Conduit and compliance responses of female canine urethra Experimental study of effects of varying amounts of instrumental dilation and urethral myotomy

The female canine urethra was subjected to varying amounts of instrumental dilation and various types of urethral myotomy, and their effects on conduit and compliant responses were studied by recording changes in urethral infusion resistance and pressure-volume relationship. Changes in the external diameter of the mid-urethra were simultaneously monitored with a displacement transducer. These studies indicated that decrease in urethral flow resistance and increase in compliance occurred commensurate with the degree of instrumental dilation. Observations on the diameter changes, however, suggested that the specific compliance was probably not increased with 45 F. dilation. Pronounced increase in expansibility and significant decrease in resistance to urethral infusion resulted following internal urethrotomy and deep external myotomy.