Effect of Catheter Tip Selection and Oil Viscosity on the Rate of Silicone Oil Injection and Extrusion

Abstract

Abstract: : Purpose: To evaluate the effect of silicone oil viscosity and differences in catheter choice on the rate of silicone oil infusion and extrusion using an automated viscous fluid injector. Methods: Known volume of 5000cs viscosity Silicone oil was placed into a graduated medicine glass. Four different tips (20ga. metal canula provided with the silicone oil kit, trimmed B–D Insyte 20ga. I.V. catheter, Visitec 19ga. metal silicone oil remover canula, and trimmed B–D Insyte 18 ga. I.V. catheter) were connected to the tubing system of a Richard James FTS–1000 fluid transfer system (set to a pressure of 60.0 psi and a vacuum setting of 60 cm/Hg). An electronic timer was used to determine time for removal and injection of the silicone oil. Measurements were carried out in duplicate for each catheter tip. The above methodology was then repeated using 1000cs silicone oil. Mean times for injection and removal were calculated for each catheter tip with both silicone oil viscosities. Results: Mean Injection and Removal Times of 4ml 5000cs Silicone Oil 

Mean Injection and Removal Times of 4ml 1000cs Silicone Oil 

Conclusion: Silicone oil injection and extrusion rates vary based on oil viscosity and catheter selection. Catheter diameter has an influence on infusion and removal rates for silicone oil as well.

Keywords: vitreoretinal surgery • vitreous substitutes • injection