| Description |
This body of work aims at establishing an approach for intraoperative discrimination of cardiac tissue types based on fiber-optics confocal microscopy (FCM). An important application of this approach is in pediatric heart surgery. A major risk of these surgeries is surgically-induced trauma to the specialized tissue of the cardiac conduction system. Current clinical practice during pediatric heart surgery is to approximate the disposition of the conduction system and scrupulously avoid it. A method for real-time delineation of the conduction system during pediatric heart surgery is needed. FCM allows for real-time imaging of cellular and sub-cellular features up to 100 micrometers below a specimens surface. We hypothesized that an approach based on FCM and fluorescent extracellular dyes would allow for delineation of the conduction system. We investigated this approach in the living arrested heart of rodent. In addition, the approach was validated in fixed tissue preparations from rodent, hearts using immunohistochemistry, three-dimensional conventional confocal microscopy, and image processing. Furthermore, we investigated dye delivery and microdosing approaches for intraoperative FCM discrimination of cardiac tissue types motivated by concerns in regards to consumption and adverse reactions of the dyes used in clinical applications of FCM. Lastly, we assessed the performance of the human and automated classification systems in identifying cardiac tissue types acquired using this novel approach. We demonstrated that it was feasible to discriminate cardiac tissue types using FCM and extracellular dyes. In our investigation into dye delivery and microdosing approaches, we showed that the developed novel local dye delivery approach based on a foam agarose dye carrier is particularly suitable for FCM during pediatric heart surgery. Furthermore, both human and automated classification systems achieved similarly high sensitivity and specificity in discriminating cardiac tissue types including tissue of the conduction system. We suggest that this work constitutes an important step in clinical translation of FCM for cardiac tissue discrimination. The imaging approach as well as the foam agarose carrier for microdosed delivery of dye and the automated methods for tissue classification have the potential to reduce the incidence of trauma to the conduction system during pediatric heart surgery. |
