Experimental Study On Applicable Coefficients Of Dextran Microspheres Injected Through Different Microcatheters During Therapeutic Embolization

Objective: To evaluate applicble coefficients of the optimal dextan microspheres that may be injected reliably through microcatheters during therapeutic embolization.Materials and Methods: The properties and characteriseics of dextran microspheres in vitro were studied. We measured the suspension time of thedextran microspheres mixture. Five different microcatheters were tested. We used angiographic catheters(5F or 6F Corbra) as contol group. Two differentsize ranges of dextran microspheres at four different concentrations were tested with each catheter. Varied velosities of injection were tested too. For each size and concentration of dextran microspheres, sixty 2-mL injections were made into each catheter with syringes and power injector. Both objective and subjective assessments were recorded. Statistical analysis was performed with SPSS9.0( LSD method). It is significant difference if P value is less than 0.05.Results: We found that when diluted in an equal mixture of contrast material and normal saline, the dextran particles remained in suspension stable. The author determined recommended size ranges and concentrations of dextran microspheres that may be injected with reasonable pressure and minimal risk of inadvertent catheter occlusion. The control group(angiographic catheters) had no occlusion phenomenon. Both the large and small particles of dextran microspheres could not be injected throughcatheters matched with < 0.014 inch guide wires.Conclusion : Dextran microspheres are good solid embolic agents ,because the microspheres remain in suspension long,don't clump or shatter. Reasonable dextran microspheres size ranges and concentrations that can be injected through large microcatheters(with > 0.014 inch guidewires) will help prevent inadverent catheter occlusion during vascular emboliztion.5 ml syringe or large one is recommended to use during the clinical interventional procedures. Still extreme care must be exercised in our daily work.