John R. Delk

Inflatable Penile Implant Infection: Predisposing Factors and Treatment Suggestions

A retrospective review of 1,337 consecutive inflatable prosthesis implantations was done to detect predisposing factors for infection. Operations were performed by the same team during a 7-year period. Of the procedures 823 were primary implantations, while the remaining 514 were either revisions (mechanical failure, iatrogenic causes or patient dissatisfaction), salvage operations or removals for infection. The etiology of impotence as a predisposition for infection in primary implantations was significant for spinal cord injury (9% of the cases) and steroid use (50%). Diabetes had a statistically insignificant 3% risk of infection, with all other causes having a 1% infection rate. A total of 428 revisions was performed with an overall infection rate of 10%. Rates of infection ranged from 8% in nondiabetics to 18% in diabetics requiring revision. Staphylococcus species were the most commonly cultured organisms. Salvage operations (29 cases) of several types were attempted for infected prostheses. Our results with salvage were poor and we currently routinely remove the entire prosthesis for infection except in cases of urethral erosion of 1 cylinder.

A NEW TREATMENT FOR PEYRONIE'S DISEASE : MODELING THE PENIS OVER AN INFLATABLE PENILE PROSTHESIS

We treated 138 patients with severe Peyronies disease by insertion of an inflatable penile prosthesis and manual modeling of the erect penis. This novel technique was successful in 118 patients (86%) in achieving a straight, rigid erection. In 11 patients (8%) penile modeling did not result in satisfactory straightening and relaxing plaque incisions were performed. Complications of penile modeling included urethral perforation in 4 patients (3%). Infection of the prosthesis occurred postoperatively in 4 patients (3%). At a mean followup of 32 months (range 9 to 84) 124 patients (90%) were actually using the penile prostheses and none reported penile shortening or impairment of glandular sensation. We suggest that penile modeling over an inflatable penile prosthesis is an important new technique for the patient with severe Peyronies disease.

LONG-TERM FOLLOWUP OF TREATMENT FOR PEYRONIE’S DISEASE: MODELING THE PENIS OVER AN INFLATABLE PENILE PROSTHESIS

PURPOSE We originally reported inflatable penile implants used to treat impotence in patients with Peyronies disease in 1993. We now present a historical prospective study of 104 patients in whom the modeling procedure was used to correct Peyronies curvature after implantation with the Mentor Alpha 1dagger and AMS 700CXdouble dagger penile prostheses. We compared revision-free survival experience of these implants with 905 similar implants in men with nonPeyronies disease. MATERIALS AND METHODS The reasons for revision were classified as mechanical failure, patient dissatisfaction, infection and medical causes, including reoperation for straightening. Overall and cause specific revision-free survival in the 2 study cohorts was compared. Maximum followup was more than 12 years and average followup was more than 5. RESULTS No significant difference in device survival was observed in the 2 study cohorts in 5 years. Similarly each prosthesis provided the same permanent straightening without the need for revision. In Peyronies disease cases mechanical survival of the Mentor Alpha 1 was superior to that of the AMS 700CX (p = 0.0270). There was no significant difference in mechanical reliability of the devices in nonPeyronies disease cases. CONCLUSIONS Implantation and modeling appear to provide permanent straightening without an increase in revisions. In the nonmodeled group there was no significant difference in mechanical reliability of the AMS 700CX or Mentor Alpha 1. In modeled cases the Mentor Alpha 1 appeared less likely to fail mechanically than the AMS 700CX when followed more than 5 years. Based on this single series modeling may predispose the AMS 700CX to earlier mechanical failure.

Comparison of mechanical reliability of original and enhanced mentor alpha I penile prosthesis

PURPOSE We report the results of a prospective study of 1,381 Mentor Alpha I penile prostheses implanted to treat impotence, and compare original and enhanced penile prosthesis mechanical reliability. MATERIALS AND METHODS The study consisted of 410 original models manufactured before November 1992 and 971 enhanced models manufactured since December 1992. Implants were further stratified as first time (virgin) or replacements of a previous implant. Mechanical failure-free survival rates for the original prosthetic and enhanced models were compared. RESULTS The 5-year survival rate increased from 75.3% for the original to 92.6% for the enhanced model overall (log rank p<0.0001), and from 75.3 to 93.6%, respectively, for the virgin implants only (log rank p<0.0001). The estimated failure rate of approximately 5.6% for the original model was fairly consistent during followup, while the significantly lower failure rate of 1.3% for the enhanced model was not. The failure rate of the enhanced model implants was about 0.8% per year during the first 3.5 years and increased to approximately 3.1% per year thereafter. CONCLUSIONS Our results strongly support the premise that mechanical reliability is superior with the enhanced compared to the original model.

The Mentor Alpha 1 Penile Prosthesis With Reservoir Lock-out Valve: Effective Prevention of Auto-inflation With Improved Capability For Ectopic Reservoir Placement

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 auto-inflation 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.

ORIGINAL RESEARCH—SURGERY: Upsizing of Inflatable Penile Implant Cylinders in Patients with Corporal Fibrosis

INTRODUCTION Placement of an inflatable penile prosthesis in a patient with scarred corporal bodies secondary to priapism or removal of a previously infected implant is a formidable surgical challenge; use of downsized implants has improved chances of successful reimplantation. Nevertheless, patients are frequently dissatisfied with the resulting short penises. AIM This study investigates the use of downsized inflatable penile prosthesis cylinders as tissue expanders in patients with corporal fibrosis. MAIN OUTCOMES MEASURES Corporal length and width were calibrated before implantation of downsized prostheses and after 1 year of their use as tissue expanders. METHODS Thirty-seven patients had insertion of Mentor Narrow Base (18), AMS CXM (9), or AMS CXR (10) into scarred corporal bodies. Etiology was previously infected and removed implant (29) or priapism (8). In each of these cases it was not possible to dilate to 12 mm in order to place standard-sized cylinders. Patients were encouraged to inflate their implant for up to 3 hours daily. After several months intracorporal stretching occurred. The patients were reoperated; corporal length and width were recalibrated. RESULTS Upon reoperation, it was possible to pass dilators of 12 mm width proximally allowing the substitution of standard-sized AMS 700 CX (23), Mentor Alpha 1 (10), or Mentor Titan (2). Additionally, corporal length measurements in the previously infected patients increased an average of 2.2 cm allowing placement of longer cylinders. Although priapism patients did not show this phenomenon of corporal lengthening, the implant space widened enough to permit replacement with standard-size cylinders improving girth, rigidity, and appearance. CONCLUSIONS Wider and sometimes longer cylinders can be substituted in patients with corporal fibrosis that required implantation with downsized cylinders because of fibrotic corpora. Prolonged inflation over an 8- to 12-month period results in expansion of the cylinder cavity, permitting standard-sized cylinders in all patients.

Ultrex Cylinders: Problems with Uncontrolled Lengthening (The S-Shaped Deformity)

PURPOSE We investigated whether the AMS Ultrex cylinder, developed to provide cylinder lengthening while controlling girth expansion, acted as a tissue expander and, thus, promoted penile lengthening. MATERIALS AND METHODS Between December 1990 and January 1992, 59 AMS Ultrex prostheses were implanted. Cylinder length corresponded to intracorporeal measurements. The results of lengthening and occurrence of an S-shaped deformity were statistically analyzed. RESULTS No penile lengthening occurred. In 19 patients (32%) cylinder replacement was required for the S-shaped deformity. CONCLUSIONS Ultrex cylinders should be downsized and prolonged inflation should be avoided. They should not be implanted in cases of Peyronies disease, or to replace malleable or self-contained inflatable implants.

An Outcomes Analysis of over 200 Revision Surgeries for Penile Prosthesis Implantation: A Multicenter Study

INTRODUCTION Inflatable penile prosthesis (IPP) implantation is a well-established treatment for medically refractory erectile dysfunction, with long-term reliability. Overall survival is 96% at 5 years and 60% at 15 years for primary (virgin) implantation. AIM The aim of this study was to explore factors associated with success and complications of IPP revision surgery in a multicenter study. MAIN OUTCOME MEASURES Reasons for revision including mechanical issues, patient dissatisfaction, corporal deformity, and supersonic transport (SST) deformity were recorded. METHODS At four institutions, 214 clinically uninfected IPP revisions were performed between November 2000 and November 2007. Data were incomplete for 28 cases (14%). Failure-free survival was estimated using Kaplan-Meiers Meier product limit method. RESULTS The majority of revisions were secondary to mechanical failure (N = 109; 65%) and combined erosion or infection (N = 17 + 15 = 32; 19%). Sixteen percent (N = 26) were carried out on functional uninfected prostheses secondary to patient dissatisfaction (N = 9), SST deformity (N = 10), scrotal hematoma (N = 2), or upsize revision because of corporal fibrosis (N = 5). Average age at revision was 66 years. Mean follow-up time was 55.7 months. In this study, 12 individuals required a secondary revision procedure or suffered a complication. Despite prior reports of high infection rates with revision surgery, only 5.7% of clinically uninfected and noneroded prostheses were complicated by infection or impending extrusion/erosion, following a revision washout protocol. Overall, 93% of cases were successfully revised, providing functioning IPPs. CONCLUSIONS For this study population, component exchange followed by revision washout showed a low incidence of infection and subsequent mechanical failure.

LONG-TERM RESULTS WITH HYDROFLEX AND DYNAFLEX PENILE PROSTHESES: DEVICE SURVIVAL COMPARISON TO MULTICOMPONENT INFLATABLES

PURPOSE We compared our experience with self-contained inflatable and multicomponent prostheses during similar intervals. MATERIALS AND METHODS We followed 295 patients with self-contained prostheses and 1,026 with multicomponent inflatable devices for up to 8 years. Revision rates for mechanical failure, infection or patient dissatisfaction were statistically analyzed. RESULTS Multicomponent inflatable prostheses were superior with regard to mechanical reliability and patient satisfaction, with no differences in rate of infection. Self-contained prostheses were best replaced with the AMS 700CX device, thus avoiding aneurysm. CONCLUSIONS Self-contained inflatable prostheses may be of limited value for the treatment of impotence. The AMS 700CX is the device of choice for replacement of explanted self-contained prostheses.

Mechanical Reliability of AMS 700 CX Improved by Parylene Coating

INTRODUCTION Parylene coating was added to the silicone layers of the American Medical Systems (AMS) 700 controlled expansion (CX) penile prosthesis cylinders in January 2001. The coating was placed on non-tissue contacting silicone surfaces to increase lubricity, reduce friction, and silicone wear AIM We compared mechanical reliability of the original and Parylene-enhanced AMS 700 CX in a large single surgical group series. METHODS Seven hundred seventy-five consecutive patients receiving the AMS 700CX prosthesis (596 first time [virgin] and 179 revisions) were followed for 3 years. Four hundred fourteen received the non-coated model and 361 received the Parylene-coated device. Revision-free survival was estimated using the Kaplan-Meier product limit method and compared using the log-rank test. MAIN OUTCOME MEASURES We calculated overall survival from revision for any reason and survival from mechanical problems such as fluid leakage, cylinder, connector or tubing breakage, pump or reservoir defects. RESULTS For the entire series (virgin + revised) the 3-year revision free survival for any cause improved from 78.6% for non-coated to 87.4% for the Parylene-coated implants. Freedom from mechanical breakage showed similar improvement from 89.2% for the non-coated to 97.5% for enhanced models. CONCLUSIONS This study documents that short-term mechanical reliability and survival from revision for any cause is significantly increased with Parylene-coated AMS 700CX cylinders compared with the earlier AMS 700CX model with non-coated cylinders.