For a study, researchers sought to measure the volume of free fragment creation and the frequency of foley catheter balloon rupture.
The usual sizes (14–20 French) of 40 Latex and 30 Silicone catheters were inflated with sterile water in an aqueous environment without positive pressure. Catheters that produced fragments, the size of the pieces, and the largest amount infused before a rupture (“burst volume”) were noted. The prescribed balloon volume was inflated in a subset of catheters before the balloon was pierced with a needle.
About 32 (80%) of the 40 latex catheters spontaneously ruptured, releasing a free fragment. The sizes of the fragments varied from 2.1 to 3.2 cm, with a 2.74± 0.33 cm average. Latex catheters had average burst volumes of 83 mL, 90 mL, 112 mL,120 mL, and 422 mL for 14 Fr, 16 Fr, 18 Fr, 16 Fr 3-way, and 20 Fr 30 cc, respectively. There were no fragments of any of the 30 silicone catheters that spontaneously ruptured. For 14 Fr, 16 Fr, and 18 Fr silicone catheters, the average burst volume was 57 mL, 45 mL, and 55 mL, respectively. No catheter balloons formed fragments when needle punctures were made at the acceptable balloon volumes.
Latex catheter balloons can withstand greater fill volumes, although they are more likely to release fragments. In lesser quantities, silicone catheters rupture, but they do not release fragments. Therefore, needle puncture is safe at standard fill volumes, and cystoscopy is probably not required.