title: Multicentre, propensity-matched study to evaluate long-term impact of implantation technique in isolated aortic valve replacement on mortality and incidence of redo surgery.
abstract: Studies suggest that the use of semicontinuous suture (SC) technique increases the risk of redo valve surgery after aortic valve replacement (AVR). The objective of this study was to identify 30-day mortality, rate of redo operation and long-term outcomes after AVR using either a semicontinuous suture or interrupted suture (IS) technique.
  
  
  
  A total of 1617 patients from 2 cardiothoracic centres, undergoing isolated AVR between April 2005 and August 2013 were included. AVR was performed using SC technique in 765 patients and IS technique in 852 patients. Data were collected prospectively and follow-up was obtained to date for all patients. We compared 30-day mortality, rate of redo operation and long-term mortality in SC and IS groups. One-to-one propensity-matching analysis was performed using IBM SPSS version 22 to evaluate outcomes.
  
  
  
  Four hundred and eleven patients in the SC group were matched to 411 patients in the IS group (total of 822 patients) using propensity-score matching. The baseline characteristics were similar between SC and IS groups after matching. There were no statistically significant differences in 30-day mortality (3.9 vs 2.7%; P = 0.328), long-term mortality at 9-year follow-up (14.4 vs 15.3%; log-rank = 0.524) or rate of redo surgery (2.9 vs 2.0%; P = 0.320) between SC and IS, respectively. However, shorter cross-clamp time (51.9 ± 15.2 vs 60.9 ± 17.6 min; P < 0.001), bypass time (71.3 ± 23.0 vs 81.3 ± 37.8 min; P < 0.001) and the use of larger valve sizes (23.4 ± 2.1 vs 21.9 ± 2.2 mm; P < 0.001) were observed in SC patients compared with IS patients. Multivariate analysis did not show the suture technique as a significant determinant of redo valve surgery.
  
  
  
  This multicentre study demonstrates that neither mortality nor the risk of redo surgery was influenced by the choice of implantation technique using semicontinuous vs interrupted suture techniques. The SC technique allowed shorter operations and larger size valves to be utilized.
authors.affiliation: Department of Cardiothoracic Surgery, Castle Hill Hospital, Cottingham, UK yama.haqzad@hey.nhs.uk.
authors.forename: Yama
authors.initials: Y
authors.lastname: Haqzad
authors.affiliation: Department of Cardiothoracic Surgery, Castle Hill Hospital, Cottingham, UK.
authors.forename: Mahmoud
authors.initials: M
authors.lastname: Loubani
authors.affiliation: Department of Cardiothoracic Surgery, Castle Hill Hospital, Cottingham, UK.
authors.forename: Mubarak
authors.initials: M
authors.lastname: Chaudhry
authors.affiliation: Department of Cardiothoracic Surgery, Castle Hill Hospital, Cottingham, UK.
authors.forename: Priyadharshanan
authors.initials: P
authors.lastname: Ariyaratnam
authors.affiliation: Department of Cardiothoracic Surgery, Northern General Hospital, Sheffield, UK.
authors.forename: Norman
authors.initials: N
authors.lastname: Briffa
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001021:Aortic Valve / Q000000981:diagnostic imaging / Q000601:surgery*; D001024:Aortic Valve Stenosis / Q000175:diagnosis / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D019918:Heart Valve Prosthesis Implantation / Q000379:methods*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011183:Postoperative Complications / Q000453:epidemiology*; D057216:Propensity Score; D012189:Retrospective Studies; D015996:Survival Rate / Q000639:trends; D013536:Suture Techniques / Q000295:instrumentation*; D013537:Sutures; D013997:Time Factors; D016896:Treatment Outcome; D006113:United Kingdom / Q000453:epidemiology
keywords: Aortic valve replacement; Aortic valve surgery; Interrupted suture; Redo aortic valve replacement; Reoperation; Semicontinuous suture; Surgical techniques