The Impact of Urethral Risk Factors on Transcorporeal Artificial Urinary Sphincter Erosion Rates and Device Survival

Author's Accepted Manuscript The Impact of Urethral Risk Factors on Transcorporal Artificial Urinary Sphincter Erosion Rates and Device Survival Stephen Mock , Roger R. Dmochowski , Elizabeth T. Brown , W. Stuart Reynolds , Melissa R. Kaufman , Douglas F. Milam

PII: DOI: Reference:

S0022-5347(15)04302-5 10.1016/j.juro.2015.06.088 JURO 12728

To appear in: The Journal of Urology Accepted Date: 21 June 2015 Please cite this article as: Mock S, Dmochowski RR, Brown ET, Reynolds WS, Kaufman MR, Milam DF, The Impact of Urethral Risk Factors on Transcorporal Artificial Urinary Sphincter Erosion Rates and Device Survival, The Journal of Urology® (2015), doi: 10.1016/j.juro.2015.06.088. DISCLAIMER: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our subscribers we are providing this early version of the article. The paper will be copy edited and typeset, and proof will be reviewed before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to The Journal pertain.

Embargo Policy All article content is under embargo until uncorrected proof of the article becomes available online. We will provide journalists and editors with full-text copies of the articles in question prior to the embargo date so that stories can be adequately researched and written. The standard embargo time is 12:01 AM ET on that date. Questions regarding embargo should be directed to [email protected].

ACCEPTED MANUSCRIPT

THE IMPACT OF URETHRAL RISK FACTORS ON TRANSCORPORAL ARTIFICIAL URINARY SPHINCTER EROSION RATES AND DEVICE SURVIVAL Stephen Mock1, Roger R. Dmochowski, Elizabeth T. Brown, W. Stuart Reynolds, Melissa R. Kaufman, Douglas F. Milam

RI PT

1 Department of Urologic Surgery, Vanderbilt University Medical Center, Nashville, TN

SC

Corresponding author:

Stephen Mock, MD

A-1302 Medical Center North Nashville, TN 37232 (610) 283-3576 Fax (615) 322-8990

AC C

EP

TE D

[email protected]

M AN U

Vanderbilt University Medical Center

ACCEPTED MANUSCRIPT

Abstract:

RI PT

Purpose: To report the impact of urethral risk factors on erosion rates and device survival outcomes after transcorporal (TC) artificial urinary sphincter (AUS) placement.

SC

Methods: We performed a retrospective analysis of all TC AUS placed at a single institution between January 2000 and May 2014. We assessed patient demographic, comorbid diseases and surgical characteristics for risk factors considered poor for device survival. Risk factors were compared to postoperative complications requiring explantation, including cuff erosion, infection and device revisions.

EP

TE D

M AN U

Results: Thirty seven TC AUS were placed in 35 men. TC AUS was performed as a primary procedure in 21/37 (56.8%) and as salvage in the remainder. In this TC population, there were 7 explantations (18.9%) for erosion (4), cuff downsizing (2), and infection (1). Median follow-up from TC to last follow-up was 8.5 months (0.9-63). Median time from TC AUS placement to explantation was 17.3 months (range 0.9-63) while the time specifically to TC erosion was 7.4 months (0.9-26). On univariate analysis, no parameters were associated with TC AUS cuff erosion but a history of inflatable penile prothesis was associated with a higher device explantation rate (60% vs. 12.5%, p=0.04). No associations were revealed on multivariate logistic analysis. All 4 cuff erosions that occurred demonstrated greater than 2 urethral risk factors of which prior radiation therapy was present in all cases. The probability of cuff erosion for those with 2+ urethral risk factors was 1.65 times the probability of cuff erosion for those with 0-1 urethral risk factors (95% CI 1.3, 2.2). The proportion of patients free of AUS erosion at 35 months was 100% for those with 0-1 urethral risk factors and 64% for those with ≥2 risk factors (log rank test, p=0.00). Similarly, the proportion of patients free of AUS explantation at 35 months was 100% for those with 0-1 urethral risk factors and 52% for those with ≥2 risk factors (log rank test, p=0.02).

AC C

Conclusion: TC AUS implantation is generally reserved for complex and high risk cases but favorable functional results are demonstrated. However, patients who have multiple urethral risk factors face a higher risk of erosion and device loss.

ACCEPTED MANUSCRIPT

Introduction:

SC

RI PT

An artificial urinary sphincter(AUS) is the gold standard treatment for moderate to severe male stress urinary incontinence with proven long-term efficacy and high patient satisfaction rates.1, 2 However, significant risks such as urethral cuff erosion or infection requiring device explantation occur in 0.46 -9.5% of primary AUS cases.3,4,5,6,7,8 Importantly, complication rates may be even higher in those with unfavorable risk factors, including prior radiotherapy, urethral stricture disease, previous surgical procedure(s) such as urethroplasty or prior AUS explantation.9,10,11,12 In compromised/frail urethras, AUS complications may be due to prior changes to urethral tissue, urethral blood flow disruption, or urethral stricture necessitating future urethral surgery with the sphincter cuff in-situ. Direct urethral injury resulting from separating an atrophic poorly vascularized urethra from the underlying corporal body is uncommon but can also occur. In these circumstances, small series have demonstrated decreased device survival compared to primary implantation.11,12

EP

Methods:

TE D

M AN U

Surgical modifications of cuff implantation technique have been introduced in an attempt to reduce cuff erosion risk. Subsequent cuff placement in a new, usually distal location is commonly employed.13,14 Wrapping the urethra with xenograft material in an effort to protect the urethra and increase urethral circumference has been described, but has not gained wide acceptance.15 Alternatively, a transcorporal(TC) technique for AUS cuff placement is a way to avoid posterior urethral dissection, preserve some blood supply and incorporate a layer of cavernosal tissue between AUS cuff and the dorsal surface of the urethra.13 While there is no randomized trial demonstrating that TC placement impacts cuff erosion and ultimately device survival rates compared with traditional approaches, multiple series have published rates similar to or lower than previously published studies of high-risk population.10,11,14,16 We report the largest single institution series of TC AUS placements to date, with a special emphasis on clinical and pre-operative parameters that may impact cuff erosion and device survival.

AC C

Following Institutional Review Board approval, a retrospective review of our series of 374 consecutive AUS placements between January 2000 to May 2014 was performed. A TC approach was utilized in 43 cases. Excluded were 5 patients who lacked follow-up after placement and 1 patient who ultimately had a supratrigonal cystectomy and urinary diversion for end-stage urethral disease. A high-volume surgeon(DFM) placed the majority of the sphincters(57%, 21 of 37) and the remainder were placed by another faculty member and former fellow using a similar surgical technique(MK). Operative technique for TC cuff placement was performed as previously described.13,17 Decision for TC placement was made on an individual basis considering both patient history and intraoperative findings(Table 1 and 2). For primary cases, TC was chosen if spongiosal atrophy was such that would preclude even the smallest cuff size and/or if the dissection between the urethra and corporal bodies was deemed too hazardous due to obliterated surgical planes.

ACCEPTED MANUSCRIPT

RI PT

Though the vast majority of this cohort was impotent at baseline, for those who were potent, TC was still offered for those whose burden from incontinence outweighed their concern for the potential risk of post TC erectile dysfunction. Closure of the corporotomies was performed selectively using 2-0 polydioxanone sutures based on a subjective determination of corporal bleeding and the fit of the AUS cuff.13 Drains were not utilized. Postoperatively, the device was locked in the deactivated position for 6 weeks. All patients were admitted overnight for observation with an indwelling 12-Fr urinary catheter, which was removed the next morning when a voiding trial was given. If the patient was unable to void, a 12-Fr indwelling catheter was inserted through the deactivated device and discontinued between 2-5 days post-operatively for voiding trial. Post operative urinary retention was defined as any re-insertion of the urinary catheter or suprapubic tube placement within 2 weeks of AUS placement.

M AN U

SC

Patient demographics and pre-operative clinical parameters are listed in Table 1. Patients were followed generally every 3 months for the 1st year via subjective assessment, standardized questionnaires, and physical exam. As our institution is a large referral center, many patients resume care from their local provider prior to this 1-year period. Subjective pad usage have been shown to have good correlation with objective leakage and was recorded.18 Social continence was defined as 0-1 pad usage/day and dry was defined as the use of no pads. Urethral and systemic risk factors were extracted from current literature and are shown in Table 1.10,11,12,14,16 Urethral risk factors were separated into two groups(0-1 vs. ≥2) for statistical analysis due to the overall small number of erosion and explantation cases.

AC C

Results:

EP

TE D

Demographic and perioperative data were analyzed to compare the cuff erosion vs. no erosion states as well as compare the AUS explantation and no explantation groups utilizing the chisquare test for categorical variables. Paired t-test was utilized to compare pre and post AUS placement pad usage. Kaplan-Meier survival analysis was performed to compare cuff erosion and AUS explantation events based on urethral risk factors using the log-rank test. Multi-variate logistic regression was employed for evaluation of any potential association between patient demographics or clinical parameters(Table 1) with erosion or explantation. The criterion for statistical significance was set at p<0.05. The statistical software program STATA version 13(College Station, TX) was employed for all statistical analysis.

Thirty-seven TC AUS were performed in 35 male patients during the time course of the analysis(Table 1). All 16 patients who underwent TC AUS as a secondary procedure were for prior erosion; 12(75%) had 1 prior AUS and 4 had 2(25%) prior AUS. In this TC population, there were 7 explantations(18.9%) for erosion(4), cuff downsizing(2), and infection(1). Two erosions occurred in the 4 and 5.5 cm cuff each. The 2 patients that underwent cuff downsizing after TC AUS(one primary, one secondary) were for bulbar atrophy and both had 3.5 cm cuff placements at a more distal location. For the 2 patients who each had 2 TC placements, both of their original TC cuffs eroded. The outcome of the 2nd TC cuff was functional in one patient, and explanted for infection in the other. Median follow-up from TC to last follow-up was 8.5 months(range 0.9-63, interquartile range 15.3). Median time from TC AUS placement to

ACCEPTED MANUSCRIPT

SC

RI PT

explantation was 17.3 months(range 0.9-63, interquartile range 29.6) while the time specifically to TC erosion was 7.4 months(0.9-26, interquartile range 12.7). On univariate analysis, no parameters were associated with TC AUS cuff erosion but a history of inflatable penile prosthesis(IPP) was associated with a higher device explantation rate(60% vs. 12.5%, p=0.04)(Table 2). No associations were revealed on multivariate logistic analysis. Sixty five percent of the cohort had greater than 2 urethral risk factors and all 4 cuff erosions that occurred were in this group of which prior radiation therapy was present in all cases. The probability of cuff erosion for those with ≥2 urethral risk factors was 1.65 times the probability of cuff erosion for those with 0-1 urethral risk factors(95% CI 1.3, 2.2). The proportion of patients free of AUS erosion at 35 months was 100% for those with 0-1 urethral risk factors and 64% for those with ≥2 risk factors(see figure, log rank test, p=0.00). Similarly, the proportion of patients free of AUS explantation at 35 months was 100% for those with 0-1 urethral risk factors and 52% for those with ≥2 risk factors(log rank test, p=0.02).

AC C

EP

TE D

M AN U

Corporotomies were closed in 15 of 37(41%) of cases. There was 1 post operative scrotal hematoma, despite corporotomy closure, which required hematoma evacuation and pump resiting. The device was activated at a median of 6.9 weeks(range 5.1-11). For those who developed cuff erosion, the time to activation was similar(6.9 weeks (6-7.1)). Three devices were not activated due to patient’s poor grip strength requiring physical rehabilitation, recurrent bladder neck contracture requiring multiple interventions, and cuff erosion prior to activation. Activation after 8 weeks was due to inability to identify pump(2), urinary retention(1), superficial skin infection(1), hematoma(1), and unknown(1). In terms of functional outcomes, 75% of men following TC AUS implant were defined as socially continent while the remaining 25% were utilizing a median of 3 pads per day(range 2-6); 28.6% were dry. For those with greater than one year of follow up(median 30.4 months), the social continence rate decreased to 43% while the dry rate was unchanged. This population demonstrated a clinically significant improvement in pad usage post implantation(6.4 vs. 1.3 pads per day, p=0.000) The median pre-operative SHIM score was 1(range 1-17) however, 3/35(8.6%) were sexually active with a median SHIM of 8. In total, 3/35(8.6%) men underwent IPP placement after TC AUS placement; these 3 made up the only sexually active men in our cohort postoperatively. Median post operative SHIM score was 1(range 1-3). Mean time to IPP after TC implantation was 17.8 months. Mean operative time was 90.3±2.1 mins. There were no immediate peri-operative complications and the IPP devices were all noted functional at last follow-up.

Discussion:

Urethral risk factors(Table 1) have previously been demonstrated to negatively impact AUS device outcomes.10,11,12,14,16 It has been postulated that these increased risks result from small vessel obliteration from radiation endarteritis or significant fibrosis and disruption of urethral blood flow from prior surgery. In re-operative cases that result from prior explantation, as the original cuff location consists of poorly perfused fibrotic tissue, the new cuff is usually placed at an alternate location distal to the prior cuff location.13 Distal placement requires more urethral mobilization and may further disrupt an already tenuous collateral blood flow. In these high risks patients with compromised or frail urethras, TC has been employed with satisfactory

ACCEPTED MANUSCRIPT

RI PT

outcomes(Table 3). In the multi-institutional study by Brant et al, a TC technique was used in 119 patients, the majority of which were considered high risk.10 Though not statistically significant(p=0.41), the TC explantation rate for erosion/infection of 11% in the high risk group was lower than the high risk group receiving AUS with traditional placement(13.4%). In the present series, we report an explantation rate for erosion/infection of 13.5%(5/37) in an equally high risk population: 76% were irradiated and TC was performed as salvage in nearly half. These rates are similar or lower than previously published studies of high-risk population,12,14,16 highlighting the usefulness of the TC approach, despite the TC approach usually being reserved for the most complex cases. Data presented here show, however, that the risk is not static as those with more risk factors have higher rates of explantation, urethral erosion, and decreased device survival outcomes(see figure).

AC C

EP

TE D

M AN U

SC

Since the 2010 introduction of the 3.5 cm AUS cuff, there is less need to perform complex ancillary maneuvers for cuff placement.19 There also may be decreased need for AUS revisions in men with spongiosal atrophy due to more precise cuff sizing and satisfactory continence rates.20 Continence may come at the expense of greater erosion risk, as multiple studies have demonstrated an increased risk of device explantation.10,16 In the series by Brant et al., of the high risk men who received the 3.5 cm cuff, nearly one third had subsequent erosion. The cuff was a predictor for explantation on both univariate analysis and multivariate logistic regression.10 In a comparative study by McGeady et al. on AUS survival in those with compromised urethras, the compromised group who received a 3.5 cm cuff were more likely to experience device failure with an explantation rate of 67%. By comparison, in a similarly compromised group, TC was selectively performed in 22 patients and the explant rate for any cause was 36%.16 Simhan et al. noted a 21% risk of erosion in irradiated patients with the 3.5 cm cuff with rare erosion(4%) in the non-irradiated 3.5 cm group.21 These authors state that they prefer the 3.5 cm cuff in most men with an atrophic spongiosum because it obviates the additional dissection needed for transcorporal surgery and reserve the TC procedure as a salvage maneuver in men with a history of open urethroplasty and/or AUS cuff erosion. In our experience, the TC procedure may be safer than dissection of the atrophic urethra off the corporal bodies in patients with urethral risk factors. Dissection of the atrophic spongiosum increases the risk of direct urethral injury as well as further de-vascularizing an already tenuous blood supply, potentially making the AUS device more susceptible to erosion. As a result, we generally favor TC in the high risk patient where the urethra is atrophic. In further support, in our series of 3.5 cm cuffs in patients with at least one urethral risk factor, the erosion rate was 28.6%(4 of 14 patients) (data unpublished). We report the largest single-institution series to date on TC AUS implantation from a large tertiary care referral center. Similar to the available TC series’ in the literature, our cohort was a high risk group with multiple risk factors tested and documented. This TC cohort mirrors the results seen in both primary and secondary implant cases in that those with more urethral risk factors are at greater risk for subsequent cuff erosion, ultimately decreasing device survival. This has not been demonstrated previously in a TC only cohort and highlights the complex nature of the group whose poor urethral “state of health” portends a diminished outcome. As a compromised urethra secondary to radiation is a dilemma encountered by high volume implanters who commonly must choose between a TC placement or a 3.5 cm cuff placement, our results add to the evidence available that TC placement is associated with clinically satisfactory outcomes. This data may help guide the decision of whether to choose a TC or a 3.5 cm cuff

ACCEPTED MANUSCRIPT

SC

RI PT

placement. This may be especially useful in light of recent reports raising concerns regarding use of the 3.5 cm cuff in high risk groups.10,21 There are several limitations to this study. Our study may not have the statistical power due to low sample size to detect outcome differences based on individual urethral risk factors. A way to increase power without the ability of increasing sample size is to group variables as we did by dichotomizing them into urethral risk factor categories.22 In this manner, we were able to detect differences in device erosion and survival despite no associations on univariate and multivariate analysis. Another limitation of the study is the short median follow up of 8.5 months. This limited follow-up results from our status as a tertiary care center where patients often resume care locally once recovered postoperatively. Functional outcomes thus have to be interpreted with caution. However, our follow up time may be sufficient for detection of serious events as the time to erosion in our series was within this follow-up window and patients with complications are usually referred back to our center for management. Indeed the 2 cases of revisions in our series re-presented after long absences. Nevertheless, the danger of missing cases is real.

M AN U

Conclusion:

1

TE D

TC AUS implantation demonstrated favorable functional results given the degree of urethral compromise. Patients who have multiple urethral risk factors face a higher risk of erosion and device loss. Our data provides insight into use of TC AUS in the compromised urethra and enhances our capability to set patient expectations in this high risk population such that expectations match outcomes.

AC C

EP

Van der Aa F, Drake MJ, Kasyan GR, et al. The artificial urinary sphincter after a quarter of a century: a critical systematic review of its use in male non-neurogenic incontinence. Eur Urol 2013; 63: 681–9 2 Gousse AE, Madjar S, Lambert MM, et al. Artificial urinary sphincter for post-radical prostatectomy urinary incontinence: long-term subjective results. J Urol 2001; 166: 1755–8 3 Lai HH, Hsu EI, Teh BS et al. 13 years of experience with artificial urinary sphincter implantation at Baylor College of Medicine. J Urol 2007;177:1021 4 Kim SP, Sarmast Z, Daignault S et al. Long-term durability and functional outcomes among patients with artificial urinary sphincters: a 10-year retrospective review from the University of Michigan. J Urol 2008;179:1912. 5 Wang R, McGuire EJ, He C et al. Long-term outcomes after primary failures of artificial urinary sphincter implantation. Urology 2012;79: 922. 6 Leibovich BC and Barrett DM. Use of the artificial urinary sphincter in men and women. World J Urol 1997;15:316 7 Elliott DS and Barrett DM. Mayo Clinic long-term analysis of the functional durability of the AMS 800 artificial urinary sphincter: a review of 323 cases. J Urol 1998;159:1206 8 Montague DK, Angermeier KW and Paolone DR. Long-term continence and patient satisfaction after artificial sphincter implantation for urinary incontinence after prostatectomy. J Urol 2001; 166:547 9 Aaronson DS, Elliot SP, McAninch JW. Transcorporal artificial urinary sphincter placement for incontinence in high risk patients after treatment of prostate cancer. Urology 2008; 72(4): 825-27 10 Brant WO, Erickson BA, Elliot SP, et al. Risk factors for erosion of artificial urinary sphincters: a multicenter prospective study. Urology 2014; 84(4): 934-39. 11 Lai HH, Boone TB. Complex artificial urinary sphincter revision and reimplantation cases-how do they fare compared to virgin cases? J Urol 2012; 187:951-55

ACCEPTED MANUSCRIPT

12

AC C

EP

TE D

M AN U

SC

RI PT

Linder BJ, de Cogain M, Elliot DS. Long term device outcomes of artificial urinary sphincter reimplantation following prior explantation for erosion or infection. J Urol 2014; 191:734-38 13 Guralnick ML, Miller E, Toh KL et al. Transcorporal artificial urinary sphincter cuff placement in cases requiring revision for erosion and urethral atrophy. J Urol 2002; 167:2075-79 14 Raj GV, Peterson AC, Webster GD. Outcomes following erosions of the artificial urinary sphincter. J Urol 2006; 175: 2186-90. 15 Rahman NU, Minor TX, Deng D, et al. Combined external urethral bulking and artificial urinary sphincter for urethral atrophy and stress urinary incontinence. BJU Int. 2005; 95:824-826 16 McGeady JB, McAninch JW, Truesdale MD, et al. Artificial urinary sphincter placement in compromised urethras and survival: a comparison of virgin, radiated and reoperative cases. J Urol 2014; 192:1756-61 17 Nelson RP. Incorporation of corpora cavernosa in bulbous urethral artificial urinary sphincter. J Urol 1986; 136:102-3 18 Nitti VW, Mourtzinos A, Brucker BM. Correlation of patient perception of pad use with objective degree of incontinence measured by pad test in men with post-prostatectomy incontinence: the SUFU Pad Test Study. J Urol 2014; 192(3): 836 19 Hudak SJ, Morey AF. Impact of 3.5 cm artificial urinary sphincter cuff on primary and revision surgery for male stress urinary incontinence. J Urol 2011; 186: 1962-66 20 Simhan J, Morey AF, Zhao LC, et al. Decreasing need for artificial urinary sphincter revision surgery by precise cuff sizing in men with spongiosal atrophy. J Urol 2014; 192:798-803 21 Simhan J, Morey AF, Singla N, et al. 3.5 cm Artificial Urinary Sphincter cuff erosion occurs predominantly in irradiated patients. J Urol 2015; 193:593-97 22 McClelland GH. Increasing power without increasing sample size. American Pyschologist 2000; 55:963-4. 23 Lee D, Zafiraskis H, Shapiro A, et al. Intermediate outcomes after transcorporal placement of an artificial urinary sphincter. Int J Urol. 2012; 19(9):861-6 24 Wiederman L, Cornu JN, Haab E, et al. Transcorporal artificial urinary sphincter implantation as a salvage surgical procedure for challenging cases of male stress urinary incontinence: surgical technique and functional outcomes in a contemporary series. BJU Int. 2013; 112(8):1163-8.

ACCEPTED MANUSCRIPT

Table 1. Patient demographics and pre operative clinical parameters Age (median)

72.2 (range 55.4-85.3)

Spongiosal atrophy Prior erosion Severe fibrosis

16 (43.2%) 16 (43.2) 5 (13.5)

6 (16%) 14 (39) 11 (31) 5 (14)

M AN U

4 4.5 5 5.5

SC

Urethral cuff size, cm

RI PT

Reason for transcorporal

Comorbidities Diabetes Smoking COPD ADT use

11 (29.7%) 3 (8.1) 3 (8.1) 6 (16.2)

Urethral risk factors

AC C

EP

TE D

Radiation Prior explantation for infection/erosion Prior IPP Prior urethroplasty Prior sling Prior tandem cuff Post implantation urinary retention History of bladder neck contractures/procedures History of urolume stent placement

28 (75.7%) 16 (43.2) 5 (13.5) 2 (5.4) 3 (8.1) 2 (5.4) 4 (10.8) 19 (51.4) 4 (10.8)

ACCEPTED MANUSCRIPT

Table 2. Univariate analysis of transcorporal AUS erosion rates by risk factors

AC C

EP

TE D

Systemic risk factors: Diabetes Use of androgren deprivation therapy Current smoker Chronic obstructive pulmonary disease

18.2 16.7 0 0

NA 3.9 (0.5, 34) 6.4 (1.1, 35.7) 5.8 (1.0, 33.8) NA NA 2.75 (0.4, 20.6) 2.8 (0.3, 24.9) NA

SC

14.3 18.8 40 50 0 0 25 15.8 0

M AN U

Urethral risk factors: History of radiation Prior explantation Prior IPP Prior urethroplasty Prior sling Prior tandem cuff Post implantation urinary retention History of bladder neck contractures/procedures History of urolume stent placement

Risk ratio (95% confidence interval)

RI PT

Erosion rate, %

2.4 (0.4, 14) 1.7 (0.2, 14) NA NA

ACCEPTED MANUSCRIPT Table 3. Summary of the existing literature on transcorporal AUS placement

Wiedemann et al.

McGeady et al. Brant et al.

10

Present series

16

24

Complications

31

17 (2-86)

0-1 pad/day: 84%

Potent preoperatively 4/31; postop 1/4 deterioration

35% radiation, 32% prior AUS explantation

no erosion/infection; 1 replacement, two mechanical dysfunction

8

28 (ND)

<2 pad/day: 88%

All impotent preoperatively

50% radiation, 25% prior AUS explantation, 63% prior urethroplasty

1 erosion, 1 infection

16

45 (3-91)

0-1 pad/day: 75%

All impotent preoperatively

44% radiation, 50% prior aus explantation

one erosion, one mechanical malfunction, four atrophy

23

26 (13-33)

0-1 pad/day: 76%

Potent preoperatively 6/23; postop 1/6 deterioration

52% radiation, 52% prior AUS explantation

3 infection, no erosion, 5 mechanical dysfunction

22

39 (1-126)

NA

NA

95% radiation, prior AUS explantation or urethral surgery

8 explantation due to erosion, infection or malfunction or atrophy

119

27.6 ± 14.4 (mean)

NA

NA

75% radiation, prior AUS explantation, urethral surgery including urethroplasty, recalcitrant bladder neck contracture, urethral stent

11% erosion in high risk group vs. 6.7% in low risk group

37

8.5 (0.9-63)

0-1 pad/day: 75%

Potent preoperatively 3/35; postop 2/3 deterioration

76% radiation, 43% prior AUS explantation

4 erosion, 2 cuff atrophy, 1 infection, 1 pump re-siting

RI PT

23

Urethral risk factors

SC

Lee et al.

9

Erectile function

M AN U

Aaronson et al.

Continence

TE D

13

Median follow up months (range)

EP

Guralnick et al.

n

AC C

Refe rence

ACCEPTED MANUSCRIPT

0

M AN U

Log rank test p=0.00

10 20 Months following TC AUS placement

Number at risk 0-1 urethral risk factors 13 2+ urethral risk factors 24

7 9

EP

TE D

0-1 urethral risk factors

AC C

SC

RI PT

% freedoml from TC AUS erosion 0.00 0.25 0.50 0.75 1.00

Figure. Kaplan Meier survival curve for transcorporal AUS erosion

5 7

2+ urethral risk factors

30 3 4

ACCEPTED MANUSCRIPT

Key of definitions and abbreviations:

AC C

EP

TE D

M AN U

SC

RI PT

AUS-Artificial urinary sphincter TC-Transcorporal IPP-inflatable penile prothesis