Recognition and Treatment of Bladder Outlet Obstruction After Sling Surgery

POINT-COUNTERPOINT Recognition and Treatment of Bladder Outlet Obstruction After Sling Surgery Wendy W. Leng, MD, Michael B. Chancellor, MD Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, PA At the University of Pittsburgh School of Medicine, our experience with urethrolysis over the past several years offered a unique opportunity to assess outcomes after delayed time to urethrolysis. We observed a highly suggestive association between prolonged time to urethrolysis and a greater likelihood of persistent bladder dysfunction. If this observation is corroborated by other studies, it would be prudent to lower our threshold of clinical suspicion to detect bladder outlet obstruction. Videourodynamics testing can be invaluable for making the distinction between outlet obstruction versus de novo urge incontinence. Here, we briefly review the literature on urethrolysis and present the urethrolysis technique utilized at our institution. The article concludes with several challenging and controversial clinical judgment questions asked of Dr Leng by Dr Chancellor. [Rev Urol. 2004;6(1):29-33] © 2004 MedReviews, LLC Key words: Urethrolysis • Sling surgery • Bladder outlet obstruction rocedures to correct stress urinary incontinence are designed to restore support to the urethrovesical junction and, in cases of intrinsic sphincter dysfunction, improve the coaptation of the urethra. Persistent bladder dysfunction resulting from postoperative urethral hypersuspension is a known, albeit not well characterized, complication following female stress incontinence surgery. In P VOL. 6 NO. 1 2004 REVIEWS IN UROLOGY 29 BOO After Sling Surgery continued patients with persistent voiding dysfunction, urethrolysis has been shown to consistently ameliorate voiding complaints and urinary retention. Some investigators have suggested waiting at least 3 months before performing urethrolysis, as some patients will have resolution of their symptoms with no surgical therapy.1 However, more recently, the trend has been to perform urethrolysis earlier, as soon as 4 weeks into the postoperative period. The available literature suggests short-term symptomatic success with this approach.2,3 Timing of Urethrolysis Although there appears to be a growing consensus that an earlier timeline for urethrolysis is indicated, there is no literature addressing the impact of delayed urethrolysis (>6 months postsurgery) on resolution of bladder symptoms. This lack of data is of particular clinical concern given the all too vague objective criteria used to diagnose female bladder outlet obstruction (BOO). In the absence of clear objective diagnostic criteria, one must wonder whether a fraction of patients who might benefit from urethrolysis instead receive treatment for the presumptive diagnosis of de novo urge incontinence. University of Pittsburgh Experience We retrospectively reviewed 21 consecutive female patients who underwent urethrolysis for postoperative voiding dysfunction. Patients with a known preoperative history of urgency, urge incontinence symptoms, or neurogenic bladder dysfunction, as well as those with a history of anticholinergic drug therapy prior to stress incontinence surgery, were excluded from the study.4 In our particular series of patients, the delay time to urethrolysis ranged from 7.1 months to as long as 44.5 months, 30 VOL. 6 NO. 1 2004 REVIEWS IN UROLOGY A B Figure 1. Urethrolysis technique: (A) A vertical midline incision is made overlying the bladder neck and midurethra. (B) After raising mucosal layers to either side of midline, the periurethral space is sharply dissected with Metzenbaum scissors, up into the retropubic space. Adapted from Nitti VW, Raz S. J Urol. 1994;152:93-98.10 prompting us to consider whether prolonged outlet obstruction could lead to irreversible bladder storage dysfunction, despite eventual urethrolysis. Recent data reported in the literature on male BOO support this theory.5,6 Our cohort of patients offered a unique opportunity to address the issue of delayed time to urethrolysis. We hypothesized that a prolonged longer period of urethral obstruction is associated with a greater incidence of refractory bladder symptoms. Urethrolysis Technique The most common urethrolysis technique is the transvaginal approach (Figure 1),7 reiterating the original transvaginal operative approach to creating the sling. We create a verti- Our post-urethrolysis data, with an average follow-up of 20 months, strongly suggest that a longer period of urethral obstruction correlates with a greater incidence of refractory bladder symptoms. period of BOO may adversely impact bladder function, a phenomenon commonly observed in the parallel model of male BOO due to benign prostatic hyperplasia or urethral stricture disease. Indeed, our post-urethrolysis data, with an average follow-up of 20 months, strongly suggest that a cal midline incision overlying the bladder neck and midurethra. After raising mucosal layers to either side of midline, the periurethral space is sharply dissected with Metzenbaum scissors, up into the retropubic space. Successful urethrolysis is guided by increased mobilization of the BOO After Sling Surgery indwelling Foley urethral catheter. Less commonly, when the transvaginal approach fails, a combined transvaginal and retropubic approach is indicated.8 Complications of Delayed Urethrolysis We theorized that a significant delay in time to urethrolysis, that is, prolonged BOO, might lead to a higher incidence of refractory bladder storage symptoms. In our series, we threshold of suspicion to detect BOO in this postoperative population. Furthermore, we must necessarily ask whether our reported incidence of BOO after incontinence surgery is underestimated and consider the possibility that a proportion of patients who receive the diagnosis of de novo urge incontinence truly have undetected BOO. Much of the challenge in managing bladder dysfunction after sling surgery can be attributed to the current Although overall success rates in most urethrolysis series are reported to range from 70% to 85%, irritative voiding symptoms often persist. sought to categorize the severity of post-urethrolysis bladder symptoms with the mean time interval between original incontinence surgery and urethrolysis surgery. In the majority of the available literature, urethrolysis is performed 4 weeks to 3 months after incontinence surgery. Our analysis certainly supports the prompt recognition and treatment of urethral hypersuspension. However, what is the fate of patients with unrecognized iatrogenic urethral obstruction who proceed to urethrolysis after a prolonged period of longer than 12 months? The common presenting symptoms of BOO range widely—from outright urinary retention to obstructive voiding symptoms to irritative lower urinary tract storage symptoms (frequency, urgency, urge incontinence). The largest series to date reviewed the symptoms of 51 patients presenting for urethrolysis and found that the majority presented with irritative complaints (75%); fewer (61%) presented with obstructive complaints, and an even smaller percentage (24%) described retention.9 Thus, we must ask ourselves whether we have a sufficiently low diagnostic quandary, that is, a lack of objective diagnostic urodynamic criteria for female BOO. Nitti and colleagues10 proposed criteria to define female urethral obstruction using videourodynamics testing: a sustained detrusor contraction of any magnitude associated with reduced flow and radiographic evidence of obstruction between the bladder neck and the urethral meatus. We rely on these same diagnostic criteria before performing urethrolysis. In clinical practice, however, videourodynamics testing is often not readily available. Some physicians rely solely on a clinical history age and/or voiding symptoms posturethrolysis. Although overall success rates in most urethrolysis series are reported to range from 70% to 85%,3,11 irritative voiding symptoms often persist. Gomelsky and colleagues3 reported that irritative voiding symptoms were improved in 75% of patients; complete resolution occurred in only 12.5% of patients. We, therefore, argue for more uniform evaluation of suspected BOO after incontinence surgery. Videourodynamics pressure-flow voiding studies, performed before urethrolysis, can truly reveal obstructive voiding patterns. Given the recognized paucity of objective data in this arena, it would be premature to streamline the objective assessment of this condition. In order to better understand the parameters associated with female urethral obstruction, we must continue to carefully collect the data. Questions and Answers Dr Chancellor: How do you diagnosis urethral obstruction after a sling operation? Because many women have mixed stress and urge incontinence preoperatively, how do you differentiate obstructive versus irritative symptoms after sling surgery? Dr Leng: Postoperatively, I take an extremely detailed history of bladder Videourodynamics pressure-flow voiding studies, performed before urethrolysis, can truly reveal obstructive voiding patterns. of new-onset voiding dysfunction after incontinence surgery to make the diagnosis of postoperative BOO. Although this method of diagnosis may be a reasonable premise when urethrolysis is successful, it leaves a void of information and presents a management quandary if the patient continues to experience bladder stor- storage and voiding symptoms in all of my patients who have undergone stress incontinence surgery. If the patient describes worsened urinary urgency, frequency, urge incontinence, and/or a new onset change in her previously normal voiding pattern, I have a high index of suspicion to look for urethral obstruction. My next VOL. 6 NO. 1 2004 REVIEWS IN UROLOGY 31 BOO After Sling Surgery continued step is to perform a videourodynamics pressure-flow voiding study. Dr Chancellor: Once urethral obstruction has been diagnosed, how do you proceed with patient management? Should you perform urethral dilation, initiate -blocker therapy, prescribe intermittent self-catheteri- Dr Chancellor: When should you perform urethrolysis? Will stress incontinence recur if urethrolysis is performed too soon? Dr Leng: I believe that urethrolysis should be performed in all cases of urodynamically proven BOO. In the event of acute urinary retention, I In the few cases in which stress urinary incontinence does recur, the condition is so mild and infrequent that the patient does not desire further treatment. zation, employ a combination of all of these strategies, or proceed directly to urethrolysis? Dr Leng: Because I conduct my own urodynamics testing, if I diagnose urethral obstruction, I perform urethral dilation that same day. Shortly thereafter, I follow up with the patient. If the patient reports no significant subjective improvement, I proceed with formal urethrolysis. I have not found conservative therapy, that is, self-catheterization and -blocker pharmacotherapy, to be of value in these patients. Moreover, I do not favor a protracted course of conservative management, because, in most cases, urethrolysis can be performed on an outpatient basis with minimal morbidity. would first institute the usual intermittent self-catheterization regimen until the sensation of urgency and voiding function return. I would then perform a videourodynamics pressureflow voiding study. I counsel patients that it is very rare to develop stress urinary incontinence after urethrolysis. In the few cases in which stress urinary incontinence does recur, the condition is so mild and infrequent that the patient does not desire further treatment. In this situation, most patients would readily accept the possible tradeoff of mild, infrequent stress incontinence for resolution of significant overactive bladder symptoms. forming urethrolysis be harmful to the patient? Dr Leng: Our patient population offered a unique opportunity to assess outcomes after delayed time to urethrolysis. With the mean time to urethrolysis ranging from 7 months to 44 months, we observed a highly suggestive association between prolonged time to urethrolysis and greater likelihood of persistent bladder dysfunction. Therefore, I believe that protracted conservative management can be harmful, leading to irreversible bladder storage symptoms. If this observation can be corroborated by other studies, it would be prudent to lower our threshold of clinical suspicion to detect BOO. Videourodynamics testing can be invaluable in making the distinction between outlet obstruction versus de novo urge incontinence. Rather than curtailing pre-urethrolysis evaluation, routine urodynamics testing can help us collect the data we are lacking for women with BOO. This project is supported by NIH grant 1K23 DK 62726-01/NIDDK. References 1. Dr Chancellor: Can managing the patient conservatively and not per- Abousasally R, Steinberg JR, Corcos J. Complications of tension free vaginal tape surgery: a multi-institutional review of 242 cases. Abstract presented at: American Urological Main Points • Much of the challenge in managing bladder dysfunction after sling surgery can be attributed to the lack of objective diagnostic urodynamic criteria for female bladder outlet obstruction (BOO). • It is possible that a proportion of patients who receive the diagnosis of de novo urge incontinence actually have undetected BOO. Videourodynamics testing can help identify patients with urethral obstruction. • The majority of women with postoperative urethral obstruction do not have complete retention. • Early urethrolysis within 4 to 8 weeks after a sling operation is generally effective and is associated with a low incidence of recurrent stress urinary incontinence. • Missed diagnosis or delayed urethrolysis can result in irreversible bladder dysfunction. 32 VOL. 6 NO. 1 2004 REVIEWS IN UROLOGY BOO After Sling Surgery 2. 3. 4. 5. Association Annual Meeting; May 25-30, 2002; Orlando, Fla. Abstract 416. Vasavada SP. Evaluation and management of postoperative bladder outlet obstruction in women. Issues in Incontinence. Fall 2002:5-7. Gomelsky A, Nitti VW, Dmochowski RR. Management of obstructive voiding dysfunction after incontinence surgery: lessons learned. Urology. 2003;62:391-399. Davies BJ. Effect of time interval to urethrolysis on post-operative voiding dysfunction [abstract]. Can J Urol. 2003;10:1958. Abstract P13. Leng WW, McGuire EJ. Obstructive uropathy induced bladder dysfunction can be reversible: 6. 7. 8. 9. bladder compliance measures before and after treatment. J Urol. 2003;169:563-566. de Nunzio C, Franco G, Rocchegiani A, et al. The evolution of detrusor overactivity after watchful waiting, medical therapy and surgery in patients with bladder outlet obstruction. J Urol. 2003;169:535-539. Foster HE, McGuire EJ. Management of urethral obstruction with transvaginal urethrolysis. J Urol. 1993;150:1448-1451. Webster GD, Kreder KJ. Voiding dysfunction following cystourethropexy: its evaluation and management. J Urol. 1990;144:670-673. Carr LK, Webster GD. Voiding dysfunction fol- 10. 11. lowing incontinence surgery: diagnosis and treatment with retropubic or vaginal urethrolysis. J Urol. 1997;157:821-823. Nitti VW, Raz S. Obstruction following antiincontinence procedures: diagnosis and treatment with transvaginal urethrolysis. J Urol. 1994;152:93-98. Leach GE, Dmochowski RR, Appell RA, et al, for the American Urological Association. Female Stress Urinary Incontinence Clinical Guidelines Panel summary report on surgical management of female stress urinary incontinence. J Urol. 1997;158:875-880. VOL. 6 NO. 1 2004 REVIEWS IN UROLOGY 33