Dynamic evaluation of the loop technique using the U-Clip.

Abstract

BACKGROUND: We set out to evaluate mitral valve repair with the loop technique under dynamic conditions, using a U-Clip to anchor the loop unit to a papillary muscle. METHODS: Mitral valve prolapse was artificially developed by resecting 4 chordae tendineae of a resected porcine heart. The loop unit was anchored to the papillary muscle using U-Clips. Each chordal loop was fixed on the prolapsed leaflet. A roller pump perfused the left ventricle. The left ventricular pressure was maintained at 250 mm Hg. Morphological assessment of the loop reconstruction was performed using an endoscope. RESULTS: 10 independent chordal reconstructions were performed. In all cases, the loop unit remained anchored against pressures exceeding 250 mm Hg. Upon increasing the water filling volume, rupture of a chorda tendinea occurred in 7 cases, rupture of the papillary muscle occurred in 2 cases, and left ventricle rupture occurred in 1 case. In all rupture cases, the loop unit remained anchored to the papillary muscle. CONCLUSION: This dynamic evaluation of the loop technique using U-Clips to anchor the loop unit to a papillary muscle showed that the loop technique using U-Clips is a safe method.