Surgical Penile Options

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).

There is emerging evidence that either implantable epidural stimulation (e.g., CAVERStim) and transcutaneous epidural stimulation may have positive sexual restoration effects, similarly to established effects on bowel and bladder function, however the data is still very preliminary.

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), and for improvement in urinary management in selected men with SCI. Generally, this option is only considered after failure of reversible treatments, including ICI of vasoactive substances, vacuum devices, and 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% of patients and resolving urinary management issues in 90% of patients. In addition, Zermann et al. (2006) found that 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 are harder to conceal due to the permanence of the erection. Aside from preference, there are no changes in satisfaction rates with malleable prostheses (Kim et al. 2008). It has been suggested that the insertion of smaller diameter prosthesis in patients using clean intermittent catheterizations can reduce the resistance during catheter insertion and potential urethral erosion (Kim et al. 2008).

Lemos et al. (2022) found that laparoscopic implantation of neuromodulation electrodes improved IIEF scores possibly due to the positive effects of stimulation on erection, however this difference was not significant. Twelve months post-operative, 71.4% patients had improved genital sensitivity (p<0.0001) (sample includes 7 women).

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. Wilson et al. (1995) reviewed the infection risk in 823 men who received an inflatable penile prosthesis (IPP). A total of 66 (8.0%) men had SCI. Infection occurred in 24 (2.9%) men within the whole cohort (SCI, 6 (9.1%) vs non-SCI, 18 (2.4%)). SCI and steroid use had statistically higher significant rates of infection. The infection rate was higher (10.1%) in revision type implants.

Results of one larger study (Zermann et al. 2006) have shown that improvements over the last 20 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 because 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 2 evidence (Lemos et al. 2022) that supports laparoscopic implantation of neuromodulation electrodes to improve genital sensitivity.

There is level 4 evidence (Glina et al. 2024) that an implantable neurostimulator (CaverSTIM) enhanced erectile function in 3 out of 4 participants.

There is level 4 evidence (Kim et al. 2008; Zermann et al. 2006) which suggests the use of penile prostheses as treatment for erectile dysfunction (ED) in men with SCI when other ED treatments have failed.
There is level 4 evidence (Zermann et al. 2006) showing that softer implant materials, improved surgical approaches (infrapubic rather than subcoronal), and better infection control measures (broad-spectrum antibiotic prophylaxis and whole-body disinfection) have reduced the likelihood of complications occurring.