Inaccuracies in manufacturer-reported deflated PTCA balloon profiles

Deflated balloon profile is an important consideration in the selection of PTCA catheters. In order to test the accuracy of manufacturer-reported balloon profiles, we measured deflated shoulder and mid-balloon profile in 107 unused catheters (2.0, 2.5, and 3.0 mm) from 6 manufacturers using a precision hole gauge with a resolution of .001 inches. A significant difference was defined as a discrepancy greater than or equal to 0.003 inches from the manufacturer's reported profile. During Phase I, measurements were obtained at room temperature on catheters directly out of the package. Of the 36 models tested, 21/36 (56%) had measured shoulder profiles that were larger than their reported profile, and 29/36 (81%) had mid-balloon profiles that were larger than their reported profile. During Phase II, measurements were made at body temperature following a 60 second inflation at 120 psi (8.16 atm). Of 33 models tested, 18/33 (55%) had measured shoulder profiles that were larger than their reported profile; 26/33 (79%) had mid-balloon profiles that were larger than their reported profile. The term "profile" is imprecisely defined. Manufacturer-reported deflated PTCA balloon profiles are not always accurate. Independent and uniform testing of balloon profiles is necessary for valid comparisons between balloons and manufacturers.