NEUROUROLOGY & FEMALE UROLOGY

Predictors of success with postoperative voiding trials after a mid urethral sling procedure
Wheeler TL 2nd, Richter HE, Greer WJ, Bowling CB, Redden DT, Varner RE
Department of Obstetrics and Gynecology, Division of Women’s Pelvic Medicine and Reconstructive Surgery, University of Alabama at Birmingham, Birmingham, Alabama, USA
J Urol. 2008; 179: 600-4

• Purpose: We identified predictors of passing a voiding trial after incontinence surgery with a mid urethral sling and examined if successful performance on a voiding trial was maintained.
• Materials and Methods: A total of 89 women scheduled for incontinence surgery were enrolled from July 2005 until April 2006. Voiding trials were performed the day of discharge from the hospital, with a two-thirds volume void after a 300 mL fill considered passing. Those who passed underwent a second voiding trial 3 hours later.
• Results: Of the participants 60 (67.4%) underwent tension-free vaginal tape surgery, 29 underwent transobturator tape (32.6%) and 64 (71.9%) underwent concurrent vaginal repairs. A total of 59 (67.0%) participants passed the first voiding trial. Univariate analysis identified 12 potential predicting variables for passing the first voiding trial. From these 12, model building via backward stepwise logistic regression found maximum flow on preoperative uroflowmetry to be the only significant predictive variable (p = 0.0002). Of the 59 women who passed the initial voiding trial 9 (16.4%) failed the second voiding trial. None of the 11 participants who had maximal flow rates greater than 30 cc per second failed the first or second voiding trial, whereas 17 of 22 subjects (77.3%) who had maximal flow rates less than 15 cc per second failed either of these trials.
• Conclusions: Maximum flow rates on preoperative uroflowmetry were the best predictor of passing an initial voiding trial after undergoing a mid urethral sling procedure for incontinence. However, the ability to maintain performance on a second voiding trial, even only 3 hours after passing an initial trial, is not assured.
  
  
• Editorial Comment
  The authors prospectively studied a cohort of patients with regard to their ability to successfully void on the day of their discharge after anti-incontinence surgery. The patients were asked to complete two “fill-pull” trial of voids using 300 cc’s of instilled fluid to see if they could go home without their urinary catheter. Successful voids were characterized by at least two-thirds of the bladder instillate being voided out over a ten-minute period. The investigators subsequently reviewed the patients’ clinical histories and urodynamic evaluations and based on 51 potential predictors noted that the maximum flow rates were the best predictor of passing the first voiding trial. Nevertheless, voiding well the first time did not guarantee that the patient would pass the second voiding test.
  I found this an interesting contribution to the literature if only to remind surgeons of the challenge of postoperative voiding function. Successful initial voiding does not rule out subsequent urinary retention: the authors noted that approximately 16% of their population failed the second voiding trial and ultimately ended up with a catheter upon discharge to home. In addition, their flow diagram reveals that approximately one-third of their patients had to leave the hospital with a catheter. We have all shared in the muted appreciation of a postoperative patient who must go home with a catheter after her surgery.

Dr. Steven P. Petrou
Associate Professor of Urology
Chief of Surgery, St. Luke’s Hospital
Associate Dean, Mayo School of Graduate Medical Education
Jacksonville, Florida, USA