Elimination of fat microemboli during cardiopulmonary bypass.
BACKGROUND
Fat emboli have been implicated in cerebral dysfunction after cardiopulmonary bypass (CPB). We sought to identify the source of fat emboli during CPB and devise a technique for their elimination.


METHODS
Patients undergoing CPB were prospectively randomized to either cardiotomy suction (n = 7) or cell-saving suction device (n = 6). Blood was collected at various intervals during CPB, and the fat emboli were identified using oil red O stain. These emboli were grouped based on their diameter into 10- to 50-microm and more than 50-microm particles. The number of fat emboli per slide examined was graded according to the following scale: 1 (1 to 10), 2 (11 to 20), 3 (21 to 30), and 4 (> 30 emboli). In the second phase of the experiment, a 21-microm filter was attached in series, distal to the cardiotomy reservoir (n = 6), and fat emboli were quantified.


RESULTS
Blood from the pericardial well was saturated with fat emboli of both sizes. Patients randomized to the cardiotomy suction had a significantly higher number of fat emboli at the end of CPB when compared with those randomized to the cell-saving suction device and dual-filter group. Processed blood from both the cardiotomy reservoir and cell-saving device was noted to have an abundance of fat emboli when compared with blood processed through the dual filters.


CONCLUSIONS
Processed blood from both the cardiotomy reservoir and cell-saving device appear to have an abundance of fat emboli that are completely eliminated by using a 21-microm arterial filter in series with the cardiotomy reservoir. This intervention could potentially reduce neurocognitive dysfunction associated with CPB.
Kaza
Aditya K
AK
Division of Thoracic and Cardiovascular Surgery, University of Virginia Health System, Charlottesville, Virginia 22908-1359, USA.
Cope
Jeffrey T
JT
Fiser
Steven M
SM
Long
Stewart M
SM
Kern
John A
JA
Kron
Irving L
IL
Tribble
Curtis G
CG
D002315:Cardiopulmonary Bypass; D004620:Embolism, Fat / Q000517:prevention & control*; D005374:Filtration; D006801:Humans; D010316:Particle Size; D011446:Prospective Studies