The artificial urinary sphincter and male sling for postprostatectomy incontinence: Which patient should get which procedure?

Surgery is the most efficacious treatment for postprostatectomy incontinence. The ideal surgical approach depends on a variety of patient factors including history of prior incontinence surgery or radiation treatment, bladder contractility, severity of leakage, and patient expectations. Most patients choose to avoid a mechanical device, opting for the male sling over the artificial urinary sphincter. The modern male sling has continued to evolve with respect to device design and surgical technique. Various types of slings address sphincteric incompetence via different mechanisms of action. The recommended surgery, however, must be individualized to the patient based on degree of incontinence, detrusor contractility, and urethral compliance. A thorough urodynamic evaluation is indicated for the majority of patients, and the recommendation for an artificial urinary sphincter, a transobturator sling, or a quadratic sling will depend on urodynamic findings and the patient’s particular preference. As advancements in this field evolve, and our understanding of the pathophysiology of incontinence and mechanisms of various devices improves, we expect to see continued evolution in device design

Incisionless Pubovaginal Fascial Sling Using Transvaginal Bone Anchors for the Treatment of Stress Urinary Incontinence

Introduction: Bladder neck suspension (BNS) for stress urinary incontinence (SUI) can have significant morbidity, including bleeding, infection and pain. In an effort to reduce this potential morbidity, we have devised a technique which provides the same suburethral support as a standard anterior vaginal wall sling (AVWS), but without a vaginal or suprapubic incision. We describe this minimally invasive technique. Methods: From April 1998 to February 1999, 85 women underwent an incisionless suburethral fascial sling procedure. A transvaginal bone drill was used to place a bone anchor loaded with #1 prolene suture into the inferior aspect of the pubic bone on either side of the urethra. A subepithelial tunnel was created at the level of the bladder neck. A 2 x 7 cm segment of cadaveric fascia lata was placed through the subepithelial tunnel. The sutures were passed through the fascia 5mm from either edge, effectively creating a 6.0 cm sling. Finally, the sutures are tied up to the pubic symphysis.Results: Follow-up was via a self-administered questionnaire and patient interview. Recurrent SUI was noted in 2/85 (3%). New onset urge incontinence was present in 4/85 (5%). Permanent urinary retention has not occurred in either group. All procedures were performed on an outpatient basis and no operative complications occurred.Conclusions: Early results for the incisionless sling compare favorably with the long term results for the AVWS. This minimally invasive approach has thus far not been associated with any significant complications. Elimination of the vaginal and suprapubic incisions has not compromised efficacy, and appears to reduce the incidence of urge incontinence. Long term follow-up will establish the lasting efficacy of this novel surgical technique

Chronic sacral nerve stimulation as a novel treatment for stress urinary incontinence-A rat model

We propose an animal model to evaluate the effect of chronic sacral nerve stimulation (SNS) on surgically induced intrinsic sphincter deficiency (ISD) secondary to transabdominal urethrolysis (U-Lys). Twenty-five 6-week old virgin female Sprague-Dawley rats were divided into four groups: control (CTRL), U-Lys only, SNS only, and both (U-Lys/SNS). Groups CTRL (N = 5) and U-Lys only (N = 5) were maintained in the animal research facility in standard fashion for 2 weeks. Groups SNS only (N = 5) and U-Lys/SNS (N = 10) underwent chronic SNS for 6 continuous hours daily for 2 weeks. Retrograde leak point pressure (RLPP) was measured at baseline and at 2 weeks following observation or treatment. Five consecutive RLPP measurements were averaged per measurement cycle. SAS 9.3 was used to evaluate means and standard deviation. Baseline mean RLPP was 65 mmHg. The U-Lys only group mean RLPP at initial urethrolysis (58 mmHg) decreased (31 mmHg, P < 0.0001) after 2 weeks of observation. In the SNS only group, mean RLPP significantly increased from baseline (73 mmHg) after 2 weeks of chronic SNS stimulation (80 mmHg, P < 0.01). In rats that underwent both U-Lys and SNS stimulation mean RLPP was initially low (46 mmHg) after U-Lys and then significantly increased after 2 weeks of SNS (65 mmHg, P < 0.0001). Chronic SNS mediates an improvement in urethral sphincteric function at stimulation parameters similar to those used in humans for treating voiding dysfunction. SNS increased urethral resistance in rats with and without surgically induced ISD

Ambulatory and cystometric response following single versus multiple onabotulinumtoxina detrusor injections in a rat model of overactive bladder induced by intravesical acetic acid

Introduction: Intradetrusor onabotulinumtoxinA (BTX) chemo-denervation is an established therapy for appropriately selectedpatients who fail first and second-line treatments for overactive bladder. There has been much variability regarding injectionpatterns and concentration of BTX described in the literatureincluding templates which generally deliver the toxin to the posterior and lateral walls of the bladder. The physiologic effect of different injection patterns deserves further investigation. Methods: Thirty-six adult female rats were divided into six (n = 6) groups. Treatment animals received intradetrusor injection of 7.5 units (in 25 μL saline) BTX to the bladder: intact control (no injection); saline vehicle control (five aliquots); trigone (one aliquot); posterior and lateral walls (three aliquots); whole bladder (five aliquots); unilateral (one aliquot). Animals were acclimated and micturition frequency and volume were assessed using metabolic cages at baseline (day 0, 7) and following injection (day 14, 21, 28). On day 7, animals underwent detrusor injection via midline incision. On day 28, overactive bladder was inducedwith acetic acid bladder instillation (0.25%, 30-minutes). Bladder function was assessed using anesthetized cystometry before and after acid instillation. Results: All but one animal survived until final testing. One rat in the trigone group expired during recovery from anesthesia after injection. Ambulatory urinary frequency and mean voided volume show consistent trends, with stable voided volume demonstrated over timein all groups.Each animal demonstrated a consistent voiding pattern at each of the five metabolic cage time points; however there was wide variability from animal to animal. All controls developed obvious detrusor overactivity when challenged with acetic acid. In contrast, BTX resulted in increased threshold pressure immediately prior to spontaneous micturition and was successful in suppressing detrusor overactivity in treated rats that underwent instillation of acetic acid. Overall bladder contractility was preserved to a greater degree in the unilateral single aliquot injection group compared to the multiple injection treatment groups. Conclusion: With equal total toxin delivery, the various BTX injection patterns did not result in clear physiologic differences in our rat model of overactive bladder. The only exception was that unilateral single aliquot BTX injection appeared to preserve bladder contractility compared to multiple BTX injections. Funding Source: SUFU Foundatio

Ambulatory and cystometric response following single versus multiple onabotulinumtoxina detrusor injections in a rat model of overactive bladder induced by intravesical acetic acid

Introduction: Intradetrusor onabotulinumtoxinA (BTX) chemo-denervation is an established therapy for appropriately selectedpatients who fail first and second-line treatments for overactive bladder. There has been much variability regarding injectionpatterns and concentration of BTX described in the literatureincluding templates which generally deliver the toxin to the posterior and lateral walls of the bladder. The physiologic effect of different injection patterns deserves further investigation. Methods: Thirty-six adult female rats were divided into six (n = 6) groups. Treatment animals received intradetrusor injection of 7.5 units (in 25 μL saline) BTX to the bladder: intact control (no injection); saline vehicle control (five aliquots); trigone (one aliquot); posterior and lateral walls (three aliquots); whole bladder (five aliquots); unilateral (one aliquot). Animals were acclimated and micturition frequency and volume were assessed using metabolic cages at baseline (day 0, 7) and following injection (day 14, 21, 28). On day 7, animals underwent detrusor injection via midline incision. On day 28, overactive bladder was inducedwith acetic acid bladder instillation (0.25%, 30-minutes). Bladder function was assessed using anesthetized cystometry before and after acid instillation. Results: All but one animal survived until final testing. One rat in the trigone group expired during recovery from anesthesia after injection. Ambulatory urinary frequency and mean voided volume show consistent trends, with stable voided volume demonstrated over timein all groups.Each animal demonstrated a consistent voiding pattern at each of the five metabolic cage time points; however there was wide variability from animal to animal. All controls developed obvious detrusor overactivity when challenged with acetic acid. In contrast, BTX resulted in increased threshold pressure immediately prior to spontaneous micturition and was successful in suppressing detrusor overactivity in treated rats that underwent instillation of acetic acid. Overall bladder contractility was preserved to a greater degree in the unilateral single aliquot injection group compared to the multiple injection treatment groups. Conclusion: With equal total toxin delivery, the various BTX injection patterns did not result in clear physiologic differences in our rat model of overactive bladder. The only exception was that unilateral single aliquot BTX injection appeared to preserve bladder contractility compared to multiple BTX injections. Funding Source: SUFU Foundatio

Outcomes of Sacral Nerve Stimulation for Treatment of Refractory Overactive Bladder Among Octogenarians

Objective Sacral nerve stimulation (SNS) is an effective treatment for refractory overactive bladder (OAB). However, advanced age is often cited as a reason to avoid SNS in the elderly. This study evaluates the safety and efficacy of SNS for refractory OAB among our octogenarian population. Methods A retrospective review from a single institution was performed on all SNS lead placements from December 1998 to June 2017 for refractory OAB. Octogenarians were characterized as 80 years of age or older at the time of Stage I. Efficacy and safety were determined by the rate of progression to Stage II, subsequent need for multimodal therapy, and rate of surgical revision and explantation. All patients were followed for a minimum of 12 months. Results Of 374 patients in this study, 37 (9.9%) were octogenarians. There was no difference in gender, race, smoking history, or prior OAB treatment regimens between cohorts. The rate of progression to Stage II was 56.8% for octogenarians compared to 60.5% for nonoctogenarians (p = 0.66). The rate of surgical revision, explantation, and need for multimodal therapy did not differ between groups. Subgroup analysis of octogenarians did not reveal any significant differences between successful and nonsuccessful Stage I patients. Conclusions The safety and efficacy of SNS was similar between cohorts. This result suggests that SNS is a safe and effective therapy that should be considered among the treatment options for refractory OAB in octogenarian patients. Further studies are needed to determine predictive factors of Stage I success in elderly patients

ISOLATED TRIGONE ONABOTULINUMTOXINA INJECTION DOES NOT ADVERSELY CHANGE AMBULATORY VOIDING FUNCTION IN A RAT MODEL OF OVERACTIVE BLADDER

INTRODUCTION AND OBJECTIVES: OnabotulinumtoxinA (BTX) chemodenervation is an established third-line therapy for overactive bladder. The aim of our study was to further characterize the physiologic effect of various BTX injection distributions on ambulatory and cystometric voiding function in conscious awake rats. METHODS: Adult female rats (n=36) were divided into six groups. Treatment animals received injection of 7.5 units BTX (in 25-125 µL saline; 25 µL/aliquot): intact control, saline vehicle control, unilateral BTX, trigone BTX, posterior-lateral BTX, whole bladder BTX. Micturition frequency and volume were assessed using metabolic cages at baseline (day 0, 7) and following injection (day 14, 21, 28). Bladder function was then assessed using anesthetized acetic acid cystometry. RESULTS: There was no overall correlation between rat weight and mean voided volume (r = -0.02, p = 0.81). Small volume voids were significantly associated with increased food intake (r = -0.21, p = 0.006) and greater stool output (r = -0.23, p = 0.003). Mean nocturnal voided volume was similar in control, vehicle, trigone and posterior-lateral groups. The ability to void small volumes was preserved in both the control and treatment groups with the exception of unilateral and whole bladder injection which demonstrated increased minimum voided volumes. On cystometry, mean voided volume was the greatest in the control and trigone groups prior to acetic acid. Increased threshold pressure was noted in both unilateral and whole bladder injection groups. Post void residual was decreased in all groups after acetic acid. The lowest number of voids and longest interval between voids was noted after unilateral and whole bladder BTX injection. Cystometric intercontractile interval correlated with increased nocturnal mean voided volume before (r = 0.33, p = 0.05) and after (r = 0.24, p = 0.17) acetic acid. Cystometric mean voided volume correlated with ambulatory nocturnal voided volume, however was almost 10-fold lower after saline instillation (r = 0.18, p = 0.30), and more closely approximated ambulatory voiding after acetic acid instillation (r = 0.30, p = 0.08). CONCLUSIONS: Unilateral and whole bladder BTX injection resulted in elevated ambulatory nocturnal mean voided volumes, with higher pressure and smaller volume voids noted on cystometry. Trigone and posterior-lateral BTX injection patterns appear to preserve contractility, with threshold and peak contraction pressures similar to control animals

PERFORMANCE ASSESSMENT AND VALIDATION OF AN ENHANCED 12-RAT METABOLIC CAGE EQUIPPED WITH A NOVEL 100-GRAM LOAD CELL SENSOR INTERFACE

Introduction: The metabolic cage is an important noninvasive tool used to assess ambulatory voiding function in conscious rodents. Other standardized assessments of lower urinary tract (LUT) function in the rat include the 2-hour filter paper test and bladder cystometry, however these tests are labor intensive and represent a single point in time.We sought to validate our enhanced metabolic cage with a novel 12-channel load cell sensor interface, which allows for realtime automated assessment of LUT function. Methods: LUT function of female Sprague-Dawley rats were assessed at multiple time points with: A) two-hour filter paper test (n = 35, 129 samples), B) Metabolic cage (n = 35, 129 cage cycles) and C) Anesthetized bladder cystometry (n = 6). Twelve rats were simultaneously housed in metabolic cages (Tecniplast, Model 3701M081) during each cage cycle (18–24 hr). For the first two hours of each cage cycle, voided volume was measured using filter paper. Urine output for each animal was then measured using twelve 100-gramWheatstone bridge load cells connected to three 4-channel bridge amplifier USB transducers (Phidgets Inc., Model 1046) and data recorded continuously at one-second intervals (DSP Robotics, FlowBotics Studio v3.0.8). Anesthetized cystometry was then performed using urethane sedation (1.2 g/kg). Results: Load cell sensor performance was assessed using a micropipette which demonstrated accurate correlation with known droplet weight (sensitivity range 100–3,000 μL), as well as urine droplet weight after passing through both clean and dirty metabolic cages (sensitivity range 200–3,000 μL). The 2-hour filter paper test demonstrated voided urine droplet volumes which significantly correlated (Pearson r = 0.55, p \u3c 0.001, alpha = 0.05) with daytime voided volumes obtained by metabolic cage. Voided volume demonstrated a non-significant (n = 6) positive correlation with cystometric mean voided volume (Pearson r = 0.48, p = 0.33, alpha = 0.05), and was consistently greater in ambulatory conscious rats (mean 1,014 μL, range 577–2,223) compared to anesthetized cystometry (mean 126 μL, range 20–211). Conclusion: Metabolic cage assessment of LUT function correlated with voided volumes using the filter paper test and anesthetized bladder cystometry. Rat bladder function and behavior patterns may be reliably assessed over time with our enhanced metabolic cage, without the need for anesthesia or terminal bladder cystometry. Funding Source: SUFU Foundatio