The Annals of thoracic surgery
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Comparative Study
The effect of arterial filtration on reduction of gaseous microemboli in the middle cerebral artery during cardiopulmonary bypass.
Noninvasive in vivo detection of gaseous microemboli in the middle cerebral artery, by transcranial Doppler ultrasound, was used to determine the effect of filtration in the arterial catheter using 25- and 40-microns filters and bubble oxygenators in patients undergoing cardiopulmonary bypass surgery. Eighteen patients undergoing coronary artery bypass surgery were studied using a closed cardiac (unvented heart) model. Group 1 patients (no filters) had the highest incidence of gaseous microemboli, as indicated by the ultrasound microemboli index, at both high and low oxygen flow rates. ⋯ The 25-microns group patients had the lowest values of all. No microemboli were detected at low oxygen flow rates, and microemboli were detected in only 0.1% of the samples at high oxygen flow rates. Additionally, observations on vented hearts in 3 patients undergoing cardiac valve surgery indicate that the origin of gaseous microemboli may be air trapped inside the heart.
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Profound hypothermia protects cerebral function during circulatory arrest in the surgical treatment of a variety of cardiac and aortic abnormalities. Despite its importance, techniques to determine the appropriate level of hypothermia vary; studies of temperatures recorded from multiple peripheral body sites show inconsistent findings. The purpose of this study is to establish objective criteria to consistently identify intraoperatively the safe level of hypothermia. ⋯ Three had neurological deficits, none clearly related to hypothermia. Two patients (3.6%) required reexploration for postoperative bleeding. We conclude that monitoring the EEG to identify ECS is a safe, consistent, and objective method of determining the appropriate level of hypothermia.
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Case Reports
Aortic valve endocarditis with aortic root abscess cavity: surgical treatment with aortic valve homograft.
Aortic valve endocarditis with an aortic root abscess cavity was treated by a modification of the standard technique of aortic homograft implantation in 3 patients. At a mean follow-up of 35 months, all 3 patients were well without reoperation or signs of aortic incompetence. This technique may, in some cases, be an alternative to the more complex procedure of homograft aortic root replacement with coronary reimplantation.