Impact of the Rudimentary Chamber on Outcomes in Fontan Patients.

Background: We sought to evaluate the influence of the rudimentary ventricle on long-term outcomes after the Fontan operation, focusing on exercise capacity and cardiac performance. Methods: Between 1995 and 2021, 290 patients underwent a total cavopulmonary connection. "Two-ventricle" Fontan circulation was defined as a rudimentary ventricle >30% of the dominant ventricle or >50% of its predicted normal value. This cohort was compared with patients with single-ventricle Fontan circulation. The primary endpoint was Fontan failure, and the secondary endpoints were VO2 and cardiac catheterization data at ten years postoperatively. Results: The median follow-up after the Fontan operation was 7.9 years (interquartile range: 1.9-13.9). No significant difference was found in Fontan failure-free survival between the "two-ventricle" Fontan circulation group and the single-ventricle Fontan circulation group (83/91, 93% vs 156/199, 78%), respectively at 20 years; P = .11). No significant difference was found in VO2 or cardiac performance except cardiac index, with 2.9 (2.3-4.8) versus 2.5 (2.3-4.3) L/min/m2 (P = .047). Fifty-one patients in the "two-ventricle" Fontan circulation group were followed up for over ten years after the Fontan operation. In the subgroup analysis of this cohort, the rudimentary ventricular end-diastolic volume/dominant ventricular end-diastolic volume ratio showed a significant positive correlation with dominant ventricular end-diastolic pressure (r = 0.58 [95% CI 0.35-0.74], P = .002) and a significant negative correlation with VO2 (r = -0.61 [95% CI -0.80 to -0.28], P = .001). Conclusions: The rudimentary ventricle was not significantly associated with any clinical disadvantages regarding Fontan failure. However, a large rudimentary ventricle was significantly associated with higher end-diastolic pressure and lower exercise capacity.

Impact of Optimal Fenestration Size on Outcomes of High-Risk Fontan Patients.

BACKGROUND: We aimed to analyze mid-term outcomes of the fenestrated Fontan procedure, focusing on the fenestration size. METHODS: We retrospectively reviewed the outcomes of the fenestrated Fontan procedure. Among 165 patients who underwent the Fontan procedure from 2011 to 2021, fenestration was created in 27 patients with the highest risks, including those with hypoplastic left heart syndrome, hypoplastic pulmonary arteries, heterotaxy syndrome with high pulmonary vascular resistance, and pulmonary arterial pressure >15 mm Hg. The patients underwent the procedure at a median age of three years (body weight, 11.4 kg; body surface area, 0.54 m2). Fenestration sizes were 3.5 to 5 mm. RESULTS: Spontaneous fenestration closure occurred within one year postoperatively in nine patients. Among them, three experienced Fontan failure, necessitating refenestration. Although fenestration size did not differ, the size corrected by body surface area at the time of surgery was smaller in patients with fenestration closure (6.4 mm/m2 vs 8.3 mm/m2, P < .05). Patients with a fenestration <7 mm/m2 were more likely to have fenestration closure within one year postoperatively, and those with a fenestration >9 mm/m2 were more likely to have severe desaturation and require home oxygen therapy following discharge. CONCLUSIONS: Spontaneous fenestration closure affected the frequency of Fontan complications. A very small fenestration size corrected by body surface area was a significant risk factor for spontaneous closure. Conversely, a very large fenestration size corrected by body surface area resulted in severe desaturation. The optimal fenestration size to prevent early spontaneous closure and severe desaturation is approximately 8 mm/m2.

Pulmonary artery coarctation repair in univentricular heart: indications and optimal timing.

BACKGROUND: To analyse surgical outcomes of pulmonary artery coarctation in univentricular hearts, focusing on surgical indications and optimal timing. METHODS: We retrospectively reviewed 49 patients with pulmonary artery coarctation in univentricular hearts treated at our institution between 1993 and 2022. Twenty-eight patients were diagnosed before first-stage palliation. Of these, 14 underwent systemic-pulmonary shunt only as first-stage palliation (Group 1), and 14 underwent systemic-pulmonary shunt plus surgical pulmonary artery plasty as first-stage palliation (Group 2). Twenty-one patients diagnosed after first-stage palliation underwent surgical pulmonary artery plasty at the time of bidirectional Glenn procedure (Group 3). RESULTS: Follow-up period after initial palliation was 6±8 years. The Fontan procedure was successful in 35 patients (71%) aged 28±26 months (range 18-139). Freedom from interstage death (Group 1, 53%; Group 2, 85%; Group 3, 93%) and interstage reintervention (Group 1, 50%; Group 2, 75%; Group 3, 73%) rates were significantly lower in Group 1 (p = 0.01). Five and four patients in Group 1 and Group 3, respectively, needed additional shunts before the bidirectional Glenn procedure. In Group 1, one patient with a non-confluent pulmonary artery achieved hemi-lung Fontan circulation. In Group 2, one patient suffering with a non-confluent pulmonary artery could not achieve Fontan circulation, whereas another patient with pulmonary venous obstruction achieved hemi-lung Fontan circulation. CONCLUSIONS: Surgical pulmonary artery plasty performed at first-stage palliation improved outcomes of pulmonary artery coarctation in univentricular hearts, particularly when pulmonary artery coarctation had already progressed during the neonatal period or early infancy.

Outlet Ventricular Septal Defect: Impact of Surgery on the Late Aortic and Pulmonary Valve Functions.

This study retrospectively evaluated long-term post-operative aortic and pulmonary valve functions in outlet ventricular septal defects. We evaluated aortic regurgitation and pulmonary regurgitation using pre- and post-operative echocardiograms. Overall, 158 patients who underwent intracardiac repair due to outlet ventricular septal defects with aortic valve deformity or congestive heart failure were included. The median follow-up period was 7 years (interquartile range: 0-17 years), without deaths or pacemaker implantations. The age, weight, ventricular septal defect size, and mild aortic regurgitation at surgery were factors associated with post-operative residual aortic regurgitation. Mild pulmonary regurgitation was observed in 12%, 30%, and 40% of patients 5, 10, and 15 years after surgery, respectively. There were no significant differences in age and weight at which surgery was performed between patients with mild pulmonary regurgitation and those with less than mild pulmonary regurgitation. However, the number of sutures across the pulmonary valve was associated with post-operative pulmonary regurgitation (P < 0.01). As some patients with mild pre-operative aortic regurgitation may not improve even after surgery, early surgical intervention is necessary when aortic regurgitation appears. Some patients may develop post-operative pulmonary regurgitation in the long term, suggesting the need for careful follow-up.

Congenital Mitral Regurgitation Repair Based on Carpentier's Classification: Long-Term Outcomes.

BACKGROUND: There are few reports of the outcomes of standardized surgical management addressing the etiologic and morphologic aspects of mitral valve malformation according to Carpentier's classification. This study aimed to evaluate the long-term outcomes of mitral valve repair in children according to Carpentier's classification. METHODS: Patients who underwent mitral valve repair at our institution between 2000 and 2021 were retrospectively reviewed. Preoperative data, surgical techniques, and outcomes were analyzed according to Carpentier's classification. The proportion of patients free of mitral valve replacement and reoperation was estimated using Kaplan-Meier analysis. RESULTS: Twenty-three patients (median operative age, four months) were followed up for 10 (range, 2-21) years. Preoperative mitral regurgitation was severe in 12 patients and moderate in 11 patients. Eight, five, seven, and three patients had Carpentier's type 1, 2, 3, and 4 lesions, respectively. Ventricular septal defect (N = 9) and double outlet of the great arteries from the right ventricle (N = 3) were the most commonly associated cardiac malformations. There were no cases of operative mortality or deaths during the follow-up. The overall five-year rate of freedom from mitral valve replacement was 91%, whereas the five-year rates of freedom from reoperation were 74%, 80%, 71%, and 67% in type 1, 2, 3, and 4 lesions, respectively. Postoperative mitral regurgitation at the last follow-up was moderate in three patients and less than mild in 20 patients. CONCLUSIONS: Current surgical management of congenital mitral regurgitation is generally considered adequate; however, more complicated cases required a combination of various surgical techniques.

Relationship of atrial function with cardiac function in the late phase more than 20 years after a Fontan operation.

OBJECTIVES: Atrial function in Fontan patients is unknown. Our goal was to report the relationship of atrial function with the cardiac index and atrial function and clinical outcome through longer follow-up periods. METHODS: Twelve patients were followed up for over 20 years after their first Fontan operation. Atrial function, including the expansion index, atrial ejection fraction, passive ejection fraction and active ejection fraction, was examined using cardiac computed tomography. The relationship of atrial function with the cardiac index and failing Fontan patients was analysed. RESULTS: Twelve Fontan patients were included. The median follow-up period after the first Fontan operation was 27 (range, 21-33) years, and the median age of those examined was 33.5 (range, 24-60) years. There were 6 male patients (50%). The cardiac index showed a significant positive correlation with the expansion index (P = 0.02), the atrial ejection fraction (P = 0.035), and the active ejection fraction (P = 0.013). The expansion index (39.2 ± 19.6 vs 64.1 ± 3.9), atrial ejection fraction (26.6 ± 10.9 vs 39.0 ± 1.5%), booster pump (15.6 ± 9.0 vs 31.3 ± 3.5) and cardiac index (2.1 ± 0.3 vs 2.5 ± 0.2 L/min/m2) were significantly lower in patients with a history of arrhythmia than in patients without a history of arrhythmia (P < 0.05). The expansion index (23.5 ± 13.5 vs 59.5 ± 8.7), atrial ejection fraction (18.1 ± 8.6 vs 37.1 ± 3.7) and active ejection fraction (7.3 ± 2.7 vs 27.7 ± 5.2) were significantly lower in failing Fontan patients than in non-failing Fontan patients (P < 0.01). CONCLUSIONS: Patients with atrial arrhythmia and signs of Fontan failure have lower atrial function than those without.

Multilayered Human Skeletal Muscle Myoblast Sheets Promote the Healing Process After Colonic Anastomosis in Rats.

Colorectal anastomotic leakage is one of the most feared and fatal complications of colorectal surgery. To date, no external coating material that can prevent anastomotic leakage has been developed. As myoblasts possess anti-inflammatory capacity and improve wound healing, we developed a multilayered human skeletal muscle myoblast (HSMM) sheet by periodic exposure to supraphysiological hydrostatic pressure during repeated cell seeding. We assessed whether the application of an HSMM sheet can promote the healing process after colonic anastomosis. Partial colectomy and insufficient suturing were employed to create a high-risk colo-colonic anastomosis model in 60 nude rats. Rats were divided into a control group (n = 30) and an HSMM sheet group (n = 30). Macroscopic findings, anastomotic bursting pressure, and histology at the colonic anastomotic site were evaluated on postoperative day (POD) 3, 5, 7, 14, and 28. The application of an HSMM sheet significantly suppressed abscess formation at the anastomotic site compared to the control group on POD3 and 5. The anastomotic bursting pressure in the HSMM sheet group was higher than that in the control group on POD3 and 5. Inflammatory cell infiltration in the HSMM sheet group was significantly suppressed compared to that in the control group throughout the time course. Collagen deposition in the HSMM sheet group on POD3 was significantly abundant compared to that in the control group. Regeneration of the mucosa at the colonic anastomotic site was promoted in the HSMM sheet group compared to that in the control group on POD14 and 28. Immunohistochemical analysis demonstrated that surviving cells in the HSMM sheet gradually decreased with postoperative time and none were detected on POD14. These results suggest that the application of a multilayered HSMM sheet may prevent postoperative colonic anastomotic leakage.

Persistent end-diastolic forward flow after pulmonary valve replacement in patients with repaired tetralogy of Fallot.

OBJECTIVES: The clinical significance of persistent end-diastolic forward flow (EDFF) after pulmonary valve replacement (PVR) remains unclear in patients with repaired tetralogy of Fallot. This study aimed to identify the characteristics of these patients and the impact of persistent EDFF on outcomes. METHODS: Of 46 consecutive patients who underwent PVR for moderate to severe pulmonary regurgitation between 2003 and 2019, 23 (50%) did not show EDFF before PVR [group (-)]. In the remaining 23 patients with EDFF before PVR, EDFF was diminished after PVR in 13 (28%) [group (+, -)] and persisted in 10 (22%) [group (+, +)]. The following variables were compared between these 3 groups: (i) preoperative right ventricular (RV) and right atrial volumes measured by magnetic resonance imaging, haemodynamic parameters measured by cardiac catheterization and the degree of RV myocardial fibrosis measured by RV biopsy obtained at PVR and (ii) the post-PVR course, development of atrial arrhythmia and need for intervention. RESULTS: A high RV end-diastolic pressure, a greater right atrial volume index and a greater RV end-systolic volume index before PVR and a high degree of RV fibrosis were significantly associated with persistent EDFF 1 year after PVR. Persistent EDFF was a significant risk factor for postoperative atrial tachyarrhythmia, and catheter ablation and pacemaker implantation were required more frequently in these patients. CONCLUSIONS: Persistent EDFF after PVR could predict a worse prognosis, especially an increased risk of arrhythmia. Close follow-up is required in patients with persistent EDFF for early detection of arrhythmia and prompt reintervention if necessary. CLINICAL TRIAL REGISTRATION NUMBER: Institutional review board of Osaka University Hospital, number 16105.

Autologous skeletal myoblast sheet implantation for pediatric dilated cardiomyopathy: A case report.

BACKGROUND: In children with dilated cardiomyopathy, heart transplantation is the last treatment option. However, new regenerative treatments, such as cell therapy, have attracted scientific attention. We have previously demonstrated the efficacy of autologous skeletal myoblast sheet implantation for treatment of ischemic and dilated cardiomyopathy in adults. Because of the mechanism underlying this cell therapy, a similar effectiveness is expected for patients with pediatric dilated cardiomyopathy. CASE: Herein, we describe the case of a child with dilated cardiomyopathy who underwent an autologous skeletal myoblast sheet implantation, which proved to be safe, and led to sustained maintenance and improvements in cardiac function and clinical status.

Bridge to recovery with Berlin Heart EXCOR in children <10 kg with dilated cardiomyopathy: a histological analysis.

OBJECTIVES: This study aimed to identify the histological characteristics associated with bridge to recovery using Berlin Heart EXCOR® (BHE) in paediatric patients <10 kg with dilated cardiomyopathy. METHODS: Of the 10 consecutive patients <10 kg with dilated cardiomyopathy who underwent BHE implantation between 2013 and 2018, 4 patients showed improvement in left ventricular (LV) function, resulting in successful BHE explantation (recovery group). The remaining 6 patients showed persistent LV dysfunction and underwent heart transplantation (non-recovery group). The following variables were compared between the 2 groups: (i) histological findings in LV myocardium obtained at BHE implantation and (ii) LV function after BHE implantation assessed with echocardiography and cardiac catheterization. RESULTS: The degree of myocardial fibrosis was significantly lower, and the capillary vascular density was significantly higher in the recovery group than in the non-recovery group [16% (standard deviation 5.9%) vs 28% (5.9%), P = 0.021, and 65 (11) vs 43 (18) units/high-power field, P = 0.037, respectively]. The changes during 3 months after BHE implantation in LV diastolic dimension (z-score) and ejection fraction were significantly greater in the recovery group than in the non-recovery group [-9.6 (3.5) vs -3.6 (4.5), P = 0.045, and 36% (13%) vs 13% (13%), P = 0.032, respectively]. CONCLUSIONS: In paediatric patients <10 kg with dilated cardiomyopathy, bridge to recovery with BHE implantation was achieved in patients with less injured LV myocardial histology at BHE implantation.

Clinical significance of right atrial volume in patients with repaired tetralogy of Fallot.

OBJECTIVES: Atrial arrhythmia and right ventricular (RV) diastolic dysfunction are associated with increased morbidity and mortality in patients with repaired tetralogy of Fallot (TOF). This study was performed to determine whether the preoperative right atrial (RA) volume can predict the development of atrial arrhythmia after pulmonary valve replacement (PVR) in patients with TOF. METHODS: Forty-seven consecutive adult patients with repaired TOF underwent PVR from 2003 to 2018. Seventeen patients showed preoperative atrial arrhythmia and underwent the Maze procedure concomitantly. The preoperative RA volume was evaluated with computed tomography and image analysis software. RESULTS: The median follow-up period after PVR was 6.8 years. Among 17 patients who underwent the Maze procedure, recurrent atrial arrhythmia developed in 8 patients. Among 30 patients without preoperative atrial arrhythmia, novel atrial arrhythmia developed in 2 patients. The RA volume index was a significant predictor according to the multivariate analysis (P = 0.003). The RA volume index showed a significant positive correlation with the RV end-diastolic pressure (P < 0.001). CONCLUSIONS: The RA volume predicts the development of atrial arrhythmia after PVR in patients with repaired TOF. RA volume measurement is strongly recommended in the management of this patient population.

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.

Stroke Volume Ratio Predicts Redilatation of the Right Ventricle After Pulmonary Valve Replacement.

BACKGROUND: This study aimed to identify the prognostic value of the preoperative stroke volume ratio (right ventricular stroke volume/left ventricular stroke volume) for redilatation of the right ventricle after pulmonary valve replacement in patients with repaired tetralogy of Fallot. METHODS: From April 2004 to November 2013, 20 patients with repaired tetralogy of Fallot underwent pulmonary valve replacement for pulmonary valve regurgitation and right ventricular dilatation. Serial changes in ventricular volume were examined by cardiac magnetic resonance or computed tomography imaging. The redilatation ratio was calculated for right ventricular end-diastolic and end-systolic volume indices by dividing the increment in right ventricular volume from the first (median, 1.1 years) to the second (median, 3.2 years) evaluations after pulmonary valve replacement by the first evaluation. The relationships between the stroke volume ratio and redilatation ratio were assessed. The degree of right ventricular myocardial fibrosis was examined in 13 patients and compared with the stroke volume ratio. RESULTS: Right ventricular volume (redilatation) significantly increased from a median of 1.1 to 3.2 years after pulmonary valve replacement. Significant positive correlations were detected between the stroke volume ratio and redilatation ratio of the right ventricular end-diastolic (r = 0.50. p = 0.02) and end-systolic volume indices (r = 0.49, p = 0.03). The stroke volume ratio also showed a significant positive correlation with the degree of right ventricular myocardial fibrosis (r = 0.73, p = 0.005). CONCLUSIONS: The preoperative stroke volume ratio can predict redilatation of the right ventricle after pulmonary valve replacement and the degree of right ventricular myocardial fibrosis.

Pulmonary artery rupture after bilateral pulmonary artery banding in a neonate with Loeys-Dietz syndrome and an interrupted aortic arch complex: report of a case.

Loeys-Dietz syndrome (LDS) is a recognized connective tissue disorder characterized by progressive aortic aneurysm and dissection. Patients are at high risk of aortic dissection or rupture at an early age, but to our knowledge, surgery on the great arteries has never been attempted in the neonatal period. We report a case of LDS with dilated pulmonary arteries and an interrupted aortic arch complex in a neonate. We performed bilateral pulmonary artery banding, but 12 days after the procedure, the infant died of rupture of the distal portion of the banding sites following massive dilatation.

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.