Left bronchial compression after aortic arch reconstruction for coarctation of the aorta.

BACKGROUND: This study aimed to investigate the preoperative positional relationships between the blood vessels and the left bronchus during the development of left bronchial compression (LBC) after aortic arch reconstruction for coarctation of the aorta (CoA). METHODS: We retrospectively reviewed data from 29 patients with CoA who underwent aortic arch reconstruction via median sternotomy between 2009 and 2019. The patients were divided into those who underwent aortic arch advancement (AAA) with (C group, six patients) or without (N group, 10 patients) postoperative LBC and those who underwent extended end-to-end anastomosis (E group, 13 patients). We determined the sterno-spinal axis (SSA) of the patients and evaluated the preoperative and postoperative positions of the vessels on the axial and three-dimensional multidetector row computed tomography (CT) angiographic images. RESULTS: The distance between the ascending and descending aortas was significantly smaller in both C and N groups postoperatively than preoperatively. The distance between the descending aorta and SSA in the C group was markedly smaller compared with that in the other groups preoperatively and was increased postoperatively. Preoperatively, the distance from the left bronchus to the aortic arch in the C group was significantly larger than that in the other groups and was decreased postoperatively. The postoperative arch angle in the C group was significantly smaller than that in the other groups. CONCLUSION: A preoperative midline position of the descending aorta and highly displaced aortic arch in relation to the left bronchus on preoperative CT images could cause the postoperative LBC after AAA.

Growing Coronary Aneurysm Secondary to Coronary Fistula Despite Decreased Pulmonary Blood Flow/Systemic Blood Flow Ratio in a Child: A Case Report.

Coronary aneurysm secondary to coronary fistula is a rare condition, with no existing report on its pathological examination. We report the case of a patient diagnosed with a right coronary artery fistula with coronary aneurysm during the fetal period. During follow-up after delivery, the aneurysm became larger, even though the shunt size decreased. We were afraid the aneurysm would rupture and therefore, planned elective catheter embolization. At the age of 4 years, the patient underwent surgery, which involved closing the fistula and making the lumen of the aneurysm smaller. However, the surgery was not catheter embolization as planned because segment 3 branched off from the largest aneurysm where we planned to embolize. Pathologically, the structure of the coronary artery differed from that of a healthy one, with thickened intima and media, fewer scattered smooth muscle cells, widely distributed elastic fibers, and mucoid degeneration in the media. The structure of the coronary artery suggested that the vessel wall was weak and that the aneurysm would rupture if not treated. Postoperative coronary angiography showed that segment 2 was obstructed, while the collaterals from the left coronary artery perfused the area. We could have treated the fistula with a catheter as scheduled.

Surgical treatment of isolated unilateral absence of pulmonary artery with pulmonary hypertension.

A one-and-a-half-month-old patient with isolated unilateral absence of the right proximal pulmonary artery with prominent left pulmonary hypertension was diagnosed using CT. Medication therapy was initiated first. Left pulmonary artery pressure decreased after the initiation of medication therapy, and single-stage reconstruction of the right pulmonary artery was performed. The patient is asymptomatic 14 months postoperatively.

Active mitral valve endocarditis with widespread interventricular septal abscesses in a paediatric patient.

We present the case of a previously healthy 2-year-old boy with extensive infective mitral valve endocarditis, with 2 huge, mobile vegetations attached to the anterior leaflet of the mitral valve and to the left ventricular outflow tract, and interventricular septal abscesses extending into the left ventricular outflow tract without any septal defects. He underwent mitral valve repair and simultaneous drainage of the interventricular septal abscesses excluding the inlet portion to avoid postoperative complications.

Pulmonary venous obstruction after extracardiac total cavopulmonary connection in right atrial isomerism.

BACKGROUND: Patients with functional single ventricle and right atrial isomerism (RAI) often have multiform cardiac pulmonary venous (PV) connection, which could be a risk factor for pulmonary venous obstruction (PVO) after extracardiac total cavopulmonary connection (EC-TCPC) owing to compression of the conduit. OBJECTIVE: To investigate the anatomical risk factors for PVO after EC-TCPC in RAI. METHODS: Twenty-nine patients with RAI without extracardiac total anomalous pulmonary venous connection were enrolled. No patients had PVO before EC-TCPC. A total of 14 and 15 patients had PV orifices ipsilateral and contralateral to the extracardiac conduit, respectively. The former 14 patients were assigned to two groups based on development of PVO after EC-TCPC (groups O and N). The pre- and post-operative cardiac morphologies and their relationship with the conduit were compared. RESULTS: After the EC-TCPC, the pressure gradients between the atrium and the PV were 5.0 ± 2.5 and 0.44 ± 0.2 mmHg in groups O and N, respectively (p < 0.01); however, the pressure gradients in the left and right PVs were not significantly different, suggesting stenosis of the common PV orifice. The ratio of the horizontal distance from the vertebrae to the PV orifice and to the lateral edge of the atrium was significantly higher (0.38 ± 0.2 vs. 0.17 ± 0.1; p = 0.04) and the orifice was smaller (8.9 ± 2.0 vs. 15 ± 4.7 mm; p < 0.01) in group O than in group N. CONCLUSION: In cases with ipsilateral locations of the conduit and PV orifice, small size and more lateral location of the PV orifice may be preoperative risk factors for development of PVO.

Hand-sewn trileaflet valve in the right ventricular outflow tract.

A 4-year-old girl with pulmonary regurgitation after complete repair of tetralogy of Fallot, underwent an alternative surgical repair for pulmonary valve replacement. Hand-sewn trileaflet valve reconstruction using expanded polytetrafluoroethylene membrane is a feasible method for pulmonary regurgitation in such a young child in whom a large-sized bioprosthetic valve cannot be implanted.

Trileaflet pulmonary valve reconstruction for pulmonary regurgitation in childhood.

A 6-year-old boy with pulmonary regurgitation after complete repair of congenital heart disease underwent an alternative surgical repair for pulmonary valve replacement. Trileaflet pulmonary valve reconstruction using expanded polytetrafluoroethylene membrane is a clinically feasible technique for pulmonary regurgitation in such a young child in whom large-sized bioprosthetic valves cannot be implanted.

An alternative technique for direct implantation of an anomalous left coronary artery arising from the pulmonary artery with complex coronary arteries.

A 2-month-old patient with anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) underwent an alternative repair involving coronary transfer with the bay window technique because of the very short left main coronary trunk. This procedure is a clinically relevant and feasible technique for ALCAPA with such a delicate coronary artery anomaly.

Modified commissural patch repair in a child with active mitral endocarditis.

A 9-year-old patient with massive destruction of the mitral apparatus caused by active infective endocarditis underwent mitral valve plasty using a modified commissural autologous pericardial patch repair. This procedure is a clinically relevant and feasible technique for pediatric patients with active mitral valve endocarditis.

Novel technique for implantation of a cardioverter defibrillator in children.

An 8-year-old boy with hypertrophic nonobstructive cardiomyopathy with ventricular fibrillation underwent implantation of an implantable cardioverter defibrillator. The lead was inserted through a pursestring suture in the right atrial appendage, and the tip of coil was placed in the right ventricular apex under fluoroscopic guidance. Another defibrillation coil was placed in the back of the left atrium and left ventricle by the transverse sinus. The device wrapped in a monofilament mesh sheet was placed in the intraperitoneal space. This case utilized a new technique for an implantable cardioverter defibrillator implantation in a small child.

Functional and pathological characteristics of reversible remodeling in a canine right ventricle in response to volume overloading and volume unloading.

PURPOSES: Patients who undergo right ventricular (RV) outflow augmentation inevitably develop RV remodeling due to pulmonary insufficiency-related volume overload (VOL). However, the reversibility of this remodeling is not fully understood. The goal of this study was to establish an animal model of VOL and unloading to characterize the functional and pathological characteristics and reversibility of RV remodeling. METHODS: VOL-RV was successfully induced by establishing direct RV-pulmonary artery (PA) bypass for 12 weeks in beagle canines. There were no procedure-related mortalities (n = 8). RESULTS: The RV developed typical functional features of VOL-related remodeling, such as a significant increase in end-diastolic/systolic volume and end-systolic pressure and a significant reduction in ejection fraction at 12 weeks, as assessed by three-dimensional echocardiography and cardiac catheterization. The RV developed typical pathological signs of remodeling, microstructural disorganization of cardiomyocytes, and/or structural/functional deterioration of the mitochondria. Volume unloading by division of the RV-PA bypass reversed the increase in the end-systolic/diastolic volume over 4 weeks when compared with a sham operation (n = 4 each). In addition, the bypass division also reversed the pathological changes seen in VOL-RV. CONCLUSIONS: VOL-RV that yielded typical functional and pathological features of RV remodeling was reproducibly achieved by direct RV-PA bypass in canines. The RV remodeling due to VOL was functionally and pathologically reversed by volume unloading via the bypass division.

Synthetic prostacyclin agonist, ONO1301, enhances endogenous myocardial repair in a hamster model of dilated cardiomyopathy: a promising regenerative therapy for the failing heart.

OBJECTIVES: Remodeling of the left ventricle (LV) in idiopathic dilated cardiomyopathy (IDCM) is known to be associated with multiple pathologic changes that endogenous factors, such as hepatocyte growth factor (HGF) and vascular endothelial growth factor (VEGF), protect against. Although a clinically relevant delivery method of these factors has not been established, ONO1301, a synthetic prostacyclin agonist, has been shown to upregulate multiple cardioprotective factors, including HGF and VEGF, in vivo. We thus hypothesized that ONO1301 may reverse LV remodeling in the DCM heart. METHODS: ONO1301 dose-dependently added to the normal human dermal fibroblasts and human coronary artery smooth muscle cells in vitro, to measure the expression of HGF, VEGF, stromal cell-derived factor (SDF)-1, and granulocyte-colony stimulating factor (G-CSF), assessed by real-time polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay. δ-Sarcoglycan-deficient J2N-k hamsters, which is an established DCM model, were treated by epicardial implantation of an atelocollagen sheet with or without ONO1301 immersion or sham operation. RESULTS: ONO1301 dose-dependently upregulated expression of these 4 factors in vitro. ONO1301 treatment, which induced dominant elevation of ONO1301 levels for 2 weeks, significantly preserved cardiac performance and prolonged survival compared with the other groups. This treatment significantly upregulated expressions of cardioprotective factors and was associated with increased capillaries, attenuated fibrosis, and upregulation of α-sarcoglycan in the DCM heart. CONCLUSIONS: ONO1301 atelocollagen-sheet implantation reorganized cytoskeletal proteins, such as α-sarcoglycan, increased capillaries, reduced fibrosis, and was associated with upregulated expression of multiple cardioprotective factors, leading to preservation of cardiac performance and prolongation of survival in the δ-sarcoglycan-deficient DCM hamster.

Sustained-release delivery of prostacyclin analogue enhances bone marrow-cell recruitment and yields functional benefits for acute myocardial infarction in mice.

BACKGROUND: A prostacyclin analogue, ONO-1301, is reported to upregulate beneficial proteins, including stromal cell derived factor-1 (SDF-1). We hypothesized that the sustained-release delivery of ONO-1301 would enhance SDF-1 expression in the acute myocardial infarction (MI) heart and induce bone marrow cells (BMCs) to home to the myocardium, leading to improved cardiac function in mice. METHODS AND RESULTS: ONO-1301 significantly upregulated SDF-1 secretion by fibroblasts. BMC migration was greater to ONO-1301-stimulated than unstimulated conditioned medium. This increase was diminished by treating the BMCs with a CXCR4-neutralizing antibody or CXCR4 antagonist (AMD3100). Atelocollagen sheets containing a sustained-release form of ONO-1301 (n = 33) or ONO-1301-free vehicle (n = 48) were implanted on the left ventricular (LV) anterior wall immediately after permanent left-anterior descending artery occlusion in C57BL6/N mice (male, 8-weeks-old). The SDF-1 expression in the infarct border zone was significantly elevated for 1 month in the ONO-1301-treated group. BMC accumulation in the infarcted hearts, detected by in vivo imaging after intravenous injection of labeled BMCs, was enhanced in the ONO-1301-treated hearts. This increase was inhibited by AMD3100. The accumulated BMCs differentiated into capillary structures. The survival rates and cardiac function were significantly improved in the ONO-1301-treated group (fractional area change 23±1%; n = 22) compared to the vehicle group (19±1%; n = 20; P = 0.004). LV anterior wall thinning, expansion of infarction, and fibrosis were lower in the ONO-1301-treated group. CONCLUSIONS: Sustained-release delivery of ONO-1301 promoted BMC recruitment to the acute MI heart via SDF-1/CXCR4 signaling and restored cardiac performance, suggesting a novel mechanism for ONO-1301-mediated acute-MI heart repair.