Back to 2016 Annual Meeting Cardiac Track

OBJECTIVE: Mitral valve (MV) repairs remain technically challenging, particularly during minimally-invasive cardiac surgery (MICS) procedures. Technologies that enable the rapid, reliable and complete surgical repair of a diseased MV without causing significant trauma to the chest wall may enable improved surgical outcomes. This pre-clinical study evaluates an automated MICS-MV repair technique employing new technologies for placing and securing artificial chordae and mitral annuloplasty suture.
METHODS: This automated technique incorporates a dual curved needle suturing device for placing artificial chordae using expanded polytetrafluoroethylene (ePTFE) suture through the mitral leaflet and subsequently through the papillary muscle. A specialized titanium fastener (TF) crimped at the base of the papillary muscle, reliably secures the replacement chordae at a desired length that can be determined during real-time infusion testing. 2-0 polyester suture is then remotely placed around the mitral annulus using a single curved needle suturing device to secure an annuloplasty ring or band. The feasibility of this MV repair technique was studied in multiple bench-top and cadaver models. In accordance with institutional guidelines, chordae replacements and TF healing was also evaluated in sheep. Mitral regurgitation (MR) was induced in both the animal and cadaver models by the transection of 1-2 native chordae. Repairs were directly assessed using saline infusion testing for MV competence and in sheep, via epicardial echocardiography.
RESULTS: The repair technique was evaluated in 10 ex vivo porcine hearts and proved feasible. Artificial chordae were successfully placed in 2 male sheep. One animal was survived for healing analysis; trace MR was noted using saline infusion and on intra-operative echocardiography. Re-operation at 6 weeks noted an intact and partially endothelialized artificial chord and TF without damage to surrounding structures. Effective and ergonomic automated MV repairs were also demonstrated in 2 cadavers.
CONCLUSIONS: This automated MV repair technique was successfully tested and demonstrated in a variety of pre-clinical surgical models. It reliably places and remotely secures artificial mitral chordae and annuloplasty suture, and can minimize the technical difficulties frequently associated with less-invasive mitral surgery. This research encourages further development and potential investigation in human clinical trials.