inflammatory process. Local intrapericardial postsurgical inflammation is believed to trigger important clinical implications, such as postoperative atrial fibrillation and postsurgical intrathoracic adhesions. Immune mediators in the pericardial space may underlie such complications. Methods: In this prospective pilot clinical study, 12 patients undergoing isolated coronary artery bypass graft surgery were enrolled. Native pericardial fluid and venous blood samples (baseline) were collected immediately after pericardiotomy. Postoperative pericardial fluid and venous blood samples were collected 48-hours after cardiopulmonary bypass and compared with baseline. Flow cytometry determined proportions of specific immune cells, whereas multiplex analysis probed for inflammatory mediators. Results: Neutrophils are the predominant cells in both the pericardial space and peripheral blood postoperatively. There are significantly more CD163lo macrophages in blood compared with pericardial effluent after surgery. Although there are significantly more CD163hi macrophages in native pericardial fluid compared with baseline blood, after surgery there are significantly fewer of these cells present in the pericardial space compared with blood. Postoperatively, concentration of interleukin receptor antagonist 6, and interleukin 8 were significantly higher in the pericardial space compared with blood. After surgery, compared with blood, the pericardial space has a significantly higher concentration of matrix metalloproteinase 3, matrix metalloproteinase 8, and matrix metalloproteinase 9. The same trend was observed with transformational growth factor ß. Conclusions: Cardiac surgery elicits an inflammatory response in the pericardial space, which differs from systemic inflammatory responses. Future work should determine whether or not this distinct local inflammatory response contributes to postsurgical complications and could be modified to influence clinical outcomes.

A Systematic Review and Meta-Analysis of Robot-Assisted Mitral Valve Repair.

OBJECTIVE: Robot-assisted surgery is a minimally invasive approach for repairing the mitral valve. This study aimed to assess its safety and clinical efficacy when compared with conventional sternotomy, partial sternotomy, and right minithoracotomy. METHODS: A systematic review of peer-reviewed studies comparing robot-assisted mitral valve repair with conventional sternotomy, partial sternotomy, and right minithoracotomy was conducted following Cochrane Collaboration guidelines. Meta-analyses were performed where possible. RESULTS: The search strategy yielded 15 primary studies, of which 12 compared robot-assisted with conventional sternotomy, 2 compared robot-assisted with partial sternotomy, and 6 compared robot-assisted with right minithoracotomy. The overall quality of evidence was low, and there was a lack of data on long-term outcomes. Individual studies and pooled data demonstrated that robotic procedures were comparable to conventional sternotomy and other minimally invasive approaches with respect to the rates of stroke, renal failure, reoperation for bleeding, and mortality. Robot-assisted mitral valve repair was superior to conventional sternotomy with reduced atrial fibrillation, intensive care unit and hospital stay, pain, time to return to normal activities, and physical functioning at 1 year. However, robot-assisted mitral valve repair had longer cardiopulmonary, aortic cross-clamp, and procedure times compared with all other surgical approaches. CONCLUSIONS: Based on current evidence, robot-assisted mitral valve repair is comparable to other approaches for safety and early postoperative outcomes, despite being associated with longer operative times. Ideally, future studies will be randomized controlled trials that compare between robot-assisted surgery, conventional surgery, and other minimally surgery approaches focusing on hard clinical outcomes and patient-reported outcomes.

A rare delayed complication after TAVR: Acute severe aortic insufficiency.

Transcatheter aortic valve replacement (TAVR) has become the standard of care for managing severe aortic stenosis (AS) in high surgical risk patients. Despite favorable outcomes, TAVR has been associated with complications, such as aortic regurgitation (AR). Post-TAVR aortic insufficiency, which can present at any time after the procedure, manifests as paravalvular leak, central leak, or a combination of the two. Herein, we describe a unique and atypical case of a patient who presented with heart failure and was found to have severe AR in the context of having had TAVR 5 years prior using an Evolut R prosthetic valve.

Right Mini-Thoracotomy Beating-Heart Mitral Valve Replacement With a SAPIEN 3 Valve for Severe Circumferential Mitral Annular Calcification.

Mitral annular calcification (MAC) is a degenerative process that can cause mitral valve stenosis. Conventional surgical mitral valve replacement (MVR) for MAC with mitral stenosis can be challenging and associated with significant risk. Open surgical MVR with a transcatheter valve can offer an alternative in select situations. When such a strategy is not feasible, a beating-heart, mini-thoracotomy MVR with a SAPIEN 3 transcatheter heart valve can be considered. The novel teaching point of this case is use of an alternative approach for managing severe mitral stenosis secondary to MAC, when conventional surgical and transcatheter strategies are not safe or possible.

La calcification de l'anneau mitral (CAM) est un processus dégénératif qui peut causer la sténose mitrale. Le remplacement valvulaire mitral (RVM) par intervention chirurgicale traditionnelle lors de CAM associée à la sténose mitrale peut être complexe et est associé à un risque important. Le RVM à cœur ouvert par cathéter peut être une solution dans certaines situations. Lorsque cette stratégie n'est pas faisable, le RVM à cœur battant par mini-thoracotomie à l'aide d'une valve cardiaque SAPIEN 3 par cathéter peut être envisagé. Le nouveau point à retenir de ce cas est l'utilisation d'une autre approche pour prendre en charge la sténose mitrale grave secondaire à la CAM, lorsque les stratégies d'intervention chirurgicale traditionnelle et de cathétérisme ne sont pas sûres ou possibles.

Clinical implications of the biomechanics of bicuspid aortic valve and bicuspid aortopathy.

Bicuspid aortic valve (BAV), which affects up to 2% of the general population, results from the abnormal fusion of the cusps of the aortic valve. Patients with BAV are at a higher risk for developing aortic dilatation, a condition known as bicuspid aortopathy, which is associated with potentially life-threatening sequelae such as aortic dissection and aortic rupture. Although BAV biomechanics have been shown to contribute to aortopathy, their precise impact is yet to be delineated. Herein, we present the latest literature related to BAV biomechanics. We present the most recent definitions and classifications for BAV. We also summarize the current evidence pertaining to the mechanisms that drive bicuspid aortopathy. We highlight how aberrant flow patterns can contribute to the development of aortic dilatation. Finally, we discuss the role cardiac magnetic resonance imaging can have in assessing and managing patient with BAV and bicuspid aortopathy.

A unique and atypical presentation of heart failure secondary to incidental left atrial myxoma in a patient post gynecological surgery.

Primary tumors of the heart are rare where nearly half of the benign cardiac masses are myxomas. Clinical features of myxoma are determined by their location, size, and mobility. Most patients present with one or more of the triad of embolism, intracardiac obstruction, and constitutional symptoms. Herein, we present the case of a 60-year-old female with a history of genital prolapse who had new onset worsening dyspnea two days after an elective total abdominal hysterectomy, bilateral salpingo-oopherectomy, and vaginal repair. She was initially thought to have a pulmonary embolism so had a computed tomography scan that revealed a cardiac mass, which was diagnosed to be a myxoma. Although rare, atrial myxomas can present in any patient population. This case report is educational as it highlights the atypical presentation of an atrial myxoma. To facilitate appropriate management, high degree of suspicion should be complemented with a comprehensive physical examination and set of investigations. .