title: Cerebral microemboli during minimally invasive and conventional mitral valve operations.
abstract: BACKGROUND
  Intraoperative cerebral microembolism may cause postoperative neurologic damage. The aim of this study was to determine the frequency of cerebral microembolic signals (MES) during minimally invasive surgery (MIS) and conventional (conv.) mitral valve operations and to determine the association of MES with various stages of the operation.
  
  
  METHODS
  Intraoperative computer-aided transcranial Doppler measurements were performed to detect cerebral microemboli in 21 patients undergoing MIS and in 14 patients undergoing conv. mitral valve operation. We calculated the mean embolic rate for three time periods: P1, start of the operation until aortic clamping; P2, aortic clamping until clamp removal; and P3, declamping until end of surgery.
  
  
  RESULTS
  There was no significant difference in the total number of detected cerebral MES between both patient groups (MIS 1,014+/-753, conv. 937+/-519; NS). In both groups, the highest number of MES were detected during the third time period when the heart regained effective ejection (MIS 875+/-746, conv. 680+/-462; p > 0.5).
  
  
  CONCLUSIONS
  Transcranial Doppler was useful to detect cerebral microemboli in MIS and conv. mitral valve operation. We found no increased risk of cerebral microembolism during the minimally invasive method compared with the conventional technique.
authors.affiliation: Department of Cardiac Surgery, Heartcenter, University of Leipzig, Germany. felix_schneider@hotmail.com
authors.forename: F
authors.initials: F
authors.lastname: Schneider
authors.forename: J F
authors.initials: JF
authors.lastname: Onnasch
authors.forename: V
authors.initials: V
authors.lastname: Falk
authors.forename: T
authors.initials: T
authors.lastname: Walther
authors.forename: R
authors.initials: R
authors.lastname: Autschbach
authors.forename: F W
authors.initials: FW
authors.lastname: Mohr
mesh_terms: D002315:Cardiopulmonary Bypass; D005260:Female; D019918:Heart Valve Prosthesis Implantation / Q000009:adverse effects*; D006801:Humans; D020766:Intracranial Embolism / Q000000981:diagnostic imaging / Q000209:etiology*; D007431:Intraoperative Complications; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures / Q000009:adverse effects*; D008943:Mitral Valve / Q000601:surgery*; D017585:Ultrasonography, Doppler, Transcranial