3D Imaging Reveals Complex Microvascular Remodeling in the Right Ventricle in Pulmonary Hypertension.

BACKGROUND: Pathogenic concepts of right ventricular (RV) failure in pulmonary arterial hypertension focus on a critical loss of microvasculature. However, the methods underpinning prior studies did not take into account the 3-dimensional (3D) aspects of cardiac tissue, making accurate quantification difficult. We applied deep-tissue imaging to the pressure-overloaded RV to uncover the 3D properties of the microvascular network and determine whether deficient microvascular adaptation contributes to RV failure. METHODS: Heart sections measuring 250-µm-thick were obtained from mice after pulmonary artery banding (PAB) or debanding PAB surgery and properties of the RV microvascular network were assessed using 3D imaging and quantification. Human heart tissues harvested at the time of transplantation from pulmonary arterial hypertension cases were compared with tissues from control cases with normal RV function. RESULTS: Longitudinal 3D assessment of PAB mouse hearts uncovered complex microvascular remodeling characterized by tortuous, shorter, thicker, highly branched vessels, and overall preserved microvascular density. This remodeling process was reversible in debanding PAB mice in which the RV function recovers over time. The remodeled microvasculature tightly wrapped around the hypertrophied cardiomyocytes to maintain a stable contact surface to cardiomyocytes as an adaptation to RV pressure overload, even in end-stage RV failure. However, microvasculature-cardiomyocyte contact was impaired in areas with interstitial fibrosis where cardiomyocytes displayed signs of hypoxia. Similar to PAB animals, microvascular density in the RV was preserved in patients with end-stage pulmonary arterial hypertension, and microvascular architectural changes appeared to vary by etiology, with patients with pulmonary veno-occlusive disease displaying a lack of microvascular complexity with uniformly short segments. CONCLUSIONS: 3D deep tissue imaging of the failing RV in PAB mice, pulmonary hypertension rats, and patients with pulmonary arterial hypertension reveals complex microvascular changes to preserve the microvascular density and maintain a stable microvascular-cardiomyocyte contact. Our studies provide a novel framework to understand microvascular adaptation in the pressure-overloaded RV that focuses on cell-cell interaction and goes beyond the concept of capillary rarefaction.

Early Outcomes of Intuity Rapid Deployment Aortic Valve Replacement Compared With Conventional Biological Valves in Japanese Patients.

BACKGROUND: This study aimed to elucidate the short-term surgical outcomes and hemodynamics of the Intuity valve compared to the standard bioprosthesis in Japanese patients.Methods and Results: Among the 307 consecutive patients who underwent aortic valve replacement (AVR) between February 2019 and March 2021, the Intuity valve was implanted in 95 patients (Intuity group) and a conventional stented bioprosthesis was implanted in 193 patients (conventional group). After propensity score matching, there was no significant difference in in-hospital mortality between the Intuity (n=2, 3%) and conventional groups (n=0, P=0.490). Operation, cardiopulmonary bypass, and aortic cross-clamping times were significantly shorter in the Intuity group. Although the effective orifice area index, trans-prosthetic mean pressure gradient, and peak velocity were similar between the 2 groups at 1 week postoperatively, the Intuity group showed a better mean pressure gradient and peak velocity at 1 year postoperatively. Complete atrioventricular block requiring permanent pacemaker implantation developed in 2 patients (3%) in the Intuity group and none in the conventional group (P=0.476). Mild or greater paravalvular leakage was present in 8 patients (13%) in the Intuity group and 2 patients (3%) in the conventional group (P=0.095). CONCLUSIONS: AVR using the Intuity valve in Japanese patients is satisfactory, with a better valve performance and a low incidence of complete atrioventricular block at 1 year postoperatively.

Surgical Strategy for Chronic Type B Dissecting Aortic Aneurysm to Prevent Aorta-Related Events.

BACKGROUND: This study was aimed to evaluate the outcomes of performing open repair or thoracic endovascular aortic repair for chronic type B dissecting aortic aneurysm. METHODS: From July 2004 to February 2019, 52 patients underwent surgery as open repair (n = 32) or endovascular repair (n = 20) for chronic type B dissecting aortic aneurysm. Replacement of the aorta was limited to the aneurysmal portion with or without reconstructing the visceral arteries or the segmental arteries. Stent grafts were deployed in the true lumen above the celiac artery to cover the primary entry for even DeBakey IIIb dissection. RESULTS: Operative mortality and morbidity rates, including spinal cord ischemia incidence, did not differ between the groups. Operative mortality and morbidity rates, including spinal cord ischemia incidence, did not differ between the groups. In the endovascular repair group, 3 patients died due to rupture of residual false lumen in the early, and late postoperative follow-up. The 5-year rate of freedom from all-cause death, aorta-related death, and aorta-related event were 84% ± 6%, 94% ± 3% and 84% ± 6%. The endovascular repair was independently associated with all-cause death (hazard ratio [HR], 5.7; confidence interval [CI], 1.02-31.6; P = 0.04) and aorta-related event (HR, 30.9; CI 4.9-195.0; P < 0.001). In the open group, postoperative residual aortic diameter was an independent predictor of aorta-related events, and the threshold was 41 mm. CONCLUSIONS: Open repair remains a better option than simple endovascular repair alone in DeBakey IIIb dissection, but the distal un-resected aortic portion over 41 mm was associated with late aortic events.

Successful surgical resection and reconstruction for a huge primary cardiac lymphoma filling the right heart.

Primary cardiac lymphoma (PCL) is rare, with a frequency of 1.0%-1.6% among cardiac malignant tumors. Chemotherapy is often selected as a first-line treatment for PCL. However, when the tumor causes heart failure or life-threatening hemodynamic collapse, antecedent urgent surgery is required. We herein report a successful case of complete tumor resection and reconstruction of the right atrium and right ventricle using a bovine pericardial patch combined with tricuspid valve replacement in a patient with a huge PCL filling the right heart that manifested as tricuspid valve stenosis and subsequent heart failure.

Influence of Induction Therapy Using Basiliximab With Delayed Tacrolimus Administration in Heart Transplant Recipients　- Comparison With Standard Tacrolimus-Based Triple Immunosuppression.

BACKGROUND: Appropriate indications and protocols for induction therapy using basiliximab have not been fully established in heart transplant (HTx) recipients. This study elucidated the influence of induction therapy using basiliximab along with delayed tacrolimus (Tac) initiation on the outcomes of high-risk HTx recipients.Methods and Results:A total of 86 HTx recipients treated with Tac-based immunosuppression were retrospectively reviewed. Induction therapy was administered to 46 recipients (53.5%) with impaired renal function, pre-transplant sensitization, and recipient- and donor-related risk factors (Induction group). Tac administration was delayed in the Induction group. Induction group subjects showed a lower cumulative incidence of acute cellular rejection grade ≥1R after propensity score adjustment, but this was not significantly different (hazard ratio [HR]: 0.63, 95% confidence interval [CI]: 0.37-1.08, P=0.093). Renal dysfunction in the Induction group significantly improved 6 months post-transplantation (P=0.029). The cumulative incidence of bacterial or fungal infections was significantly higher in the Induction group (HR: 10.6, 95% CI: 1.28-88.2, P=0.029). CONCLUSIONS: These results suggest that basiliximab-based induction therapy with delayed Tac initiation may suppress mild acute cellular rejection and improve renal function in recipients with renal dysfunction, resulting in its non-inferior outcome, even in high-risk patients, when applied to the appropriate recipients. However, it should be carefully considered in recipients at a high risk of bacterial and fungal infections.

Central conversion from peripheral extracorporeal life support for patients with refractory congestive heart failure.

Conversion from peripheral extracorporeal life support (ECLS) to the central one can improve and stabilize hemodynamics in patients with refractory congestive heart failure-related multiorgan failure, whereas indication and selection of the type of the central ECLS have not been fully established. Institutional outcome of the conversion therapy was herein reviewed to verify indication and selection of three types of central ECLS. This study enrolled an institutional consecutive surgical series of 24 patients with refractory congestive heart failure under peripheral ECLS, related to fulminant myocarditis (n = 15), dilated cardiomyopathy (n = 5), or acute myocardial infarction (n = 4). They were converted to central Y-extracorporeal membrane oxygenation (ECMO, n = 6), extracorporeal ventricular assist device (EC-VAD, n = 12), or pump catheter (n = 6), dependent upon the degree of multiorgan failure. Despite the different degree of multiorgan failure prior to the conversion, improvement in end-organ perfusion and reduction in right atrial and pulmonary artery pressure were promptly achieved regardless of the type of the central ECLS. There were five in-hospital mortalities (21%) during the central ECLS, whereas mechanical support was weaned-off in 11 cases (46%) and durable LVAD was subsequently implanted for bridge to transplantation in eight cases (33%). Conversion from the peripheral ECLS to the central ones, such as central Y-ECMO, EC-VAD or pump catheter, promptly established a sufficient support with heart and lung unloading in patients with refractory congestive heart failure.

Benefits of the Modified Bicaval Anastomosis Technique for Orthotopic Heart Transplantation From a Size-Mismatched Marginal Donor.

BACKGROUND: Size-mismatched heart transplantation (HTx) is associated with a risk of stenosis of the caval anastomosis site or low cardiac output syndrome. We developed a modified bicaval anastomosis technique (mBCAT) that achieved an adjustable caval anastomosis to compensate for size mismatch. This study was performed to validate the rationale of the mBCAT for size-mismatched HTx.Methods and Results:This institutional consecutive series involved 106 patients who underwent HTx with the mBCAT during an 18-year period. The cohort was divided into 3 groups according to the donor-to-recipient body weight ratio: <0.8, undersized group (n=17); 0.8-1.3, size-matched group (n=68); and >1.3, oversized group (n=21); outcomes were compared. The undersized, size-matched, and oversized groups showed no significant differences in the rate of mild or worse echocardiographic tricuspid regurgitation at 1 month [1 (5.8%), 7 (10.2%), and 1 (4.8%), respectively; P=0.87] or the survival rate at 10 years [100%, 93.9%, and 100%, respectively; P=0.25]. The right heart catheter study revealed no pressure gradient across the orifices of both cavae in any patient. Additionally, the cardiac index immediately post-HTx was significantly low in the undersized group (P=0.008), but was similar to the other groups at 6 months post-HTx (P=0.16). CONCLUSIONS: The mBCAT prevented caval anastomosis-related complications in size-mismatched HTx and achieved excellent hemodynamics regardless of donor size.

Microvascular Dysfunction Related to Progressive Left Ventricular Remodeling due to Chronic Occlusion of the Left Anterior Descending Artery in an Adult Porcine Heart.

Occlusion of a major coronary artery induces myocardial infarction (MI), leading to left ventricle (LV) remodeling due to progressive microvasculature dysfunction. Irreversible impairment in microvascular function has been suggested to extend from the infarcted region into the infarct-border or remote regions, depending on the time to revascularization. Our aim was to determine whether the occlusion of a major coronary artery induces microvascular dysfunction in the adjacent area perfused by intact coronary arteries using a porcine model for chronic total occlusion of the left anterior descending artery (LAD). MI was induced via an ameroid constrictor ring around the LAD in adult Göttingen pigs (Sus scrofa domesticus, n = 5). Age-matched normal pigs were treated as controls (n = 3). Cardiac magnetic resonance showed reduced systolic regional wall motion in the left circumflex (LCx) and right coronary artery (RCA) territories, with a progressively worsening motion in the infarction-adjacent area over an eight-week period. On 13N-ammonia positron emission tomography (PET), myocardial blood flow (MBF) during hyperemia was significantly greater in the LCx and RCA territories (particularly in the infarction-adjacent area) compared to that in the LAD territory at four weeks after infarct induction. Subsequently, the flow significantly decreased, approaching that in the LAD territory at eight weeks after infarct induction. Fluoroscopy-guided pressure-wire studies showed significantly higher microvascular resistance in the LCx area at eight weeks compared to that in controls. Electron microscopy showed endothelium swelling and microvasculature disruption in areas adjacent to the LCx and RCA territories. Anterior MI caused coronary microvascular dysfunction in the adjacent area, associated with a reduced MBF and regional wall motion.

Development of a vitrification method for preserving human myoblast cell sheets for myocardial regeneration therapy.

BACKGROUND: Tissue-engineered cardiac constructs have potential in the functional recovery of heart failure; however, the preservation of these constructs is crucial for the development and widespread application of this treatment. We hypothesized that tissue-engineered skeletal myoblast (SMB) constructs may be preserved by vitrification to conserve biological function and structure. RESULTS: Scaffold-free cardiac cell-sheet constructs were prepared from SMBs and immersed in a vitrification solution containing ethylene glycol, sucrose, and carboxyl poly-L-lysine. The cell sheet was wrapped in a thin film and frozen rapidly above liquid nitrogen to achieve vitrification (vitrification group, n = 8); fresh, untreated SMB sheets (fresh group, n = 8) were used as the control. The cryopreserved SMB sheets were thawed at 2 days, 1 week, 1 month, and 3 months after cryopreservation for assessment. Thawed, cryopreserved SMB sheets were transplanted into rat hearts in a myocardial infarction nude rat model, and their effects on cardiac function were evaluated. Cell viability in the cardiac constructs of the vitrification group was comparable to that of the fresh group, independent of the period of cryopreservation (p > 0.05). The structures of the cell-sheet constructs, including cell-cell junctions such as desmosomes, extracellular matrix, and cell membranes, were maintained in the vitrification group for 3 months. The expression of cytokine genes and extracellular matrix proteins (fibronectin, collagen I, N-cadherin, and integrin α5) showed similar levels in the vitrification and fresh groups. Moreover, in an in vivo experiment, the ejection fraction was significantly improved in animals treated with the fresh or cryopreserved constructs as compared to that in the sham-treated group (p < 0.05). CONCLUSIONS: Overall, these results show that the vitrification method proposed here preserves the functionality and structure of scaffold-free cardiac cell-sheet constructs using human SMBs after thawing, suggesting the potential clinical application of this method in cell-sheet therapy.

Definitive Determinant of Late Significant Tricuspid Regurgitation After Aortic Valve Replacement.

BACKGROUND: Uncertainties remain regarding the course of existing tricuspid regurgitation (TR) after aortic valve replacement (AVR), and its long-term impact on outcome. We investigated changes in existing TR after isolated AVR for severe aortic stenosis (AS), the impact of preoperative TR on long-term outcome, and predictors of late significant TR.Methods and Results:After excluding mild mitral regurgitation and severe TR, 226 consecutive patients undergoing isolated AVR for severe AS between 2002 and 2015 were reviewed. Patients were classified into a non-TR (none/trivial preoperative TR, n=159) and a TR group (mild/moderate preoperative TR, n=67). During follow-up (median, 4.3 years), late significant TR was more prevalent in the TR group (n=20; 35.0%) than in the non-TR group (n=13; 9.6%; HR, 10.0; 95% CI: 4.44-24.7; P<0.001). The TR group developed more right heart failure (n=3; 5% vs. no patients in the non-TR group, P=0.007), and had a decreased estimated glomerular filtration rate (relative to baseline) until 5 years postoperatively. The tricuspid annulus diameter index was an independent predictor of late significant TR development. CONCLUSIONS: Preoperative mild or moderate TR is aggravated after isolated AVR, resulting in a high incidence of renal dysfunction and right heart failure. Concomitant tricuspid valve intervention should be considered in patients undergoing AVR for severe AS with mild or moderate TR accompanied by dilated tricuspid annulus.

Symptomatic peripheral artery disease is associated with decreased long-term survival after coronary artery bypass: a contemporary retrospective analysis.

PURPOSE: Little has been documented about whether the severity of peripheral artery disease (PAD) affects the postoperative outcomes of coronary artery bypass grafting (CABG). METHODS: We performed a retrospective analysis of 683 patients who underwent isolated CABG, comparing preoperative profiles and postoperative outcomes between patients with PAD (n = 116) and those without PAD (n = 567). Kaplan-Meier analysis was done to examine the long-term survival and the Cox proportional hazard model was used to establish the preoperative risk factors associated with survival. RESULTS: The PAD patients were older and had more preoperative comorbidities than those without PAD. There were three operative deaths in each group (p = 0.07). The patients with PAD had more postoperative complications related to transfusion requirement (p = 0.004), the need for re-exploration for bleeding (p = 0.04), longer ventilation time (p < 0.001), and longer ICU stay (p = 0.001), than those without PAD. The 10-year survival rate of the PAD patients was lower than that of the non-PAD patients (p < 0.001). Univariate and multivariate analyses revealed that symptomatic PAD (p = 0.008) was associated with decreased long-term survival. CONCLUSION: Symptomatic PAD was found to be an independent factor for poor long-term survival after CABG. Thus, aggressive screening measures for coronary disease, early surgical revascularization, and secondary prevention may improve the early and long-term outcomes of these patients.

Stromal cell-derived factor-1 alpha improves cardiac function in a novel diet-induced coronary atherosclerosis model, the SR-B1ΔCT/LDLR KO mouse.

BACKGROUND AND AIMS: There are a limited number of pharmacologic therapies for coronary artery disease, and few rodent models of occlusive coronary atherosclerosis and consequent myocardial infarction with which one can rapidly test new therapeutic approaches. Here, we characterize a novel, fertile, and easy-to-use HDL receptor (SR-B1)-based model of atherogenic diet-inducible, fatal coronary atherosclerosis, the SR-B1ΔCT/LDLR KO mouse. Additionally, we test intramyocardial injection of Stromal Cell-Derived Factor-1 alpha (SDF-1α), a potent angiogenic cytokine, as a possible therapy to rescue cardiac function in this mouse. METHODS: SR-B1ΔCT/LDLR KO mice were fed the Paigen diet or standard chow diet, and we determined the effects of the diets on cardiac function, histology, and survival. After two weeks of feeding either the Paigen diet (n = 24) or standard chow diet (n = 20), the mice received an intramyocardial injection of either SDF-1α or phosphate buffered saline (PBS). Cardiac function and angiogenesis were assessed two weeks later. RESULTS: When six-week-old mice were fed the Paigen diet, they began to die as early as 19 days later and 50% had died by 38 days. None of the mice maintained on the standard chow diet died by day 72. Hearts from mice on the Paigen diet showed evidence of cardiomegaly, myocardial infarction, and occlusive coronary artery disease. For the five mice that survived until day 28 that underwent an intramyocardial injection of PBS on day 15, the average ejection fraction (EF) decreased significantly from day 14 (the day before injection, 52.1 ± 4.3%) to day 28 (13 days after the injection, 30.6 ± 6.8%) (paired t-test, n = 5, p = 0.0008). Of the 11 mice fed the Paigen diet and injected with SDF-1α on day 15, 8 (72.7%) survived to day 28. The average EF for these 8 mice increased significantly from 48.2 ± 7.2% on day 14 to63.6 ± 6.9% on day 28 (Paired t-test, n = 8, p = 0.003). CONCLUSIONS: This new mouse model and treatment with the promising angiogenic cytokine SDF-1α may lead to new therapeutic approaches for ischemic heart disease.

Biomechanical engineering analysis of neochordae length's impact on chordal forces in mitral repair.

OBJECTIVES: Artificial neochordae implantation is commonly used for mitral valve (MV) repair. However, neochordae length estimation can be difficult to perform. The objective was to assess the impact of neochordae length changes on MV haemodynamics and neochordal forces. METHODS: Porcine MVs (n = 6) were implanted in an ex vivo left heart simulator. MV prolapse (MVP) was generated by excising at least 2 native primary chordae supporting the P2 segments from each papillary muscle. Two neochordae anchored on each papillary muscle were placed with 1 tied to the native chord length (exact length) and the other tied with variable lengths from 2× to 0.5× of the native length (variable length). Haemodynamics, neochordal forces and echocardiography data were collected. RESULTS: Neochord implantation repair successfully eliminated mitral regurgitation with repaired regurgitant fractions of approximately 4% regardless of neochord length (P < 0.01). Leaflet coaptation height also significantly improved to a minimum height of 1.3 cm compared with that of MVP (0.9 ± 0.4 cm, P < 0.05). Peak and average forces on exact length neochordae increased as variable length neochordae lengths increased. Peak and average forces on the variable length neochordae increased with shortened lengths. Overall, chordal forces appeared to vary more drastically in variable length neochordae compared with exact length neochordae. CONCLUSIONS: MV regurgitation was eliminated with neochordal repair, regardless of the neochord length. However, chordal forces varied significantly with different neochord lengths, with a preferentially greater impact on the variable length neochord. Further validation studies may be performed before translating to clinical practices.

Four decades of progress in heart-lung transplantation: Two hundred seventy-one cases at a single institution.

OBJECTIVE: The objective of this study is to evaluate survival for combined heart-lung transplant (HLTx) recipients across 4 decades at a single institution. We aim to summarize our contemporary practice based on more than 271 HLTx procedures over 40 years. METHODS: Data were collected from a departmental database and the United Network for Organ Sharing. Recipients younger than age 18 years, those undergoing redo HLTx, or triple-organ system transplantation were excluded, leaving 271 patients for analysis. The pioneering era was defined by date of transplant between 1981 and 2000 (n = 155), and the modern era between 2001 and 2022 (n = 116). Survival analysis was performed using cardinality matching of populations based on donor and recipient age, donor and recipient sex, ischemic time, and sex matching. RESULTS: Between 1981 and 2022, 271 HLTx were performed at a single institution. Recipients in the modern era were older (age 42 vs 34 y; P < .001) and had shorter waitlist times (78 vs 234 days; P < .001). Allografts from female donors were more common in the modern era (59% vs 39%; P = .002). In the matched survival analysis, 30-day survival (97% vs 84%; P = .005), 1-year survival (89% vs 77%; P = .041), and 10-year survival (53% vs 26%; P = .012) significantly improved in the modern era relative to the pioneering era, respectively. CONCLUSIONS: Long-term survival in HLTx is achievable with institutional experience and may continue to improve in the coming decades. Advances in mechanical circulatory support, improved maintenance immunosuppression, and early recognition and management of acute complications such as primary graft dysfunction and acute rejection have dramatically improved the prognosis for recipients of HLTx in our contemporary institutional experience.

Large Animal Translational Validation of 3 Mitral Valve Repair Operations for Mitral Regurgitation Using a Mitral Valve Prolapse Model: A Comprehensive In Vivo Biomechanical Engineering Analysis.

BACKGROUND: Various mitral repair techniques have been described. Though these repair techniques can be highly effective when performed correctly in suitable patients, limited quantitative biomechanical data are available. Validation and thorough biomechanical evaluation of these repair techniques from translational large animal in vivo studies in a standardized, translatable fashion are lacking. We sought to evaluate and validate biomechanical differences among different mitral repair techniques and further optimize repair operations using a large animal mitral valve prolapse model. METHODS: Male Dorset sheep (n=20) had P2 chordae severed to create the mitral valve prolapse model. Fiber Bragg grating force sensors were implanted to measure chordal forces. Ten sheep underwent 3 randomized, paired mitral valve repair operations: neochord repair, nonresectional leaflet remodeling, and triangular resection. The other 10 sheep underwent neochord repair with 2, 4, and 6 neochordae. Data were collected at baseline, mitral valve prolapse, and after each repair. RESULTS: All mitral repair techniques successfully eliminated regurgitation. Compared with mitral valve prolapse (0.54±0.18 N), repair using neochord (0.37±0.20 N; P=0.02) and remodeling techniques (0.30±0.15 N; P=0.001) reduced secondary chordae peak force. Neochord repair further decreased primary chordae peak force (0.21±0.14 N) to baseline levels (0.20±0.17 N; P=0.83), and was associated with lower primary chordae peak force compared with the remodeling (0.34±0.18 N; P=0.02) and triangular resectional techniques (0.36±0.27 N; P=0.03). Specifically, repair using 2 neochordae resulted in higher peak primary chordal forces (0.28±0.21 N) compared with those using 4 (0.22±0.16 N; P=0.02) or 6 neochordae (0.19±0.16 N; P=0.002). No difference in peak primary chordal forces was observed between 4 and 6 neochordae (P=0.05). Peak forces on the neochordae were the lowest using 6 neochordae (0.09±0.11 N) compared with those of 4 neochordae (0.15±0.14 N; P=0.01) and 2 neochordae (0.29±0.18 N; P=0.001). CONCLUSIONS: Significant biomechanical differences were observed underlying different mitral repair techniques in a translational large animal model. Neochord repair was associated with the lowest primary chordae peak force compared to the remodeling and triangular resectional techniques. Additionally, neochord repair using at least 4 neochordae was associated with lower chordal forces on the primary chordae and the neochordae. This study provided key insights about mitral valve repair optimization and may further improve repair durability.

Does the residual aorta dilate after replacement of the bicuspid aortic valve and ascending aorta?

Background: Although a bicuspid aortic valve (BAV) is known to be associated with progressive ascending aortic dilatation, the fate of the residual aorta after aortic valve and ascending aorta surgery is unknown. We reviewed surgical outcomes and explored serial changes in the size of the sinus of Valsalva (SOV) and distal ascending aorta (DAAo) in 89 patients with a BAV undergoing aortic valve replacement (AVR) and graft replacement (GR) of the ascending aorta. Methods: We retrospectively examined patients who underwent AVR and GR of the ascending aorta for BAV-and related disease and thoracic aortic dilatation at our institution between January 2009 and December 2018. Patients who underwent AVR alone or required intervention for the aortic root and aortic arch and patients with connective tissue diseases were excluded. Aortic diameters were examined using computed tomography (CT). Late CT more than 1 year after surgery was performed in 69 patients (78%) with a mean follow-up of 4.9±2.8 years. Results: The surgical indication for aortic valve etiology was stenosis in 61 patients (69%), regurgitation in 10 (11%), and mixed in 18 (20%). Preoperative maximum short diameters of the ascending aorta, SOV, and DAAo were 47.3±4.7, 36.0±5.2, and 37.2±3.6 mm, respectively. The diameter of the SOV increased non-significantly by 0.08±0.45 mm per year [95% confidence interval (CI): -0.12 to 0.11, P=0.150], while that of the DAAo increased significantly by 0.11±0.40 mm per year (95% CI: 0.02-0.21, P=0.005). One patient required reoperation 6 years postoperatively due to a pseudo-aneurysm at the proximal anastomotic site. No patient required reoperation due to progressive dilatation of the residual aorta. According to the Kaplan-Meier analysis, the long-term survival rates were 98.9%, 98.9%, and 92.7% at 1, 5, and 10 years postoperatively, respectively. Conclusions: Rapid dilatation of the residual aorta rarely occurred in patients with a BAV who underwent AVR and GR of the ascending aorta in the mid-term follow-up. For selected patients with a surgical indication for ascending aortic dilatation, simple AVR and GR of the ascending aorta may be sufficient surgical options.

Chordal force profile after neochordal repair of anterior mitral valve prolapse: An ex vivo study.

Objective: This study aimed to biomechanically evaluate the force profiles on the anterior primary and secondary chordae after neochord repair for anterior valve prolapse with varied degrees of residual mitral regurgitation using an ex vivo heart simulator. Methods: The experiment used 8 healthy porcine mitral valves. Chordal forces were measured using fiber Bragg grating sensors on primary and secondary chordae from A2 segments. The anterior valve prolapse model was generated by excising 2 primary chordae at the A2 segment. Neochord repair was performed with 2 pairs of neochords. Varying neochord lengths simulated postrepair residual mitral regurgitation with regurgitant fraction at >30% (moderate), 10% to 30% (mild), and <10% (perfect repair). Results: Regurgitant fractions of baseline, moderate, mild, and perfect repair were 4.7% ± 0.8%, 35.8% ± 2.1%, 19.8% ± 2.0%, and 6.0% ± 0.7%, respectively (P < .001). Moderate had a greater peak force of the anterior primary chordae (0.43 ± 0.06 N) than those of baseline (0.19 ± 0.04 N; P = .011), mild (0.23 ± 0.05 N; P = .041), and perfect repair (0.21 ± 0.03 N; P = .006). In addition, moderate had a greater peak force of the anterior secondary chordae (1.67 ± 0.17 N) than those of baseline (0.64 ± 0.13 N; P = .003), mild (0.84 ± 0.24 N; P = .019), and perfect repair (0.68 ± 0.14 N; P = .001). No significant differences in peak and average forces on both primary and secondary anterior chordae were observed between the baseline and perfect repair as well as the mild and perfect repair. Conclusions: Moderate residual mitral regurgitation after neochord repair was associated with increased anterior primary and secondary chordae forces in our ex vivo anterior valve prolapse model. This difference in chordal force profile may influence long-term repair durability, providing biomechanical evidence in support of obtaining minimal regurgitation when repairing mitral anterior valve prolapse.

Biomechanics and clinical outcomes of various conduit configurations in valve sparing aortic root replacement.

Background: Several conduit configurations, such as straight graft (SG), Valsalva graft (VG), anticommissural plication (ACP), and the Stanford modification (SMOD) technique, have been described for the valve-sparing aortic root replacement (VSARR) procedure. Prior ex vivo studies have evaluated the impact of conduit configurations on root biomechanics, but the mock coronary artery circuits used could not replicate the physical properties of native coronary arteries. Moreover, the individual leaflet's biomechanics, including the fluttering phenomenon, were unclear. Methods: Porcine aortic roots with coronary arteries were explanted (n=5) and underwent VSARR using SG, VG, ACP, and SMOD for evaluation in an ex vivo left heart flow loop simulator. Additionally, 762 patients who underwent VSARR from 1993 through 2022 at our center were retrospectively reviewed. Analysis of variance was performed to evaluate differences between different conduit configurations, with post hoc Tukey's correction for pairwise testing. Results: SG demonstrated lower rapid leaflet opening velocity compared with VG (P=0.001) and SMOD (P=0.045) in the left coronary cusp (LCC), lower rapid leaflet closing velocity compared with VG (P=0.04) in the right coronary cusp (RCC), and lower relative opening force compared with ACP (P=0.04) in the RCC. The flutter frequency was lower in baseline compared with VG (P=0.02) and in VG compared with ACP (P=0.03) in the LCC. Left coronary artery mean flow was higher in SG compared with SMOD (P=0.02) and ACP (P=0.05). Clinically, operations using SG compared with sinus-containing graft was associated with shorter aortic cross-clamp and cardiopulmonary bypass time (P<0.001, <0.001). Conclusions: SG demonstrated hemodynamics and biomechanics most closely recapitulating those from the native root with significantly shorter intraoperative times compared with repair using sinus-containing graft. Future in vivo validation studies as well as correlation with comprehensive, comparative clinical study outcomes may provide additional invaluable insights regarding strategies to further enhance repair durability.

Total arch replacement for a subacute type A dissection in a patient with a terminal tracheostoma after total laryngectomy: report of a case.

Standard full median sternotomy for total arch replacement in tracheostomy patients may lead to mediastinitis and graft infection. Several approaches for typical cardiac surgery, including a T-shaped sternotomy, have been used in patients with both terminal and transient tracheostomas; however, these procedures offer inadequate surgical exposure of the arch vessels. We herein report the case of a 67-year-old man with a subacute type A aortic dissection with a terminal tracheostoma after total laryngectomy, who successfully underwent total arch replacement by a fourth intercostal thoracotomy performed using an anterior bilateral approach and the arch-first technique. To our knowledge, this is the first report of a case of total arch replacement in a patient with subacute aortic dissection and a terminal tracheostoma.

Late spontaneous internal thoracic artery graft dissection after coronary bypass grafting: a case report.

Background: Internal thoracic artery (ITA) grafts are commonly used for coronary artery bypass grafting, with dissection to the graft being a rare occurrence. Herein, we describe a case of spontaneous ITA graft dissection occurring 11 years after grafting, with no clear precipitating incidence. Case summary: The patient was a 61-year-old man who presented with a 3-month history of chest pain and dyspnoea. Dissection of the left internal thoracic artery (LITA) graft was observed on angiography, with a thrombolysis in the myocardial infarction (TIMI) grade 2 blood flow. Intravascular ultrasound confirmed an intimal tear in the proximal graft, with an intramural haematoma. In the absence of atherosclerotic changes, the dissection was treated directly using multiple drug-eluting stents to prevent further extension of the intramural haematoma proximally into the subclavian artery and distally to the anastomosis site. Post-procedural angiography revealed an enlarged true lumen of the LITA, shrinking of the intramural haematoma, and improvement in blood flow to a TIMI grade 3. Chest symptoms resolved immediately after the procedure, with the patient remaining asymptomatic over the 6-month period following the procedure. Discussion: Dissection of the ITA graft can occur spontaneously long after the initial grafting. Intravascular ultrasound is useful for diagnosis. Ensuring adequate coverage of the edges of the dissection with stenting could prevent further extension of the intramural haematoma.