RESUMO
A large number of PTCA balloon catheters from different manufacturers were examined following their use. Several of these balloons had been previously used for PTCA for the mere purpose of guide wire support. Each balloon was evaluated starting at 8 atm. The pressure was increased in steps of 1 atm until rupture. This stepwise increase of pressure was documented at each level in a short cine film. During dilatations, balloons were in room air until rupture. None of the balloons ruptured before the rated burst pressure. A few of the balloons tolerated pressures of approximately 27 atm. With increasing pressure the shape of the balloons became distorted. Most assumed a banana shape. Most of the balloons ruptured after developing a small hole. Increasing pressure produced increasing diameter, and, generally, we found a linear increase. Most balloons increased by > 15% in diameter over the nominated diameter before rupture. The burst pressure in all balloons was not influenced by the prior mode of dilation, duration of dilation, maximum pressure applied, or length of the balloon. Balloons with smaller diameter ruptured later than compared to those with larger diameters. Our findings demonstrated that all of the balloons tolerated the manufacturers' recommended inflation pressure supporting the safety in their use.