Embolic material generated by multiple aortic crossclamping: a perfusion model with human cadaveric aorta.
BACKGROUND
Atherosclerosis of the ascending aorta and use of aortic crossclamping are risk factors for neurologic injury during cardiac surgery.


OBJECTIVE
Repeated aortic manipulation is part of the surgical approach to most cardiac operations. The aim of this study was to assess the amount and size of particulate matter that is dislodged from the aortic wall as a function of repeated aortic crossclamping.


METHODS
In 10 subjects undergoing autopsy the aorta was dissected and mounted in a perfusion model. The ascending aorta was crossclamped and washed out 10 times, with the perfusate collected in aliquots (1 to 10). The aliquots were examined by computerized image processing, both macroscopically and under the microscope for calcified and cellular material.


RESULTS
Aortic crossclamping produced substantial output of particulate matter. After repeated aortic crossclamping the number of particles decreased (P =.012) and approached the baseline for aliquots 6 to 10. The average particle diameter was 0.63 +/- 0.03 mm, with a maximum of 4.74 mm. Similar variability in particle outputs were recorded microscopically, with findings of both calcified and cellular material. Nine of 10 aortas had calcifications seen during simple visual inspection.


CONCLUSIONS
The washouts of dislodge material at aortic crossclamping had embolic potential. During the initial aortic crossclamping procedures the amount of particles was substantial, both macroscopically and microscopically. On the microscopic scale noncalcified cellular debris represents a significant pool of embolic material. Repeated aortic crossclamping reduced the amount of particles. These findings question surgical techniques associated with repeated aortic crossclamping.
Boivie
Patrik
P
Department of Surgical and Perioperative Science, Umeå University Hospital, Umeå, Sweden. patrik_bovie@hotmail.com
Hansson
Magnus
M
Engström
Karl Gunnar
KG
D000368:Aged; D000369:Aged, 80 and over; D001011:Aorta / Q000473:pathology / Q000601:surgery*; D002102:Cadaver; D002114:Calcinosis / Q000473:pathology; D004617:Embolism / Q000209:etiology* / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008953:Models, Anatomic; D010316:Particle Size; D010477:Perfusion; D013525:Surgical Instruments