Melissa A. Laudano1 , James M. Weinberger2 , Rajveer S. Purohit1 and Jerry G. Blaivas1, 3
(1)
Department of Urology, Weill Medical College of Cornell University, New York Presbyterian Hospital, New York, NY, USA
(2)
Institute for Bladder and Prostate Research, New York, NY, USA
(3)
SUNY Downstate College of Medicine, New York, NY, USA
Melissa A. Laudano
Email: Melissa.laudano@gmail.com
James M. Weinberger
Email: jmweinberger@mednet.ucla.edu
Rajveer S. Purohit
Email: rajpu@yahoo.com
Jerry G. Blaivas (Corresponding author)
Email: jgblvs@gmail.com
Background
Bladder outlet obstruction (BOO) in women is rare, with an incidence ranging from 2.7 % to 8.3 % [1, 2]. However, these rates may underestimate the true incidence because diagnostic parameters and normative values to diagnose female BOO remain controversial. In addition, the presentation of female BOO can range widely from obstructive symptoms associated with voiding to irritative voiding symptoms. Given the variability in presentation and diagnosis, urologists must have a high suspicion for obstruction when managing patients with voiding dysfunction following surgical interventions for stress urinary incontinence (SUI).
Presentation
The difficulty in diagnosing female BOO is, in part, due to the variety of presenting symptoms. While it makes sense that women with urethral obstruction would present with voiding difficulties (hesitancy, decreased stream strength, incomplete emptying, or complete urinary retention), the fact remains that most women present with overactive bladder symptoms [3]. In the immediate, postoperative period many of these symptoms are expected but typically resolve within 4 weeks of surgery [3].
Etiology
We classify the etiology of female BOO into anatomic and functional causes. Anatomic causes may be extrinsic (prolapse, prior surgery, urethral diverticulum, tumor) or intrinsic (stricture, tumor). Functional causes include primary bladder neck obstruction, neurogenic detrusor-external sphincter dyssynergia, and acquired voiding dysfunction [4, 5].
Carr and Webster classified obstruction based on its location. They found that the most common cause of proximal urethral obstruction was extrinsic compression or an abnormal urethral angle [1]. Distal obstruction was typically a functional problem related to the inadequate relaxation of the muscles of the pelvic floor. Extrinsic compression can occur from nearby structures, such as the uterus, vagina, bladder, ureter; abnormal angulation due to an anti-incontinence procedure; or can be luminal due to stricture, neoplasm, foreign body, or urethral valve [1]. Iatrogenic obstruction following anti-incontinence surgery has been cited as the most common etiology of BOO with rates ranging from 2.5 % to 27 % [6–9].
Synthetic Mid-urethral Sling
A meta-analysis conducted by the American Urological Association Stress Urinary Incontinence (AUA SUI) Panel assessed outcomes following surgical management of female SUI. Rates of de novo urge incontinence (UI) at 12–23 months following surgical intervention for SUI in 323 females undergoing synthetic midurethral slings was 6 % [10]. The rate of retention, defined as retention lasting longer than 1 month or requiring intervention, was 3 %. The same retention rate existed following synthetic mid-urethral sling in women who underwent concomitant prolapse repair and those who did not [10]. Rates of retention were comparable to those reported in the TOMUS trial that randomized 597 women to retropubic midurethral sling (RMS) or transobturator midurethral sling (TMS). With 12 months of follow-up, this trial found rates of voiding dysfunction requiring surgery, use of catheter, or both to be 2.7 % in the RMS arm and 0 % in the TMS group [9].
Autologous Pubovaginal Sling
Based on the AUA Guideline Update review, the rate of de novo UI was 9 % for women who underwent autologous fascial sling without bone anchors [10]. The estimated retention rate following autologous fascial sling was 8 % for patients who did not receive concurrent prolapse repair and 5 % for women who did [10]. With 24 months of follow-up, the SISTEr Trial found that 20/326 (6 %) women who underwent autologous pubovaginal sling developed voiding dysfunction that necessitated surgical intervention [11]. Extended 5-year follow-up was reported on patients from the SISTEr Trial. Of the 183 women with 5-year follow-up after sling, 3 (1.6 %) developed de novo UI, 6 (3.3 %) required persistent catheterization, and 4 (2.2 %) required another surgical procedure for voiding dysfunction [6].
Burch Colposuspension
In the AUA Update review, the rate of de novo UI based on 695 women undergoing a Burch colposuspension (BC) was 8 % with 12–23 months of follow-up [10]. The rate of retention following BC was 3 % in women with no simultaneous prolapse treatment and 1 % in women with prolapse repair [10]. The SISTEr Trial found that with a follow-up of 24 months, 0/329 women who underwent a BC experienced voiding dysfunction leading to surgical revision [11]. The extended SISTEr Trial reported that of the 174 women with 5-year follow-up after BC, there were 7 (4 %) with de novo UI and 1 (0.6 %) patient who required persistent catheterization [6].
Marshall–Marchetti–Krantz
Retrospective reviews approximate rates of prolonged urinary retention following the Marshall–Marchetti–Krantz (MMK) procedure to range from 2 % to 4 % [12, 13]. In a retrospective analysis of 151 women treated for SUI with an MMK procedure, 8.7 % of patients had difficulty voiding/retention in the immediate postoperative period, but only 4 (3.8 %) had prolonged difficulty voiding that required urethral dilation. Mean follow-up in this study was 51.5 months [13].
Evaluation and Diagnosis
Several diagnostic tools, such as pressure-flow studies (PFS), video urodynamics, and nomograms combining several factors, have been proposed. Chassagne et al. used pressure-flow studies (PFS) of 35 women who were clinically obstructed compared to 124 controls with stress urinary incontinence (SUI) to generate a definition of female BOO defined as having a maximum flow rate (Qmax) <15 ml/s and detrusor pressure at maximum flow rate (Pdet Q max) >20 cm H2O [14]. A second study by Defreitas et al., compared 169 women with clinical anatomic BOO to 20 normal female controls without urologic complaints. The recommended cutoffs for BOO was Qmax < 12 ml/s and Pdet Qmax > 25 cm H2O [15]. Differences in normal values between series may also be related to the normal population used.
Nitti et al. described a combined radiographic and urodynamic approach to the diagnosis of female BOO [16]. In this study, obstruction was defined as radiographic evidence of obstruction between the bladder neck and distal urethra in the presence of a sustained detrusor contraction of any magnitude. Using this definition, patients who were identified as obstructed had a lower mean Qmax, higher mean PdetQ max, and higher mean post-void residual (PVR). In 11.8 % of obstructed patients, Qmax was greater than 15 ml/s and in 10.5 % of obstructed patients P det Qmax was less than 20 cm H2O [16]. As a result, the authors felt that video-urodynamics identified cases of obstruction that would have been missed using PFS alone [16].
Finally, Blaivas and Groutz published a BOO nomogram for women with lower urinary tract symptoms (LUTS) that combined free-flow values, PFS, and voiding cystourethrography [2]. This nomogram stratified patients into four zones: no obstruction, mild obstruction, moderate obstruction, and severe obstruction, and had a positive correlation with subjective symptoms on AUA Symptom Index score (Fig. 9.1a–c) [2].
Fig. 9.1
(a) Blaivas–Groutz nomogram for bladder outlet obstruction. (b) Urodynamic tracing shows severe urethral obstruction (Type 2 in Blaivas-Groutz nomogram). Q max: maximum flow rate; Pdet@Q max: detrusor pressure at maximum flow rate; Pves: vesicle pressure; Pabd: abdominal pressure; Pdet: detrusor pressure; EMG: electromyogram; VH2O: volume of water. (c) X-ray exposed at Qmax shows obstruction in the distal third of the urethra. Patient underwent excision of the suburethral portion of the sling and subsequently voided normally (Qmax: 19 ml/s, voided volume: 150 ml, post-void residual: 49 ml), but developed sphincteric incontinence and underwent successful autologous fascial sling 4 months later. (a: Adapted with permission from Blaivas JG, Groutz A. Bladder outlet obstruction nomogram for women with lower urinary tract symptomatology. Neurourol and Urodynam 2000;19:553; b, c: Used with permission from Blaivas JG, Purohit RS, Weinberger JM, Tsui JF, Chouhan J, Sidhu R, Saleem K. Salvage Surgery after Failed Treatment of Synthetic Mesh Sling Complications. J Urol 2013; 190:1281–1286)
Techniques of Repair
There are two basic approaches to correcting urethral obstruction after incontinence surgery—sling incision/excision and urethrolysis. Urethral stricture is a very rare complication after incontinence surgery and will be discussed in Chap. 13. No matter what technique is used, there is always a fine balance between relieving obstruction and the development of recurrent sphincteric incontinence.
Sling Incision/Excision
Simple sling incision is the least invasive and most successful procedure for women who are obstructed after sling surgery. It is indicated as a primary procedure and can be done at any time after the original surgery when a synthetic sling has been done, but is usually reserved for those who are at least a month or two after the original surgery to lessen the likelihood of recurrent sphincteric incontinence. For patients who have undergone biologic slings, we prefer to wait at least 3 months. The technique is straightforward. The patient should be placed in the dorsal lithotomy or Trendelenburg position to achieve optimal visualization of the anterior vaginal overlying the urethra [17]. A Foley catheter should be placed and by placing it on traction, it is usually possible to palpate the sling which appears as a subtle transverse ridge. If that is not successful, urethroscopy with a cystoscope or placement of a urethral sound can aide in the identification of the constricting band by torqueing upward [18]. We prefer to make a transverse incision just distal to the sling; others describe an inverted-U or midline. Some reports advocate using the prior incision or making a lateral incision to release one side of the sling, but by the time we see the patient, the site of the old incision is not apparent [19]. The incision continues down to the surface of the normal urethra distal to the sling and the dissection proceeds proximally until the sling is identified. Sometimes it is obvious, sometimes subtle, and apparent only as a thickened scar. Once identified, we place an Allis clamp on the sling in the midline and exert traction. This takes some tension off the sling and facilitates the dissection between the urethra and sling. We prefer to do the entire dissection sharply with a Metzenbaum scissor (Fig. 9.2a). If the surgical plane is obvious, it can be continued with a fine blunt instrument like a right angle clamp, but great care should be exercised so that the urethra is not damaged. In some cases the sling has been incorporated in the wall of the urethra or has eroded into the lumen. In either instance, it is necessary to excise part of the urethral wall, and we believe the entire vaginal portion of the sling should be excised as well. The defect in the urethra repaired as necessary with absorbable monofilament or chromic sutures.
Fig. 9.2
(a) Once the sling has been dissected free of the urethra, a right angle clamp is placed between it and the urethra; the sling is transected with a scissors or knife. (b) Once the sling has been transected, it usually springs apart. If not, it should be sharply dissected off of the urethra. (Both used with permission from Nitti VW, Carlson KV, Blaivas JG, Dmochowski RR. Early results of pubovaginal sling lysis by midline sling incision. Urology 2002;59:47)
Once the sling is freed from the periurethral tissue, it is incised in the midline and the cut ends should spring apart (Fig. 9.2b). The ends of the sling material can be removed or left in place [18]. Gomelsky et al. [3] recommend that the suburethral portion of synthetic slings be excised at this point but that biologic slings be simply incised. We do not make such a distinction. If the cut edges of any type sling do not retract, we dissect them out lateral to the urethral wall on either side and then make a decision about whether or not to do more or less urethrolysis as described below.
If the sling cannot be identified by the technique described above, the dissection can be done lateral to the urethra from meatus to bladder neck if necessary and, using this method, we have always been able to identify the sling. At the conclusion of the procedure, a Foley catheter is left indwelling and in most cases, the patient is given an active voiding trial once she has fully recovered from anesthesia. The bladder is filled with saline until the patient is comfortably full, and then the catheter is removed. If she fails the trial, we would prefer to start intermittent self-catheterization, but so far, that has not been necessary in our experience. The patient is discharged home the same day [17].
Urethrolysis
Urethrolysis is indicated in women with obstruction due to periurethral scarring, usually after Burch colposuspension, Marshall–Marchetti–Krantz procedures, and in those who have undergone multiple prior urethral surgeries including sling incision and prior urethrolysis. It is rarely necessary after synthetic sling surgery unless there have been prior failed attempts at sling incision.
Urethrolysis may be performed by a variety of techniques—retropubic, transvaginal, and suprameatal. No matter what method is used, it is important to recognize that, unlike sling incision or excision, there is no clear-cut end point with urethrolysis; deciding when the dissection is complete is a matter of judgment and experience and must be individualized depending on operative findings. We begin the procedure by inserting first a Q-tip to assess urethral mobility and angle; then a Foley catheter is inserted to assess bladder neck mobility by pulling down on the catheter. As the periurethral dissection proceeds, we periodically pull down on the catheter and reinsert the Q-tip to assess the progress being made in freeing up the urethra. The goal of the surgery is to restore some, but not too much mobility. We have not found any measurements to be useful in this except that the Q-tip angle should be restored to 0 or a positive angle if it was negative to begin with.
Retropubic Approach
The retropubic approach was described in 1990 by Webster and Kreder, primarily for urethral obstruction after retropubic colposuspension or urethropexy [20]. Access to the retropubic space is gained through a low midline or Pfannensteil incision. The urethra, bladder neck, and anterior vaginal wall are freed from any adhesions with sharp dissection, including freeing of the urethra anteriorly away from the pubic bone. If there is severe scarring, the dissection can proceed laterally to the ischial tuberosities; however, this will leave a defect in the paravaginal region. An omental flap may be utilized in the space between the urethra and pubic bone to prevent future adhesions, especially in cases of recurrent obstruction after prior urethrolysis [20, 21].
Transvaginal Approach
Transvaginal urethrolysis can be performed through an inverted-U or midline incision that is made in the anterior vaginal wall over the mid urethra. A transverse incision is made over the midurethra or bladder neck as dictated by the local anatomy (Fig. 9.3a–d). The dissection is then carried proximally to the level of the bladder neck or distally to the meatus as necessary to free up the urethra. Unlike the simple sling incision, the dissection proceeds laterally, perforating the endopelvic fascia with a Metzenbaum scissors and the urethra is freed from its attachments to the vaginal sidewall and pubic symphysis as needed using blunt dissection with an index finger, with a Metzenbaum scissors, or right angle clamp. If necessary, it can be completely freed up circumferentially [3]. After circumferential urethrolysis, particularly if it is done as a tertiary procedure, a Martius graft can be mobilized and tunneled between the labia and vaginal dissection. The graft is passed anteriorly to the urethra and wrapped circumferentially around to minimize scarring and recurrent obstruction [22]. In rare instances we have completely circumscribed the entire urethra from meatus to bladder neck. If that is done, we recommend a Martius flap and autologous sling; otherwise the patient will almost assuredly have severe sphincteric incontinence [23]. A urethroscopy is performed to ensure that no urethral injury occurred.
Fig. 9.3
(a) A transverse incision is made over the urethra and an Allis clamp placed on the proximal edge of the vaginal incision in the midline. With the non-dominant hand, traction is placed on the Allis clamp and the index finger holding the clamp pushes upward putting the vaginal wall on tension. A plane is dissected with a Metzenbaum scissors between the pubocervical fascia and the vaginal wall. (b) Keeping in the plane between the pubocervical fascia, with the curve of the scissors pointed laterally, the dissection proceeds in the direction of the patient’s ipsilateral shoulder, hugging the undersurface of the pubis and ileum. The technique is not spread and cut, but rather by opening and closing the tips of the scissors, and you push against the bones. The retropubic space is entered sharply with the scissors or bluntly with an index finger. (c) Once the retropubic space is entered, the urethrolysis is completed, by dissecting with an index finger medially and laterally on the undersurface of the bone. (d) If a circumferential urethrolysis is necessary, the scissor is directed medially between the pubis and urethra on either side. Once a window is created, a penrose drain is passed around the urethra and, using it as traction, the dissection can be extended proximally or distally. (a, b, c: Used with permission from Blaivas JG, Chaikin. Pubovaginal fascial sling for the treatment of all types of stress urinary incontinence: surgical technique and long-term outcome. Urol Clin North Am 2011;387–15; d: Used with permission of Shlomo Raz, MD. With permission of and from Nitti VW, Raz S: Obstruction Following Anti-Incontinence Procedures Diagnosis and Treatment with Transvaginal Urethrolysis. J Urol 1994; 152:93–98)
Suprameatal Approach
A variation on the transvaginal approach is the suprameatal technique, which begins with an inverted-U incision between the clitoris and urethral meatus (Fig. 9.4a–d). The apex of the U is anterior to the urethral meatus at the 12 o’clock position [3]. The dissection is done with a Metzenbaum scissors and it is generally easy to find a bloodless plane…for a while. At the proximal most portion of the dissection, there is sometimes a gush of bleeding which is controlled by finger pressure or by temporarily packing with a sponge. We have not found it necessary to look for individual bleeders (nor is it usually possible). It is usually possible to palpate retropubic slings and Burch sutures and to visualize them, but the space is too small to cut them under direct vision. We use a curved Mayo scissors with the curve pointed upward and cut the sling or sutures by feel. The remainder of the dissection and freeing up of the urethra is as described in the transvaginal approach. A Martius flap can also be performed in conjunction with this technique.
Fig. 9.4
(a) An inverted “U” incision is made 0.5–1 cm above the urethral meatus. (b).The pubo-urethral ligament is sharply taken down in the midline. (c) Finger dissection in the midline is utilized to further free up the urethra. Once the proximal surface of the pubis is reached, the retropubic space can be entered either bluntly or sharply, being careful to apply pressure in an upward direction against the bone so as not to injure the bladder neck. (d) Once the retropubic space has been entered, the sling or sutures from retropubic suspension are usually easily palpated, but may be difficult to visualize directly because of the narrow wound. It is usually possible to cut the sling or sutures blindly by palpation and cutting with the tips of the scissors pointing outward against the bone while the index finger of the non-dominant hand is pressing downward on the urethra (not pictured in this figure). (a–d: From Petrou S P, Brown J. A., Blaivas, J. G.: Suprameatal transvaginal urethrolysis. J Urol 1999; 161: 1268, 1999. Used by permission of Mayo Foundation for Medical Education and Research. All Rights Reserved)
Outcomes in the Literature
Success rates for a formal urethrolysis (retropubic, transvaginal, or suprameatal) range from 43 % to 94 % [22, 24–31]. More recently, success rates ranging from 80 % to 100 % have been described for sling incision [8, 17–19]. A review of the literature yields many retrospective studies looking at various types of surgical intervention to relieve iatrogenic obstruction following anti-incontinence procedures in women, but the number of patients is small and so many different types of primary and secondary procedures have been done that it is not possible to come to any firm conclusions except that retropubic urethropexies are much more difficult to treat successfully. Of note, the definition of success varies by study. Many categorize patients by symptom improvement, either complete or partial.
Sling Incision
Goldman et al. described a simple sling incision for iatrogenic urethral obstruction in 14 women. In this retrospective analysis, 11 women had a biologic pubovaginal sling and 3 women had a synthetic midurethral sling. With 12 months of follow-up, 11/14 had complete resolution of symptoms and 2 had significant improvement. Overall, 93 % of women had a complete or significant improvement in symptoms. One patient went on to formal urethrolysis and one underwent surgery for recurrent SUI [17]. Croak et al. reported a retrospective analysis of five women who underwent sling incision after tension-free vaginal tape (TVT) placement for SUI. All women were able to void postoperatively; however, one woman had recurrent SUI and one had persistent dysuria following urethrolysis [8]. Nitti et al. presented a retrospective analysis of 19 women with both storage and voiding symptoms who underwent lysis of a pubovaginal sling. With 12 months follow-up, 84 % had resolution or improvement of their presenting symptoms. SUI recurred in 17 % of women and three women went on to require a formal urethrolysis [18]. Kusada also described five patients who underwent incision of a pubovaginal sling for obstructive symptoms that resolved in all patients [19]. Amundsen et al. reported outcomes on a retrospective series combining sling incision and transvaginal urethrolysis. Success rates for complaints related to voiding were 94 % and 67 % for complaints related to storage [25]. These rates were not subdivided by type of urethrolysis.
Urethrolysis: Retropubic
Anger et al. performed a retrospective review of 16 women who underwent either transvaginal (7 patients) or retropubic urethrolysis (9 patients) after obstructed BC. With a mean follow-up of 7 months, 43 % of women who underwent transvaginal urethrolysis had resolution of obstructive or irritative symptoms compared to 78 % who underwent a retropubic approach [24]. One woman in the transvaginal and one in the retropubic had recurrent SUI [24]. A second retrospective review reported by Petrou and Young included 12 women who underwent retropubic urethrolysis. Ten women felt that their obstruction had been successfully relieved, and two women had improvement but did not characterize it as a success [26]. Three women (25 %) had new or persistent SUI after urethrolysis and two (17 %) had urge incontinence [26]. A second study comparing retropubic versus transvaginal urethrolysis was conducted by Carr and Webster. In this retrospective review of 51 consecutive women who underwent urethrolysis, 35 women underwent the retropubic approach, 15 women the vaginal approach, and 4 women had an infrapubic approach. Success, defined as cure or improvement in symptoms, occurred in 86 % of women who underwent the retropubic lysis and 73 % for vaginal (no statistical difference by technique) [27].
Urethrolysis: Transvaginal
In addition to the studies comparing the transvaginal approach to a retropubic approach that are described above, several analyses were performed on series including only transvaginal urethrolysis. A retrospective review performed by Carey et al. examined 23 women who underwent transvaginal urethrolysis with Martius labial fat pad grafting. With this technique, 20/23 (87 %) of women had complete resolution of symptoms and 3/23 continued to require CIC with a mean follow-up of 15 months [22]. SUI occurred de novo following transvaginal urethrolysis in three women (16 %) and persisted in three women. De novo urge incontinence occurred in 20 % of patients and persisted in 37 % [22]. Goldman et al. reported on 31 patients treated with transvaginal urethrolysis without resuspension. Of these women, 26 (84 %) voided well or had significant improvement in symptoms. SUI persisted in 19 % of women [28]. A third analysis performed by Cross et al. analyzed outcomes following 39 transvaginal urethrolysis procedures for urethral obstruction. With 16 months of follow-up, obstructive symptoms resolved in 84 % of women and UI resolved in 79 %. One patient ultimately required resuspension for SUI and two patients required a secondary urethrolysis procedure [29]. Finally, Austin et al. reported a series of 16 women who underwent transvaginal urethrolysis for irritative and obstructive symptoms. Of these women, 69 % had improvement in irritative symptoms [30]. Three women underwent urethrolysis for obstructive symptoms and only one was able to successfully urinate following the urethrolysis. Two women were scheduled for repeat urethrolysis [30].
Urethrolysis: Suprameatal
With regard to the suprameatal approach, Petrou et al. reported outcomes of 32 consecutive women treated with transvaginal suprameatal urethrolysis who presented with retention or irritative voiding symptoms. Obstructive symptoms resolved in 65 % of women and urgency resolved in 67 %. One patient developed SUI [31].
Repeat Urethrolysis
A review of the literature yields many series that reported success rates of urethrolysis by approach. Another factor to consider when discussing success rates is whether the patient had a prior failed urethrolysis. Scarpero et al. presented a retrospective review of 24 women who underwent repeat urethrolysis for iatrogenic BOO [32]. The first attempted urethrolysis was transvaginal in 23 women and retropubic in 1 woman. The repeat urethrolysis was retropubic in 12 women, transvaginal in 10, and a combined approach in 2 cases. Repeat urethrolysis restored normal emptying with relief of symptoms and normalization of PVR in 22 women (92 %) with a mean follow-up of 14 months. Urge incontinence was completely resolved in 12 %, improved in 69 %, and remained unchanged in 19 %. Stress incontinence recurred in 4/22 (18 %) and persisted in 2/22 (9 %) [32]. Based on these results the authors concluded that a repeat urethrolysis can successfully treat obstructive symptoms; however, rates of improvement of storage symptoms were less promising [32].
Timing of Urethrolysis
In addition to controversy regarding the diagnosis of BOO in women, debate also exists about when to intervene once the diagnosis has been made. Many authors would advocate repair if voiding dysfunction persists for 3 months postoperatively; however, this is an arbitrary waiting period [3]. There is some concern that persistent obstruction could lead to permanent damage to the bladder and continued voiding dysfunction even after urethrolysis. This hypothesis was tested by Leng et al. [33] who performed a retrospective analysis of 15 patients who underwent transvaginal urethrolysis for post-sling voiding dysfunction. Seven patients underwent urethrolysis and had no persistent bladder storage or voiding complaints. An additional eight patients underwent urethrolysis and subsequently required anticholinergics to control significant urgency. Mean time to urethrolysis in those patients who had resolution of symptoms was 9.0 ± 10.1 months, compared to 31.3 ± 21.9 months in patients who continued to complain of urgency (p = 0.02). The mean follow-up was 17 months. The authors concluded that prolonged time delay to treatment of obstruction might lead to persistent storage symptoms, such as frequency and urgency. Of note, this is a small, retrospective cohort that overall had a higher than average time delay to treatment of obstruction in both groups [33].
Outcome Measures
Diagnosis of urethral obstruction prompting urethrolysis is typically a clinical diagnosis made by urodynamic findings such as a combination of high detrusor pressure and low flow (Q), or findings on exam such as urethral angulation or tethering. It is also often based on clinical history by correlating the development of de novo voiding symptoms after anti-incontinence surgery [31, 34]. Studies describing resolution of post-urethrolysis symptoms typically employ a global instrument such as a patient reported outcome measure or an un-validated assessment of pre- and postoperative symptoms. Reports with objective quantification of outcomes with respect to urinary symptoms through symptom questionnaires are rare. Change in PVR has been used as an outcome measure in conjunction with a subjective assessment of relief of storage and voiding symptoms [17, 24]. Other studies define success simply by the ability to void with little to no PVR and patient reported symptom resolution [18]. Success has also been defined in the literature as patient reported resolution of the presenting symptom even in the absence of any additional clinical information (e.g., flow rate or residual). In this context, standardization of comparative postoperative outcomes is difficult.
A standardized outcome measure would aid in comparing outcomes with different techniques for urethrolysis. An ideal standardized outcome measure would assess Q & PVR pre- and postoperatively and incorporate urodynamic criteria, a validated measure of symptoms as well as patient reported outcome measures. Further, some symptoms, such as the ability to void only in a certain position, may not be amenable to being progressively graded. To account for a symptom that cannot be measured quantitatively, a unified outcome measure may include the Patient Global Impression of Improvement (PGI-I) in order to encompass patients’ subjective assessment of their health. In this way, a physician may be able to attribute success or failure in a manner that is specific and therefore meaningful to other physicians.
Complications in the Literature
Recurrent Stress Incontinence
Recurrent SUI is a known complication of urethrolysis. Rates of recurrent SUI vary by study and depend on several factors. Some studies include patients who are already experiencing SUI prior to urethrolysis and others perform concomitant resuspension to prevent SUI. Nonetheless, recurrence of SUI after urethrolysis occurred in 3–25 % of patients [22, 26, 31]. Specific rates of recurrent SUI by urethrolysis approach are outlined in the outcomes section.
Overactive Bladder
Another complication that is somewhat difficult to quantify in terms of prevalence is overactive bladder or storage symptoms following urethrolysis. Many patients experience storage symptoms, such as urgency, frequency, urge incontinence, or dysuria prior to urethrolysis. In fact, these symptoms may be the reason the women seeks evaluation after the original anti-incontinence procedure. Rates of persistent storage symptoms range from 10 % to over 50 % [18, 35]. One study by Carey et al. reported the rate of de novo urge incontinence after transvaginal urethrolysis to be 20 % [22]. A retrospective, case-control study by Starkman et al. looked specifically at the prevalence of overactive bladder symptoms following urethrolysis in 40 women. OAB persisted in 56 % of women in this cohort [35]. The study cohort was stratified into two groups: persistent OAB and resolved OAB. Patients who had persistent OAB symptoms were more likely to demonstrate detrusor overactivity during urodynamics; however, there was no difference in symptoms on presentation, rates of elevated PVRs, or rates of CIC between the groups. Not surprisingly, patients with persistent OAB symptoms reported greater symptom bother and decreased improvement in quality of life [35]. Time to urethrolysis did not alter rates of persistent OAB symptoms, unlike the findings in the Leng et al. study [33].
Conclusions
Bladder outlet obstruction (BOO) in women is rare, with an incidence ranging from 2.7 % to 8.3 % [1, 2]. The presentation ranges widely from obstructive symptoms with voiding to irritative storage symptoms. Given this complex presentation, the combination of several diagnostic tools, such as pressure-flow studies (PFS), video urodynamics, and nomograms, has been recommended. Potential treatment options range from excision of the sling to a complete urethrolysis through a retropubic, transvaginal, or suprameatal approach. Complications following urethrolysis include recurrent stress urinary incontinence and overactive bladder symptoms. Given the complexity of these cases, patients should be closely followed for resolution of symptoms following urethrolysis.
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