Solid and gaseous cerebral microembolization during off-pump, on-pump, and open cardiac surgery procedures.

Full Abstract

BACKGROUND: Neurocognitive dysfunction remains a limitation of cardiac surgery with cardiopulmonary bypass. Intraoperative cerebral microembolization is believed to be one of the most important etiologic factors. Using a new generation of transcranial Doppler ultrasonography, we compared the number and nature of intraoperative microemboli in patients undergoing on-pump and off-pump cardiac surgery procedures. METHODS: Bilateral continuous transcranial Doppler monitoring of the middle cerebral arteries was performed in 45 patients (15 off-pump coronary artery bypass grafting, 15 on-pump coronary artery bypass grafting, and 15 open cardiac procedures). All recordings were performed using a multi-range, multifrequency system to allow both measurement of the number and discrimination of the nature of microemboli in the 3 different groups. RESULTS: The median number (interquartile range) of microemboli in the off-pump coronary artery bypass grafting, on-pump coronary artery bypass grafting, and open procedure groups were 40 (28-80), 275 (199-472), and 860 (393-1321), respectively (P <.01). Twelve percent of microemboli in the off-pump coronary artery bypass grafting group were solid compared with 28% and 22% in the on-pump coronary artery bypass grafting and open procedure groups, respectively (P <.05). In the on-pump groups, 24% of microemboli occurred during cardiopulmonary bypass, and 56% occurred during aortic manipulation (cannulation, decannulation, application, and removal of crossclamp or sideclamp). CONCLUSIONS: Cerebral microembolization is significantly reduced with avoidance of cardiopulmonary bypass. The majority of microemboli occurring during cardiac surgery are gaseous, with a higher proportion of solid microemboli in the on-pump group, and may have a different significance for cerebral injury than solid microemboli. The ability to reliably discriminate gas and solid microemboli may have an important role in the implementation of neuroprotective strategies.

Author information

Author/s: Abu-Omar, Yasir (Y); Balacumaraswami, Lognathen (L); Pigott, David W (DW); Matthews, Paul M (PM); Taggart, David P (DP);

Affiliation: Department of Cardiothoracic Surgery, John Radcliffe Hospital, Oxford, United Kingdom.

Journal and publication information

Publication Type: Comparative Study; Journal Article; Research Support, Non-U.S. Gov't

Journal: The Journal of thoracic and cardiovascular surgery (J Thorac Cardiovasc Surg), published in United States. (Language: eng)

Reference: 2004-Jun; vol 127 (issue 6) : pp 1759-65

Dates: Created 2004/06/02; Completed 2004/07/13; Revised 2006/11/15;

PMID: 15173734, status: MEDLINE (last retrieved date: 2/18/2009)

Sourced from the National Library of Medicine. Abstract text and other information may be subject to copyright.

Comments and Corrections

CommentIn: J Thorac Cardiovasc Surg. 2005 May;129(5):1194; author reply 1194-5. (PMID: 15867810)

External Links for this article
(including full text providers, if available):

Click Electronic Full-text Provider Links to see options for finding the electronic full text links to this article. Note there may be a subscription or fee required for access to the full text. See our FAQ for information on finding FREE full text articles.

This article may also be located in paper journal collections available in many libraries. Use the Journal and Publication Information above to find the full article.