Journal of Urology
A Multicenter Study on the Perineal Versus Penoscrotal Approach for Implantation of an Artificial Urinary Sphincter: Cuff Size and Control of Male Stress Urinary Incontinence
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Purpose: In a single center retrospective study we previously reported superior dry rates and fewer artificial urinary sphincter revisions when the sphincter cuff was placed via the traditional perineal approach compared with a penoscrotal approach. A multicenter study was performed to compare the approaches further and explain the disparity in outcomes.

Materials and Methods: We performed a retrospective review of 158 patients who underwent these procedures from April 1987 to October 2007 at 4 centers.

Results: During 184 surgeries in 158 patients 201 artificial urinary sphincter cuffs were placed (90 penoscrotal and 111 perineal). Among patients with known followup the completely dry rate for single cuff artificial urinary sphincters was 17 of 62 (27.4%) in the penoscrotal group and 41 of 93 (44.1%) in the perineal group (p = 0.04). Continued incontinence necessitated subsequent tandem cuff in 7 of the 62 (11.3%) penoscrotal cases compared to only 5 of the 93 (5.4%) perineal cases. Cuff size in the penoscrotal group was 5.0 cm in 1 patient (1.1%), 4.5 cm in 11 (12.2%) and 4.0 cm in 78 (86.7%). Cuff size in the perineal group was 5.5 cm in 1 patient (0.9%), 5.0 cm in 8 (7.2%), 4.5 cm in 30 (27.0%) and 4.0 cm in 72 (64.9%).

Conclusions: There appears to be a higher completely dry rate with fewer subsequent tandem cuff additions with the perineal approach compared to the penoscrotal approach. This disparity may be explained by a more proximal artificial urinary sphincter cuff placement in the perineal group as evidenced by a larger cuff size.

A Survey Of Patients With Inflatable Penile Prostheses For Satisfaction
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Purpose: We assessed patient satisfaction with 3 types of penile prostheses, namely the AMS 700 Series®, Mentor Alpha 1® and Mentor Alpha NB®.

Materials and Methods: The subjects consisted of 330 patients selected by stratified, systematic random sampling from among 1,298 subjects undergoing virgin 3-piece inflatable penile implant surgeries performed by the same surgical team at 1 hospital between January 1992 and December 1998. Data were collected by computer assisted telephone interviewing with a survey developed by the authors. The survey consisted of 37 questions in 7 sections, including 1 demographic section and 6 patient satisfaction sections.

Results: Of the 330 patients selected 248 (75%) could be contacted. Of these, 199 (80%) responded to the full survey and the remaining 49 (20%) agreed to respond only to the question, “How satisfied are you with the prosthesis?” Of the 199 full responders 12 (6%) had AMS implants and 187 (94%) had Mentor implants. Of the 49 single question responders 5 (10%) had AMS implants and 44 (90%) had Mentor implants. Of the 248 patients the overall satisfaction rate was 69%. Although there was no significant difference at the 5% level in patient satisfaction by implant type, responses tended to favor the Alpha IPPs in terms of overall sexual satisfaction (p = 0.058), natural feeling of the prosthesis (p = 0.061), flaccid appearance of the penis when deflated (p = 0.054), and education with demonstration of inflation and deflation (p = 0.075).

Conclusions: There was a high degree of overall patient satisfaction across implant types.

Biofilm Formation on Clinically Noninfected Penile Prostheses
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Purpose: Biofilms are matrix enclosed bacterial populations that adhere to each other and/or to surfaces of implanted medical devices. Biofilm formation has consistently been demonstrated in association with infected penile prosthetic material. Clinically noninfected patients undergoing revision for mechanical malfunction have a surprisingly high rate of positive intraoperative cultures. After revision replacement prostheses have a higher rate of postoperative infection than first time implants. We characterized biofilm formation on penile prostheses in clinically noninfected patients undergoing revision surgery.

Materials and Methods: Ten patients undergoing revision or removal of inflatable penile prosthetic devices due to mechanical malfunction were included. Specimens from the corporeal cylinders, scrotal pump and reservoir were analyzed. Bacterial biofilm coverage was detected and characterized using confocal scanning laser microscopy.

Results: Bacterial biofilm formation associated with multiple microorganisms was demonstrated on 8 of 10 prostheses. Biofilms consisted of gram-positive rods, cocci and fungal elements.

Conclusions: The degree of biofilm formation on these prosthetic devices suggests that most patients have bacterial coverage on the implant. Host mechanisms to control infection may lead to a homeostatic balance that enables biofilms to exist on the surface of the prosthesis without generating clinical infection. A critical threshold of biofilm extent may exist beyond which clinical infection may occur. These results justify further evaluation of biofilms and penile prosthesis infections. Furthermore, the findings help to explain why strategies such as mini salvage procedures to eliminate subclinical biofilms may decrease the postoperative infection risk in patients undergoing repair or replacement of penile prostheses.

Centers of Excellence Concept and Penile Prostheses: An Outcome Analysis
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Purpose: Outcome analysis has shown that the center of excellence concept, in which all of a specific type of surgery is done by 1 surgeon rather than by multiple surgeons in a group, provides superior outcomes for total joint replacement, radical cancer and heart valve surgery. We compared penile prosthesis implantation outcomes between the center of excellence and multiple surgeon approaches in a large, single specialty urological surgical practice.

Materials and Methods: Between February 2001 and August 2004 a total of 57 penile prostheses were implanted by 10 surgeons at a large urology practice (multiple surgeon group). Between July 2004 and April 2005 a total of 57 penile prostheses were placed by a single surgeon (center of excellence group). Chart review of the 2 patient groups was performed.

Results: The patient groups showed no statistical differences in age, race, cause of impotence or percent with diabetes. The median cylinder length of prostheses placed by the center of excellence surgeon was 2 cm greater than the length of the cylinders placed by the multiple surgeon team (p<0.0001). Excluding cases requiring additional procedures the median placement time was considerably shorter for the center of excellence surgeon than for the multiple surgeon team (34 vs 94 minutes, p<0.0001). There were 8 iatrogenic failures (infection, erosion and poor positioning) requiring surgical removal in the multiple surgeon group but none in the COE group (p<0.05). Although followup for the multiple surgeon team was longer, Kaplan-Meier revision-free survival curves showed significantly longer survival for the center of excellence group (log rank test p = 0.0283).

Conclusions: The center of excellence concept in penile prosthesis surgery appears to deliver superior surgical outcomes in terms of shorter operative time, longer cylinders and fewer iatrogenic complications.

New Surgical Technique For Sphincter Urinary Control System Using Upper Transverse Scrotal Incision
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Purpose: Traditional implantation of the AMS Sphincter 800 Urinary Control System (American Medical Systems, Minnetonka, Minnesota) requires 2 incisions. The cuff is placed via a perineal incision, and the pressure regulating balloon and pump are placed through a separate suprapubic incision. We describe a novel implantation of all the artificial urinary sphincter components using a single upper scrotal incision. The scrotal incision allows excellent access to the proximal bulbar urethra and retropubic and subdartos spaces, and leaves the bulbocavernosus muscle intact.

Materials and Methods: A total of 37 patients have undergone artificial urinary sphincter implantation using the new operative technique for revisions or reimplantations of a sphincter previously removed for infection/erosion (12) or as an initial procedure (25). In 9 of the 25 patients and 2 of the 12 dual implantation of a 3-piece penile prosthesis through the same incision was performed.

Results: All patients are using the devices. Of the patients 66% are completely dry with no pad use and the remainder use 1 pad for accident prevention. Operative time was reduced due to easier exposure of the urethra and a second incision for placement of the pressure regulating balloon was not necessary. Followup at 1 year shows no difference in complication rate with the single incision technique compared to the traditional method.

Conclusions: Artificial urinary sphincter implantation through a single scrotal incision is easier and faster than the traditional 2-incision technique. Success in achieving continence is similar to traditional methods. Long-term followup is necessary to ensure that complications remain low.

Penile Prosthesis Cultures During Revision Surgery: A Multicenter Study
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Purpose: Initial implantation of inflatable penile prosthesis has a 3% risk of infection. Reoperation of penile implants has a higher rate of infection, estimated between 10% and 18%. To explain the higher risk in revision surgery in this prospective study we cultured clinically uninfected prostheses requiring revision. Prosthesis pain was also investigated as a predictor of positive culture.

Materials and Methods: 

At 3 institutions cultures were prospectively obtained from 77 clinically uninfected penile prostheses at revision surgery. Immediately upon surgical exposure of the pump cultures were obtained. If a bacterial biofilm was noted on any component it was additionally cultured. All culture isolates positive for a staphylococcus species were tested for sensitivity to rifampin and tetracycline (minocycline). An implant is now available that is coated with these antibiotics. Patient history of chronic prosthesis pain was ascertained.

Results: Culture positive bacteria were found in 54 of 77 (70%) patients with clinically uninfected penile prostheses. In some patients more than 1 organism grew and, occasionally, the pump culture was negative but the biofilm was positive. Of 54 patients 49 had positive (90%) culture for staphylococcus genus with 10 different species. All staphylococcal species were sensitive to rifampin and/or tetracycline. We did not find a significant association between prosthesis related pain and culture laboratory results.

Conclusions: The majority of clinically uninfected penile prostheses have organisms growing in the implant spaces at reoperation. Most of these organisms are staphylococcal species that are sensitive to rifampin/minocycline.

Perineal Approach for Artificial Urinary Sphincter Implantation Appears to Control Male Stress Incontinence Better Than the Transscrotal Approach
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Purpose: Traditionally cuff placement of an artificial urinary sphincter is done through a perineal approach. A new approach through a penoscrotal incision or transscrotal approach is reportedly more rapid and easier than the traditional incision. These 2 approaches were evaluated to determine which one controlled male stress urinary incontinence better.

Materials and Methods: We performed a retrospective chart review of 94 patients who underwent artificial urinary sphincter placement procedures from April 1987 to March 2004.

Results: A total of 126 artificial urinary sphincter cuffs (120 procedures, including double cuff placement in 6) were placed in 94 patients with 63 placed penoscrotally and 63 placed perineally. Of the double cuff placements 1 was perineal and 5 were transscrotal. In patients with a single initial or revision cuff the self-reported completely dry rate was 28.6% with the penoscrotal approach and 56.5% with the perineal approach (p = 0.01), while for initial cuffs only the dry rate was 28.0% and 56.7% for the penoscrotal and perineal approach, respectively (p = 0.03). Five of 28 patients (17.9%) with initial penoscrotal placement later underwent tandem cuff placement for continued incontinence, whereas only 1 of 32 (3.1%) with initial perineal placement later had a tandem cuff added (p = 0.06). There was no difference in the estimated failure-free survival (failure for any reason) of the device.

Conclusions: When the artificial urinary sphincter cuff is placed through a perineal approach, there appears to be a higher completely dry rate and fewer subsequent tandem cuff additions than when the artificial urinary sphincter cuff is placed through a penoscrotal incision.

Revision Washout Decreases Implant Capsule Tissue Culture Positivity: A Multicenter Study
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Purpose: Positive cultures, visible biofilm and confocal micrography confirm bacterial presence on clinically uninfected inflatable penile prostheses at revision surgery. Salvage irrigation has been proved to rescue patients with clinically infected inflatable penile prostheses. Similar washout at revision for noninfectious reasons significantly lowers subsequent infection rates. We investigated a larger series of patients for positive culture rates and evaluated implant capsule tissue culture rates before and after revision washout.

Materials and Methods: At 4 institutions a total of 148 patients with inflatable penile prostheses underwent revision surgery for noninfectious reasons between June 2001 and September 2005. Swab cultures of the fluid around the pump and visible biofilm were obtained. Also, in 65 patients a wedge of tissue from the capsule that forms around the pump was cultured. After implant removal revision washout of the implant spaces was performed and a second wedge of tissue was cultured.

Results: Of the 148 patients 97 (66%) had positive bacterial swab cultures of the fluid around the pump or biofilm. A total of 124 isolates were cultured. Of the 65 implant capsule tissue cultures obtained before washout 28 (43%) were positive for bacteria, while 16 (25%) obtained after revision washout were positive.

Conclusions: Positive cultures and visible bacterial biofilm are present on clinically uninfected inflatable penile prostheses at revision surgery in most patients. Revision washout appears to decrease the bacterial load on implant capsule tissue at revision surgery of inflatable penile prostheses for noninfectious reasons.

Revision Washout Decreases Penile Prosthesis Infection In Revision Surgery: A Multicenter Study
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Purpose: Reoperation of penile implants carries a higher risk of infection (7% to 18%). Positive cultures and visible bacterial biofilm have been shown to be present on clinically uninfected inflatable penile prostheses (IPPs) at revision. A salvage irrigation protocol has proved to rescue patients with a clinically infected IPP. During revision surgery for noninfectious reasons we investigated washing out the implant space at revision surgery and using an antibiotic coated replacement prosthesis to determine if it would decrease subsequent infection rates.

Materials and Methods: At 3 institutions 183 patients with a penile prosthesis underwent revision surgery for noninfectious reasons between June 2001 and October 2003. Of these patients 140 had the entire implant removed and then underwent antiseptic solution lavage of the implant spaces (revision washout), followed by replacement with a 3 piece IPP. This revision washout is a modification of the original Mulcahy salvage procedure. In the remaining 43 patients the implant was removed but they did not undergo antiseptic irrigation before replacement with an antibiotic coated IPP. Patients were followed for 6 to 33 months, while observing for failure.

Results: Four of the 140 patients (2.86%) who underwent removal of the entire implant with irrigation of the implant spaces with antiseptic solutions and replacement with an IPP have had infection. In the remaining group 5 of the 43 patients (11.6%) who did not undergo antiseptic irrigation had infection. The difference was statistically significant at the 5% level (Fisher’s exact test p = 0.034).

Conclusions: Early results of combining complete implant removal and modified salvage protocol indicate a markedly decreased incidence of infection in patients with a penile prosthesis undergoing revision for noninfectious reasons.

The Mentor Alpha 1 Penile Prosthesis With Reservoir Lock-Out Valve: Effective Prevention Of Auto-Inflation With Improved Capability For Ectopic Reservoir Placement
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Purpose: Auto-inflation is a common and annoying complication of 3-piece penile prostheses. In the published literature the rate is approximately 11% with a 2% operative revision rate. We report the results of a review of 160 Alpha 1 and NB implants (Mentor Corp., Santa Barbara, California) with the new lock-out valve located on the reservoir to treat impotence. We compared it with 339 Alpha 1 implants with the standard reservoir. We also investigated the lock-out reservoir for ectopic nonretropubic implantation.

Materials and Methods: We compared 339 Alpha prostheses with the standard reservoir that were implanted between January 1, 1998 through December 31, 1999 and 160 with the new lock-out valve placed since January 2000 with at least 6 months of followup. Implants were further stratified as first time (virgin) or revision-replacement of a previous implant. In 8 patients with a scarred or obliterated retroperitoneal space the lock-out reservoir was placed superior to the transversalis fascia and beneath the abdominal musculature.

Results: Kaplan-Meier estimated 1-year survival was not significantly different in terms of mechanical failure (p = 0.57 and 0.85) revision for any cause (p = 0.92 and 0.92), patient dissatisfaction (p = 0.35 and 0.11) or infection (p = 0.64 and 0.94) for all implants and virgin implants only, respectively. Only 2 patients (1.3%) with a lock-out valve complained of autoinflation initially and the problem resolved in each after instruction on how to operate the device. Of the patients in the earlier series 11% complained of auto-inflation and 2% required operative correction. None of the 8 patients with an ectopic reservoir location complained of auto-inflation.

Conclusions: Our results indicate that the lock-out valve prevents early auto-inflation. Addition of the lock-out valve does not impact the revision rate compared with the same implant with a standard reservoir. In patients with a scarred retropubic space the lock-out valve offers the penile implant surgeon a decreased probability of auto-inflation with ectopic reservoir placement.

Vascular Endothelial Growth Factor Restores Corporeal Smooth Muscle Function In Vitro
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Purpose: The therapeutic use of vasculogenic growth factors has been successfully demonstrated in models of organ ischemia. We determined whether vascular endothelial growth factor (VEGF) would reverse corporeal smooth muscle dysfunction in the hypercholesterolemic rabbit model of erectile dysfunction.

Materials and Methods: A total of 36 New Zealand White rabbits were fed a normal (12) or 1% cholesterol (24) diet and treated after 6 weeks with 0.9 mg. VEGF or vehicle. At 6 weeks 24 rabbits received a single intracavernous dose and 12 received a single intravenous bolus of either drug. Ten days after injection corporeal smooth muscle function was analyzed after relaxation to acetylcholine and sodium nitroprusside using isometric tension studies. Corporeal sections were assessed for smooth muscle content with f-actin staining and VEGF expression by immunohistochemical study and enzyme-linked immunosorbent assay.

Results: Endothelium dependent (acetylcholine) and nitric oxide mediated (sodium nitroprusside) smooth muscle relaxation were impaired in cholesterol fed animals (p = 0.021 and 0.003, respectively). Intracavernous VEGF treatment restored sodium nitroprusside mediated relaxation to normal (p = 0.015) and intravenous VEGF restored acetylcholine and sodium nitroprusside mediated relaxation (p = 0.014 and 0.018, respectively). Decreased smooth muscle content was noted in cholesterol fed animals versus normal diet controls (p = 0.008), which was not affected by VEGF treatment (p = 0.450). Corporeal endothelial cell content was increased after intracavernous but not intravenous VEGF treatment (p = 0.001 and 0.385, respectively). VEGF expression was augmented after treatment with recombinant VEGF (p < 0.001).

Conclusions: VEGF administration variably mitigated the impairment of corporeal smooth muscle relaxation in the hypercholesterolemic rabbit model of erectile dysfunction.