Longitudinal and Horizontal Load Testing of Inflatable Penile Implant Cylinders of Two Manufacturers: An Ex Vivo Demonstration of Inflated Rigidity.

INTRODUCTION: Since the inception of the inflatable penile prosthesis, a new era has been ushered in for the management of erectile dysfunction. Despite multiple innovations to improve function and reliability, there are no current data comparing the biomechanical properties of these devices. AIM: To compare the resistance of the Coloplast Titan (Minneapolis, MN, USA) with that of the AMS 700 LGX (Minnetonka, MN, USA) penile prosthesis cylinders to longitudinal (penetration) and horizontal (gravity) forces. METHODS: We compared two cylinder sizes from each company: the Coloplast Titan (18 and 22 cm) and the AMS 700 LGX (18 and 21 cm). To evaluate axial rigidity, which simulates forces during penetration, we performed a longitudinal load compression test to determine the load required to cause the cylinder to kink. To test horizontal rigidity, which simulates the horizontal forces exerted by gravity, we performed a modified cantilever test and measured the degrees of bend for each device. All devices were tested at 10, 15, and 20 PSI to simulate in vivo pressures. MAIN OUTCOME MEASURES: The main outcome measurement for the longitudinal load test (penetration) was the force required for the inflated cylinder to bend, thereby affecting its rigidity. The main outcome for the horizontal rigidity test (gravity) was the angle of displacement, in which a smaller angle represents a more horizontally rigid device. RESULTS: Longitudinal column testing (penetration) demonstrated that less force was required for the AMS device to kink compared with the Coloplast implant across all three fill pressures tested. The Coloplast Titan also had a smaller angle of displacement at the modified cantilever test (gravity) compared with the AMS implant across all fill pressures. CONCLUSION: The Coloplast Titan demonstrated greater resistance to longitudinal (penetration) and horizontal (gravity) forces in this study. The AMS device was very sensitive to fill pressures. In contrast, the Coloplast Titan's ability to resist these forces was less dependent on the device fill pressure.

Standard operating procedures for Peyronie's disease.

INTRODUCTION: Peyronie's disease (PD) refers to a penile deformity that is associated with sexual dysfunction. AIM: To provide recommendations and Standard Operating Procedures (SOPs) based on best evidence for diagnosis and treatment of PD. METHODS: Medical literature was reviewed and combined with expert opinion of the authors. MAIN OUTCOME MEASURES: Recommendations and SOPs based on grading of evidence-based medical literature. RESULTS: PD is a fibrotic wound-healing disorder involving the tunica albuginea of the corpora cavernosa. The resulting scar is responsible for a variety of deformities, including curvature, shortening, narrowing with hinge effect, and is frequently associated in the early phase with pain. Patients frequently experience diminished quality erections. All of these conditions can compromise sexual function for the affected male. The etiopathophysiology of PD has yet to be clarified and as a result, effective, reliable, mechanistic directed non-surgical therapy is lacking. CONCLUSIONS: The management of PD consists of proper diagnosis and treatment, ranging from non-surgical to surgical interventions. The main state of treatment for PD rests at this time on surgical correction that should be based on clear indications, involve surgical consent, and follow a surgical algorithm that includes tunica plication, plaque incision/partial excision and grafting, and penile prosthesis implantation.

A catalog of magnetic resonance imaging compatibility of penile prostheses.

INTRODUCTION: Erectile dysfunction has been successfully treated with penile prosthesis implantation for over 50 years. Ferromagnetic implants or devices may create a potentially hazardous or painful situation during magnetic resonance imaging (MRI). A modern catalog of the MRI compatibility of penile prostheses is not available. AIM: Evaluate the safety profile of implanted, penile prostheses during MRI. MAIN OUTCOME MEASURE: Review available in vitro safety data and reported patient complications experienced during MRI with a penile prosthesis in place. METHODS: A search of PubMed™ for articles documenting a penile prosthesis present during MRI was performed. Radiology texts and product information from manufacturers' producing a penile prosthesis were reviewed. Direct discussion with product manufacturers was also performed to obtain additional safety and compatibility information. RESULTS: Nine clinical articles noted the presence of a penile prosthesis at the time of magnetic resonance imaging. No articles documented a complication from MRI of a man with a penile prosthesis. A single patient with an unnamed malleable prosthesis was noted to have twisting of the device during MRI which did not result in discomfort or malfunction of the device. In vitro studies support the safety of most prostheses during MRI. CONCLUSION: The available data suggests there is little risk for most patients with a penile prosthesis who undergo MRI. Notable exceptions include Dacomed's Omniphase and Duraphase device and the MRI-conditional Spectra device manufactured by AMS. Current manufacturers of penile implants provide wallet cards and medical letters to support safety when undergoing an MRI. Prior prosthesis implantation should not preclude patients from having an MRI.

MRI and its role in the evaluation and surgical decision making in patients with challenging IPP presentations: descriptions of MRI findings and algorithm for patient management.

UNLABELLED: Study Type - Diagnostic (case series) Level of Evidence 4 What's known on the subject? and What does the study add? It is known that magnetic resonance imaging (MRI) is safe and effective for imaging patients with inflatable penile prostheses (IPPs). Previous series have reported results of MRI for imaging series of patients with IPPs. The impact on management in particular with regard to salvage procedures is not well defined. This study represents the largest known experience with MRI evaluation of IPPs. This also provides an algorithm that assists with decisions regarding utilization of MRI and treatment planning based on results. OBJECTIVE: • In some patients who undergo placement of an inflatable penile prosthesis (IPP) the device may function inadequately. We describe the use of magnetic resonance imaging (MRI) for anatomical localization and detection of prosthesis malrotation, angulation, displacement and erosion in IPPs with equivocal clinical examination. PATIENTS AND METHODS: • We prospectively performed MRI by a defined protocol including T1-weighted imaging, and transaxial, sagittal and coronal fat-saturated fast spin-echo T2-weighted imaging in both deflated and inflated states to evaluate patients seen at our referral centre for IPP-related complaints. • We retrospectively reviewed 32 such MRI studies performed as a supplement to clinical examination between 2000 and 2008. RESULTS: • Of 32 cases, 75% (24/32) underwent surgical intervention. Of these, 45% (11/24) underwent device salvage procedures including cylinder revision in 33% (8/24), cylinder replacement in 8% (2/24) and pump replacement in 4% (1/24). • MRI was most useful for determination of surgical approach in those with abnormal physical examination, and for justification of either surgical or expectant management in those with indeterminate physical examination. CONCLUSIONS: • MRI is safe and effective for imaging genitourinary prostheses. • We found MRI to be a valuable adjunct for evaluation of IPP-related complaints when clinical examination is equivocal as it detected a variety of prosthetic and corporal abnormalities and impacted management decisions regarding observation, replacement or device salvage procedures. • We provide technique, results and an algorithm that can be beneficial in this complex subset of patients.

Evaluation of three penile prosthesis pump designs in a blinded survey of practitioners.

Erectile dysfunction continues to be a problem that can be successfully treated either through medical or surgical management. A cohort of self-identified experts in teaching the operation of penile implants completed a series of questions and tasks associated with three implant pump designs. This study examines the responses and impressions of these expert teachers in regard to three penile prosthesis pump designs. The goal of this project was to establish if one prosthesis pump was superior in the user's ability to correctly identify components in a blinded, scrotal simulation study.

Long-term survival of inflatable penile prostheses: single surgical group experience with 2,384 first-time implants spanning two decades.

INTRODUCTION: Long-term revision-free survival, greater than 10 years has never been reported for inflatable penile prostheses. We conducted a historical prospective study to estimate 10 and 15 years survival of first time (virgin) implantations in 2,384 patients with four different models. AIM: Evaluation of 10- and 15-year mechanical and overall revision-free survival of inflatable penile prostheses. MAIN OUTCOME MEASURES: Kaplan-Meier product limit method, and comparison using the log rank test, were used to estimate the 10- and 15-year revision-free survival. METHODS: Data were obtained from medical records and patient interviews, entered into a computerized database, and analyzed by a third party. Information included implant type, date, revision history with date, and reason. Fourteen different inflatables were examined. Mentor Alpha 1, Mentor Alpha NB, AMS 700 CX, and AMS 700 Ultrex had usage for an extended period of time. Because of failure times being confounded as a result of prior implants, only virgin implants were examined. RESULTS: For the entire series, estimated 10-year revision-free survival for all reasons was 68.5% and the 15-year revision-free survival was 59.7%. Freedom from mechanical breakage at 10 years was 79.4%; 15 years was 71.2%. Recent mechanically enhanced models did even better. In 1992, Mentor Alpha added pump reinforcement to forestall mechanical breakage. This improved 10-year survival from 65.3% to 88.6% (P = 0.0001). In January 2001, AMS CX added a parylene coating to the cylinders that increased 3-year mechanical survival from 88.4 to 97.9% (P = 0.0002). CONCLUSIONS: This is the first report on long-term reliability of inflatable penile prostheses. We estimated 60% of these virgin implants would survive 15 or more years without revision or extraction. Newer enhanced models are currently available, and our tracking predicts even better long-term survival for these devices.

Technical advances in penile prostheses.

Despite the introduction of oral phosphodiesterase inhibitors, penile prostheses continue to be an important form of treatment for erectile dysfunction (ED). Penile prostheses are associated with high satisfaction rates due to their ease of use, reliability, and ability to provide excellent rigidity. Advances over the last decade include steps to reduce mechanical failures and surface coatings to prevent prosthetic infections. These advances make the penile prosthesis an excellent option for the treatment of ED, particularly for men who fail oral therapy.

The hydrophilic-coated inflatable penile prosthesis: 1-year experience.

INTRODUCTION: Penile prosthesis infections are a devastating complication for both patient and surgeon. Efforts to reduce the risk of infection from these elective procedures are a major focus of research and development by the major prosthesis companies. The Titan inflatable penile prosthesis (Mentor Corporation, Santa Barbara, CA) is coated with polyvinylpyrrolidone (PVP), a hydrophilic substance that reduces bacterial adherence and absorbs and elutes the antibiotics the device is immersed in intraoperatively. The Titan device was introduced to the American market in September 2002. This study reports the 1-year experience in the U.S. with the Titan and compares infection rates with the noncoated Alpha-1 IPP made by Mentor. MATERIALS AND METHODS: Two thousand three hundred and fifty-seven Titan prostheses were implanted in the U.S. from September 2002 to August 2003, compared with the 482 noncoated Alpha-1 IPPs implanted over the same time period. Infection rates were compared, along with bacterial culture data. All data were collected from Mentor's internal database, as generated from the FDA's mandatory reporting of explanted medical devices, and available on the internet. RESULTS: The infection rate for the coated Titan IPP was 1.06% (25/2,357). During the same time period, the infection rate for the Alpha-1 noncoated prosthesis was 2.07% (10/482). Staphylococcus species predominated in both groups (9/25 Titan, 6/10 Alpha-1). CONCLUSIONS: At 1 year of follow-up, the data demonstrate that the hydrophilic coating on the Titan IPP confers a significant advantage in reducing the rate of infection over the noncoated device. Long-term follow-up on this first year database is needed before this innovation is accepted as the standard of care for prosthetic surgery. Nevertheless, the theoretical reduction in bacterial adhesion conferred by the hydrophilic PVP surface and the ability to choose which antibiotic the device is immersed in intraoperatively gives the implanting surgeon distinct advantages with this new product.

Prospective long-term results and quality-of-life assessment after Dura-II penile prosthesis placement.

OBJECTIVES: To evaluate prospectively the long-term device reliability and patient satisfaction after Dura-II malleable penile prosthesis implantation. METHODS: Between 1992 and 1996, 94 patients underwent Dura-II implantation for erectile dysfunction. Patients were prospectively examined and completed standardized questionnaires regarding sexual activity, prosthesis function, intercourse satisfaction, and overall quality of life. An independent statistician analyzed these data. RESULTS: The mean patient age was 63 years, and the mean patient follow-up was 5.7 years. Eighty-five patients were available for long-term evaluation. Fourteen patients died during the follow-up period. One patient was lost to follow-up, and eight prostheses (9%) were explanted; however, no mechanical defects were found in the explanted prostheses. Seventy-six percent and 87% of patients reported satisfactory rigidity and ease of concealing the device, respectively. Seventy-six percent of patients remained sexually active during the evaluation period, and 87% of patients reported that the prosthesis improved their overall quality of life. Eighty-five percent would undergo the implant surgery again, and 88% percent of patients would recommend the Dura-II prosthesis to a friend. CONCLUSIONS: The Dura-II malleable penile prosthesis provides good rigidity, ability to conceal the device, and mechanical reliability, as demonstrated by the results of this long-term study. Most patients stated they would have the prosthesis placed again and would recommend it to a friend.

Optimization of design and surgical positioning of inflatable penile prostheses.

The interaction between the cylinders of an inflatable penile prosthesis (IPP) and the surrounding tissues during IPP-aided erection may result in local elevated stresses. These stresses may reach values that can obstruct penile blood vessels and cause ischemia and/or stimulate nerves around the operation site, thereby inducing sensations of pain. A new numerical model was used to analyze penile stresses postimplantation of different IPP types, in order to optimize prosthesis design and surgical positioning by enabling minimal stress transfer to dorsal blood vessels and nerves. The results suggest that intraluminal pressures should be maintained at low levels (about 80 kPa) while cylinder thickness and stiffness should be kept just high enough (approximately 15% of the radius and 1000 MPa, respectively) to eliminate deleterious cylinder-tissue contact stresses. Smaller prosthetic cylinders, i.e., occupying about 45% of the cavernosal space, may be advantageous in terms of reducing dorsal stresses, but lower penile rigidity should be expected. A significant decrease of dorsal stresses can also be achieved by encouraging the surgeon to position the cylinders toward the lower part of the corpora. The numerical simulations indicate that circular cylinders may allow greater biomechanical compatibility of the IPP with the penis structure than elliptic ones, and this should be a subject for clinical investigations.

Clinical experience with 80 inflatable penile prostheses.

OBJECTIVES: Prosthetic surgery for impotence has been transformed by the use of inflatable prostheses, superseding the old semi-rigid designs. Our objective is to report the functional results and the complications of this type of surgery. METHODS: 80 inflatable prostheses were implanted between October 1987 and October 1994. The mean follow-up was 3 years and assessment of the objective (mechanical functioning of the prosthesis and complications) and subjective results (sexuality of the patients) was made in 68 patients. RESULTS: There were: 54.5% functional disturbances, 7% infections, and 27.5% prosthesis removals. Most of the patients were satisfied, although only 65% returned to regular sexual activity. CONCLUSIONS: The choice between an inflatable and a semi-rigid prosthesis should be carefully discussed because of the frequent mechanical complications that have been reported for the sophisticated designs. Inflatable penile prostheses nevertheless remain the design of choice. Their reliability has been increasing since the manufacture of monobloc designs. Such a device is costly, and should be compared with that of intracavernous injections.

Inflatable penile prosthesis: results of 150 cases.

OBJECTIVES: To evaluate the reliability of the prosthesis and the rate of complications in organically impotent men who were implanted with an inflatable penile prosthesis. PATIENTS AND METHODS: A consecutive series of 150 men (mean age 60 years, range 25-90) were followed for a mean of 19 months (range 0-65) after implantation of the Mentor Alpha 1 penile prosthesis. Information was obtained from their medical records and by telephone interview, but the satisfaction of the patients was not assessed quantitatively. RESULTS: There were no complications in 145 of the patients and they currently have functioning prostheses. Complications occurred in five patients (3%), including two peri-prosthetic infections (1%) and two intra-operative and one post-operative cylinder aneurysm. Complications requiring re-operation occurred in three (2%) of patients; none of the implants leaked. CONCLUSIONS: These results suggest that for men with organic impotence, a Mentor Alpha 1 implant is an effective treatment option with acceptable morbidity and good mechanical reliability.

[Implantation of the Ultrex type inflatable penile prosthesis. Four years experience]. / Implantation de prothese pénienne gonflable type Ultrex. L'experiencede 4 ans.

During the last 4 years, 12 patients had an implantation of the AMS Ultrex2 penile prosthesis : 4 of these patients were impotent after a cystoprostatectomy, 4 patients had vascular insufficiency, 2 patients had psychogenic impotency, one patient was diabetic and one patient had a spinal cord injury. The complication rate was low (16%): one patient necessitated a surgical revision of the prosthesis after disconnection of the tubulure. A second patient had a urethral stenosis treated by dilation. The degree of satisfaction of both patient and partner was satisfactory.

Understanding federal medical device statutes and their application to various penile prostheses.

Medical devices have become an important component of our professional armamentarium. This paper exposes the practitioner to the Food and Drug Administration and its control over medical devices. Specifically, the 1976 amendment to the Food and Drug Administration Acts is described, along with the subsequent federal laws. Because of all the new technology available, physicians should be aware of the applicable laws and regulations. In addition, a review of the penile prosthesis includes its history and evolution, as well as the entire product line available for use. Attention is directed to the problems that have arisen from malfunctioning components.

Ten years of experience with various penile prosthesis in Korean.

Currently there are more than 10 types of penile prosthesis available, ranging from the very simple to the very sophisticated. We review our experiences with various penile prosthesis, with particular regard to the complication rate. From Dec. 1983 to Jul. 1993, we implanted 295 penile prosthesis of eight different types. The average age of patients was 44 years. Every patient was evaluated with various multidisplinary diagnostic approaches. The etiologies of impotence were vasculogenic 29%, diabetogenic 22%, spinal cord injury 16%, pelvic bone injury 11%, etc. The types of implanted prosthesis were AMS malleable 143, Jonas 42, Dynaflex 36, Hydroflex 8, Uni-Flate 1000 2, AMS 700 CXM 58, Ultrex 3, Mentor alpha-1 3 and the mean follow-up period was 34 months. The diameters of implanted prosthesis were from 9.5 mm to 13 mm, mostly 9.5 mm (52.9%). The length of implanted prosthesis were from 10 cm to 20 cm, mostly 16 approximately 18 cm (68.8%). Cases with uneven diameters or lengths were 20 (6.8%). The int aoperative complications were 1 corporeal rupture and 1 bladder rupture, and the postoperative complications were 2 prosthesis infections, 2 mechanical failures, and 1 prosthesis infection with mechanical failure. In those 4 patients reimplantations were successful. More than 99% (290/291) patients still have functioning prosthesis. Every prosthesis has their advantages and disadvantages. Factors to be analysed in the selection of proper prosthesis should include patients economic status, education, personality, social activity, hand dexterity, and penile size.(ABSTRACT TRUNCATED AT 250 WORDS)