Use of multi-lumen catheters to preserve injected stem cell viability and injectant dispersion

Infusion catheters, when used with balloons, are susceptible to compression of the catheter lumen. A consequence is that shear stress is increased in the fluid that passes through the lumen. When the injected fluid contains viable cells, hemolysis of the cells can result. This study investigates the effect of a new injection catheter design which is intended to resist the deleterious effect of balloon compression on cell viability for various flowrates, balloon pressures, and fluid viscosity values. Two types of catheters were employed for the study; a standard single-lumen device and a newly designed multi-lumen alternate. Experimental and numerical simulations show that for a single-lumen injection catheter, balloon pressures in excess of 7-8 atm have the potential for causing hemolysis for flows of approximately 1-4 ml/min. The critical balloon pressure is dependent on the viscosity of the cell-carrying fluid and the injectant flowrate. Higher injection rates and viscosities lead to lower threshold balloon pressures. The results show a sharp rise in cell death when pressures rose above approximately 7 atm. On the other hand, the multi-lumen design was shown to resist hemolysis for all tested and simulated balloon pressures and flowrates up to 10 ml/min. Experimental results confirmed the numerical findings that hemolysis-causing shear stress was not found with the multi-lumen, up to 12 atm. This study indicates that a pressure-resistant multi-lumen catheter better preserves cell viability compared to the standard.