Retrospective study of preoperative sildenafil in prolonged pleural effusion after Fontan

Background : By rerouting the systemic venous return into the pulmonary circulation, the Fontan operation is perhaps the most effective palliative procedure in patients with complex congenital heart disease. The Fontan, however, still comes with several significant complications and morbidities, one of them being postoperative prolonged pleural effusion. In our center from 2017 to 2021, 10% of all our patients who underwent Fontan operation developed prolonged pleural effusion. With this study, we aimed to analyze the preoperative use of sildenafil for 6 months and its role in prolonged pleural effusion after the Fontan operation. Materials and Methods : In total, 158 patients were included in the analysis. The cohort was divided into patients who developed prolonged pleural effusion after Fontan surgery (n = 17) and those who did not (n = 141). We analyzed several risk factors and the history of sildenafil use in each group in the cohort. We found that patients who used sildenafil for at least 6 months prior to Fontan surgery versus those who did not use (n = 112 vs. n = 46) were found to be at lower risk of developing prolonged pleural effusion (odds ratio [OR]: 0.32 [confidence interval 95%: 0.11–0.88], P = 0.027). Conclusion : Preoperative administration of sildenafil for at least 6 months before Fontan might reduce the risk of postoperative prolonged pleural effusion

Transcriptome Analysis Reveals Differential Gene Expression between the Closing Ductus Arteriosus and the Patent Ductus Arteriosus in Humans

The ductus arteriosus (DA) immediately starts closing after birth. This dynamic process involves DA-specific properties, including highly differentiated smooth muscle, sparse elastic fibers, and intimal thickening (IT). Although several studies have demonstrated DA-specific gene expressions using animal tissues and human fetuses, the transcriptional profiles of the closing DA and the patent DA remain largely unknown. We performed transcriptome analysis using four human DA samples. The three closing DA samples exhibited typical DA morphology, but the patent DA exhibited aorta-like elastic lamellae and poorly formed IT. A cluster analysis revealed that samples were clearly divided into two major clusters, the closing DA and patent DA clusters, and showed distinct gene expression profiles in IT and the tunica media of the closing DA samples. Cardiac neural crest-related genes such as JAG1 were highly expressed in the tunica media and IT of the closing DA samples compared to the patent DA sample. Abundant protein expressions of jagged 1 and the differentiated smooth muscle marker calponin were observed in the closing DA samples but not in the patent DA sample. Second heart field-related genes such as ISL1 were enriched in the patent DA sample. These data indicate that the patent DA may have different cell lineages compared to the closing DA

Tissue-type plasminogen activator contributes to remodeling of the rat ductus arteriosus

<div><p>Aims</p><p>The ductus arteriosus (DA) closes after birth to adapt to the robust changes in hemodynamics, which require intimal thickening (IT) to occur. The smooth muscle cells of the DA have been reported to play important roles in IT formation. However, the roles of the endothelial cells (ECs) have not been fully investigated. We herein focused on tissue-type plasminogen activator (t-PA), which is a DA EC dominant gene, and investigated its contribution to IT formation in the DA.</p><p>Methods and results</p><p>ECs from the DA and aorta were isolated from fetal rats using fluorescence-activated cell sorting. RT-PCR showed that the t-PA mRNA expression level was 2.7-fold higher in DA ECs than in aortic ECs from full-term rat fetuses (gestational day 21). A strong immunoreaction for t-PA was detected in pre-term and full-term rat DA ECs. t-PA-mediated plasminogen-plasmin conversion activates gelatinase matrix metalloproteinases (MMPs). Gelatin zymography revealed that plasminogen supplementation significantly promoted activation of the elastolytic enzyme MMP-2 in rat DA ECs. <i>In situ</i> zymography demonstrated that marked gelatinase activity was observed at the site of disruption in the internal elastic laminae (IEL) in full-term rat DA. In a three-dimensional vascular model, EC-mediated plasminogen-plasmin conversion augmented the IEL disruption. <i>In vivo</i> administration of plasminogen to pre-term rat fetuses (gestational day 19), in which IT is poorly formed, promoted IEL disruption accompanied by gelatinase activation and enhanced IT formation in the DA. Additionally, experiments using five human DA tissues demonstrated that the t-PA expression level was 3.7-fold higher in the IT area than in the tunica media. t-PA protein expression and gelatinase activity were also detected in the IT area of the human DAs.</p><p>Conclusion</p><p>t-PA expressed in ECs may help to form IT of the DA via activation of MMP-2 and disruption of IEL.</p></div