Rigi10™ Malleable Penile Prosthesis
Also Known As
Spontaneous prosthesis inflation, IPP autoinflation, unwanted prosthesis inflation, prosthesis self-inflation, spontaneous device tumescence, unintended prosthesis activation
Definition
Device autoinflation refers to the spontaneous inflation of a penile prosthesis without patient activation.¹ This phenomenon occurs when an inflatable penile prosthesis (IPP) does not deflate completely or does not stay deflated after proper deflation by the patient.² It is characterized by unwanted tumescence of the penis with a hardness scale of ≥4/10, despite no manual activation of the pump mechanism by the patient.³ Device autoinflation is considered an uncommon but bothersome mechanical complication of penile prosthetic surgery that can significantly impact patient satisfaction and may necessitate revision surgery in cases of severe bother.⁴
Clinical Context
Device autoinflation is primarily observed in patients who have undergone implantation of an inflatable penile prosthesis (IPP) for the treatment of erectile dysfunction (ED).¹ The literature cites an incidence rate of approximately 3-5% over the past decade, with historical reports suggesting rates as high as 11%.²⁻³
Patient selection factors that may increase the risk of autoinflation include prior pelvic surgery, particularly radical prostatectomy, which can obliterate the space of Retzius where the reservoir is typically placed.⁴ This anatomical alteration may lead to insufficient space creation at the time of reservoir placement, contributing to autoinflation risk.
The most common causes of device autoinflation include:
- Mechanical factors such as failure of the lockout valve³
- Over-filling of the reservoir during device implantation⁴
- Insufficient space creation for the reservoir⁴
- Capsule formation around the reservoir causing compression⁴
- Rarely, arteriocavernosal fistula formation during prosthesis insertion that mimics autoinflation¹
Clinical management options include:
- Observation for mild cases
- Device revision surgery to address mechanical issues
- Reservoir repositioning or replacement
- In rare cases of arteriocavernosal fistula, minimally invasive percutaneous angioembolization¹
- Novel approaches such as robot-assisted laparoscopic reservoir capsulotomy and mobilization⁴
Patient bother from autoinflation ranges from mild to severe, with symptoms including embarrassment from unwanted erections, pain, and discomfort.²⁻³ In cases of high bother, reoperation rates of approximately 2% have been reported.² Successful management can lead to resolution of symptoms and restoration of normal device function.⁴