Aim To investigate the changes in urethral and suprapubic catheter balloons following deflation and removal.

Method Observations were made on a selection of catheter materials, using three different deflation methods. Measurements were recorded before inflation and following deflation of catheter balloons.

Results The analysis identified that before inflation all catheter balloons were 1-2mm wider than the Charriere size. Following balloon inflation, five balloons were unchanged in appearance, four were slightly misshapen and the Coude balloon inflated at the side of the catheter shaft.

Conclusion The study has shown that manual syringe aspiration results in the formation of creases and ridges, and an increase in catheter balloon diameter size on deflation. Self-syringe aspiration should not be used when deflating catheter balloons. It does not, however, cause the balloon membrane to collapse or become deformed.