Configuration of the neoaortic root after chimney reconstruction in the Norwood procedure.

OBJECTIVES: After staged reconstruction for hypoplastic left heart syndrome, the neoaortic root tends to dilate, and the incidence of significant neoaortic valve insufficiency increases with time. This study aimed to evaluate the mid-term outcomes of the neoaortic root geometries and valve function after chimney reconstruction in the Norwood procedure. METHODS: Between 2013 and 2021, 20 consecutive patients who underwent chimney reconstruction during the Norwood procedure for hypoplastic left heart syndrome and its variants in our institution were enrolled. The actual diameters of the following points were measured, and Z-scores were calculated based on the normal aortic root geometries using the long axis view of echocardiography at the pre-Norwood stage and the lateral view of angiography at pre-Glenn, pre-Fontan, post-Fontan and follow-up (age 5-6 years) stages: neoaortic valve annulus; sinus of Valsalva; sinotubular junction; and ascending aorta just proximal to the anastomosis to the aortic arch. The degree of neoaortic valve regurgitation was evaluated by echocardiography at each stage. RESULTS: The median follow-up period was 3.9 years. Neoaortic roots after chimney reconstruction were spared from progressive dilation over time. With growth, the conical configuration of the neoaortic roots was preserved without geometrical distortion. The Z-scores of the annulus, sinus of Valsalva, sinotubular junction and ascending aorta ranged roughly from 4 to 6, 4 to 6, 2 to 4 and 0 to 2, respectively. All neoaortic valves at each stage had mild or no regurgitation. CONCLUSIONS: Chimney reconstruction prevented neoaortic root dilation and avoided significant neoaortic valve regurgitation in the mid-term. These neoaortic dimensions with smooth flow profiles in the neoaorta after chimney reconstruction may have contributed to the current results. Further studies are needed to clarify the long-term outcomes.

Effectiveness of cardiac palliative surgery for trisomy 18 patients with increased pulmonary blood flow.

Congenital heart disease (CHD) is common among patients with trisomy 18 (T18), but cardiac surgery has been rarely indicated for T18 patients due to their short life span. Although the therapeutic effects of aggressive interventions were recently demonstrated for T18 patients, the subjects and factors examined varied, resulting in inconsistent findings. Therefore, the effects of cardiac surgery for T18 remain unclear. We herein investigated the outcomes of cardiac palliative surgery for CHD with increased pulmonary blood flow in T18 patients. 27 patients were examined: 13 (48.1%) underwent cardiac palliative surgery and 14 (51.9%) did not. Median survival times in the no-surgery and surgery groups were 223.0 days (95% confidence interval [CI]: 46-361 days) and 723.0 days (95% CI: 360-1447 days), respectively. The number of patients with pulmonary hypertension significantly differed between the two groups (5 of 14 in the no-surgery group and 0 in the surgery group). Five of 14 patients in the no-surgery group and 10 of 13 in the surgery group were discharged to home care (odds ratio: 10.8 [95% CI: 1.07-110.0]). Therefore, cardiac palliative surgery may be used to treat CHD with increased pulmonary blood flow in T18 patients.

A new predictor of the optimal pulmonary artery reconstruction method during the arterial switch operation.

OBJECTIVES: The aim of this study was to more accurately predict the optimal pulmonary artery (PA) reconstruction procedure (Lecompte manoeuvre or original Jatene procedure) during the arterial switch operation, we focused on the horizontal sectioning (HS) angle between the left hilum PA and the great arteries using preoperative computed tomography imaging. METHODS: We defined the HS angle α (ß) as the angle between the tangential line from the posterior (anterior) wall of the left PA at the hilum to the left anterior (right posterior) surface of the main PA and the tangential line from the left surface of the ascending aorta to the left anterior (right posterior) surface of the main PA. We identified 14 consecutive patients diagnosed with transposition of the great arteries or transposition of the great artery-type double-outlet right ventricle who underwent preoperative computed tomography imaging. The original Jatene or Lecompte procedure was used for 9 (OJ group) and 5 (L group) patients. Relationships of the great arteries of the OJ and L groups were side by side in 8 and 2 patients, oblique in 1 and 1 patient and anteroposterior in 0 and 2 patients, respectively. RESULTS: In the OJ group, ß was greater than α in all patients. The median α/ß value was 0.618. In group L, α was greater than ß in all patients. The median α/ß was 1.307. Left PA stenosis caused by stretching was not observed in the L group. Coronary obstruction was not identified in the OJ group. Left PA stenosis behind the neo-ascending aorta was observed in 1 patient in the OJ group and required reoperation. CONCLUSIONS: The HS angle may be a useful predictor of optimal intraoperative PA reconstruction during arterial switch operation, especially for side-by-side or oblique relationships.

Characteristic differences in the abundance of tumor-infiltrating lymphocytes and intratumoral developing T cells in thymoma, with special reference to PD-1 expression.

PURPOSE: Though programmed cell death-1 (PD-1) inhibitors mainly target tumor-infiltrating lymphocytes (TILs) expressing PD-1, developing T cells in thymus also express PD-1 in their process of maturation. To predict the therapeutic effect of PD-1 inhibitors for thymoma, it is necessary to clarify the proportions of TILs and intratumoral developing T cells. METHODS: The expressions of CD4, CD8, and PD-1 on T cells were analyzed by flow cytometry in 31 thymomas. The amount of T cell receptor excision circles (TRECs), which can be detected in newly formed naïve T cells in the thymus, was evaluated using sorted lymphocytes from thymomas by quantitative PCR. The expressions of granzyme B (GZMB) and lymphocyte activation gene-3 (LAG-3) in PD-1 + CD8 T cells were analyzed by image cytometry using multiplex immunohistochemistry. RESULTS: The PD-1 + rate in both CD4 and CD8 T cells was significantly higher in type AB/B1/B2 than in type A/B3 thymomas. The amounts of TRECs in CD4 and CD8 T cells were significantly higher in type AB/B1/B2 than in type A/B3 thymomas and comparable to normal thymus. PD-1 expression at each stage of T cell development of type AB/B1/B2 thymomas was comparable to that of normal thymus. Both the percentages and cell densities of PD-1 + CD8 T cells expressing GZMB or LAG-3, which are known to contain tumor-reactive T cells, were significantly lower in type AB/B1/B2 thymomas. CONCLUSION: Most PD-1 + T cells in type AB/B1/B2 thymomas are intratumoral developing T cells and are not TILs.

Multiple Pulmonary Artery Plasty With Tissue-Engineered Vascular Grafts.

In pediatric cardiovascular surgery, the autologous pericardium is useful for pulmonary artery augmentation. However, in some cases, the autologous pericardium may not be available for various reasons. Since 2014, we have developed tissue-engineered vascular grafts (TEVGs) and obtained good results. We report a successful case of multiple pulmonary artery plasty with TEVGs for pulmonary atresia/ventricular septal defect with major aortopulmonary collateral arteries. TEVGs are useful alternatives to autologous pericardium in pediatric cardiovascular operations that often require multistage procedures.

Effect of procedural volume on the outcomes of congenital heart surgery in Japan.

OBJECTIVES: The present study developed a new risk model for congenital heart surgery in Japan and determined the relationship between hospital procedural volume and mortality using the developed model. METHODS: We analyzed 47,164 operations performed between 2013 and 2018 registered in the Japan Cardiovascular Surgery Database-Congenital and created a new risk model to predict the 90-day/in-hospital mortality using the Japanese congenital heart surgery mortality categories and patient characteristics. The observed/expected ratios of mortality were compared among 4 groups based on annual hospital procedural volume (group A [5539 procedures performed in 90 hospitals]: ≤50, group B [9322 procedures in 24 hospitals]: 51-100, group C [13,331 procedures in 21 hospitals]: 101-150, group D [18,972 procedures in 15 hospitals]: ≥151). RESULTS: The overall mortality rate was 2.64%. The new risk model using the surgical mortality category, age-weight categories, urgency, and preoperative mechanical ventilation and inotropic use achieved a c-index of 0.81. The observed/expected ratios based on the new risk model were 1.37 (95% confidence interval, 1.18-1.58), 1.21 (1.08-1.33), 1.04 (0.94-1.14), and 0.78 (0.71-0.86) in groups A, B, C, and D, respectively. In the per-procedure analysis, the observed/expected ratios of the Rastelli, coarctation complex repair, and arterial switch procedures in group A were all more than 3.0. CONCLUSIONS: The risk-adjusted mortality rate for low-volume hospitals was high for not only high-risk but also medium-risk procedures. Although the overall mortality rate for congenital heart surgeries is low in Japan, the observed volume-mortality relationship suggests potential for improvement in surgical outcomes.

In Vitro Modelling for Bulging Sinus Effects of an Expanded Polytetrafluoroethylene Valved Conduit Based on High-Speed 3D Leaflet Evaluation.

The study aimed to develop a pulmonary circulatory system capable of high-speed 3D reconstruction of valve leaflets to elucidate the local hemodynamic characteristics in the valved conduits with bulging sinuses. Then a simultaneous measurement system for leaflet structure and pressure and flow characteristics was designed to obtain valve leaflet dynamic behaviour with different conduit structures. An image preprocessing method was established to obtain the three leaflets behaviour simultaneously for one sequence with two leaflets images from each pair of three high-speed cameras. Firstly, the multi-digital image correlation analyses were performed, and then the valve leaflet structure was measured under the static condition with fixed opening angles in the water-filled visualization chamber and the pulsatile flow tests simulating paediatric pulmonary flow conditions in the different types of conduit structures; with or without bulging sinuses. The results showed the maximum 3D reconstruction error to be around 0.06 mm. In the steady flow test, the evaluation of opening angles under the different flow rates conditions was achieved. In the pulsatile flow test, each leaflet's opening and closing behaviours were successfully reconstructed simultaneously at the high-frequency recording rate of 960fps. Therefore, the system developed in this study confirms the design evaluation method of an ePTFE valved conduit behaviour with leaflet structures interacting with local fluid dynamics in the vicinity of valves. Clinical Relevance- The system reveals the bulging sinus effects on ePTFE valve leaflet motion by the 3D reconstruction using multi-camera high-speed sequential imaging in vitro.

Cardiogenic Shock Due to Unsuspected Tachycardia in a Child.

A 10-year-old girl experienced cardiac failure due to atrial tachycardia originating from a left atrial appendage. Surgical appendectomy was done after a recurrence of the atrial tachycardia just after the first attempt at catheter ablation. A second ablation attempt was avoided because of the risk of cardiac perforation. (Level of Difficulty: Intermediate.).

Surgical repair of a posterior left ventricular aneurysm in a 4-year-old boy.

Left ventricular aneurysms are rarely encountered in pediatric patients. A 4-year-old boy was diagnosed with severe mitral regurgitation and a posterior left ventricular aneurysm associated with a viral infection. The aneurysm was surgically resected and plicated longitudinally with a combination of an interrupted mattress and continuous over-and-over sutures with an outer felt reinforcement. The mitral regurgitation was reduced to a trivial degree postoperatively. The patient's postoperative recovery was good. He was discharged 31 days after surgery without cardiac dysfunction or lethal arrhythmia. Considering the location and spread of the aneurysm, an appropriate surgical procedure should be adopted for pediatric patients.

Long-term surgical results of transposition of the great arteries with left ventricular outflow tract obstruction.

OBJECTIVE: The objective of this study was to evaluate the long-term surgical results of transposition of the great arteries with left ventricular outflow tract obstruction. METHODS: We conducted a retrospective study of patients with transposition of the great arteries or double outlet right ventricle with left ventricular outflow tract obstruction undergoing biventricular repair between 1980 and 2017. RESULTS: One hundred and eleven patients were enrolled and classified into five groups: atrial switch (n = 20), arterial switch (n = 12), Nikaidoh (n = 7), Rastelli (n = 48), and REV operation groups (n = 24). Early mortality was highest in Nikaidoh group (29%). Median follow-up was 18.2 years. Long-term survival was by far lowest in Nikaidoh group and comparable among the other 4 groups. Freedom from reoperation at 20 years was lowest in Rastelli group (32.1%) due to right ventricular outflow tract-related reoperations. While having no recurrence of left ventricular outflow tract obstruction, the arterial switch operation group had a high proportion of substantial neo-aortic regurgitation (29%). CONCLUSIONS: The long-term survival was satisfactory regardless of the surgical technique except Nikaidoh group. The surgical option for transposition of the great arteries with left ventricular outflow tract obstruction should be selected based on the features of the respective procedures.

Coronary artery bypass grafting for coronary artery anomalies in infants and young children.

OBJECTIVES: Coronary artery bypass grafting (CABG) has been reported for coronary artery diseases in patients with Kawasaki disease and coronary artery complications after arterial switch operations for transposition of the great arteries. However, only a few studies have explored this modality for congenital coronary artery anomalies. As congenital coronary artery anomalies, particularly left coronary artery atresia and stenosis, are one of the reasons for sudden death, coronary revascularization is often required in infants and young children. Therefore, we aimed to investigate the outcome of CABG for such anomalies in infants and young children. METHODS: From 2014 to 2018, 3 infants and 2 children (median age: 10 months; range: 6-40 months) with coronary artery anomalies underwent CABG at our hospital. The indications for the procedure included left main coronary artery atresia and stenosis in 2 and 3 patients, respectively. Graft patency was evaluated postoperatively by contrast-enhanced computed tomography or coronary angiography, and postoperative outcomes (including death and cardiac events) were assessed during the follow-up period. RESULTS: No 30-day or in-hospital mortalities were noted. Postoperative examinations revealed patent grafts in all patients. They were discharged without any cardiac complications. Regarding the outcomes at the follow-up period, the graft patency rate was 80.0% (4/5 grafts), with no deaths or cardiac events. CONCLUSIONS: CABG is a useful strategy for coronary revascularization in infants and young children with coronary artery anomalies. Although the mid-term outcomes and patency are satisfactory, careful follow-up is necessary because the long-term outcomes remain unknown.

Pulmonary artery augmentation and aortic valve repair using novel tissue-engineered grafts.

Objectives: The objectives of this study were to evaluate the results when tissue-engineered vascular grafts (TEVGs) are used as alternatives to autologous pericardium for surgically augmenting the pulmonary artery (PA) or aortic valve. Methods: TEVG molds were embedded into subcutaneous spaces for more than 4 weeks preoperatively. Since 2014, 6 patients have undergone PA reconstruction, whereas 1 has undergone aortic valve plasty (AVP) with TEVGs. The time from mold implantation to the operation was 8.9 (range, 6.0-26.4) months. The age and body weight at the time of operation were 2.7 (range, 1.8-9.2) and 11.6 (range, 7.9-24.4) kg, respectively. Concomitant procedures comprised the Rastelli, palliative Rastelli, and Fontan operations in 2, 2, and 1 patient, respectively. Results: The median follow-up period was 14.4 (range, 3-39.6) months. There were no early or late mortalities. Moreover, there were no TEVG-related complications, including aneurysmal changes, degeneration, and infection. In 5 patients who underwent PA augmentation, the postoperative PA configuration was satisfactorily dilated. The reconstructed aortic valve function was good in the patient who underwent AVP. Decreased leaflet flexibility due to leaflet thickening was not observed. One patient had postoperative PA re-stenosis; therefore, re-PA augmentation with TEVGs was performed. On histological examination, TEVGs consisted of collagen fibers and few fibroblasts, and elastic fiber formation and/or smooth muscle cells were not observed. Conclusions: The midterm results of PA reconstruction and AVP with TEVGs were satisfactory. TEVGs might be a useful alternative to autologous pericardium in pediatric cardiovascular surgeries that often require multistage operations.

Histological finding of maternal antibody-associated congenital heart block accompanied by large atrial septal defect and severe cardiac dysfunction.

Cardiac dysfunction commonly occurs in congenital heart block associated with maternal anti-SSA antibodies, especially after pacemaker implantation. We report the case of a 4-year-old girl with antibody-associated congenital heart block and a large secundum atrial septal defect who presented with significant cardiac dysfunction 4 years after pacemaker implantation. Histological findings were useful for determining the course of treatment and perioperative risk of intracardiac repair.

Hemodynamic Parameters for Cardiovascular System in 4D Flow MRI: Mathematical Definition and Clinical Applications.

Blood flow imaging becomes an emerging trend in cardiology with the recent progress in computer technology. It not only visualizes colorful flow velocity streamlines but also quantifies the mechanical stress on cardiovascular structures; thus, it can provide the detailed inspections of the pathophysiology of diseases and predict the prognosis of cardiovascular functions. Clinical applications include the comprehensive assessment of hemodynamics and cardiac functions in echocardiography vector flow mapping (VFM), 4D flow MRI, and surgical planning as a simulation medicine in computational fluid dynamics (CFD).For evaluation of the hemodynamics, novel mathematically derived parameters obtained using measured velocity distributions are essential. Among them, the traditional and typical parameters are wall shear stress (WSS) and its related parameters. These parameters indicate the mechanical damages to endothelial cells, resulting in degenerative intimal change in vascular diseases. Apart from WSS, there are abundant parameters that describe the strength of the vortical and/or helical flow patterns. For instance, vorticity, enstrophy, and circulation indicate the rotating flow strength or power of 2D vortical flows. In addition, helicity, which is defined as the cross-linking number of the vortex filaments, indicates the 3D helical flow strength and adequately describes the turbulent flow in the aortic root in cases with complicated anatomies. For the description of turbulence caused by the diseased flow, there exist two types of parameters based on completely different concepts, namely: energy loss (EL) and turbulent kinetic energy (TKE). EL is the dissipated energy with blood viscosity and evaluates the cardiac workload related to the prognosis of heart failure. TKE describes the fluctuation in kinetic energy during turbulence, which describes the severity of the diseases that cause jet flow. These parameters are based on intuitive and clear physiological concepts, and are suitable for in vivo flow measurements using inner velocity profiles.

Expanded Polytetrafluoroethylene Conduits With Bulging Sinuses and a Fan-Shaped Valve in Right Ventricular Outflow Tract Reconstruction.

We developed a handmade expanded polytetrafluoroethylene (ePTFE) pulmonary valvular conduit (PVC) with bulging sinuses and a fan-shaped ePTFE valve for right ventricular outflow tract (RVOT) reconstruction. We aimed to investigate the results of this device in this multicenter study. From 2001 to 2020, 1776 patients underwent RVOT reconstruction using ePTFE PVCs at 65 institutions in Japan. The median age and body weight were 4.1 years (range, 3 days to 67.1 years) and 13.3 (range, 1.8-91.3) kg, respectively. The median PVC size was 18 (range, 8-24) mm. The median Z-value of the ePTFE PVC was 1.1 (range, -3.8 to 5.0). The ePTFE PVC conditions were investigated by cardiac echocardiography and catheterization. The median follow-up period was 3.3 years (range, 0 day to 16.2 years). There were only 9 cases (0.5%) with PVC-related unknown deaths. Reintervention was performed in 283 patients (15.9%), and 190 patients (10.7%) required explantation. Freedom from reintervention and explantation at 5/10 years were 86.7/61.5% and 93.0/69.1%, respectively. At the latest echocardiography, PVC regurgitation grade was better than mild in 88.4% patients. The average peak RVOT gradient was 15.7 ± 15.9 mm Hg at the latest cardiac catheterization. ePTFE PVC infection was detected in only 8 patients (0.5%). Relative stenosis due to somatic growth was the most common cause of PVC explantation. The performance of ePTFE in terms of durability, valvular performance, and the resistance against infection is considerable and may replace conventional prosthetic materials. Further improvement of the ePTFE membrane is essential to prevent valvular dysfunction.

A case of redo tricuspid valve repair after neonatal cone operation for Ebstein's anomaly.

Cone reconstruction for Ebstein's anomaly, although effective, is challenging in neonatal cases. Very few reports have discussed recurrent regurgitation. Herein, we report a successful redo tricuspid valve repair for recurrent regurgitation 5 years after cone reconstruction. A 5-year-old boy underwent cone reconstruction for Ebstein's anomaly in the neonatal period. Although tricuspid regurgitation reduced initially, it subsequently worsened. The mechanisms of regurgitation are dilatation of the anteroseptal commissure, indentation in the septal leaflet, and foreshortening of the anterior leaflet. Augmentation of the anterior leaflet using an elliptic autologous pericardium and mending of the gaping commissure and indentation markedly reduced the regurgitation.

Outcome of Pulmonary Autograft After the Ross Procedure.

BACKGROUND: The purpose of this study was to assess autograft function after the Ross procedure and to review surgical outcomes associated with autograft reoperations. METHODS: This is a retrospective study of patients undergoing the Ross procedure since 1993. Autograft function and autograft reoperation were studied. Autograft failure was defined as more than moderate autograft regurgitation or autograft dilatation to more than 50 mm diameter or z-score of more than +4 in children. One hospital death was excluded from analysis as were patients with unknown late autograft status. RESULTS: Among 75 patients analyzed, preoperative diagnosis before the Ross procedure included aortic regurgitation in 26, aortic stenosis in 19, combined lesions in 28, and 2 mechanical valve malfunctions. Median age at the Ross procedure was 12.1 (0.4-43.6) years with 44 children less than 15 years old. Six patients had greater than mild autograft regurgitation at post-Ross hospital discharge. During median follow-up of 14.9 years, there were 23 autograft failures. Eighteen autograft reoperations were performed on 17 patients (13 children), including 12 aortic valve replacements, 5 aortic root replacements (including 1 valve-sparing root replacement), and 1 Konno procedure. Freedom from autograft failure and autograft reoperation at 20 years after the Ross procedure was 52.0% and 66.3%, respectively. Multivariate analysis identified greater than mild autograft regurgitation at hospital discharge from Ross procedure as a risk factor for autograft failure (P < .01). All patients who underwent autograft reoperation survived and had good health status at a median of 6.9 years after the reoperation. CONCLUSIONS: The Ross procedure is effective in delaying prosthetic aortic valve replacement, although the time-related risk of autograft failure is a real consideration.

Chimney reconstruction provides a wider subaortic space and reduces the risk of pulmonary artery compression in the Norwood-type aortic arch reconstruction without patch supplementation.

OBJECTIVES: Pulmonary artery (PA) compression by the neoaorta is a serious complication after the Norwood-type palliation (NP) for hypoplastic left heart syndrome. Either excess patch tailoring or limited use of autologous tissue may cause narrowing of the subaortic space. The chimney technique could theoretically provide a wide subaortic space. METHODS: Twenty-nine patients with both pre- and post-NP computed tomography data available of the 37 consecutive patients who underwent NP in our institution were reviewed. Arch height, arch width, sinus of Valsalva diameter, area under the neoaortic arch and arch angle were measured. These patients were divided according to the neo-arch reconstruction technique, chimney reconstruction technique (CR) or conventional direct reconstruction technique (DR). RESULTS: Median age and weight at NP were 2.1 months and 3.5 kg, respectively. Twenty-two patients underwent previous bilateral PA banding. During NP, 17 CR and 12 DR were performed. Four patients in the DR group developed PA compression. No neoaortic arch dilatation was found in either group. Post-NP arch width, area under the neo-arch and the arch angle were significantly larger in the CR group. Pre-NP arch height was significantly smaller in DR patients with PA compression than in those without. CONCLUSIONS: The chimney technique decreased the risk of PA compression and provided a wider subaortic space and a less acute arch angle. This technique had no short-term effect on the neoaortic root. Small preoperative arch height is a potential risk factor for PA compression in DR, and the chimney technique could be an effective solution.