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Publication

Timing van longslagaderklepvervanging in Tetralogie van Fallot

Book - Dissertation

Surgically corrected tetralogy of Fallot (TOF) patients with trans-annular patch frequently have an important pulmonary regurgitation (PR) resulting in chronic right ventricular volume overload, which has been proven to increase the risk for adverse outcomes. These patients require a valve replacement early versus late to avoid the development of life-threatening arrhythmias, heart failure and sudden cardiac death. There is, however, no consensus on the optimal timing of pulmonary valve replacement (PVR). The PVR can be done either surgically or percutaneously. In both techniques bioprosthetic valves are used. The procedural mortality is low (<1%), but there is not negligible and low morbidity. Importantly, the functional integrity of all available bioprosthetic valves deteriorates over time, mostly repeat valve replacement is required within 10 years. The current recommendations for PVR are a moderate to severe PR (PR fraction >25% on MRI) with important RV overload (end-diastolic volume > 160 ml/m² on MRI) and clinical symptoms of reduced exercise intolerance, heart failure, syncope or ventricular arrhythmias. The current guidelines for PVR are not proven to increase the long term survival and reduce the burden of arrhythmia and SCD, therefore an earlier PVR seems to be more appropriate. The early results of PVR have been well described by several groups, showing resolution or marked reduction of pulmonary regurgitation, 30% to 40% reduction in RV end-diastolic and end-systolic volumes, unchanged RV ejection fraction, slightly increased left ventricular size with unchanged ejection fraction, decrease in RV systolic pressure in those with pre-procedural RVOT obstruction, and consistent improvement in New York Heart Association (NYHA) functional class without a clear change in objective exercise parameters or arrhythmia burden. The aim for the research project is in the clinical part to evaluate the feasibility, morbidity and mortalitiy of percuteneous valve replacement in the pulmonary position. The role of prestenting the right ventricular outflow tract and feasibility of this technique in patients with TOF. In the experimental part the aim is to create a chronic surviving large animal model with the pathophysiology comparable to patients with TOF in order to use this model for evaluation of timing of (percuteneous) valve replacement and its effect on right ventricular remodeling.
Publication year:2021
Accessibility:Open