Aneurysms of Aortic Sinus of Valsalva Dissecting through the Interventricular Septum With Rupture into the Left Ventricle: Case Series and Literature Review.

Aneurysm of Aortic sinus of Valsalva (ASOV) dissecting into the interventricular septum (IVS) and rupturing into the left ventricle (LV) is a rare clinical diagnosis. Systemic inflammatory diseases like tuberculosis can aggravate this condition. We describe three cases of ASOV dissecting into the IVS and rupturing into the LV. All three patients underwent surgical intervention; two had a successful outcome. A literature review was conducted and19 previously reported cases were studied. The extent and direction of septal dissection determined the associated cardiac valvular and rhythm problems. Patch closure of the mouth of the aneurysm is the surgical method of choice. In the presence of multiple sinus tracts or if there is recurrence after surgical closure, aortic sinus or root replacement techniques have better outcomes.

Aortic Origin of a Branch Pulmonary Artery: Early and Mid-Term Single Center Outcomes.

BACKGROUND: Anomalous origin of pulmonary artery (AOPA) is a rare congenital cardiac anomaly. It requires early surgical intervention (<6 months) to prevent irreversible pulmonary vaso-occlusive disease. This study was conducted to determine the surgical outcomes of this rare and intriguing anomaly. METHODS: From January 2015 to 2022, we have studied, 20 patients who underwent surgical correction for this anomaly with a mean age of 6.25 ± 3.7 months. There were 12 patients of <6 months of age. Their preoperative, intraoperative, and postoperative data were collected. They were followed up at every three months for the first year, every six months for two years, and then annually. RESULTS: Among three early mortalities, two were operated before six months of age and one was older than six months (ten months). Those patients presented after six months had longer ventilation time (P = .001). There was no difference in their pulmonary artery pressure (P = .06), right ventricle systolic pressure (RVSP) (P = .85), postoperative saturation (P = .51), inotropic score (P = .06), hospital and intensive care unit stay (P > .05), or mortality (P = .79). There was no late mortality at mean follow-up of 51.31 ± 20.27 months with Kaplan-Meier survival of 85% at 1, 5, and ten years. All patients were asymptomatic, with normal biventricular function and RVSP. One patient required balloon dilatation of the anastomotic site, with Kaplan-Meier event-free survival of 100% at one year, 92% at five and ten years. CONCLUSION: Surgical correction of AOPA in patients beyond six months is still feasible with a higher early morbidity and comparable mortality with good clinical and echocardiographical outcomes at mid-term follow-up.

Center Volume Predicts Improved Early Outcomes in Multiorgan Heart Transplantation.

PURPOSE: Center volume is associated with improved survival after isolated heart transplant, but its impact on multiorgan heart transplant (MHT) outcomes is unknown. This study examines the impact of institutional MHT volume on MHT outcomes. METHODS: Adult patients undergoing first time MHT from 2011 to 2021 were identified in the United Network for Organ Sharing database. Transplant centers were annually classified as low-, medium-, or high-volume if they performed <3, 3 to 5, or ≥6 MHTs that year, respectively. Graft failure was defined as death, failure, or re-transplantation of any allograft. RESULTS: A total of 1860 MHTs were performed at 104 centers, including 482 (26%) at low-, 601 (32%) at medium-, and 777 (42%) at high-MHT volume centers. Noncardiac allografts included kidney (83%), liver (16%), and lung (2%). The proportion of MHTs performed at high-volume centers increased from 10% in 2011 to 62% in 2021. Recipient age, race, and body mass index did not vary by center volume (all P > .05). Patients at high-volume centers were more likely to be in the intensive care unit pre-transplant (58% vs 44%, P < .001) and have shorter waitlist times (47 vs 92 days, P < .001) than those at low-volume centers. 30-day graft survival was higher in combined medium- and high-volume compared with low-volume centers (95% vs 92%, P = .004). Increasing center MHT volume was protective against 30-day graft failure (adjusted hazard ratio 0.93 [0.88-0.98]) on multivariate Cox regression. CONCLUSIONS: Higher MHT volume is associated with improved early graft survival after MHT, which may justify centralizing the performance of MHTs to high-volume centers.

Insights into nanomechanical behavior of B. mori silk fibroin-hydroxyapatite bio-nanocomposite using MD simulations: Role of varying hydroxyapatite content.

Nanocomposite material composed of Bombyx mori Silk Fibroin and hydroxyapatite (B. mori SF-HA) is a potential biomaterial for bone tissue engineering. Here, Bombyx mori Silk Fibroin (B. mori SF) is a flexible and tough organic, polymer phase, and hydroxyapatite (HA) is hard and stiff mineral phase. Knowledge about mechanical deformation behavior together with governing mechanisms, and the role of the two phases (SF and HA phase) and interfacial interactions between them, in B. mori SF-HA biomaterial, at fundamental level is an important factor to consider while developing the tissue grafts. Such nanometer scale behavior is often preferably investigated using molecular dynamics method. Present study aims at understanding the mechanical deformation behavior and associated physical mechanisms in B. mori SF-HA bio-nanocomposite, at nanoscale. For this purpose, computational atomistic models of B. mori SF-HA bio-nanocomposite are developed with varying HA content. Mechanical behavior analysis of these composite models under tensile loading were performed using Molecular Dynamics (MD) simulations. Elastic modulus and tensile strength values in the range of 7-20 GPa and 200-700 MPa, respectively, are obtained for B. mori SF-HA composite, in case of different HA contents, wherein, increased mechanical properties are observed with increase in HA content. Analyses of the deformation trajectories show that the deformation flow behavior in B. mori SF-HA bio-nanocomposites is mainly defined by the soft SF phase. However, energetics analyses show that, the HA phase and SF-HA interfacial interactions also play a considerable role in mechanical performance of B. mori SF-HA bio-nanocomposite. Additionally, interfacial shear strength values in B. mori SF-HA bio-nanocomposite, for different HA contents, have also been obtained. The observations made and insights gained in present work has contribution and impact in gaining an insight into the mechanistic interactions occurring at nanoscale between SF and HA phases in B. mori SF-HA bio-composite.

Short stature is a risk factor for heart transplant morbidity and mortality.

BACKGROUND: Short stature is associated with mortality after cardiac surgery and may increase size mismatch risk among transplant recipients. Yet, stature's impact on heart transplant outcomes is not well-characterized. METHODS: The Scientific Registry of Transplant Recipients was queried for data on all adult heart transplants in the United States from 2000 to 2022. Recipients were stratified into five cohorts by sex-corrected stature. Morbidity was assessed with Kruskal-Wallis and chi-squared tests. Mortality was analyzed using Kaplan-Meier estimation. Risk factors for mortality were assessed with multivariable Cox regression. RESULTS: Among 43,420 transplant recipients, 5321 (12.2%) had short stature (females >4'11″ & ≤5'1″; males >5'4″ & ≤5'7″) and 765 (1.8%) had very short stature (females ≤4'11″; males ≤5'4″). Very short stature patients had higher waitlist status (1A and 1), more congenital heart disease, and received more oversized donor hearts than other cohorts (all p < 0.05). Very short stature patients had decreased 30-day, 1-, 5-, and 10-year survival (94.6%, 84.3%, 69.3% and 52.5%, respectively, all p < 0.001), but less acute rejection (p = 0.005) and comparable stroke rates (p = 0.107). On multivariable regression adjusting for congenital heart disease and oversized donor hearts, very short and short stature were associated with 10-year mortality (hazard ratios: 1.40 and 1.12, respectively, both p < 0.005). CONCLUSIONS: Short stature confers increased mortality risk for heart transplant recipients and merits inclusion in prognostic models.

Emerging Racial Differences in Heart Transplant Waitlist Outcomes for Patients on Temporary Mechanical Circulatory Support.

Temporary mechanical circulatory support (tMCS) is increasingly used for patients awaiting heart transplantation. Although examples of systemic inequity in cardiac care have been described, biases in tMCS use are not well characterized. This study explores the racial disparities in tMCS use and waitlist outcomes. The United Network for Organ Sharing database was used to identify adults listed for first-time heart transplantation from 2015 to 2021. White and non-White patients on extracorporeal membrane oxygenation, intra-aortic balloon pump, or temporary left ventricular assist device were identified. Waitlist outcomes of mortality, transplantation, and delisting were analyzed by race using competing risks regression. The effect of the new heart allocation system was also assessed. A total of 16,811 patients were included in this study, with 10,377 self-identifying as White and 6,434 as non-White. White patients were more often male, privately ensured, and had less co-morbidities (p <0.05). tMCS use was found to be significantly higher in non-White patients (p <0.001). Among those on tMCS, non-White patients were more likely to be delisted because of illness (subhazard ratio 1.34 [1.09 to 1.63]) and less likely to die while on the waitlist (subhazard ratio 0.76 [0.61 to 0.93]). This disparity was not present before the implementation of the new heart allocation system. tMCS use was proportional to the risk factors identified in the non-White cohort. After the implementation of the new heart allocation system, White patients were more likely to die, whereas non-White patients were more likely to be delisted. Further work is needed to determine the causes of and potential solutions for disparities in the waitlist outcomes.

Aortic valve replacement for moderate aortic stenosis during mitral surgery improves survival free from severe stenosis.

BACKGROUND: Optimal management of moderate aortic stenosis during surgery for another indication is unclear. We assessed the effects of surgical aortic valve replacement for moderate aortic stenosis during mitral surgery. METHODS: An institutional mitral surgery database was queried for patients with preoperative moderate aortic stenosis. Patients were stratified by whether they underwent concomitant surgical aortic valve replacement. Morbidity was analyzed using Student's t tests, Wilcoxon rank sum, chi-squared, and Fisher's exact tests. Survival was analyzed using Kaplan-Meier estimation and Cox regression. RESULTS: Of 85 mitral surgery recipients with moderate aortic stenosis from 2012 to 2019, 62 (73%) underwent concomitant surgical aortic valve replacement. Surgical aortic valve replacement recipients were more likely to have bicuspid (11% vs. 0%, p = 0.019) or rheumatic (18% vs. 0%, p = 0.019) aortic valves, and to undergo mitral repair (32% vs. 9%, p = 0.028). Groups did not differ with respect to mitral etiology, New York Heart Association class, or cardiac intervention history (p > 0.05). Postoperatively, groups had similar stroke and gastrointestinal bleed rates (3% vs. 0% and 2% vs. 0% in the surgical aortic valve replacement vs. no surgical aortic valve replacement group respectively, both p > 0.99). Five-year survival free from severe aortic stenosis was higher in the surgical aortic valve replacement group (66% vs. 17%, p = 0.002). Surgical aortic valve replacement protected against the composite of death and progression to severe aortic stenosis at 5 years (hazard ratio: 0.32, p = 0.003). CONCLUSIONS: Surgical aortic valve replacement for moderate aortic stenosis at time of mitral surgery is a well-tolerated strategy to reduce aortic disease progression.

Molecular mechanics and failure mechanisms in B. mori Silk Fibroin-hydroxyapatite composite interfaces: Effect of crystal thickness and surface characteristics.

Bombyx mori Silk Fibroin-hydroxyapatite (B. mori SF-HA) bio-nanocomposite is a prospective biomaterial for tissue engineered graft for bone repair. Here, B. mori SF is primarily a soft and tough organic phase, and HA is a hard and stiff mineral phase. In biomaterial design, an understanding about the nanoscale mechanics of SF-HA interface, such as interfacial interaction and interface debonding mechanisms between the two phases is essential for obtaining required functionality. To investigate such nanoscale behavior, molecular dynamics method is a preferred approach. Present study focuses on understanding of the interface debonding mechanisms at SF-HA interface in B. mori SF-HA bio-nanocomposite at nanometer length scale. For this purpose, nanoscale atomistic models of SF-HA interface are also developed based on the HA crystal size and HA surface type (Ca2+ dominated and OH- dominated) in contact with SF. Mechanical behavior analysis of these SF-HA interface models under pull-out type test were performed using Molecular Dynamics (MD) simulations. Surface pull-off strength values in the range of 0.4-0.8 GPa were obtained for SF-HA interface models, for different HA crystal thicknesses, wherein, the pull-off strength values are found to increase with increase in HA thicknesses. Analyses show that deformation mechanisms in SF-HA interface deformation, is a combination of shear deformation in SF phase followed by disintegration of SF phase from HA block. Furthermore, higher rupture force values were obtained for SF-HA interface with Ca2+ dominated HA surface in contact with SF phase, indicating that SF protein has a higher affinity for Ca2+ dominated surface of HA phase. Current work contributes in developing an understanding of mechanistic interactions between organic and inorganic phases in B. mori SF-HA composite nanostructure.

Tricuspid surgery at time of mitral surgery improves survival free from severe tricuspid regurgitation but not quality of life.

Objective: The choice to operate on moderate tricuspid regurgitation (TR) during mitral surgery is challenging owing to limited mid-term data. We assess whether concomitant tricuspid operations improve mid-term quality of life, morbidity, or mortality. Methods: An institutional database identified mitral surgery recipients with moderate TR at the time of surgery from 2010 to 2019. Patients were stratified by the presence of a concomitant tricuspid operation. Quality of life at the last follow-up was assessed with the Kansas City Cardiomyopathy Questionnaire (KCCQ-12). Morbidity was compared using the χ2 test, Mann-Whitney U test, and Student t test. Survival was analyzed with Kaplan-Meier estimation. Results: Of 210 mitral surgery recipients, 67 (31.9%) underwent concomitant tricuspid surgery. The concomitant tricuspid surgery cohort had greater preoperative dialysis use (10.5% vs 3.5%; P = .043) but similar age, New York Heart Association class, and cardiac surgery history relative to the nonconcomitant cohort (P > .05 for all). The concomitant tricuspid surgery cohort had a longer cardiopulmonary bypass time (144 minutes vs 122 minutes; P = .005) but a similar rate of mitral repair (P = .220). Postoperative KCCQ-12 scores reflected high quality of life in both cohorts (95.1 vs 89.1; P = .167). The concomitant tricuspid surgery cohort trended toward a higher perioperative pacemaker placement rate (22.8% vs 12.7%; P = .088) but were less likely to develop severe TR (0.0% vs 13.0%; P = .004). Overall survival was comparable between the 2 cohorts at 1 year (84.9% vs 81.6%; P = .628) and 5 years (73.5% vs 57.9%; P = .078). Five-year survival free from severe TR was higher in the concomitant cohort (73.5% vs 54.3%; P = .032). Conclusions: Concomitant tricuspid surgery for moderate TR is associated with increased 5-year survival free from severe TR but not with increased quality of life.

Subpulmonary pseudoaneurysm-a rare complication following surgical ventricular septal defect closure.

In this report, we describe the surgical management of a subpulmonary pseudoaneurysm following surgical closure of ventricular septal defect in an infant. Diagnosis, pathogenesis, and surgical considerations for management of this complication are discussed.

Cor Triatriatum Dexter: A Rare Cause of Aneurysmal Right Atrium.

Cor triatriatum dexter (CTD) is a rare congenital cardiac anomaly with a diverse presentation in every age group. We report a case of CTD in a 36-year-old female who presented with palpitations due to giant right atrium (RA), which we managed successfully with surgical excision of the membrane and RA reduction.

Truncus Arteriosus With Double Aortic Arch.

Truncus arteriosus (TA) or common arterial trunk is a congenital cardiac anomaly having high association with arch anomalies such as right aortic arch or aortic arch interruption. However, TA with double aortic arch (DAA) is a rare occurrence. We report a case of TA with DAA where the diagnosis of DAA was missed initially.

Phenomenological models of Bombyx mori silk fibroin and their mechanical behavior using molecular dynamics simulations.

Bombyx mori silk fibroin (B. mori SF) is a promising biopolymer for use in biomedical applications such as tissue engineered grafts and as a load bearing biopolymer with biocompatible and bioresorbable properties. B. mori SF is a hierarchical bio- macro-molecule made up of amino acid (residue) chains consisting of a crystalline phase and an amorphous phase arranged in a specific order. Understanding about the mechanical behavior of B. mori SF at multiple length scales is of importance when developing tissue grafts, which requires a deeper understanding of the mechanics of its nanostructure. Four phenomenological models of B. mori SF nanostructures were developed, based on crystalline and amorphous phase connectivity. Tensile loading based mechanical behavior analysis of these models were performed using molecular dynamics (MD) simulations and compared with existing results from literature for selection of best performing model. Elastic modulus of ~7.4GPa and tensile strength of ~340 MPa were obtained for this model. Analysis of results reveals that deformation mechanisms in B. mori SF at nanoscale are a combination of tensile and shear deformations, wherein, the tensile deformation of amorphous region results into excessive extension of B. mori SF, whereas, shear deformation of crystalline region results into a high tensile strength. Overall, this work is instrumental in development of a right computational nanoscale model of SF nanostructure and provides deeper insights into the mechanistic interactions and mechanisms between amorphous and crystalline regions of B. mori SF, which would be useful for further studies of silk based biomaterials.

Intramural Aortic Course Should Always Be Considered for Anomalous Origin of the Left Coronary Artery From the Right Pulmonary Artery.

Anomalous origin of the left coronary artery (LCA) from the right pulmonary artery (ALCARPA) is an extremely rare subset of an already rare entity, anomalous origin of the LCA from the pulmonary artery. Whenever it is diagnosed preoperatively, one should be extremely vigilant about the potential intramural course of the descending part of the LCA in the aorta. Preoperative imaging frequently fails to delineate this intramural course. We report our experience with one such case where we had accidentally injured the LCA during dissection from the right pulmonary artery. Although it was successfully managed, it reinforces our aforementioned point concerning the importance of vigilance in seeking to identify intramurality as a component of this anomaly of coronary artery origin.