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

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.