title: 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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of General and Cardiothoracic Surgery, Kanazawa University, Kanazawa, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Moriyama
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Tomita
authors.forename: Go
authors.initials: G
authors.lastname: Watanabe
mesh_terms: D000818:Animals; D002815:Chordae Tendineae / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D004195:Disease Models, Animal; D004724:Endoscopy; D004867:Equipment Design; D006341:Heart Rupture / Q000209:etiology / Q000503:physiopathology; D008943:Mitral Valve / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D058386:Mitral Valve Annuloplasty / Q000009:adverse effects / Q000295:instrumentation* / Q000379:methods; D008945:Mitral Valve Prolapse / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D010210:Papillary Muscles / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D013314:Stress, Mechanical; D013525:Surgical Instruments; D013536:Suture Techniques; D013552:Swine; D013997:Time Factors; D016277:Ventricular Function, Left; D017725:Ventricular Pressure
keywords: Chordae tendineae; Mitral valve prolapse; Surgical instruments; Suture techniques