Also Known As
Lock-out valve reservoir, Reservoir lock-out valve, Anti-autoinflation valve, Autoinflation prevention valve
Definition
A lock-out valve is a specialized mechanism incorporated into penile prosthesis reservoirs designed to prevent autoinflation, which is the unintentional transfer of fluid from the reservoir to the cylinders resulting in unwanted cylinder inflation.1 The valve works by creating a mechanical barrier that prevents fluid migration under normal physiological pressures while still allowing intentional inflation when the pump is activated.2 This innovation significantly reduces the occurrence of autoinflation, a troublesome complication that may be potentiated by prevesical scarring following radical prostatectomy or other pelvic surgeries.3
Clinical Context
The lock-out valve is primarily used in three-piece inflatable penile prostheses for the treatment of erectile dysfunction.1 This innovation was first introduced in 2000 within the reservoir of the Mentor Alpha 1 device (Mentor Corporation, Santa Barbara, CA, USA, later acquired by Coloplast Corporation).3
The clinical significance of the lock-out valve becomes particularly evident in patients with a scarred retropubic space, such as those who have undergone radical prostatectomy, cystectomy, or radiation therapy.2 In these patients, the lock-out valve offers the penile implant surgeon a decreased probability of auto-inflation with ectopic reservoir placement.1
Before the introduction of lock-out valves, autoinflation was reported in approximately 11% of cases, with 2% requiring surgical revision.1 Studies have shown that the implementation of lock-out valves has reduced the incidence of autoinflation to 1.3-3%.1,3 In one comparative study, 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, compared to 11% of patients with standard reservoirs who experienced autoinflation.1
The development of lock-out valves has also enabled the evolution of alternate reservoir placement (ARP) techniques, as they permit higher ambient pressure on the system without causing autoinflation.3 This has expanded surgical options, particularly for patients with hostile pelvic anatomy or previous pelvic surgeries.3