Pre-clinical laboratory evaluation of the new 'AF' arterial line filter range.

Introduction: The presence of emboli was recognised relatively early in the history of open heart surgery. The emboli produced during cardiopulmonary bypass have the predisposition to distribute into, and ultimately obstruct, microvessels of all tissues. The Sorin Group has recently developed a new range of arterial line filters. Before the Sorin AF range of filters was released for pre-launch clinical trials, our group performed in vitro laboratory testing of the AF range against a selection of commercially available filters on the global market.

Results: The Sorin AF620 and AF640 demonstrate both the smallest prime volume and smallest surface contact area (92ml and 290 cm(2), respectively).The results of the GME Handling Efficiency experiments ranged by 39.6%, from 95.9% to 56.3%. In terms of an air bolus handling, the results of the Limit Bolus experiment ranged by 97 ml, from 147.5 ml down to 50 ml. The pressure drop across all the filters was measured under steady state experimental conditions. All of the above investigations were considered against surface area and prime volume.

Conclusion: It is clear from the results that some commercially available arterial line filters perform better than others, not only in overall performance, but also with regard to individual characteristics. Evaluating arterial line filters for hospital-specific use has to balance pressure drop, surface area, micro air handling, prime volume and gross air handling; all points need to be considered. In the AF620 and AF640, Sorin boast that they are the two smallest prime and smallest surface area filters commercially available on the global market. The Sorin AF filter range performs well in all of the areas we investigated and will be a competitive option for centres, irrespective of which characteristics they use to evaluate and select their arterial line filter.