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Intracardiac cement embolism after percutaneous vertebroplasty is a rare, but dangerous, complication, and guiding principles for its management are not well described. The management of this present case of intracardiac cement embolism offers insight to facilitate the treatment decision-making process in symptomatic patients requiring extraction., (Copyright © 2022 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Early stenosis of stentless bioprosthetic valves is rarely reported. In this report, we discuss a 75-year-old woman who presented with signs of congestive heart failure 5 months after a stentless aortic valve replacement, complicated by postoperative heparin-induced thrombocytopenia. Intraoperative findings were highly unusual, consisting of a fibrous band in the subvalvular apparatus linking the interventricular septum to the free wall of the left ventricle, resulting in significant left ventricular outflow tract obstruction. The possible causes of the fibrous band are discussed., (Copyright © 2012 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Background: The mechanism by which marrow stromal cells (MSCs) improve cardiac function after myocardial infarction (MI) is still unclear. Because MI patients with lower circulating proinflammatory/antiinflammatory cytokine ratios have been reported to have a better prognosis and in vitro studies showed that MSCs express antiinflammatory cytokines, we hypothesized that changes in cytokine ratios in the infarct microenvironment after MSC therapy may play a role in improving early cardiac function after MI., Methods: Sixty-three rats that survived left coronary artery ligations were injected with culture media (group M) or MSCs (group C). Cardiac functional changes were assessed with echocardiography. Cytokine gene expressions of interleukin (IL)-1beta, IL-6, IL-8, (proinflammatory) and IL-10 (antiinflammatory) were quantified by real-time polymerase chain reaction. Extracellular matrix deposition, injury score, and the matrix metallopeptidase 2/tissue inhibitor of metallopeptidase 1 ratio were also analyzed., Results: The ratio of proinflammatory/antiinflammatory cytokine gene expression was decreased in group C at various times, particularly in the early postoperative period. In group C, the matrix metallopeptidase 2/tissue inhibitor of metallopeptidase 1 gene expression ratio was significantly lower than group M at the early phase (12 hours), which in group C was translated into significantly lower extracellular matrix deposition at 24 hours, 1, and 2 weeks. Functional recovery was also significantly better in cell therapy group C., Conclusions: Our data demonstrate that MSC therapy decreases the proinflammatory/antiinflammatory cytokine ratio in the microenvironment early after MI. This is associated with subsequent less scar formation and improved cardiac function., (Copyright 2010 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Stem cell transplantation is a promising approach for improving cardiac function after severe myocardial damage for which use of autologous donor cells have been preferred to avoid immune rejection. Recently however, rodent, porcine, and even human bone marrow stromal cells have been reported to be uniquely immune tolerant, both in the in vitro mixed lymphocyte co-culture studies and in the in vivo allo-transplant and xeno-transplant models. In this review, we explore the current understanding of the underlying immunologic mechanisms, which can facilitate the use of such cells as "universal donor cells" with fascinating therapeutic implications.

Background: Recently rodent and porcine bone marrow stromal cells (MSCs) have been reported to be uniquely immune tolerant. To confirm these findings in human cells, we tested whether human MSCs are also immune tolerant, such that they can be used as universal donor cells for myocardial regenerative therapy., Methods: Immunocompetent female rats underwent coronary ligations (n = 90). In group I, lacZ-labeled male human MSCs were implanted into the peri-infarcted area. In groups II, III, and IV, isogeneic rat MSCs, culture medium, or human fibroblasts were injected, respectively. Echocardiography was carried out to assess cardiac function, and the specimens were examined serially for up to 8 weeks with immunohistochemistry, fluorescent in situ hybridization, and polymerase chain reaction to examine MSCs survival and differentiation., Results: Human MSCs survived within the rat myocardium for more than 8 weeks without immunosuppression. Furthermore, the implanted MSCs significantly contributed to the improvement in ventricular function and attenuated left ventricular remodeling. No cellular infiltration characteristic of immune rejection was noted in contrast to group IV., Conclusions: Human MSCs survived within this xenogeneic environment, and contributed to the improvement in cardiac function. Our findings support the feasibility of using these cells as universal donor cells for xenogeneic or allogeneic cell therapy, as they can be prepared and stored well in advance for urgent use. Allogeneic MSCs from healthy donors may be particularly useful for severely ill or elderly patients whose own MSCs could be dysfunctional.

Background: In the past two decades, cases involving patients requiring cardiac surgery have become more complex, presenting with more comorbidities. Outcome analysis has become very important in assessing the quality of cardiac surgical care in these patients. The latest version of the Parsonnet scoring system was developed in 2000 and is the most recent system available., Objective: To evaluate the accuracy of the Parsonnet scoring system in a major Canadian university-based cardiac surgery centre with a population of high-risk patients., Methods: Data on 4883 consecutive patients operated on between 2000 and 2005 were prospectively collected, and a standardized mortality rate was calculated using the Parsonnet score as the ratio of observed deaths to expected deaths. Analyses were conducted on the whole group and on subgroups, based on Parsonnet score distribution quantiles, age and surgery status., Results: The mean Parsonnet score was 18.8+/-13.7 (range 0 to 83). The overall mortality rate was 6.4%. The overall standardized mortality ratio was 0.52 (95% CI 0.420 to 0.568), which was statistically significant (P=0.01). The observed mortality rate was significantly lower than expected in all categories., Conclusions: Despite more complex cases with multiple comorbidities, the results of cardiac surgery in a Canadian university hospital show better results than expected when using the Parsonnet score.

We report a case of a 20-year-old man with a functional single left ventricle who underwent a successful Fontan operation into a single left pulmonary artery, the right pulmonary artery being atretic. The literature of a single-lung Fontan procedure is also reviewed.

Background: We have previously reported that marrow stromal stem cells (MSCs), when implanted into myocardium, can undergo milieu-dependent differentiation to express phenotypes similar to the cells in the immediate microenvironment. We tested the hypothesis that by in vitro preprogramming of MSCs, we may be able to guide their differentiation to express a therapeutically desirable phenotype that is different from those in their microenvironment., Methods: MSCs were isolated from isogenic Lewis rats, culture expanded, and labeled with beta-gal using retrovirus carrying the lac-Z gene. A subset of the transfected MSCs was then treated with 5-aza-2'deoxycytidine (5-aza). Three weeks after the left ventricles were cryoinjured, either 5-aza-pretreated (n = 10) or untreated (n = 8) MSCs were injected into the myocardial scar. The hearts were harvested 4 to 8 weeks later and stained immunohistochemically for phenotypic markers., Results: The labeled MSCs within the scars that were 5-aza pretreated appeared to be morphologically distinct from the untreated ones. The treated cells (8/10 rats) appeared more myotube-like, with elongated nuclei, linearly aligned with one another, and stained positive for the cardiomyocyte-specific marker troponin I-C. Untreated MSCs (5/8 rats), in contrast, were poorly differentiated, and some appeared to express other phenotypes seen in the scar tissue., Conclusions: Our findings indicate that in cellular cardiomyoplasty using MSCs, one may select different strategies to achieve specific therapeutic goals. By milieu-dependent differentiation, unmodified MSCs may augment myocardial angiogenesis and myogenesis, whereas converting scar into myogenic tissue may be facilitated by preprogramming of MSCs before implantation.