Multimodality imaging (3D Echocardiography, 3D printing and confocal microscopy) for paravalvular leak visualization
Authors: Jedrzejek M , Garczyk - Mundala Z , Peszek Przybyla E , Kozlowski M , Jadczyk T , Pysz P , Wojakowski W , Swinarew A , Smolka G 
Published: June 2023

Abstract

Funding Acknowledgements
Type of funding sources: Public grant(s) – EU funding. Main funding source(s): National Center for Research and Development as part of the strategic program "Prevention and treatment of civilization
diseases" Strategmed II Project "Integrated paravalvular leak closure system" -acronym VALE,
Paravalvular leak (PVL) may occur in 15% of patients undergoing surgical mitral valve replacement. Visualization of PVL channels may be challenging due to its proximity to the prosthetic valve and complex anatomy. The main aim of this study was to use a confocal microscope to measure PVL channel dimensions. With 3D-TEE (Philips Epiq) an anteromedial mitral defect was visualized. Qlab Station was used to export the 3D recording of the PVL with surrounding tissue in cartesian DICOM format. Next Slicer, a free open-source software, was used for segmentation and preparation of a STL (stereolithography) file. The PVL model was printed with Starsys Object 30 printer using Med620 material. PVL diameters were measured both after MPR of source echocardiographic data and in the printed model with a confocal microscope. The same results were obtained. Thus, the possibility of using the standard 3D-TEE and open source software for preparation of 3D models of anatomically complex mitral PVLs was confirmed. In addition, a confocal microscope can be used to measure PVL dimensions of models printed from echocardiographic data.

Background
Paravalvular leak (PVL) may occur in almost 15% of patients undergoing surgical mitral valve replacement. This complication can cause patient’s significant deterioration (congestive heart failure and hemolysis). Visualization of PVL channel may be challenging due to its proximity to prosthetic valve (shadowing) and complex and tortuos anatomy. 3D imaging from CT and echocardiography is essential for assessment of PVLs. 3D-TEE-based 3D-printing might be useful in preprocedural planning of PVL closure for the optimization of transcatether procedures. As feasibility of such printing is proven, now we are looking for best techniques to measure PVL channels. Purpose
Confocal microscope appliance to measure PVL chanel dimensions

Methods
In case of a significant PVL around a mitral prosthetic valve is presented. In 3DTEE (Philips Epiq) anteromedial defects were visualized (surgical view). Qlab Station was used to export the 3D recording of PVLs with surrounding tissue in cartesian DICOM format. Next Slicer, a free open-source software, was used for segmentation and preparation of a STL (stereolithography) file. The PVL model was printed with Starsys Object 30 printer using Med620 material. PVL diameters were measured in MPR from 3D Echocardiography and after analysis in confocal microscope at printed model. Measurements were the same 10/5 mm.

Results
Confocal microscope can be used to measure PVL dimensions from printed models from echocardiography. Figure1 MPR 2D measurements of PVLs, and printed model of PVL. Figure 2 Measurements form confocal microscope.

Conclusion(s)
Proof of concept study confirms feasibility of using multimodality imagine for measurements of PVL. Further studies to assess clinical applicability of the presented methodology are ongoing.