title: Second transcatheter aortic valve implantation for treatment of suboptimal function of previously implanted prosthesis: review of the literature.
abstract: OBJECTIVE
  To systematically review reported cases of second transcatheter aortic valve deployment within a previously implanted prosthesis (TAV-in-TAV).
  
  
  BACKGROUND
  TAV-in-TAV deployment is one of the rescue strategies undertaken due to an unsuccessful or suboptimal transcatheter aortic valve implantation (TAVI) result. Currently, there are no clear indications for second valve implantation and outcomes of patients with 2 prostheses deployed remain poorly known.
  
  
  METHODS
  The MEDLINE and PubMed databases were searched for cases of TAV-in-TAV implantations of aortic valve.
  
  
  RESULTS
  Forty-three articles reporting on TAV-in-TAV deployment were included in the review. The most frequently observed indication for second valve implantation was aortic regurgitation (AR) occurring shortly after TAVI. There was a strong dominance of paravalvular over intravalvular AR, with prosthesis malposition being the main underlying cause of TAVI failure (81% of all identified cases). Perioperative echocardiographic images are crucial in identifying causes of failure and helpful in optimal rescue strategy selection. Success rate of TAV-in-TAV implantation varies from 90% to 100% with mortality rate of 0-14.3% at 30 days. Despite similar aortic valve function in follow-up, TAV-in-TAV may be an independent predictor of increased cardiovascular mortality.
  
  
  CONCLUSIONS
  TAV-in-TAV implantation is feasible and results in favorable short- and mid-term outcomes in patients with acute failure of TAVI without recourse to open-heart surgery. Further studies are needed to establish algorithm of the management of unsuccessful or suboptimal implantation results.
authors.affiliation: Interventional Cardiology and Angiology Department, Institute of Cardiology, Warsaw, Poland.
authors.forename: Adam
authors.initials: A
authors.lastname: Witkowski
authors.forename: Jan
authors.initials: J
authors.lastname: Jastrzebski
authors.forename: Maciej
authors.initials: M
authors.lastname: Dabrowski
authors.forename: Zbigniew
authors.initials: Z
authors.lastname: Chmielak
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001021:Aortic Valve / Q000601:surgery*; D001022:Aortic Valve Insufficiency / Q000209:etiology / Q000601:surgery; D001024:Aortic Valve Stenosis / Q000601:surgery*; D006328:Cardiac Catheterization / Q000379:methods; D019544:Equipment Failure Analysis; D005260:Female; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000009:adverse effects* / Q000379:methods; D006801:Humans; D008297:Male; D063868:Patient Outcome Assessment; D011183:Postoperative Complications / Q000601:surgery*; D011474:Prosthesis Design; D012086:Reoperation / Q000295:instrumentation / Q000379:methods; D065467:Transcatheter Aortic Valve Replacement / Q000295:instrumentation / Q000379:methods; D016896:Treatment Outcome