Surgical Penile Implants
Surgical implantation of a penile prosthesis is one option for erectile dysfunction which involves inserting an implant into the erectile tissue. Different types exist including malleable (semi-rigid) and inflatable (hydraulic).
| Author Year; Country Score Research Design Total Sample Size |
Methods | Outcome |
|---|---|---|
| Overgoor et al. 2015; The Netherlands Case series Level 4 N=30 |
Population: 30 low spinal lesion (T12 (incomplete) to sacral) patients (mean age=29.5 years, range=13-59 years), 13 with spina bifida and 17 with a spinal cord injury. Treatment: Researchers wanted to test whether self-report of reflex erections (RE) or bulbocavernosus reflex (BCR) testing was sufficient to determine whether patients should have unilateral or bilateral (surgery) to maximize sexual function. Outcome Measures: The integrity of the sacral-reflex-arc and DNP function was tested pre-operatively using bilateral needle electromyography (EMG)– bulbocavernosus reflex (BCR) measurements, and an interview about reflex erections (RE) ability. |
1. Neither Self-report of RE nor BCR testing can independently predict which surgery protocol should be used (7 patients reported RE, 4 of which had positive bilateral BCR; 9 patients had positive BCR, 4 of which had RE.) 2. No significant association between BCR function and RE. |
| Overgoor et al. 2014 The Netherlands Case series Level 4 N=40 |
Population: 40 low-spinal lesion men with no penile but intact groin sensationMethodology: The “TOMAX” (TO MAXimize sensation, sexuality, and quality of life) procedure restores genital sensation in men with low spinal lesions, improving sexual health, as shown previously. It connects the dorsal nerve of the penis to the intact ipsilateral ilioinguinal nerve, unilaterally or bilaterally. This study reports on the technical aspects based on 43 TOMAX nerve transfers. 43 nerve transfers were performed on the participants.Outcome Measures: Data on patient selection, surgical history, anatomy of the ilioinguinal nerve and dorsal nerve of the penis, unilateral or bilateral surgery, surgical technique, complications, and patient information were collected prospectively. |
1. Regardless of origin, all patients with no penile but good groin sensation are eligible for the procedure, provided the ilioinguinal nerve is not damaged because of former inguinal surgery or absent because of anatomical variations. 2. Selection of a unilateral or bilateral procedure depends on the presence or absence of reflex erections and bulbocavernosus reflex. 3. Preliminary experience with the first three bilateral cases shows that it is technically feasible, with encouraging results. The surgical technique has evolved (described in detail, including video) to enhance outcome and reduce complications. 4. The TOMAX procedure can then be used to restore erogenous penile sensation and improve the quality of sexual health in patients with absent penile but good groin sensation. |
| Kim et al. 2008; Korea Case series Level 4 N=48 |
Population: 48 participants with SCI and erectile dysfunction, mean age 58.9 (range 39-74). Treatment: malleable penile prosthesis insertion. Outcome Measures: Subjective satisfaction questionnaire; possibility of intercourse. |
1. 38 (79.2%) of the participants reported some degree of satisfaction with their prosthesis. 2. Intercourse was possible in 44 participants. 3. Complications occurred in 8 participants: 4 had infections, 2 had erosion towards the urethra and glans, 1 experienced pain due to the insertion of an overly large prosthesis, and 1 was dissatisfied with the small size of the inserted prosthesis. |
| Zermann et al. 2006; Germany Case series Level 4 N=245 |
Population: Men with neurological impairment, n=197 with SCI; Age: mean 40.8 yrs, range 17-75; Injury level: paraplegia (n=188), tetraplegia (n=57); Diagnostic groups: urinary management (n=134), erectile dysfunction (ED) (n=60),urinary management and ED (n=51). Treatment: Penile prosthesis: semirigid Jonas (n=147), self-contained inflatable AMS Hydroflex or AMS Dynaflex (n=113), and inflatable 3-piece AMS 700 CX (n=33). Outcome Measures: Sexual intercourse success, treatment satisfaction, secure condom fixation, urinary management, adverse events. |
1. Sexual intercourse was possible in 83.7% of individuals with penile prosthesis for ED. 2. 67% of female were satisfied with result of their partner’s treatment. 3. Adverse events: infection rate 5%, perforation rate 18.1% (semi-rigid Jonas), 2.4% (self-contained inflatable Dynaflex), and 0% (inflatable 3-piece AMS 700), respectively. |
| Gross et al. 1996; Germany Case series Level 4 N=209 |
Population: Men with SCI; Age: mean 39.9 yrs, range 16-72; Injury level: paraplegia (n=128), tetraplegia (n=38); Impairment: erectile dysfunction (n=49), penile retraction (n=113), both (n=47). Treatment: Penile prosthesis. Outcome measures: Use of prosthesis, satisfaction with sexual intercourse, adverse events. |
1. Use of prosthesis: 83 out of 96 men with ED used prosthesis at 5 yrs after surgery. 2. Satisfactory sexual intercourse was reported by 84% of men with ED. 3. Adverse events: perforation in 7% of men: 9.4% occurred with semi-rigid prosthesis vs 2.7% of semi-flexible prosthesis, infection in 5.6% leading to removal of prosthesis. |
| Collins & Hackler 1988; USA Post-test Level 4 N=63 |
Population: 63 men with SCI. Treatment: Penile implantation of semirigid device or Mentor inflatable prosthesis. Outcome Measures: Penile implantation functionality. |
1. 53 patients with a semi-rigid implant, 44 currently have functional prosthesis (83% overall success rate). 2. 10 patients received inflatable penile prostheses: 4 were lost, 2 had successful reimplantation. 3. Overall complication rate in the 63 patients=33% (lost prosthesis). 4. After reimplantation, 52/63 patients had functional device, resulting in 82% ultimate success rate. |
| Iwatsubo et al. 1986; Japan Case series Level 4 N=37 |
Population: Men with SCI, Age: mean 42 yrs, range 21-63, Injury level: tetraplegia (n=10), paraplegia (n=23), cauda equina lesions (n=4). Treatment: Shirai-type silicone implants; follow up from 6-46 months. Outcome measures: Impact on sexual function, adverse events. |
1. Impact on sexual function: 15 (41%) men reported improvement, 18 (48%) men reported no sexual benefit, 4 (11%) men were dissatisfied. 2. Adverse events: extrusion of prosthesis due to infection (n=2) and removal due to causalgia in LE (n=1), posterior migration of prosthesis (n=1). |
| Green & Sloan 1986; USA Observational Level 5 N=40 |
Population: 40 men; Age range: 21-60 yrs, Impairment grade: AIS A (n=31), B-D (n=9). Treatment: Penile prosthesis. Outcome Measures: Sexual questionnaire. |
1. 31 patients have intercourse regularly and pleased with decision to have device. 2. 4 patients dissatisfied all had semirigid implant. |
Discussion
There are no RCT studies in this area. Penile prostheses have been used for over 25 years to treat ED, penile retraction (or a combination of both) or for improvement in urinary management in selected men with SCI. Generally, for ED, this option was considered after failure of more conservative treatments, including ICI of vasoactive substances, vacuum devices and, more recently, oral PDE5i. Five case-series reports and one cohort study in over 500 men with SCI have revealed a high level of satisfaction with the use of penile prostheses for the treatment of ED, making intercourse possible in almost 85%, as well as resolution of urinary management issues in 90% of patients. In addition, in one study (Zermann et al. 2006), 67% of females interviewed were satisfied with results of treatment of their partner’s ED. Inflatable prostheses (although more expensive) are often preferred over semi-rigid malleable prosthesis as the semi-rigid prosthesis is more difficult to conceal due to the permanence of the erection. These factors, although affecting preference, have not altered the overall satisfaction rates associated with malleable prostheses (Kim et al. 2008).
However, serious complications may occur in about 10% of patients, including infection (4-8%) and perforations depending on implant type (9-18% of semi-rigid devices vs 0-2.7% of semi-flexible/inflatable devices). It has been suggested that the insertion of smaller diameter prosthesis in patients performing clean intermittent catheterizations is more appropriate to reduce the resistance at the time of catheter insertion and potential urethral erosion. Results of two larger studies (Gross et al. 1996; Zermann et al. 2006) have shown that improvements over the last 10 years in device design (with the introduction of softer implant materials), surgical approach (infrapubic rather than subcoronal) and infection control measures (broad-spectrum antibiotic prophylaxis and whole body disinfection) have dramatically reduced the likelihood of these complications occurring. Under these improved circumstances, implantation of a penile prosthesis appears to be a relatively safe and viable option, perhaps best reserved for when reversible ED therapies have failed or for those men (or their partners) who find other alternatives, such as intracavernosal injections unacceptable. This decision requires careful consideration in view of the fact that if explanation of penile prosthesis is necessary, the person may no longer be a candidate for other treatment options, such as ICI or a VCD, due to possible extensive penile damage and scarring.
Conclusion
There is level 4 evidence (Kim et al. 2008; Zermann et al. 2006; Gross et al. 1996) which suggests the use of penile prostheses as treatment for erectile dysfunction (ED) in men with SCI when other ED treatments have failed.
