Cannulation of the noncalcified aorta generates particles of microembolic nature: an experimental study using pig aorta.
OBJECTIVE
Aortic cannulation during cardiac surgery is a potential etiological factor for perioperative stroke. Cannulae may dislodge aortic-wall calcifications. In addition, the sharp edge of the cannula-tip may shear off vessel-wall tissue, which can be expelled into the lumen. This hypothesis concerning source of emboli was tested in a noncalcified aortic perfusion model.


METHODS
Pig aortas were pressurized and cannulated. Washout samples were collected before and after cannulation (n = 40). Particles were deposited onto a 10-microm filter and evaluated by microscopy and digital image analysis.


RESULTS
A higher incidence of particles generated by cannulation was noted as compared to before the maneuver (p < 0.001). This increase included small (<0.1 mm, p < 0.001) and intermediate-size particles (0.1-0.5 mm, p < 0.001). Particles above 0.5 mm were few and were not associated with cannulation.


CONCLUSIONS
Cannulation was a source of embolic material in the noncalcified aortic model. However, these particles were less than 0.5 mm in diameter and may contribute to neurocognitive decline after cardiac surgery.
Hedberg
Magnus
M
Department of Surgical and Perioperative Science, Heart Center, Cardiothoracic Division, Umeå University Hospital, Umeå, Sweden. magnus.hedberg@vll.se
Funck
Bertil
B
Engström
Karl Gunnar
KG
D000818:Animals; D001011:Aorta; D002404:Catheterization / Q000009:adverse effects*; D004195:Disease Models, Animal; D004617:Embolism / Q000209:etiology*; D020521:Stroke / Q000517:prevention & control*; D013552:Swine