title: Stentless aortic valve reoperations: a surgical challenge.
abstract: BACKGROUND
  Stentless aortic valve reoperations may become more common as these bioprostheses reach the limits of their durability. Relatively few studies have examined stentless valve reoperation, and we therefore reviewed our results for these procedures.
  
  
  METHODS
  All patients with stentless valves undergoing redo aortic valve replacement (AVR) at our institution were examined (n = 57). Ten patients had a prior Freestyle valve (Medtronic, Minneapolis, MN), and 47 patients had a Toronto stentless porcine valve (SPV; St. Jude Medical St Paul, MN).
  
  
  RESULTS
  Redo AVR was performed 8.4 +/- 3.7 years (range, 0.1 to 16.5 years) after stentless valve implantation. Reoperations were elective in 27 patients (49%), and 30 (51%) underwent urgent or emergency procedures. The indication for redo AVR was structural valve dysfunction in 48 patients (84%), acute endocarditis in 7 (12%), and other in 2 (4%). Aortic insufficiency was present in 47 patients (82%). A total of 36 aortic root replacement operations (63% of patients) were required, of which 19 were secondary to severe adhesions between the stentless valve and the native aortic root. Operative mortality was 11% (n = 6) for the entire group. Mortality was higher in patients undergoing redo AVR less than 1 year after stentless valve implantation versus more than 1 year (67% versus 7%, p = 0.03). Long-term survival at 5 years postoperatively was 79% +/- 7% in all patients, and 81% of survivors were in New York Heart Association class I or II.
  
  
  CONCLUSIONS
  Reoperation after stentless AVR is a challenging procedure that frequently requires aortic root replacement. Stentless valve reoperation is associated with an increased risk of death, particularly in patients operated on within 1 year of implantation.
authors.affiliation: Division of Cardiovascular Surgery, Toronto General Hospital, and Department of Surgery, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Borger
authors.forename: Kriengchai
authors.initials: K
authors.lastname: Prasongsukarn
authors.forename: Susan
authors.initials: S
authors.lastname: Armstrong
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Feindel
authors.forename: Tirone E
authors.initials: TE
authors.lastname: David
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D001021:Aortic Valve / Q000601:surgery*; D001705:Bioprosthesis; D005260:Female; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000009:adverse effects / Q000379:methods* / Q000401:mortality; D006801:Humans; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000209:etiology; D012086:Reoperation; D012189:Retrospective Studies; D015607:Stents; D013552:Swine; D014183:Transplantation, Heterologous