Presentation Authors: John Masterson*, Laura Horodyski, Ronak Patel, Omer Kineish, Miami, FL, Taylor Kohn, Baltimore, MD, Ranjith Ramasamy, Miami, FL
Introduction: Overall satisfaction rates for inflatable penile prosthesis (IPP) are estimated at over 80%. Due to frailty or scrotal sensitivity, some men are unable to successfully use the IPP due to difficulty with pump. The objective of the present study is to determine if key pinch strength is predictive of patient preference for a single IPP model among three currently available models (Coloplastâ„¢ Titan, Coloplastâ„¢ Titan Touch, and the Boston Scientific AMS 700â„¢).
Methods: IPP-naÃ¯ve men over 65 years were prospectively recruited from our outpatient urology clinic. Demographic and selected medical history were recorded. Study participants were asked to squeeze a dynamometer between their thumb and index finger while seated with their arm resting at 90 degrees to measure their key pinch strength. The strongest of three attempts was recorded. Participants were then asked to operate three separate IPP devices (Coloplast Titan, Coloplast Titan Touch, and AMS 700) installed within identical penis models. The number of pumps required to achieve erection with each device was recorded. Patients were asked to rate the difficulty of pumping each device from 1 to 5. Participants were then asked to rank, from best to worst, which device they preferred based on ease of inflation. Multivariate linear regression at the 95% confidence interval was utilized to identify factors associated with difficulty of pumping rated 1 to 5. The order in which the models were presented to participants was randomized to eliminate patient fatigue and bias.
Results: A total of 100 men have completed the study. Median age and mean key pinch strength were 70.0 (range 65 to 87) years and 19.5 (SD Â±4.2) lbs (comparable to published data among men older than 65 years). The Coloplast Titan pump was ranked the most favored pump based on ease of inflation (58%). AMS 700 was favored by 29% and Coloplast Titan Touch model was favored by 13% of the men. Interestingly, the median age (70.0, 69.0, and 73.0) and mean key pinch strength (19.6, 19.7, and 19.1 pounds) were similar among men that favored Coloplast Titan as compared to the AMS and Coloplast Titan Touch pump. The median number of pumps required to achieve erection (5.0, 5.0, 6.0) was also similar across the Coloplast Titan, AMS 700, and Coloplast Titan Touch models. Multivariate linear regression of the 1 to 5 difficulty of inflation rating scale showed decreasing grip strength to be associated with increased difficulty of inflation for the Coloplast Titan Touch model (p = 0.045). No other factors were significantly associated increased difficulty of inflation. Strengths of our study include strict inclusion criteria, homogeneity of our study population, and randomization of models presented to participants. Limitations include small sample size.
Conclusions: Overall the Coloplast Titan pump was preferred compared to the AMS 700 or the Coloplast Titan Touch pumps based on ease of inflation using a penile implant model. Men with below average key pinch strength can benefit with ease of inflation from being offered a model other than Coloplast Titan Touch. Whether these findings translate to when men receive implants remains to be determined. Nevertheless, key pinch strength should be considered in men prior implantation of IPP.