Intraluminal aortic manipulation by means of intra-aortic filter, cannulation, and external clamp maneuvers evaluated versus dislodged embolic material.

OBJECTIVES: Aortic atherosclerosis is an important risk factor for cerebrovascular accidents in cardiac surgery. An intra-aortic filter might reduce this risk. We aimed to analyze the risks for emboli associated with intraluminal aortic manipulation and intra-aortic filter handling in relation to cannulation and external clamp maneuvers.
METHODS: A model was designed with a cadaver aorta and retrograde perfusion (n = 16). A crossclamp was positioned on the ascending aorta and repeatedly opened under pressure to collect aliquots with dislodged particles. Cannulation was performed after 10 clamp maneuvers, followed by positioning and removing the intra-aortic filter, with each step followed by a washout sequence to collect perfusate. The removed filter was also analyzed. Evaluation was by means of digital image analysis, with differentiation of particles into different spectra.
RESULTS: Intra-aortic filter manipulation produced a significant washout of embolic particles; in particular, this was seen for the macroscopic cellular spectrum (P = .006 and P = .002 for filter insertion and removal, respectively). Particles were also found to be collected by the filter (P = .004). In addition, cannulation and aortic crossclamp manipulation generated a notable number of particles (P = .001 and P = .013, respectively).
CONCLUSIONS: The intra-aortic filter collects material during aortic manipulation. However, intraluminal aortic manipulation from filter handling can also dislodge particles, possibly related to shedding of intimal debris. This is in addition to substantial amounts of particles that are generated by aortic cannulation and aortic crossclamping.