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.

Congenital Non-Confluent Pulmonary Artery Sourced from Bilateral Arterial Ducts: A Rare Anomaly.

This study aimed to identify the influence of the non-confluent pulmonary artery originating from the bilateral arterial ducts (AD) on the outcomes of the Fontan circulation. We retrospectively reviewed the records of nine patients with bilateral AD and a non-confluent pulmonary artery in a single ventricle at our institution between 1993 and 2023. Three patients showed maintained AD or underwent a systemic-pulmonary shunt for stenotic AD, followed by the Glenn procedure. Four patients underwent systemic-pulmonary shunt with angioplasty as the first palliation, followed by the Glenn procedure. Two patients underwent systemic-pulmonary shunt or AD stenting as the first palliation and systemic-pulmonary shunt with angioplasty as the second palliation. There were no cases of interstage mortality. Pulmonary arteries grew and achieved a good balance (pre-Fontan pulmonary artery index [PAI], 164 ± 27 mm2/m2; right/left PAI ratio, 1.06 ± 0.23). All patients underwent the Fontan procedure (median, 3.5 years; range, 2.3-6.4 years) and were followed up for 7.8 years (range, 0.1-16.4 years) after the procedure. One patient required hospitalization for heart failure at 1.8 years, and three patients required catheter intervention for pulmonary stenosis within 2 months after the Fontan procedure. Non-confluent pulmonary arteries originating from the bilateral AD do not preclude Fontan completion and good Fontan outcomes by restoring balance to pulmonary blood flow. Due to the limited sample size in this study, additional research is imperative to delve deeper into our findings and enhance understanding of the most effective surgical approach for this disease.

Norwood Operation with Right Ventricular-Pulmonary Artery Shunt Versus Comprehensive Stage II After Bilateral Pulmonary Artery Banding Palliation.

As a strategy for the primary Norwood operation, the right ventricular-pulmonary artery shunt is associated with satisfactory early outcome. However, use of this shunt after bilateral pulmonary artery banding remains controversial. This study compared the operative outcomes and late hemodynamics in patients who underwent the Norwood operation, preceded by bilateral pulmonary artery banding, with a right ventricular-pulmonary artery shunt or with bidirectional Glenn anastomosis (comprehensive stage II strategy). We retrospectively reviewed 38 patients who underwent the Norwood operation preceded by bilateral pulmonary artery banding between 2004 and 2017. Of these, 17 underwent the Norwood operation with a right ventricular-pulmonary artery shunt (Group S), whereas 21 underwent the comprehensive stage II strategy (Group G). 5 years after the Norwood operation, 10 (60%) and 17 (81%) patients in Group S and Group G, respectively, underwent the Fontan procedure. Group S showed significantly lower pressure in the superior vena cava after bidirectional Glenn anastomosis than Group G (13 ± 2 mmHg vs. 18 ± 3 mmHg; p < 0.01), but pressures were similar after the Fontan procedure. The right ventricular end-diastolic volume at 1 year post-Fontan procedure was significantly higher in Group S than in Group G (142 ± 41% vs. 91 ± 28%; p < 0.01). In terms of early outcomes, the Norwood operation with a right ventricular-pulmonary artery shunt enabled low pressure in the superior vena cava, but in the long term, this shunt adversely influenced the right ventricular volume.

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.

Influence of Bovine Arch Anatomy on Surgical Outcomes of Coarctation of the Aorta.

This study aimed to evaluate the outcome of coarctation of the aorta (CoA) repair with a special interest in bovine arch anatomy. Fifty-six patients who underwent CoA repair between 2010 and 2021 were included in this retrospective study. Of these, 11 patients had bovine arch anatomy. Surgical outcomes were reviewed. Computed tomography was used to analyze aortic arch geometry for all cases preoperatively. The gap between anastomotic sites was calculated at the linear region of the lesser curvature of the aortic arch between the distal ascending aorta and the proximal descending aorta. CoA repair was performed at a median age of 39 days (median body weight 3.3 kg). Thirty-two patients underwent extended direct anastomosis, 22 patients underwent direct anastomosis, and two patients underwent lesser curvature patch augmentation. The median follow-up period was 47 months. There were no early deaths. In patients who underwent direct and extended direct anastomosis, nine recoarctation and one left pulmonary venous obstruction events occurred. Moreover, freedom from these adverse events was 81% in normal arch and 50% in bovine arch patients at 10 years (P = 0.04). Two patients with a bovine arch anatomy who underwent lesser curvature patch augmentation had good outcomes. The distal arch was narrower and longer, and the gap between anastomotic sites was longer in patients with a bovine arch anatomy than with a normal arch (P < 0.01). In CoA with a bovine arch anatomy, the gap between anastomotic sites was long. This adversely influenced the outcomes of the CoA repairs.

Scaffold-free tissue-engineered arterial grafts derived from human skeletal myoblasts.

Tissue-engineered vascular grafts (TEVGs) are in urgent demand for both adult and pediatric patients. Although several approaches have utilized vascular smooth muscle cells (SMCs) and endothelial cells as cell sources for TEVGs, these cell sources have a limited proliferative capacity that results in an inability to reconstitute neotissues. Skeletal myoblasts are attractive cell sources as they possess high proliferative capacity, and they are already being tested in clinical trials for patients with ischemic cardiomyopathy. Our previous study demonstrated that periodic hydrostatic pressurization (PHP) promoted fibronectin fibrillogenesis in vascular SMCs, and that PHP-induced extracellular matrix (ECM) arrangements enabled the fabrication of implantable arterial grafts derived from SMCs without using a scaffold material. We assessed the molecular response of human skeletal myoblasts to PHP exposure, and aimed to fabricate arterial grafts from the myoblasts by exposure to PHP. To examine the PHP-response genes, human skeletal myoblasts were subjected to bulk RNA-sequencing after PHP exposure. Gene-set enrichment analysis revealed significant positive correlations between PHP exposure and vascular development-related genes. Real-time polymerase chain reaction (RT-PCR) demonstrated that PHP significantly upregulated collagen and elastic fiber formation-related gene expression, such as fibronectin, lysyl oxidase, collagen type I α1, collagen type IV α1, and tropoelastin. Based on these findings showing the potential role of PHP in vessel formation, we fabricated arterial grafts by repeated cell seeding and exposure to PHP every 24 hours. The resultant 15-layered myoblast grafts had high collagen content, which provided a tensile rupture strength of 899 ± 104 mm Hg. Human skeletal myoblast grafts were implanted as patch grafts in the aorta of immunosuppressed rats and found to be endothelialized and completely patent until the endpoint of 60 postoperative days. Implanted human myoblasts were gradually replaced by host-derived cells, which successfully formed vascular neotissues with layered elastic fibers. These findings suggest that human skeletal myoblasts have the potential to be a feasible cell source for scaffold-free implantable arterial grafts under PHP culture conditions.

External compression due to seroma of ventricular assist device outflow graft.

A 45-year-old woman with repaired complex congenital heart disease, who underwent placement of Jarvik 2000, a ventricular assist device (VAD) for 4 years, experienced abdominal pain due to outflow graft compression caused by seroma formation between the outflow graft and ringed Gore-Tex graft. We exchanged the pump of Jarvik 2000 and punched several small holes in the new ringed Gore-Tex graft. Seroma formation between the two grafts should be considered as a cause of outflow graft obstruction in patients with the long-term support of VAD, and additional surgical interventions to the ringed Gore-Tex graft may prevent this complication.

Pediatric patient with restrictive cardiomyopathy on staged biventricular assist device support with Berlin Heart EXCOR® underwent heart transplantation successfully: the first case in Japan.

Pure restrictive cardiomyopathy is a strong risk factor for poor outcomes in children with cardiomyopathy on ventricular assist devices. Owing to concomitant right heart failure, children with end-staged restrictive cardiomyopathy who are supported with a ventricular assist device often require a biventricular assist device, which is another risk factor for waitlist mortality in heart transplantation candidates. Herein, we report the case of a 3-year-old boy with pure restrictive cardiomyopathy who successfully underwent heart transplantation after 12 months of support with staged biventricular assist devices. Owing to the progression of diastolic dysfunction, the left ventricular assist device could not provide adequate circulation support. Despite the provision of biventricular assist device support, the patient required a complex management strategy that involved balancing the left and right ventricular assist device supports. We were able to stabilize the patient by careful synchronization of the supports and proceeded to heart transplantation. TRIAL REGISTRATION: Clinical Registration No.: Institutional Review Board of Osaka University Hospital, approval no. 16105.

Impact of Long-Term Support with Berlin Heart EXCOR® in Pediatric Patients with Severe Heart Failure.

Berlin Heart EXCOR® (BHE) ventricular assist device (VAD) (Berlin Heart, Berlin Heart AG, Berlin, Germany) implantation is prevalent in patients with severe heart failure. However, clinical outcomes of pediatric patients on long-term BHE support remain mainly unknown. This study aimed to report our clinical experience with long-term support of pediatric patients with severe heart failure supported by BHE VAD. Clinical outcomes of 11 patients (median age 8.4 months; two male), who underwent LVAD implantation of the Berlin Heart EXCO® (BHE) VAD (Berlin Heart, Berlin Heart AG, Berlin, Germany) between 2013 and 2017 at our institution were reviewed. The median support period was 312 (range 45-661) days and five patients were supported for more than 1 year. The longest support duration was 661 days. No mortality occurred, and six patients were successfully bridged to heart transplantation, while three patients were successfully weaned off the device. Two patients are currently on BHE support while they await heart transplantation. Four patients had cerebral bleeding or infarction, but only one case of persistent neurological deficit occurred. No fatal device-related infection occurred during LVAD support. BHE VAD can provide long-term support for pediatric patients with severe heart failure with acceptable mortality and morbidity rates with long-term support.

Pulmonary Valve Replacement With Fresh Decellularized Pulmonary Allograft for Pulmonary Regurgitation After Tetralogy of Fallot Repair　- First Case Report in Japan.

BACKGROUND: Pulmonary valve replacement (PVR) is a common reoperation, typically required approximately 10 years following right ventricular outflow tract reconstruction and especially true in cases of tetralogy of Fallot. However, an improved prosthetic valve is required. METHODS AND RESULTS: A fresh decellularized pulmonary allograft was used for PVR to correct pulmonary valve regurgitation in a 35-year-old man 33 years following tetralogy of Fallot repair. The postoperative course and short-term valve function were excellent. This is the first case of a decellularized pulmonary allograft in Japan. CONCLUSIONS: Fresh decellularized pulmonary allografts have the potential to become a new source of material for PVR in patients who have undergone right ventricular outflow tract reconstruction.

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.

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.

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.

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.

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.

Innovative therapeutic strategy using prostaglandin I2 agonist (ONO1301) combined with nano drug delivery system for pulmonary arterial hypertension.

Clinical outcomes of pulmonary arterial hypertension (PAH) may be improved using targeted delivery system. We investigated the efficacy of ONO1301 (prostacyclin agonist) nanospheres (ONONS) in Sugen5416/hypoxia rat models of PAH. The rats were injected with saline (control) or ONONS (n = 10, each) on days 21 and 28, respectively. Hepatocyte growth factor (HGF)-expressing fibroblasts and inflammatory cytokines were measured. Cardiac performance was assessed and targeted delivery was monitored in vivo, using Texas red-labeled nanoparticles. Compared with control, HGF-expressing fibroblasts and HGF expression levels were significantly higher in the ONONS group, while the levels of interleukin-6, interleukin-1ß, transforming growth factor-ß, and platelet-derived growth factor were lower. Histological assessment revealed significant amelioration of the percent medial wall thickness in pulmonary vasculature of rats in the ONONS group. Rats in the ONONS group showed decreased proliferating cell nuclear antigen-positive smooth muscle cells and improved right ventricle pressure/left ventricle pressure. No difference was seen in the accumulation of Texas red-labeled nanoparticles in the brain, heart, liver, and spleen between PAH and normal rats. However, a significant area of nanoparticles was detected in the lungs of PAH rats. ONONS effectively ameliorated PAH, with selective delivery to the damaged lung.

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.

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.

Synthetic Prostacyclin Agonist Attenuates Pressure-Overloaded Cardiac Fibrosis by Inhibiting FMT.

Fibroblast-to-myofibroblast transition (FMT) is the primary inducer of cardiac fibrosis. ONO-1301, a synthetic prostacyclin agonist, reportedly promotes tissue fibrosis repair by enhancing anti-fibrotic cytokine production. We hypothesized that ONO-1301 attenuates pressure-overloaded cardiac fibrosis by modulating FMT and generated a pressure-overloaded murine model via transverse aortic constriction (TAC) to evaluate the in vivo effects of ONO-1301. Cardiac fibrosis, left ventricular dilatation, and systolic dysfunction were established 4 weeks after TAC; however, ONO-1301 treatment initiated 2 weeks after TAC significantly attenuated those effects. Furthermore, ONO-1301 treatment significantly upregulated expression levels of cardioprotective cytokines such as vascular endothelial growth factor and hepatocyte growth factor in TAC hearts, whereas FMT-related factors, including transforming growth factor (TGF)-ß1 and connective tissue growth factor, were significantly downregulated. The number of α-smooth muscle actin (α-SMA)- and vimentin-positive cells, representing fibroblast-originated cells transitioned into myofibroblasts, was significantly reduced in ONO-1301-treated TAC hearts. We isolated cardiac fibroblasts (CFs) from the left ventricles of adult male mice and assessed the effects of ONO-1301 on CFs stimulated by TGF-ß. Results showed that ONO-1301 co-incubation significantly suppressed TGF-ß-induced α-SMA expression and collagen synthesis, and significantly inhibited TGF-ß-induced CF proliferation and migration. Our findings suggest that ONO-1301 ameliorates pressure overloaded cardiac fibrosis by inhibiting TGF-ß-induced FMT.