title: Force Required to Cinch the Tricuspid Annulus: An Ex-Vivo Study.
abstract: OBJECTIVE
  Tricuspid annuloplasty is the most preferred technique for the treatment of functional tricuspid regurgitation (FTR). However, high incidences of recurrent regurgitation and risky reoperation demands a deeper insight into the technique. The cinching force required to bring a dilated annulus back to the original size is unknown. The study aim was to quantify the cinching force in the tricuspid annulus which can contribute to the long-term durability of tricuspid annuloplasty and percutaneous device design.
  
  
  METHODS
  In ten ovine hearts, a suture was anchored around the free wall of the tricuspid annulus with the free end attached to a force transducer. The force transducer was mounted on a slider system which pulled the suture at regular intervals. Closure of the tricuspid valve was achieved by pressurizing the right ventricle at 30 mmHg through the pulmonary valve. The suture was pulled to cinch the tricuspid annulus. The tricuspid annulus area was measured from images taken at each increment, and the corresponding force was recorded. The hearts were tested for three conditions: (i) non-pressurized (NP); (ii) pressurized (P; normal), and (iii) dilated-pressurized (DP; diseased). Leakage data were also collected for pressurized and dilated pressurized conditions. Annulus dilation was created by injecting phenol into the annulus.
  
  
  RESULTS
  The maximum annulus dilation obtained was 8.82%, and the maximum cinching force was 0.38 +/- 0.09 N. Leakage was increased by 81.73% from the pressurized to dilated condition.
  
  
  CONCLUSIONS
  The minimal force required to cinch a tricuspid annulus with severe FTR (23.98% dilation) can be approximated to 0.25 N. The required cinching force can play a major role in the long-term durability of the tricuspid annuloplasty.
authors.forename: Amy
authors.initials: A
authors.lastname: Adkins
authors.forename: Jesus
authors.initials: J
authors.lastname: Aleman
authors.forename: Lori
authors.initials: L
authors.lastname: Boies
authors.forename: Edward
authors.initials: E
authors.lastname: Sako
authors.forename: Shamik
authors.initials: S
authors.lastname: Bhattacharya
mesh_terms: D000818:Animals; D058385:Cardiac Valve Annuloplasty / Q000295:instrumentation / Q000379:methods*; D004108:Dilatation, Pathologic; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000295:instrumentation / Q000379:methods*; D006439:Hemodynamics; D023421:Models, Animal; D011312:Pressure; D011474:Prosthesis Design; D012720:Severity of Illness Index; D012756:Sheep; D013314:Stress, Mechanical; D013536:Suture Techniques; D013997:Time Factors; D014160:Transducers, Pressure; D014261:Tricuspid Valve / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D014262:Tricuspid Valve Insufficiency / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*