Effectiveness of alteplase infusion for the management of prosthetic mitral valve thrombosis in paediatric age group and proposed algorithm.

INTRODUCTION: The incidence of prosthetic valve implantation is increasing in the paediatric population. Prosthetic valve thrombosis leading to obstruction could potentially be a life-threatening complication. There is a debate regarding optimal management of this complication, and there is limited use of thrombolytic therapy in childhood in the setting of valve thrombosis. OBJECTIVE: We aim to share our experience of successfully using fibrinolytic therapy in terms of alteplase for paediatric prosthetic mitral valve thrombosis and to propose a management algorithm. METHODS: This retrospective analysis of the database was conducted at our hospital including patients who underwent thrombolysis (alteplase) for prosthetic mitral valve thrombosis from June, 2011 to June, 2021. A total of 10 patients with 20 attempts of alteplase infusion were found in our record. RESULTS: Alteplase was successful in 19 attempts to relieve valve thrombosis. The safe and effective dose of alteplase was between 0.1 and 0.3 mg/kg/hour. There were no associated major bleeding complications and alteplase was administered either by central or peripheral line. CONCLUSION: Thrombolysis by alteplase infusion was found to be successful in relief of prosthetic mitral valve thrombosis in paediatric population without major bleeding complications.

Retrograde approach for device closure of muscular ventricular septal defects in children and adolescents, using the Amplatzer muscular ventricular septal defect occluder.

This study presents technique and initial experience of retrograde deployment of the Amplatzer muscular ventricular septal defect occluder (AmVSDo) for closure of muscular ventricular septal defects (VSDs). The conventional technique for closing muscular VSDs involves the creation of an arteriovenous guidewire circuit and use of a transvenous approach for device deployment. Seven patients aged 2.2-15 years underwent transcatheter closure of a muscular VSD using the retrograde approach without making the arteriovenous wire circuit. Mean fluoroscopy and procedural times were compared to those previously reported in publications describing the use of the antegrade approach. Unpaired Student's t-test was used to compare the two parameters in two groups. Our technique was successful in all patients reported. The mean fluoroscopy time in the retrograde versus the antegrade group was 33.8 +/- 20.9 and 41.9 +/- 6.2 minutes, respectively (not significant), and the mean procedural time in the two groups was 91.1 +/- 22.1 and 114 +/- 33.9 minutes respectively (p = 0.025). No complications were noted. We suggest that some muscular VSDs can be safely closed retrogradely without the use of an arteriovenous loop, thus reducing the radiation exposure and also the cost of the procedure. Further studies are needed to confirm this initial experience.