title: Circulating microemboli after composite replacement or valve-sparing aortic root surgery.
abstract: BACKGROUND
  The purpose of this study was to determine whether microembolic signals (MES) occur after valve-sparing operations on the aortic root. One of the advantages of these procedures relates to the freedom of macroemboli without anticoagulation. Whether this holds true for circulating microemboli has not yet been verified.
  
  
  METHODS
  For comparison, 8 male patients (mean age: 51.8 +/- 12.8 years) were investigated 20.5 +/- 8.4 months after implantation of a mechanical composite graft (group I) and 9 female and 7 male patients (mean age 55.0 +/- 13.4 years) 23.5 +/- 20.0 months after valve-sparing replacement of the aortic root (group II). The middle cerebral artery was insonated for 2 periods of 30 min, breathing room air or O 2 at 9 l/min.
  
  
  RESULTS
  Breathing room air, the amount of MES was considerably smaller in group II (0.94 +/- 1.95 vs. 56.1 +/- 58.9 per 30 min, p = 0.006). The difference was less pronounced (0.5 +/- 1.3 vs. 28.9 +/- 42.6 per 30 min, p = 0.009) breathing oxygen. Breathing oxygen reduced MES significantly in group I (p < 0.05) but not in group II (p > 0.05).
  
  
  CONCLUSIONS
  Aortic valve-sparing operations induce MES at a significantly lower rate than composite aortic valve replacement using a mechanical valve.
authors.affiliation: Department of Cardiac Surgery and Neurology, Medical University of Lübeck, Germany. noetzold@medinf.mu-luebeck.de
authors.forename: A
authors.initials: A
authors.lastname: Nötzold
authors.forename: T
authors.initials: T
authors.lastname: Gerriets
authors.forename: J
authors.initials: J
authors.lastname: Eggers
authors.forename: G
authors.initials: G
authors.lastname: Kupiske
authors.forename: G
authors.initials: G
authors.lastname: Seidel
authors.forename: M
authors.initials: M
authors.lastname: Kaps
authors.forename: H-H
authors.initials: HH
authors.lastname: Sievers
mesh_terms: D001011:Aorta / Q000601:surgery*; D001021:Aortic Valve / Q000601:surgery*; D004617:Embolism / Q000000981:diagnostic imaging* / Q000209:etiology; D005260:Female; D005500:Follow-Up Studies; D006350:Heart Valve Prosthesis / Q000009:adverse effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging; D010100:Oxygen / Q000008:administration & dosage; D011183:Postoperative Complications / Q000000981:diagnostic imaging*; D011474:Prosthesis Design; D018608:Ultrasonography, Doppler
chemical_list: D010100:Oxygen