• The primary hypothesis is that the two tests will have equivalent “fail” rates. If this is not true, the test with the higher “fail” rate would be determined to have a higher false positive rate.
  

• Safety (false negative rate, expected to be near zero) will be assessed as a secondary outcome.
  

Postoperative voiding dysfunction is commonly encountered following gynecologic surgery. This dysfunction is usually short term, with normal function returning within a few days. Following uro/gynecologic surgery, most patients require drainage with either a transurethral or suprapubic catheter in the immediate postoperative period. Within our practice, we prefer drainage with a transurethral catheter.

At some point after surgery, the urethral catheter is removed and normal bladder function allowed to resume. At present, there is no generally accepted regimen to assess voiding efficiency. In our practice, we currently employ two regimens to both assess voiding efficiency and expedite catheter removal. In one technique, the catheter is removed and the patient’s bladder is allowed to fill spontaneously. Patients are asked to void when they experience a strong urge. The voided volume is recorded and a post-void residual (PVR) is then measured by transurethral straight catheterization.

In the second technique, the patient’s bladder is retrogradely filled with 300 cc of sterile fluid and the catheter removed. They are asked to void within 15 minutes of instillation and the voided volume is measured. The PVR is then obtained by transurethral straight catheterization.

In both cases, if the patient voids >2/3 the total volume (voided volume + residual) the trial is considered “passed” and the catheter is removed. If a patient voids < 2/3 of the total volume, the trial is considered “failed” and indicative of urinary retention. In this case the catheter replaced.

We aim to assess the ability of these techniques to accurately predict voiding efficiency and to determine if one technique is superior to the other.