Right Anterior Minithoracotomy Approach for Aortic Valve Replacement.

By sparing the sternum, the right anterior minithoracotomy (RAMT) approach may facilitate a quicker functional recovery when compared with conventional aortic valve replacement (AVR). In the following review, outcomes after RAMT AVR are compared with full sternotomy AVR. The RAMT approach is described, including suggestions for patient selection. The application of the RAMT approach for other cardiac procedures is also discussed.

The Unique Case of Acute Limb Ischemia in a Patient With a Patent Foramen Ovale.

Acute limb ischemia (ALI) is the sudden onset of decreased blood supply to the extremities and carries a poor prognosis for the affected limb and survival. A rare but well-recognized embolic etiology is a paradoxical embolism, the translocation of a thrombus from venous to arterial circulation through an intracardiac communication, most commonly a patent foramen ovale. The presentation of ALI secondary to a PFO-mediated paradoxical embolism is most often accompanied by combinations of deep vein thrombosis (DVT), pulmonary embolism (PE), and an acute cerebral or visceral ischemia. We present the first documented case of a Rutherford class I ALI secondary to a PFO-mediated paradoxical embolism, ipsilateral DVT, and PE in a 29-year-old female who was surgically managed for her disabling claudication rather than limb salvage. The overlapping presentation of a viable ALI and ipsilateral DVT created a challenging clinical diagnosis. Our review of the literature on PFO-mediated paradoxical emboli involved 43 reports including 51 patients with various arterial thromboses; 19 of these cases involved lower extremity ALI. This case report is the first case to date that demonstrates a paradoxical embolism causing acute lower extremity ischemia with ipsilateral DVT and no additional limb/visceral ischemia to suggest the diagnosis of ALI. We also highlight the role that quality of life plays in vascular surgical decision-making, extending ALI management goals to not only reducing mortality and major amputations, but also improving quality of life.

Takotsubo cardiomyopathy associated with free wall rupture and ventricular septal defect: a case report.

Takotsubo cardiomyopathy is a rare cardiac presentation. It can be associated with severe complications such as hemodynamically significant ventricular septal defect and cardiac free wall rupture. In cases of mechanical complications, surgical repair is often indicated. Despite best medical and surgical efforts, patients with Takotsubo cardiomyopathy and mechanical complications carry significant mortality risk. Herein, we present an unusual presentation of Takotsubo cardiomyopathy that was associated with a mechanical complication. Although the patient underwent a successful surgical repair, she passed away from multiorgan failure during the postoperative period.

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Acute pericardial postischemic inflammatory responses: Characterization using a preclinical porcine model.

BACKGROUND: Pericardial fluid (PF) contains cells, proteins, and inflammatory mediators, such as cytokines, chemokines, growth factors, and matrix metalloproteinases. To date, we lack an adequate understanding of the inflammatory response that acute injury elicits in the pericardial space. OBJECTIVE: To characterize the inflammatory profile in the pericardial space acutely after ischemia/reperfusion. METHODS: Pigs were used to establish a percutaneous ischemia/reperfusion injury model. PF was removed from pigs at different time points postanesthesia or postischemia/reperfusion. Flow cytometry was used to characterize the immune cell composition of PF, while multiplex analysis was performed on the acellular portion of PF to determine the concentration of inflammatory mediators. There was a minimum of 3 pigs per group. RESULTS: While native PF mainly comprises macrophages, we show that neutrophils are the predominant inflammatory cell type in the pericardial space after injury. The combination of acute ischemia/reperfusion (IR) and repeatedly accessing the pericardial space significantly increases the concentration of interleukin-1 beta (IL-1ß) and interleukin-1 receptor antagonist (IL-1ra). IR significantly increases the pericardial concentration of TGFß1 but not TGFß2. We observed that repeated manipulation of the pericardial space can also drive a robust pro-inflammatory response, resulting in a significant increase in immune cells and the accumulation of potent inflammatory mediators in the pericardial space. CONCLUSION: In the present study, we show that both IR and surgical manipulation can drive robust inflammatory processes in the pericardial space, consisting of an increase in inflammatory cytokines and alteration in the number and composition of immune cells.

Predicting Aneurysmal Degeneration in Uncomplicated Residual Type B Aortic Dissection.

The formation of an aneurysm in the false lumen (FL) is a long-term complication in a significant percentage of type B aortic dissection (AD) patients. The ability to predict which patients are likely to progress to aneurysm formation is key to justifying the risks of interventional therapy. The investigation of patient-specific hemodynamics has the potential to enable a patient-tailored approach to improve prognosis by guiding disease management for type B dissection. CFD-derived hemodynamic descriptors and geometric features were used to retrospectively assess individual aortas for a population of residual type B AD patients and analyze correlations with known outcomes (i.e., rapid aortic growth, death). The results highlight great variability in flow patterns and hemodynamic descriptors. A rapid aortic expansion was found to be associated with a larger FL. Time-averaged wall shear stress at the tear region emerged as a possible indicator of the dynamics of flow exchange between lumens and its effect on the evolution of individual aortas. High FL flow rate and tortuosity were associated with adverse outcomes suggesting a role as indicators of risk. AD induces complex changes in vessel geometry and hemodynamics. The reported findings emphasize the need for a patient-tailored approach when evaluating uncomplicated type B AD patients and show the potential of CFD-derived hemodynamics to complement anatomical assessment and help disease management.

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.

Current concepts in the epigenetic regulation of cardiac fibrosis.

Cardiac fibrosis is a significant driver of congestive heart failure, a syndrome that continues to affect a growing patient population globally. Cardiac fibrosis results from a constellation of complex processes at the transcription, receptor, and signaling axes levels. Various mediators and signaling cascades, such as the transformation growth factor-beta pathway, have been implicated in the pathophysiology of cardiac tissue fibrosis. Our understanding of these markers and pathways has improved in recent years as more advanced technologies and assays have been developed, allowing for better delineation of the crosstalk between specific factors. There is mounting evidence suggesting that epigenetic modulation plays a pivotal role in the progression of cardiac fibrosis. Transcriptional regulation of key pro- and antifibrotic pathways can accentuate or blunt the rate and extent of fibrosis at the tissue level. Exosomes, micro-RNAs, and long noncoding RNAs all belong to factors that can impact the epigenetic signature in cardiac fibrosis. Herein, we comprehensively review the latest literature about exosomes, their contents, and cardiac fibrosis. In doing so, we highlight the specific transcriptional factors with pro- or antifibrotic properties. We also assimilate the data supporting these mediators' potential utility as diagnostic or prognostic biomarkers. Finally, we offer insight into where further work can be done to fill existing gaps to translate preclinical findings better and improve clinical outcomes.

Exploring the role of pericardial miRNAs and exosomes in modulating cardiac fibrosis.

The potential of the pericardial space as a therapeutic delivery tool for cardiac fibrosis and heart failure (HF) treatment has yet to be elucidated. Recently, miRNAs and exosomes have been discovered to be present in human pericardial fluid (PF). Novel studies have shown characteristic human PF miRNA compositions associated with cardiac diseases and higher miRNA expressions in PF compared to peripheral blood. Five key studies found differentially expressed miRNAs in HF, angina pectoris, aortic stenosis, ventricular tachycardia, and congenital heart diseases with either atrial fibrillation or sinus rhythm. As miRNA-based therapeutics for cardiac fibrosis and HF showed promising results in several in vivo studies for multiple miRNAs, we hypothesize a potential role of miRNA-based therapeutics delivered through the pericardial cavity. This is underlined by the favorable results of the first phase 1b clinical trial in this emerging field. Presenting the first human miRNA antisense drug trial, inhibition of miR-132 by intravenous administration of a novel antisense oligonucleotide, CDR132L, established efficacy in reducing miR-132 in plasma samples in a dose-dependent manner. We screened the literature, provided an overview of the miRNAs and exosomes present in PF, and drew a connection to those miRNAs previously elucidated in cardiac fibrosis and HF. Further, we speculate about clinical implications and potential delivery methods.

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.

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.

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.

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.