title: Mitral loop cerclage as a variant form of mitral cerclage annuloplasty that adds a device (CSTV) for preventing potential complications: a preclinical proof of concept and feasibility study.
abstract: OBJECTIVE
  Although mitral cerclage annuloplasty can reduce mitral regurgitation, the potential risks for erosion of the surrounding tissue or conduction blockage are barriers to human translation. This preclinical study aimed to provide a proof of concept for a novel approach, mitral loop cerclage (MLC), designed to address these shortcomings.
  
  
  RESULTS
  MLC consists of: (1) a novel appliance termed a coronary sinus and tricuspid valve protective device (CSTV) that includes a tension locker, and (2) a nylon-coated, braided stainless steel rope (0.6 mm thick) with a coronary artery protective device in a single unit (cerclage rope). Nine healthy farm swine underwent MLC in short-term (two weeks, n=4) and midterm (six weeks, n=5) survival experiments under X-ray fluoroscopic guidance imaging. The procedural success rate was 100%. MLC resulted in a significant reduction of the septal lateral dimension of the mitral annulus (24.58±2.16 vs. 21.26±1.43 mm, p=0.04) and left ventricular (LV) volume in diastole (75.9±3.9 vs. 70.6±5.0 ml, p=0.04) in the midterm group. No conduction abnormalities or serious complications were noted beyond trivial tricuspid regurgitation in all cases (n=9). Necropsy showed no evidence of tissue erosion and an excellent biocompatibility of the implanted devices.
  
  
  CONCLUSIONS
  MLC, as a novel approach for catheter-based mitral valve repair, appeared feasible in this short-term preclinical model. Further studies with longer follow-up in a cardiomyopathic animal model are needed to verify the clinical feasibility and safety of MLC.
authors.affiliation: School of Medicine, Pusan National University & Cardiovascular Center, Yangsan Hospital, Yangsan, South Korea.
authors.forename: June-Hong
authors.initials: JH
authors.lastname: Kim
authors.forename: Si-Chan
authors.initials: SC
authors.lastname: Sung
authors.forename: Min-Ku
authors.initials: MK
authors.lastname: Chon
authors.forename: Jun-Oh
authors.initials: JO
authors.lastname: Kim
authors.forename: Sang-Hyun
authors.initials: SH
authors.lastname: Lee
authors.forename: Soo-Yong
authors.initials: SY
authors.lastname: Lee
authors.forename: Hyung-Gon
authors.initials: HG
authors.lastname: Je
authors.forename: Ki-Seok
authors.initials: KS
authors.lastname: Choo
authors.forename: Jong-Min
authors.initials: JM
authors.lastname: Hwang
authors.forename: Jeong-Su
authors.initials: JS
authors.lastname: Kim
authors.forename: Yong-Hyun
authors.initials: YH
authors.lastname: Park
authors.forename: Kook-Jin
authors.initials: KJ
authors.lastname: Chun
authors.forename: Cheol-Min
authors.initials: CM
authors.lastname: Kim
mesh_terms: D000818:Animals; D006328:Cardiac Catheterization / Q000295:instrumentation*; D003331:Coronary Vessels / Q000601:surgery; D004452:Echocardiography / Q000379:methods; D005240:Feasibility Studies; D005260:Female; D019918:Heart Valve Prosthesis Implantation / Q000379:methods; D006352:Heart Ventricles / Q000601:surgery; D058386:Mitral Valve Annuloplasty / Q000295:instrumentation*; D008944:Mitral Valve Insufficiency / Q000601:surgery*; D011183:Postoperative Complications / Q000517:prevention & control*; D013552:Swine; D014262:Tricuspid Valve Insufficiency / Q000601:surgery