An in-vitro evaluation of aortic arch vessel perfusion characteristics comparing single versus multiple stream aortic cannulae

Objective: During extracorporeal circulation design and orientation of aort ic cannulae tips mainly determine flow pattern in the aortic arch and arch vessels which is the objective of this in vitro study, comparing single ver sus multiple stream cannulae. Methods: In an aortic arch glass model, jet s treams of 21-24 French aortic cannulae which were inserted in the ascending aorta were directed alternatively at the different arch vessels. Flows and pressures in the arch vessels were measured at pump flows of 3-6 l/min. Re sults: With optimal orientation of the jet stream in the aortic arch, no pr eferential flow in the arch vessels was seen. In the single jet stream aort ic cannulae group a significant parallel increase in flow and pressure in t he jet streamed arch vessels compared to the non-jet streamed arch vessels occurred (P < 0.05). With the jet stream directed on vessel 2 (left carotid vessel) there was a significant pressure and flow difference comparing the two non-jet streamed vessels with each other (P < 0.03). In the single str eam 24 French cannulae the highest vessel pressure of 168 mmHg and an incre ase in flow of 186 ml/min was measured in the jet streamed left carotid art ery at 6 l/min pump Aow. The multiple stream cannulae provoked the highest vessel pressure of 106 mmHg in the corresponding jet streamed vessel and an increase in flow of 20 ml/min. Conclusion: Tip design of aortic cannulae a nd the orientation of its jet stream are potential sources of remarkable im balance of arch vessel perfusion especially with single jet stream cannulae . These effects are more pronounced with single jet stream cannulae. These results may have important clinical implications regarding perfusion of arc h vessels during extracorporeal circulation. (C) 1999 Elsevier Science B.V. All rights reserved.