MO60. A Novel Technique for Measuring Mitral Valve Coaptation Height Using Fiberscope Technology: A Developing Approach for Intraoperative Evaluation of Mitral Valve Repair
Boston Children's Hospital
Dedham, MA
United States - Contact Me
Dominic Recco is currently a General Surgery Resident at Beth Israel Deaconess Medical Center. He is completing his research years under the mentorship of Dr. Hoganson in the Cardiac Surgery Department at Boston Children's Hospital. Prior to starting his residency, he graduated from The Pennslvania State University with BS in biomedical engineering and from the Lewis Katz School of Medicine at Temple University. Upon joining BIDMC in 2020, Dominic had interest in pursuing specialization in cardiac surgery and his research interests involve applying engineering principles to challenge dogmatic surgical practices and optimize outcomes of congenital cardiac procedures including aortic arch reconstruction, aortic valve repair, and pulmonary valve monocusp reconstruction.
Description
Methods: Ex vivo testing was performed on 3 adult porcine hearts. The LA was resected, leaving ~3mm of atrium above the MV annulus. The LV was pressurized through the aorta to 26.8±1mmHg. A 4mm endoscope was inserted into the LV apex, centered under the MV orifice, and secured by purse-strings. A FS system, consisting of a Milliscope II camera and 0.7mm diameter x 15cm long 90° semi-rigid scope, with 1.2mm focal length (Zibra Corp, Westport, MA), was mounted above the MV annulus in a 3D-printed fixture that enabled orthogonal placement of the device and attachment of calipers for real-time measurements. Two locations on each MV A2 and P2 segments were selected by LV endoscopic evaluation of the MV leaflets and chordae attachments. Three measurements at each location, from the top of coaptation to the leaflet edge, were recorded using the FS. In blinded fashion, the FS was used to identify the leaflet edge. Accuracy was verified using the endoscope. A control (metal rod of similar thickness) was used for comparison, with leaflet length recorded when the control was seen in the LV with the apical endoscope. The FS vs control methods were compared.
Results: Coaptation measurements were similar for the control and FS methods across all hearts at the A2 and P2 locations (A2 11.5±1.1mm control vs 11.3±0.8mm FS; P2 11.5±1.5mm control vs 11.7±2.1mm FS). Both methods had similar variability across the three measurements taken at each leaflet segment location (control SD 0.09-0.95mm and FS SD 0.03-0.90mm). One outlier was excluded from analysis (n=11/12). The difference between measurement methods was less than 1.1mm with a median absolute difference of 0.46 (0.20-0.88)mm. Percent error between measurement methods was less than 8% with a median absolute percent error of 4.03 (1.68-7.57)%.
Conclusions: Utilization of a miniaturized FS enabled precise and accurate quantification of MV coaptation. This novel technique is promising for evaluating post-repair valve competence and coaptation height. Further study and validation in vivo are necessary prior to intraoperative use.